species diversity, growth, status, and biovolume of taia

Research ArticleSpecies Diversity Growth Status and Biovolume of Taia RiverRiparian Forest in Southern Sierra Leone Implications forCommunity-Based Conservation

Moses Fayiah 12 Baimba F Kallon2 Shikui Dong1 Mathew S James3 and Sanjay Singh4

1State Key Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal UniversityBeijing 100875 China2Department of Forestry School of Natural Resources Management Njala University Moyamba DistrictSouthern Province Sierra Leone3Department of Biological Sciences School of Environmental Sciences Njala University Moyamba DistrictSouthern Province Sierra Leone4Biodiversity and Climate Change Division Indian Council of Forestry Research and Education Dehradun India

Correspondence should be addressed to Moses Fayiah mosesfayiahyahoocouk

Received 22 August 2019 Accepted 28 December 2019 Published 18 November 2020

Academic Editor Qing-Lai Dang

Copyright copy 2020 Moses Fayiah et al is is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Riparian forest inventory is essential in understanding the floristic biodiversity and provides necessary information on thegrowth trend and status of plant diversity along forest ecosystem especially the riparian forests is study was undertaken toassess the species diversity growth status and bio-volume of Taia riparian forest for community-based conservation in-tervention In this study we enumerated 602 individual trees which comprised 49 species that belong to 37 genera in 25families In total 14 rectangular plots of dimension 20 times 50m2 were demarcated All trees species within the sampled plotshaving diameter at breast height [Dbh] ge7 cm were identified and height measured using the Haga altimeter girth andmeasuring tape to determine the growth statuse result shows that 83 of the trees enumerated have [Dbh] that range from 7to 30 cm whereas 17 had [Dbh] greater than 30 cm Funtumia africana and Trichilia heudelotii were the dominant species inalmost all aspects in the study area Meliaceae Apocynaceae and Mimosaceae were the dominant families with the highestspecies e Shannon diversity index was 3094 whereas the Simpson and Evenness diversity was 09303 and 04502 re-spectively Other diversity indices estimated were Margalef 7544 Equitability 07949 and Fisher_alpha 1277 e overallbiovolume was 28305m3 with a total basal cover of 1254m2 Height and [Dbh] were not significantly correlated with thebiovolume Biotic pressure such as fuelwood collection unsustainable charcoal production pole harvesting bushfires andother traditional and cultural functions contributes greatly to the exploitation of the riparian forest erefore urgent strategicconservation and protection measures should be adopted to prevent further degradation of forest ecosystems along river banksin the district and other ecologies in Sierra Leone

1 Introduction

Sierra Leone (coordinatesmdash6deg55primendash10deg14primeN and 10deg14primendash13deg17primeW)with a land area of 72300 sq km is situated on the WestCoast of Africa along the East Atlantic Coast in Africa ecountryrsquos geographic location is a quintessential factor thatdetermines the diversity of its ecosystems vegetation andbiodiversity [1 2] Sierra Leone is located within the UpperGuinean biodiversity hot spot of West Africa [1 3ndash7] ere

are five major terrestrial ecosystems in Sierra Leone namely(1) wetland and freshwater (2) lowland rainforest (3)coastal and marine (4) montane forests and (5) savannawoodlands [8] Sierra Leone is endowed with nine majorrivers ese rivers and their tributaries host long tracks ofriparian forests along their banks with diverse plant andanimal species World Bank [1] report stated that thewetlands of Sierra Leone including riparian forests man-groves and swamps account for 4 800 km2 and are host to

HindawiInternational Journal of Forestry ResearchVolume 2020 Article ID 2198573 13 pageshttpsdoiorg10115520202198573

diverse biodiversity According to Karim [9] riverine orriparian and gallery forests accounted for 35870 ha which is05 of the countryrsquos total land area However based on FAO[10] report about 126 of the estimated 381 forest area ofSierra Leone was lost between 1990 and 2010 In a nutshellthe country lost an average of 390 00 ha of forest cover overthis period at 063 per year A recent FAOFRA [11] reportgave the annual forest change statistics of Sierra Leone from1990 to 2015 as follows minus 44 1990ndash2000 minus 812000ndash2010 11 1990ndash2015 and minus 48 1990ndash2015 re-spectively However Wadsworth and Lebbie [3] cautionedthe accuracy and credibility of forest area figures given byFAO every five years ey argue that the classificationsystem used by FAO and the data supplied by the countryrsquosauthorities on forest cover of Sierra Leone are most timesexaggerated and ambiguous

Typical riparian forests are known to consist offreshwater swamp forests and are mostly found in lowlandrainforest along with narrow water bodies In these envi-ronments the temperature is milder and the humidity ishigher than the surrounding highlands Rodrigues andShepherd [12] noted that riparian forests are one of thebiospherersquos most complex ecological systems rich in bio-diversity and essential for maintaining the vitality of thelandscape and flow of rivers [13] e riparian forests areessential for the protection of watersheds [1] and whenthey are destroyed siltation and degradation of the wa-tercourses become severe Additionally riparian zonesform the interface between aquatic and terrestrial eco-systems and are often characterized by unique plant di-versity with different ecosystem function as compared withsurrounding communities [13] e flora of these ecosys-tems provides essential ecosystem functions (eg stabi-lizing stream banks controlling nutrients and providinghabitat) and services such as flood mitigation andgroundwater recharge [14ndash16]ese forests also play a rolein the mitigation and movement of many terrestrial animalspecies forming corridors of connectivity between dif-ferent forest patches [17] Furthermore humans as well asaquatic biota and other animals depend on these servicesfor their well-being and as habitat [18] ey are a reservoirfor wild plants and animals facing extinction in the typicalforest as a result of urbanization and other biotic activitiesStudies have also shown that riparian forests serve ascorridors for maintaining regional biodiversity [19] pro-viding vital links in the landscape for birds and smallmammals [20ndash22] Despite their size in patches riparianforests are highly complex diverse and productive systemsof significant ecological social and economic values[23ndash26]

ough the riparian forests along the Taia River areessential in protecting the river however little or lessconsideration has been attached to its conservation norhave any or regular scientific studies been conducted toassess its status and biodiversity in recent years e TaiaRiver and its riparian forest serve as a livelihood hub formost of the local residents along its path thereby makingit a focal point of conservation Besides the direct eco-system services such as nontimber forest products and

other woody product functions of the Tai riparian forest itprovides aesthetic and recreational scenery and addsvalue to the landscape However the degradation of ri-parian forests caused by agriculture and population set-tlements globally drives the loss of environmental qualityin watersheds [27] e alteration of the forest structure isbrought about primarily through massive vegetal clear-ance for agriculture charcoal production and sandmining Biswas and Mallik [28] noted that the disturbanceintensity of riparian forests is likely to have direct effectson plant diversity and biovolume as a result of environ-mental changes and this decreases the ecosystem habitatstability Habitat destruction and degradation is the mostpotent threat to biodiversity in Sierra Leone and has beensubjected to severe threats both direct and indirect [2]Many of these riparian forests in the world were spared inthe past few decades from human destruction due todifficulty in accessing them and also to periodic floodingregimes [29]

Many researchers [30ndash41] have conducted variousstudies on riparian forest globally Nevertheless very littledocumentation is available for the riparian forests withinSierra Leone with Taia riparian forest in particular and evenwhere was the said piece of information is available it isunpublished and outdated

In Sierra Leone although few quantitative plant diversitystudies are available however no comprehensive study onriparian forests has been done in recent years Reference from[2 3 42] confirmed that literature on plant diversity and forestcover is scarce and uncertain where available As tree speciesdiversity varies significantly from location to location due to thevariations in biogeographic habitat and disturbance [43] it isessential for inventories to be conducted in riparian and allforest types to make available quantitative data on plant di-versity forest cover structure and composition of tree speciesin all forests in Sierra Leone is work intends to give aninsight into the plant diversity growth status and biovolume ofriparian forests with a focus on Taia riparian forests Resultsfrom this study will provide useful insight into the ecologicalstatus and plant diversity of forests along river banks in SierraLeone Hence the primary motive for undertaking this study isto provide adequate knowledge and bridge the riparian forestsdiversity status uncertainties gap that have existed over the pastdecades in Sierra Leone

2 Methodology

21 Description of the Study Area e study was conductedin a Riparian forest along the Taia River within KoriChiefdom Moyamba District Southern Sierra Leone withcoordinates ranging from N 08deg06prime31PrimeW 012deg05prime002Prime to N08deg19prime248PrimeW012deg10prime281Prime e study area has two pro-nounce and distinct seasons e rainy season starts mostlyin May and ends in October whereas the dry season startsin November and ends in April e average annual rainfallranges between 2000 and 3500mm e maximummonthly mean temperature ranges between 21 and 23degree Celsius for the substantial part of the day and nightmost notably during the rainy season [44] e study area is

2 International Journal of Forestry Research

located approximately 150 km from the capital cityFreetown Taia riparian forest is in close proximity toresidential settlements and the main occupation in thisarea is farming fishing pole harvesting and charcoalproduction

e clay classification in the study area is called theldquoNyawama Seriesrdquo e Nyawama soils make up an essentialpart of the nearly level (0 to 3 per cent slope) terraces alongthe meanders of Taia River ldquoTextures are sandy clay loam toclay loam in the topsoil usually changing towards clay orsandy clay in the subsoilrdquo [45]

22 Tree Species Identification e botanical name of spe-cies family and genera of all the trees encountered in thesample plots was identified using flora of Sierra Leone by[46] In cases where a treersquos scientific name was not knownimmediately such a tree was identified by its commercial orlocal name and representative parts of the tree collected andpressed for further identification at the National Herbariumat Njala University

23 StudyDesign andMethod e study was carried out inJune 2017 Fourteen (14) rectangular plots of dimension20 times 50m were laid out within the study area e sys-tematic sampling design as per Mishra [47 48] was usedin conducting the field inventory e [Dbh] of trees wasrecorded at 13 m breast height of trees in each plot Atape rule was used to determine the directions of theperpendicular baselines and also the length of these linesof dimension 140 m and 100 m respectively Along the140m line transect a peg with a tag was placed at each20-m distance and a straight line was cut through toreach the 50 m dividing line to indicate one side of the20 times 50m rectangular plot Seven 20 times 50-m plots werelaid out on either side of this dividing line All treeswithin each plot with a [Dbh] ge 7 cm were identified asper Mishra [47 48] and their [Dbh] was measured usinga girthing tape e Spiegel Relascope was used to de-termine values of elevation and depression that wereused to determine the height of each tree whose [Dbh]was measured

231 Data Analysis e relative density and dominancewere obtained using the formula given by [45 47]methods e frequency and abundance of species werecalculated using the standard methodology as describedby [47] Basal area of all the trees was calculated as per[49]

Multidiversity indices were calculated by Shannon andWiener [50] Kent and Coker [51] and Gaines et al [52] andusing Simpson diversity index by [47 53 54] Speciesevenness [E] was determined using Shannonrsquos equitability[EH] as stated by [49 51 55]

(1) Basal area calculation the basal area of all trees wascalculated using the formula BA= πD24 where BAis the basal area (m2) D is the diameter at breastheight (cm) and π is pie [314]

(2) Biovolume calculation the biovolume of individualtrees was estimated using the equation developed fortrees biovolume estimation in lowland rainforests[56] e equation is expressed as follows

V e minus 8433 plusmn 2331 Ln[D] (1)

where V is the volume of a tree (m3) and D isDbh (cm)

(3) ShannonndashWeiner diversity index (H) the Shan-nonndashWiener diversity index (Shannon and Wiener[50] Kent and Coker [51] and Gaines et al [52]) wascalculated using the formula

SHDI minus 1113944S

i1Pi times lnPi( 1113857 (2)

where H1 is the ShannonndashWiener index of diversityPi is the proportion of individuals of a species S is thenumber of species in the community Σ is thesummation symbol and ln is the natural logarithmto the base e

(4) Simpsonrsquos Diversity Index (D) Simpson diversitywas calculated by methods of [47 53 54]

SIDI 1 minus 1113944S

i1P2i (3)

where D is the dominance of the index Pi is theproportion of the ith species and S is the number ofindividuals of all the species

(5) Species evenness [E] was determined using Shan-nonrsquos equitability [EH] as stated by Kent and Coker[51]

Jprime Hprime

Log(S) (4)

where S represents the species total number in eachcommunity

(6) Importance Value Index (IVI) importance valueindex (IVI) = relative frequency + relative densi-ty + relative dominance e percentage value ofthe relative frequency relative density and relativedominance is summed up together and this valueis designated as IVI of the species [47] Speciesrelative density and dominance were obtainedusing the formula given by [45 47 48 57]methods

International Journal of Forestry Research 3

the density of a species total number of individuals of species in all plots laid

total area of the plot laid

relative density of a species density of a species

density of all the plotstimes 100

dominance of a species total basal area of each individual of a species in all plots laid

total area of the plots laid

relative dominance of a species() dominance of a species

dominance of all the speciestimes 100

frequency of species total number of quadrat of occurrence of species

total number of plots laid

relative frequency of species() frequency of a species

frequency of all the speciestimes 100

(5)

3 Results

31 Species CompositionAssessment Parameters e variousspecies composition ecological parameters such as speciesdiversity richness density frequency basal cover domi-nance importance value index and other diversity indiceswere calculated for the study site (Table 1) Summary of alldiversity indices is presented in Table 2

32 Species Diversity and Richness A total of 602 individuals[Dbhge 7 cm] of 49 species from 37 genera and 25 families wererecorded from the study area (Table 1) Funtumia africana andTrichilia heudelotii show dominance in almost all aspects of thestudy area Meliaceae Apocynaceae and Mimosaceae are thedominant families with the highest individuals in the studiedriparian forest ecosystem (Table 3) Combretaceae and Rhi-zophoraceae were the only two families that had only onemember each in the entire study area e Shannon diversityfor the study area was 3094 whereas the Simpson andevenness diversity was 09303 and 04502 respectively Otherdiversity indices values are recorded in Table 2

33 Species Growth Parameters About 83 of the treesdocumented had [Dbh] that ranges from 7 to 30 cm whereas39 of the trees had [Dbh] ranges within 7ndash12 cm (Figure 1)e total basal area in the sample plots is 5605m2 whereasthe mean basal area for the plots was 0114m2 e size classdistribution [SCD] of individuals in the study area showedthat most of the individual species [389] in the sampledcommunity fall within ge7ndash12 cm size class whereas[2076] fell in size class of 13ndash18 cm (Figure 2) Plot 13recorded higher mean [Dbh] of 330 cm whereas plot 6recorded the least of 145 cm e overall tree density for thestudy area was 414 29 Indiha e height class distributionof the site ranges from 5m to 60m (Figure 1) e overallbiovolume for the study site was 28305m3 with a total basal

cover of 1254m2 (Table 1) e cumulative regenerationstatus of the site is presented in Figure 3 e negative slopevalue [minus 1943] of the SCD curve represents a fair regener-ation in the riparian forest [58] A positively weak rela-tionship was seen to exit between height of trees and theirdiameter at breast height (Figure 4)

4 Discussion

Based on recent scientific evidence it is hypothesized thatriparian forests are rich in biodiversity due to their prox-imity to constant water supply [59] Riparian forests that aresustainably managed have the ability to provide watersupport throughout the season in an adequate quantityGomez-Roxas et al [60] stated that herbaceous woody planthas the ability to slow and check floodwater flow rate and atthe same time protects soil from being eroded by the waterforce e Taia riparian forest is moderately diverse whencompared with recent species composition studies carriedout in the country in different ecological zones [2] efindings of the study reveal that though Taia Riparian forestis under massive pressure from the surrounding commu-nities for services such as fuelwood and charcoal productionhowever the forest shows signs of resilience and the po-tential of maintaining rich biodiversity if protection orconservation methods are instituted (Figure 5) e resultsof this finding however disagree with the conclusions madeby [23 61] that riparian forest demonstrates a high level ofbiodiversity Across the West African region for exampleSambare et al [26] recorded a total of 196 species repre-senting 139 genera and 51 families in riparian forests withinBurkina Faso Additionally Natta et al [23] in Benin re-public recorded 1002 species (about 13 of the estimatedBenin flora from 120 families and 515 genera in 19 ha withthe most species-rich families being Leguminosae PoaceaeRubiaceae Euphorbiaceae Cyperaceae Asteraceae andAcanthaceae respectively) Similarly Pereki et al [62] in


Togo also recorded a total of 258 plant species belonging to119 genera from 63 families in Abdoulaye Wildlife Reservedry forests In East Africa Mligo [59] in Tanzania reported atotal of 261 plant species from 68 families in the Wami Riversystem with a Shannon diversity index in the range of163ndash294 e dominant plant families recorded were

Meliaceae Apocynaceae and Mimosaceae Trichilia heu-delotii from the Meliaceae family recorded the highestnumber of the individual followed by Rauvolfia vomitoriafrom the Apocynaceae family and Fucus mucosa from theMoraceae family e abundance of these species in thestudy area is believed to be attributed to their strong

Table 1 Species composition parameters and biovolume

Trees species Indiv PltsO ADb Av ht ABA Dom D (ha) Freq BC (h) Rden RF Rdom IVI Bio-VTrichilie heudelotii 94 9 129 104 001 1044 6714 6429 088 1621 703 700 3024 912Funtumia africana 70 10 122 112 001 700 5000 7143 058 1207 781 466 2454 654Myrianthus arboreus 43 8 110 99 001 538 3071 5714 029 741 625 233 1599 289Measa lanceolate 41 6 130 149 001 683 2929 4286 039 707 469 310 1486 579Albizia zygia 36 7 114 137 001 514 2571 5000 026 621 547 209 1377 359Pynanthus angolensis 31 4 136 183 001 775 2214 2857 032 534 313 256 1103 588Cola gigantean 30 7 105 144 001 429 2143 5000 019 517 547 148 1212 267Synsealus brevepics 28 6 161 134 002 467 2000 4286 041 483 469 325 1276 545Diealiun pobeguinii 25 5 153 158 002 500 1786 3571 033 431 391 262 1083 518Pterocarpus santaliniodes 22 4 184 222 003 550 1571 2857 042 379 313 333 1025 927Milicia regia 13 3 179 139 003 433 929 2143 023 224 234 186 645 325Chassalia carollifere 13 4 189 94 003 325 929 2857 026 224 313 208 744 245Spondias mombin 11 2 170 196 002 550 786 1429 018 190 156 142 488 349Cheistopholis patens 9 2 168 190 002 450 643 1429 014 155 156 114 425 271Ochthocosmus africanus 9 3 214 240 004 300 643 2143 023 155 234 184 574 555Dryptes aubrevillei 9 3 234 163 004 300 643 2143 028 155 234 220 610 450Ficus vogelii 9 2 490 318 019 450 643 1429 121 155 156 967 1278 3853Cordial platyfolis 8 2 232 171 004 400 571 1429 024 138 156 193 487 413Ceiba guineansis 7 2 194 321 003 350 500 1429 015 121 156 118 395 474Albezia ferrginea 6 1 241 232 005 600 429 714 020 103 078 156 337 453Ficus mucoso 6 2 207 159 003 300 429 1429 014 103 156 115 375 229Cordial plathyrsa 5 2 234 190 004 250 357 1429 015 086 156 122 365 292Cola lataritia 5 2 263 173 005 250 357 1429 019 086 156 155 397 335Diacaena ovate 4 1 274 242 006 400 286 714 017 069 078 134 281 407Sterculia trigacantha 4 3 256 203 005 133 286 2143 015 069 234 117 421 298Cassio sieberiana 4 2 314 272 008 200 286 1429 022 069 156 176 402 601Albizia adialthifolia 3 1 332 380 009 300 214 714 019 052 078 148 278 705Canarium schweinfurthii 3 1 201 201 003 300 214 714 007 052 078 054 184 137Diosbyros elliotii 2 1 362 258 010 200 143 714 015 034 078 117 230 379Macaranga hurifola 2 2 324 341 008 100 143 1429 012 034 156 094 285 401Afzelia Africana 2 1 296 325 007 200 143 714 010 034 078 078 191 319Diosbyros elliotii 2 1 414 310 013 200 143 714 019 034 078 153 266 596Piptandeniastrum africanum 2 1 452 312 016 200 143 714 023 034 078 183 295 715Dracaena fragans 2 1 393 164 012 200 143 714 017 034 078 138 251 284Xyopia guintasi 2 1 313 321 008 200 143 714 011 034 078 088 200 353Parinari excelsa 2 1 295 360 007 200 143 714 010 034 078 078 190 351Anthocleista djalonensis 2 2 341 239 009 100 143 1429 013 034 156 104 295 312Klainedoxe gabonesis 2 1 475 153 018 200 143 714 025 034 078 202 314 387Trichilia lantana 2 2 315 192 008 100 143 1429 011 034 156 089 280 214Diospyros heudelotii 1 1 170 220 002 100 071 714 002 017 078 013 108 036Xylopia aethiopica 1 1 476 120 018 100 071 714 013 017 078 101 197 152Terminalia ivorensis 1 1 534 521 022 100 071 714 016 017 078 128 223 833Anisophylla laurina 1 1 507 272 020 100 071 714 014 017 078 115 210 392Anthocleista nobilis 1 1 631 113 031 100 071 714 022 017 078 178 273 252Alchonea cordifolia 1 1 743 124 043 100 071 714 031 017 078 247 342 384Arthrocapus spp 1 1 911 516 065 100 071 714 047 017 078 371 467 2401Dracaena alliotii 1 1 958 392 072 100 071 714 051 017 078 411 506 2017Dracaena heudelotii 1 1 872 339 060 100 071 714 043 017 078 340 435 1445Octhococosmos africanus 1 1 215 187 004 100 071 714 003 017 078 021 116 048Total 602 14 41429 91429 1254 10000 1000 10000 30000 28305Note Indiv means individual trees PltO plots of occurrence ADb average diameter at breast height Avht average height ABA average basal area(m2) Dorm dominance BC (h) basal cover (m2) Freq frequency (percentage) D (h) density (individuals per ha) Rden relative densityRdom relative dominance RF relative frequency IVI importance value index Bio bio-volume (m3)


Table 2 Summary of multidiversity indices of all quantifiable parameters

Diversity indices Values of indices Lower UpperTaxa_S 49 41 49Individuals 602 602 602Dominance_D 006972 006318 008067Simpson_1-D 09303 09193 09368Shannon_H 3094 2959 3144Evenness_eHS 04502 04286 05169Brillouin 2954 2834 3006Menhinick 2035 1702 2035Margalef 7544 6286 7544Equitability_J 07949 07792 08248

Table 3 Numbers of individual species collected their plant families and botanical names

Family Genera Scientific name Individual trees Species per familyAnacardiaceae 1 Spondias mombin 11 1

Mimosaceae 2

Albizia Ferruginea

47 4Albezia zygiaAlbezia adianthifolia

Piptadensiastrum Africanum

Meliaceae 1 Trichilia Heudilotii 96 2Trichilia lantana

Caesalpiniaceae 3

Afzelia Africana

38 4Dialum PubeguiniiDialim guineasisCassiavsieberia

Apocyanaceae 3Rauvolfia vomitoria

72 3Funtumia AfricanaAlstonia boonei

Sapotaceae 1 Synsepalous brevepis 28 1

Annonaceae 2Cleistopholis patens

12 3Xylopia aethiopicaXylopia quintasii

Boraginaceae 1 Cardia platythyrsa 14 2Cardia platyfolis

Moraceae 3

Ficus mucoso

71 4Ficus vogeliiMelicia regia

Merianthus arboreusIxonanthaceae 1 Octhocosmos africanus 9 1

Ebanaceae 1 Dyospyros eloitii 3 2Dyrospyros heudelotiiMyristicaceae 1 Pycnanthus angolensis 31 1

Loganiaceae 1 Anthocleista vogelii 4 2Antholeista djaloneasisMyrsinaceae 1 Maesa lanceolata 41 1

Dracaenaceae 1

Dracaena alliotii

9 4Dracaena ovateDracaena fragans

Dracaena heudelotiiBombacaceae 1 Ceiba pentandra 8 1Burseraceae 1 Canarium schweinfurthii 3 1Rubiaceae 1 Chassalia carolifera 13 1Papilionaceae 1 Pterocarpus santalinoides 23 1


adaptability characteristic as well as their lesser ability to beutilized as firewood charcoal pole or timber Appiah [63]and Rad et al [64] however warn that diversity is on thedecrease when few species dominate an area It is most likelythat the edaphic condition of the study area is more

favorable for certain species than the rest of the species Inother forest ecosystems in West Africa Fabaceae MeliaceaeRubiaceae Sterculiaceae Euphorbiaceae CombretaceaeMimosaceae Ebenaceae Moraceae and Bombacaceae wererecorded as the most dominant plant families in Burkina

Table 3 Continued

Family Genera Scientific name Individual trees Species per family

Sterculiaceae 2Cola lateritia

39 3Cola giganteanSterculia trigacantha

Euphorbiaceae 2 Drypetes aubrevillei 11 2Macaranga hurifoliaRosaceae 1 Parinari excelsa 2 1Irvingiaceae 1 Klainedoxe gabonensis 2 1Combretaceae 1 Terminalia ivorensis 1 1Rhizophoraceae 1 Anisophyllea laurina 1 125 37 49 602 49

8deg0prime0primeprimeN 8deg0prime0primeprimeN

12deg0prime0primeprimeW


Map showing Njala Taia Riparian forest N

Moyamba

Taia

Rive

r

Njala Taia riparian forest

0 5 10 20 30 40kilometers

Study Area

Taia Rivers

Kori Chiefdom

Moyamba District

Figure 2 Map showing Taia River and its Riparian Forest

0

50

100

150

200

250

7ndash12

13ndash1

819

ndash24

25ndash3

031

ndash36

37ndash4

243

ndash48

49ndash5

455

ndash60

61ndash6

667

ndash72

73ndash7

879

ndash84

85ndash9

091

ndash96

97ndash1

02lt1

02

Num

ber o

f tre

es

Dbh class

Figure 1 Dbh class distribution of trees


Faso [26] whereas Anogeissus leiocarpa Pouteria Alnifo-liavar alnifolia Spondias mombin Pterocarpus erinaceusand C giganteava were the most dominant plant speciesrecorded in Togo [62] Reynal-Roques [65] acknowledgesthat these families and their respective species are commonin most tropical rain forest regions around the world

e rationale for the differences plant diversity across thedifferent riparian forests in West Africa could be attributedto anthropogenic activities such as logging pole harvestingfuelwood and charcoal production wildfires and proximityto settlement [1] Across Africa in general biodiversity isunder severe threats with very little being done in somecountries to mitigate the situation [59] When the demandfor forest ecosystem services supersedes its carrying capacity

because of intensive biotic disturbance and the collection ofnontimber products its biodiversity will decline at a ratefaster than it can regenerate According to Houehanou et al[66] bushfires have proven to have adverse effects on treesspecies and hence affecting its density especially in lowerregions Additionally Pereki et al [62] stated that socialpressure open gap in the forest canopies through tree cuttingor logging and this may expose the lower layer to fire andother threats

Shannon index of diversity is an information index itconfounds two components of diversity species richnessand evenness [54] e diversity value in the current studywas recorded to be 3094 which is similar to (32) the valuerecorded by Fayiah et al [42] e Shannon Wiener value of

0

10

20

30

40

50

60

0 20 40 60 80 100 120

Hei

ght (

m)

Diameter at breast height (cm)

y = 02628x + 14225R2 = 02927

Figure 4 Relationship between height and diameter at breast height

ndash2ndash1

012345

0 2 4 6 8 10 12 14 16 18

Ln ( fclass interval)

Ln ( fclass interval)Log (Ln( fclass interval))

y = ndash1943ln(x) + 46139R2 = 09374

Figure 5 SCD curve showing regeneration status based on the log of frequency over a class interval Ln log F frequency

050

100150200250300

lt5

6ndash10

11ndash

15

16ndash2

0

21ndash2

5

26ndash3

0

31ndash3

5

36ndash4

0

41ndash4

5

46ndash5

0

51ndash5

5

56ndash6

0

Num

ber o

f tre

esHeight class

Figure 3 Height class distribution of trees


Taia riparian forest is within the suggested or expected rangeas stated by [54] which is 15 and 35 as it rarely goes above50 Compared with the Simpson index for diversity theShannonndashWiener diversity index indicates the diversity ofspecies in the community e recorded value is a clearindication of the diversity potential of the Taia riparianforest hence if conservation measures are put in placenatural regeneration is a possibility Additionally theSimpson and evenness values of (09) is encouraging for aforest close to settlements like Taia riparian forests oughfrom different ecologies the Shannon diversity values withinforests in the West African subregion as seen in [67] for AfiRiver Forest Reserve and Oban Forest Reserve (Nigeria)were 3827 and 3795 and it is a signal of diversity resiliencein these ecosystems Elsewhere Sahoo et al [68] alsorecorded higher Shannon and Simpson diversity index of366 and 010 respectively in Odisha India e size andforest conservation policies of India are believed to be fareffective than those of other countries in the sub-Africanregion hence higher diversity is expected

41Comparing theRiparianDiversityandOtherEcosystems inSierra Leone e ecological landscape of Sierra Leone isdiverse with unique flora biodiversity across differentecosystems [1] A recent study conducted in Kambui forestin the Eastern part of Sierra Leone by Fayiah et al [42]recorded 36 trees species 22 families from 122 individualtrees within an area of 10 ha Based on species richness andabundance Taia riparian forest is slightly more biologicallydiverse than the Kambui forest is could be attributed tomany biotic and abiotic factors in play along the differentecologies Similarly weak forest protection policies arepaving ways for more forest exploitation across SierraLeone with Taia riparian forest not being an exceptionContrastingly a study conducted a decade ago by Kargbo[69] recorded 132 plant families within an area of 101 ha inthe same Kambui forest Alternately Bangura [70] reported(58) plant families from 1150 individual trees in an area of140 ha in the Singamba forest reserve within MoyambaDistrict Southern Sierra Leone However it is not clear ifthe Singamba forest reserve still maintains such diversityover the years due to the trend of deforestation in thecountry Although the forests ecosystem of the study areadiffers from other forests ecosystems mentioned above theclimate soil type anthropogenic pattern and demandsfrom surrounding communities are more or less the samee occurrence of diverse species within the same districtand other parts of the country depicts unique flora bio-diversity and terrestrial ecosystems Fayiah et al [42]suggested that high rainfall potential sunlight soil typeanthropogenic actions and topography could be the causeof variation in flora diversity in different ecologies in SierraLeone Exceptionally Gola forest reserve is the onlyremaining and adequately protected natural forest in SierraLeone with rich biodiversity

42 Growth Assessment Parameters e diameter at breastheight and a total height of trees are critical parameters in

assessing the growth of vegetation [71] and they help usunderstand the trend of forest development Size classdistribution has been long used to study forest dynamicschanges in species composition and regeneration [72]From our results it could be seen that the riparian forest ismade up of mostly poles and sapling species in nature(Figures 1ndash3) ere is a significantly weak relationshipbetween height and diameter of trees species recorded in thestudy area (Figure 4) is implies that as the height in-creases the diameter at breast height also increases Simi-larly the biovolume values estimated depict that the forest isdepleted and the current vegetation is young with majorityplant species being categorized as poles In comparisonFayiah et al [42] recorded a volume of 39178m3 in KambuiForest Reserve as compared with 2840m3 (Table 1) in thisstudy Soares et al [73] and Moores et al [74] stated that forthe sustainable utilization of available forest resources thevolume is essential information Additionally Dia-mantopoulou [75] ascertain that volume is the most usedmeasure of wood quantity to satisfy manrsquos financial desiree [Dbh] decrease as seen in (Figure 1) automaticallyaffected the total biovolume of the study area Also it isbelieved that species abundance and diversity directly havelinks with the biovolume and thus sound restoration andcommunity conservation projects will improve both thebiovolume and species abundance of riparian forestsCharacterization of SCD serves and is a means of projectingpopulation trends and to some extent past trends [76] andits interpretation has been useful in assessing the state of thepopulation for management purpose [77ndash81] e negativeslope value for the SCD curve indicates that there are moreindividuals in the lower size class and thus the forest in theriparian zone of Taia River is regenerating successfully(Figure 5) However the height and diameter values aregood indicators for the classification of forest types in anygiven ecosysteme SCD curve slope shows that more plantspecies fell in the sapling or pole category indicating thattree species in the study area are smaller [Dbh] in size eabsence of larger big trees implies that logging is not takingplace in this forest due to tree sizes

43 lte Impacts of Human Activities on Taia and Other Ri-parian Forests in Sierra Leone Riparian forests render greatsupport to rural livelihood in the form of wood energymedicines poles and other nontimber forest products[82 83] Based on these ecosystem services derived its ex-ploitation has skyrocketed especially in Sierra Leone NBSAP[1] report stated that biodiversity loss in Sierra Leone ismostlyattributed to deforestation drivers such as poor miningpractices and farming bushfires overgrazing lack of re-sources and poverty population pressure [1 4] inappropriatepolicies institutional weakness and socioeconomic factorsHowever these anthropogenic disturbance factors are notconsistent across regions or ecosystem [84] in Sierra LeoneOn the contrary Martın et al [85] highlighted factors such asroad construction dumping of solid and industrial wasteagricultural expansion and modification of fluvial terraceswere some of the factors that led to the deterioration of theriparian forests Factors such as topography settlement


proximity soil type weak forest policies and primitiveshifting cultivation methods are the primary culprit of forestresources exploitation in the study area Generally the naturalnature and ability of Taia riparian forests to maintain itsvegetation in both seasons attracts roaming animals browsingstimulate poles harvesting and fuelwood and charcoalburning across the forest According to a research done byFayiah et al [86] Spratt et al [4] and USDA Forest Service[87] approximately more than 80 of Sierra Leonersquos pop-ulation depend on fuelwood and charcoal for daily householdenergy e high demand of forest resources for daily energyneeds has placed huge pressure on forest across Sierra Leoneand has resulted in forest reserve exploitation nationwideelevel of exploitation of the Taia riparian forest is believed tohave a direct link with trees diameter size and height of treesenumerated in this studye lower number of trees in highersize class (Figure 1) indicates that Taia riparian forest isundergoing exploitation constantly However favorable soilnutrients andmoisture conditions within the forests providedby the riparian zone and aided with seed dispersal through thewater-body support high regeneration in the study area(Figure 3) With proper protection and awareness aboutsustainable utilization of the wood resources the diversity ofthe forest can be restored

Alternately the increase in the density of trees is stronglybelieved to be connected with the proximity of Taia riparianforests to the stream canopy pattern and temperature of theimmediate environment Scientific evidence has proven thatthe diversity of species is mostly dependent on communitystability interference level and adaptability potential of thespecies [60] Settlement proximity socioeconomic statusand occupation of nearby indigenes play a crucial role in theexploitation of the Taia riparian forests Typically riparianforests are smaller in size but their ecological economicbenefits are enormous to local indigenes [41] Natta et al[88] noted that resources availability in riparian forests forutilization by neighboring inhabitants must satisfy theirbasic needs and serve as a source of income as well eabsence of community forest protection by-law within theKori Chiefdom contributes to more biotic pressure on theforests

5 Conclusion

Decades of intense biotic activity couple with weak com-munity forest protection by-laws has contributed to the lossof Sierra Leone forest estates especially the riparian forestse plant diversity of Taia riparian forest is moderate withthe majority of the stems being the size of poles and saplingse sizes of plant species resulted in to the low biovolumeand hence the need for strategic management and conser-vation approaches e height and [Dbh] values recordedindicate that the riparian forest is immature and is underenormous pressure and needs urgent conservation attentionAlthough the diversity of species does not necessarily poseimmediate threats of extinction now they certainly possesslong-term decline threats especially if the riparian forestsare continued to be altered at a rate faster than they canrecover It was however observed that the forests have good

regeneration potential due to the climatic pattern andabundant soil water content in the study area e assess-ment of species composition growth and biovolume of Taiariparian forest highlight the importance of community-based conservation policies and serve as a baseline for futureassessment of riparian forest ecosystems in Sierra Leone Fora continuous supply of essential ecosystem services differentstalk holders and nongovernmental organizations concernwith environmental management and biodiversity conser-vation should partner with local indigenes Based on thefindings of this study if appropriate conservation measuresare not instituted urgently Taia Riparian forest maybe at theverge of being reduced to a farm bush as a result of polesfuelwood and nonwood forest products collection Addi-tionally charcoal burning has emerged as a big threat tovegetation growth and has reduced catchment areas alongstreams in Kori Chiefdom erefore urgent strategicconservation and protection measures should be adopted toprevent further degradation of forest ecosystems along riverbanks in the district and other ecologies in Sierra Leone

Data Availability

Data for this article will be made available upon request

Conflicts of Interest

e authors declare that they have no conflicts of interest

Acknowledgments

is research was financially supported by the grants fromthe Second Tibetan Plateau Scientific Expedition and Re-search Program (2019QZKK0307) National Key RampDProgram of China (2016YFC0501906) Qinghai ProvincialKey RampD Program (2019-SF-145 and 2018-NK-A2) andQinghai Innovation Platform Construction Project (2017-ZJ-Y20)

References

[1] N Weber R Wistuba J Astrin and J Decher ldquoNew recordsof bats and terrestrial small mammals from the Seli River inSierra Leone before the construction of a hydroelectric damrdquoBiodiversity Data Journal vol 7 Article ID e34754 2019

[2] NBSAP Sierra Leonelsquos Second National Biodiversity Strategyand Action Plan (NBSAP) 2017-2026 Government of SierraLeone through the Environment Protection Agency SierraLeone West Africa 2017

[3] R A Wadsworth and A R Lebbie ldquoWhat happened to theforests of Sierra Leonerdquo Land vol 8 p 80 2019

[4] S Spratt P Kargbo P E Marfo E Ngungoh andS R Suominen Forest Taxation and REDD+ An Analysis ofPotential Impacts in Cameroon Ghana and Sierra LeoneInstitute of Development Studies Falmer UK 2018

[5] O Brown and A Crawford Conservation and Peace Buildingin Sierra Leone International Institute for Sustainable De-velopment (IISD) Winnipeg Canada 2000

[6] M Bakarr J F Oates J Fahr M P E Parren M O Rodeland R Demey ldquoGuinean forests of West Africardquo in HotspotsRevisited Earthrsquos Biologically Richest and Most Endangered


Terrestrial Ecoregions R A Mittermeier P Robles GilM Hoffman et al Eds CEMEX and Conservation Inter-national Washington DC USA 2004

[7] N Myers R A Mittermeier C G Mittermeier G A B daFonseca and J Kent ldquoBiodiversity hotspots for conservationprioritiesrdquo Nature vol 403 no 6772 pp 853ndash858 2000

[8] World Bank ldquoSierra Leone biodiversity conservation projectrdquoReport No AB2770World BankWashington DC USA 2010

[9] A B Karim ldquoAssessment of damage caused to the envi-ronment and biodiversity mining and agriculturerdquo in Pro-ceeding to the National Workshop on the Protection andRehabilitation of Sierra Leonersquos Environment Freetown SierraLeone lte Way Forward SLANGO UNDP and GOSLFreetown Sierra Leone 1996

[10] FAOFRA ldquoGlobal forest resource assessmentrdquo CountryReport Sierra Leone FRA 2010189 FAO Rome Italy 2010

[11] FAOFRA ldquoGlobal forest resource assessment 2015rdquo CountryReport Sierra Leone FAO Rome Italy 2015

[12] R R Rodrigues and G J Shepherd ldquoFatorescondicionantesda vegetacaociliarrdquo in MatasCiliares conservacao e recuper-acao R R Rodrigues and H F LeitaoFilho Eds pp 101ndash107EduspFapesp Sao Paulo Brazil 2000

[13] R J Naiman and H Decampus ldquoe ecology of the interfaceriparian zonesrdquo Annual Review of Ecological System vol 28pp 621ndash658 1997

[14] R D Barling and I D Moore ldquoRole of buffer strips inmanagement of waterway pollution a reviewrdquo EnvironmentalManagement vol 18 no 4 pp 543ndash558 1994

[15] W G Hood and R J Naiman ldquoVulnerability of riparianzones to invasion by exotic vascular plantsrdquo Plant Ecologyvol 148 no 1 2000

[16] D U Hooper F S Chapin J J Ewel et al ldquoEffects ofbiodiversity on ecosystem functioning a consensus of currentknowledgerdquo Ecological Monographs vol 75 no 1 pp 3ndash352005

[17] USAIDNigeria Biodiversity and Tropical Forestry AssessmentMaximizing Agricultural Revenue in Key Enterprises forTargeted Sites (Markets) USAID Washington DC USA2008

[18] K L Fetherston R J Naiman and R E Bilby ldquoLarge woodydebris physical process and riparian forest development inmontane river networks of the Pacific Northwest geomor-phology terrestrial and freshwater systemsrdquo Bio-geomorphology Terrestrial and Freshwater Systems vol 13no 1ndash4 pp 133ndash144 1995

[19] R J Naiman H Decamps and M Pollock ldquoe role of ri-parian corridors in maintaining regional biodiversityrdquo Eco-logical Applications vol 3 no 2 pp 209ndash212 1993

[20] K L Cockle and J S Richardson ldquoDo riparian buffer stripsmitigate the impacts of clear-cutting on small mammalsrdquoBiological Conservation vol 113 no 1 pp 113ndash140 2003

[21] S C Rottenborn ldquoPredicting the impacts of urbanization onriparian bird communitiesrdquo Biological Conservation vol 88no 3 pp 289ndash299 1999

[22] R B Blair ldquoLand use and avian species diversity along anurban gradientrdquo Ecological Applications vol 6 no 2pp 506ndash519 1996

[23] A K Natta B Sinsin and L J G van der Maesen ldquoRiparianforests and biodiversity conservation in Benin (West Africa)rdquoin Proceedings of a Paper Submitted to the XII World ForestryCongress Quebec City Canada September 2003

[24] N Ceperley F Montagnini and A Natta ldquoImportance dessites sacres pour la conservation des foretsgaleries a centre

Beninrdquo Bois et Forets Des Tropiques vol 303 no 303pp 5ndash23 2010

[25] R J Naiman J J Latterell N E Pettit and J D Olden ldquoFlowvariability and the biophysical vitality of river systemsrdquoComptes Rendus Geoscience vol 340 no 9-10 pp 629ndash6432008

[26] O Sambare F Bognounou R Wittig and A iombianoldquoWoody species composition diversity and structure of ri-parian forests of four watercourses types in Burkina FasordquoJournal of Forestry Research vol 22 no 2 pp 145ndash158 2011

[27] W Barrella J R M Petrere W S Smith and L F A MontagldquoAsrelacotildees entre as matasciliares osrios e ospeixesrdquo inMatasCiliares conservacao e recuperacao R R Rodrigues andH d F LeitaoFilho Eds pp 187ndash207 Edusp Sao PauloBrazil 2000

[28] S R Biswas and A U Mallik ldquoDisturbance effects on speciesdiversity and functional diversity in riparian and upland plantcommunitiesrdquo Ecology vol 91 no 1 pp 28ndash35 2010

[29] Geomatics International lte Assessment of Vegetation andLand Use Changes in Nigeria between 197678 and 199395Prepared for the Forest Management Evaluation and Co-ordinating Unit Nigerian Federal Department of Forestryunder the World Bank Environmental Management ProjectMabushi Nigeria 1998

[30] L Rocha-Uriartt D F P Becker V Graeff N M Koch andJ L Schmitt ldquoFunctional patterns and species diversity ofepiphytic vascular spore-producing plants in riparian forestswith different vegetation structure from southern BrazilrdquoPlant Ecology and Evolution vol 149 no 3 pp 261ndash271 2016

[31] N Hough-Snee B B Roper and J M Wheaton Multi-scaleDrivers of Riparian Vegetation A Case from the Upper Co-lumbia and Missouri River Basins Utah State UniversitySpring Runoff Logan UT USA 2013

[32] C S Meek D M Richardson and L Mucina ldquoA river runsthrough it land-use and the composition of vegetation along ariparian corridor in the Cape Floristic Region South AfricardquoBiological Conservation vol 143 no 1 pp 156ndash164 2010

[33] L V Reynolds and D J Cooper ldquoEnvironmental tolerance ofan invasive riparian tree and its potential for continued spreadin the Southwestern USrdquo Journal of Vegetation Sciencevol 21 pp 733ndash743 2010

[34] M McBride W C Hession and D M Rizzo ldquoRiparianreforestation and channel change how long does it takerdquoGeomorphology vol 116 no 3-4 pp 330ndash340 2010

[35] A-M Truscott S C Palmer C Soulsby S Westaway andP E Hulme ldquoConsequences of invasion by the alien plantMimulus guttatus on the species composition and soilproperties of riparian plant communities in Scotlandrdquo Per-spectives in Plant Ecology Evolution and Systematics vol 10no 4 pp 231ndash240 2008

[36] A Ghermandi V Vandenberghe L Benedetti W Bauwensand P A Vanrolleghem ldquoModel-based assessment of shadingeffect by riparian vegetation on river water qualityrdquo EcologicalEngineering vol 35 no 1 pp 92ndash104 2009

[37] D M Richardson P M Holmes K J Esler et al ldquoRiparianvegetation degradation alien plant invasions and restorationprospectsrdquo Diversity and Distributions vol 13 no 1pp 126ndash139 2007

[38] N Prins P M Holmes and D M Richardson ldquoA referenceframework for the restoration of Criparian vegetation in theWestern Cape South Africa degraded by invasive AustralianAcaciasrdquo South African Journal Botany vol 70 pp 767ndash7762005


[39] M L Burton L J Samuelson and S Pan ldquoRiparian woodyplant diversity and forest structure along an urban-ruralgradientrdquo Urban Ecosystems vol 8 no 1 pp 93ndash106 2005

[40] R A Obedzinski C G Shaw and D G Neary ldquoDecliningwoody vegetation in riparian ecosystems of the westernUnited Statesrdquo Western Journal of Applied Forestry vol 16no 4 pp 169ndash181 2001

[41] A H Winward Monitoring the Vegetation Resources in Ri-parian Areas US Department of Agriculture Forest ServiceRocky Mountain Research Station Ogden UT USA 2000

[42] M Fayiah M K Swarray G Otesile and B Chen ldquoCom-parative study of the regeneration potential of kasewe and Taiariverine forests Moyamba District Sierra Leonerdquo in Pro-ceedings of the 40th annual Conference of Forestry Associationof Nigeria (FAN) Lagos Nigeria March 2018

[43] T C Whitmore An Introduction to Tropical Rain Forest OxfordUniversity Press New York NY USA 2nd edition 1998

[44] S S Leone Population and Housing Census Government ofthe Republic of Sierra Leone University Of Sierra LeoneTower Hills Sierra Leone 2004

[45] A K Mishra S K Behera K Singh R M MishraL B Chaudhary and B Singh ldquoEffect of abiotic factors onunderstory community structures in moist deciduous forestsof Northern Indiardquo Forest Science and Practice vol 15 no 4pp 261ndash273 2013

[46] P S Savill and J E D Fox lte Trees of Sierra Leon Gov-ernment Printing Press Freetown Sierra Leone 1967

[47] RMishra EcologyWorkbook Oxford and IBH Publishing CoLtd New Delhi India 2013

[48] P Michael Ecological Methods for Field and Laboratory In-vestigation Tata McGrawHill Publishing Co Ltd New DelhiIndia 1990

[49] S M PhilipMeasuring Trees and Forests A Textbook Writtenfor a Student in Africa UDSM Division of Forestry Dar esSalaam Tanzania 1983

[50] C E Shannon and W Wiener lte Mathematical lteory ofCommunication University of Juionis Press Urbana IL USA1963

[51] M Kent and P Coker Vegetation Description and Analysis aPractical Approach p 363 Bell-Heaven Press London UK1992

[52] P Gaines C T Woodard and J R Carlson ldquoAn enhancertrap line identifies the Drosophila homolog of the L37a ri-bosomal proteinrdquo Gene vol 239 no 1 pp 137ndash143 1999

[53] E H Simpson ldquoMeasurement of diversityrdquo Nature vol 163no 4148 p 688 1949

[54] A E Magurran Ecological Diversity and its MeasurementPrinceton University Press Princeton NJ USA 1988

[55] E C Pielon Ecological Diversity John Wiley amp SonsHoboken NJ USA 1975

[56] FORMECU National Forest Resource Survey TrainingManual Federal Department of Forestry Abuja Nigeria1997

[57] M Fayiah and E Bendu ldquoPlant species diversity at kaseweforest reserverdquo in Proceedings of the 39th Annual Conferenceof the Forestry Association of Nigeria Minna Nigeria No-vember 2016

[58] A E Magurran Measuring Biological Diversity BlackwellScience Ltd Oxford UK 2004

[59] C Mligo ldquoDiversity and distribution pattern of riparian plantspecies in the Wami River system Tanzaniardquo Journal of PlantEcology vol 10 no 2 pp 259ndash270 2017

[60] P Gomez-Roxas R D Boniao E M Burton A Gorospe-Villarino and S S Nacua Community-Based Inventory and

Assessment of Riverine and Riparian Ecosystems in theNortheastern Part of Mt Malindang Misamis OccidentalBiodiversity Research Programme (BRP) for Development inMindanao Focus on Mt Malindang and Environs SEAMEOSEARCA Los Bantildeos Philippines 2005

[61] R Pither andM Kellman ldquoTree species diversity in small tropicalriparian forest fragments in Belize Central Americardquo Biodiversityand Conservation vol 11 no 9 pp 1623ndash1636 2002

[62] H Pereki K Wala T iel-Clemen et al ldquoWoody speciesdiversity and important value indices in dense dry forests inAbdoulaye Wildlife Reserve (Togo West Africa)rdquo Interna-tional Journal of Biodiversity and Conservation vol 5 no 6pp 358ndash366 2013

[63] M Appiah ldquoTree population inventory diversity and deg-radation analysis of a tropical dry deciduous forest in AframPlains Ghanardquo Forest Ecology and Management vol 295pp 145ndash154 2013

[64] J E Rad M Manthey and A Mataji ldquoComparison of plantspecies diversity with different plant communities in decid-uous forestsrdquo International Journal of Environmental Scienceamp Technology vol 6 no 3 pp 389ndash394 2009

[65] A Reynal-Roques La Botanique Redecouverte HumensisParis France 1994

[66] T D Houehanou R L Glele Kakaı A E Assogbadjo et alldquoChange in the woody floristic composition diversity andstructure from protected to unprotected savannahs inPendjari Biosphere Reserve (Benin West Africa)rdquo AfricanJournal of Ecology vol 51 no 2 pp 358ndash365 2012

[67] H I Aigbe T O Adeyemo and B A Oyebade ldquoAssessmentof tree biodiversity of two tropical rainforest in cross riverstate Nigeriardquo International Journal of Scientific amp Engi-neering Research vol 66 pages 2015

[68] T Sahoo P C Panda and L Acharya ldquoStructure compo-sition and diversity of tree species in tropical moist deciduousforests of Eastern India a case study of Nayagarh ForestDivision Odishardquo Journal of Forest Research vol 28pp 12ndash19 2017

[69] I Kargbo ldquoVolume estimation of merchantable trees ofKambui North forest Kenema District Sierra Leonerdquo ADissertation submitted to the School of Agriculture in PartialFulfillment for the Award of Higher Diploma in ForestrySchool of Forestry and Horticulture Njala UniversityMoyamba Sierra Leone 2009

[70] A Bangura ldquoComparative assessment of two Vegetationwithin Njama community Moyamba Districtrdquo A DissertationSubmitted to the Department of Forestry School of NaturalResources Management Njala University Freetown SierraLeone 2013

[71] J Castantildeo-Santamarıa F Crecente-Campo J L Fernandez-Martınez M Barrio-Anta and J R Obeso ldquoTree heightprediction approaches for uneven-aged beech forests innorthwestern Spainrdquo Forest Ecology and Managementvol 307 pp 63ndash73 2013

[72] S Singh ldquoEcological studies and assessment of regenerationpotential of different stands of Jatropha curcas Linn Atdifferent localities in Uttarakhandrdquo Doctoral dissertationHemwati Nandan Bhauguna Garhwal University Srinagar(Garhwal) Uttarakhand India 2013

[73] F A A M N Soares E L Flores C D CabacinhaG A Carrijo and A C P Veiga ldquoRecursive diameter pre-diction and volume calculation of eucalyptus trees usingMultilayer Perceptron Networksrdquo Computers and Electronicsin Agriculture vol 78 no 1 pp 19ndash27 2011


[74] L J Moores B Pittman and G Kitchen ldquoForest ecologicalclassification and mapping their application for ecosystemmanagement in Newfoundlandrdquo Global to Local EcologicalLand Classification vol 39 no 1ndash3 pp 571ndash577 1996

[75] A Diamantopoulou ldquoTree-bole volume estimation onstanding pine trees using cascade correlation artificial NeuralNetwork modelsrdquo Agricultural Engineering International lteCIGR Ejournal vol 8 2006

[76] W Suzuki K Osumi T Masaki K Takahashi H Daimaruand K Hoshizaki ldquoDisturbance regimes and communitystructures of a riparian and an adjacent terrace stand in theKanumazawa Riparian Research Forest Northern JapanrdquoForest Ecology and Management vol 157 no 1ndash3 pp 285ndash301 2002

[77] B G Wilson and E T F Whitkowiski ldquoe seed bank barkthickness and changes in age and size structure (1978ndash1999) ofAfrican savanna tree Burkeardquo Plant Ecology vol 167 no 1pp 151ndash162 2003

[78] J Botha E T F Witkowski and C M Shackleton ldquoeimpact of commercial harvesting on Warburgia salutaris(ldquopepper-bark treerdquo) in Mpumalanga South Africardquo Biodi-versity and Conservation vol 13 no 9 pp 1675ndash1698 2004

[79] K P McLaren M A McDonald J B Hall and J R HealeyldquoPredicting species response to disturbance from size classdistributions of adults and saplings in a Jamaican tropical dryforestrdquo Plant Ecology vol 181 no 1 pp 69ndash84 2005

[80] E N Mwavu and E T F Witkowski ldquoPopulation structureand regeneration of multiple-use tree species in a semi-de-ciduous African tropical rainforest implications for primateconservationrdquo Forest Ecology and Management vol 258no 5 pp 840ndash849 2009

[81] J Obiri M Lawes and M Mukolwe ldquoe dynamics andsustainable use of high-value tree species of the coastalPondoland forests of the Eastern Cape Province SouthAfricardquo Forest Ecology and Management vol 166 no 1ndash3pp 131ndash148 2002

[82] L L Osborne and D A Kovacic ldquoRiparian vegetated bufferstrips in water-quality restoration and stream managementrdquoFreshwater Biology vol 29 no 2 pp 243ndash258 1993

[83] B W Sweeney ldquoEffects of streamside vegetation on macroinvertebrate communities of White Clay Creek in easternNorth Americardquo Proceedings of the Academy of NaturalSciences of Philadelphia vol 144 pp 291ndash340 1993

[84] USEPA Methods for Evaluating Wetland Condition Vege-tation-Based Indicators of Wetland Nutrient EnrichmentUSEPA Washington DC USA 2002

[85] G Martın L Sirombraa and M Mesab ldquoA method forassessing the ecological quality of riparian forests in sub-tropical Andean streamsrdquo QBRy Index Ecological Indicatorsvol 20 pp 324ndash331 2012

[86] M Fayiah S Dong and S Singh ldquoStatus and challenges ofwood biomass as the principal energy in Sierra Leonerdquo In-ternational Journal of Biomass amp Renewables vol 7 no 2pp 1ndash11 2019

[87] USDA Forest Service Overview of the Western PeninsularForest Reserve (WPFRP) USDA Forest Service WashingtonDC USA 2000

[88] A K Natta Ecological assessment of riparian forests in Beninphytodiversity phytosociology and spatial distribution of treesspecies PhD thesis Wageningen University Wageningene Netherlands 2003


diverse biodiversity According to Karim [9] riverine orriparian and gallery forests accounted for 35870 ha which is05 of the countryrsquos total land area However based on FAO[10] report about 126 of the estimated 381 forest area ofSierra Leone was lost between 1990 and 2010 In a nutshellthe country lost an average of 390 00 ha of forest cover overthis period at 063 per year A recent FAOFRA [11] reportgave the annual forest change statistics of Sierra Leone from1990 to 2015 as follows minus 44 1990ndash2000 minus 812000ndash2010 11 1990ndash2015 and minus 48 1990ndash2015 re-spectively However Wadsworth and Lebbie [3] cautionedthe accuracy and credibility of forest area figures given byFAO every five years ey argue that the classificationsystem used by FAO and the data supplied by the countryrsquosauthorities on forest cover of Sierra Leone are most timesexaggerated and ambiguous

Typical riparian forests are known to consist offreshwater swamp forests and are mostly found in lowlandrainforest along with narrow water bodies In these envi-ronments the temperature is milder and the humidity ishigher than the surrounding highlands Rodrigues andShepherd [12] noted that riparian forests are one of thebiospherersquos most complex ecological systems rich in bio-diversity and essential for maintaining the vitality of thelandscape and flow of rivers [13] e riparian forests areessential for the protection of watersheds [1] and whenthey are destroyed siltation and degradation of the wa-tercourses become severe Additionally riparian zonesform the interface between aquatic and terrestrial eco-systems and are often characterized by unique plant di-versity with different ecosystem function as compared withsurrounding communities [13] e flora of these ecosys-tems provides essential ecosystem functions (eg stabi-lizing stream banks controlling nutrients and providinghabitat) and services such as flood mitigation andgroundwater recharge [14ndash16]ese forests also play a rolein the mitigation and movement of many terrestrial animalspecies forming corridors of connectivity between dif-ferent forest patches [17] Furthermore humans as well asaquatic biota and other animals depend on these servicesfor their well-being and as habitat [18] ey are a reservoirfor wild plants and animals facing extinction in the typicalforest as a result of urbanization and other biotic activitiesStudies have also shown that riparian forests serve ascorridors for maintaining regional biodiversity [19] pro-viding vital links in the landscape for birds and smallmammals [20ndash22] Despite their size in patches riparianforests are highly complex diverse and productive systemsof significant ecological social and economic values[23ndash26]

ough the riparian forests along the Taia River areessential in protecting the river however little or lessconsideration has been attached to its conservation norhave any or regular scientific studies been conducted toassess its status and biodiversity in recent years e TaiaRiver and its riparian forest serve as a livelihood hub formost of the local residents along its path thereby makingit a focal point of conservation Besides the direct eco-system services such as nontimber forest products and

other woody product functions of the Tai riparian forest itprovides aesthetic and recreational scenery and addsvalue to the landscape However the degradation of ri-parian forests caused by agriculture and population set-tlements globally drives the loss of environmental qualityin watersheds [27] e alteration of the forest structure isbrought about primarily through massive vegetal clear-ance for agriculture charcoal production and sandmining Biswas and Mallik [28] noted that the disturbanceintensity of riparian forests is likely to have direct effectson plant diversity and biovolume as a result of environ-mental changes and this decreases the ecosystem habitatstability Habitat destruction and degradation is the mostpotent threat to biodiversity in Sierra Leone and has beensubjected to severe threats both direct and indirect [2]Many of these riparian forests in the world were spared inthe past few decades from human destruction due todifficulty in accessing them and also to periodic floodingregimes [29]

Many researchers [30ndash41] have conducted variousstudies on riparian forest globally Nevertheless very littledocumentation is available for the riparian forests withinSierra Leone with Taia riparian forest in particular and evenwhere was the said piece of information is available it isunpublished and outdated

In Sierra Leone although few quantitative plant diversitystudies are available however no comprehensive study onriparian forests has been done in recent years Reference from[2 3 42] confirmed that literature on plant diversity and forestcover is scarce and uncertain where available As tree speciesdiversity varies significantly from location to location due to thevariations in biogeographic habitat and disturbance [43] it isessential for inventories to be conducted in riparian and allforest types to make available quantitative data on plant di-versity forest cover structure and composition of tree speciesin all forests in Sierra Leone is work intends to give aninsight into the plant diversity growth status and biovolume ofriparian forests with a focus on Taia riparian forests Resultsfrom this study will provide useful insight into the ecologicalstatus and plant diversity of forests along river banks in SierraLeone Hence the primary motive for undertaking this study isto provide adequate knowledge and bridge the riparian forestsdiversity status uncertainties gap that have existed over the pastdecades in Sierra Leone

2 Methodology

21 Description of the Study Area e study was conductedin a Riparian forest along the Taia River within KoriChiefdom Moyamba District Southern Sierra Leone withcoordinates ranging from N 08deg06prime31PrimeW 012deg05prime002Prime to N08deg19prime248PrimeW012deg10prime281Prime e study area has two pro-nounce and distinct seasons e rainy season starts mostlyin May and ends in October whereas the dry season startsin November and ends in April e average annual rainfallranges between 2000 and 3500mm e maximummonthly mean temperature ranges between 21 and 23degree Celsius for the substantial part of the day and nightmost notably during the rainy season [44] e study area is













SHDI minus 1113944S





i1P2i (3)



Jprime Hprime

Log(S) (4)
















(5)

3 Results





4 Discussion












Mimosaceae 2

Albizia Ferruginea




Caesalpiniaceae 3

Afzelia Africana








Moraceae 3

Ficus mucoso





Dracaenaceae 1

Dracaena alliotii






Table 3 Continued









Moyamba

Taia

Rive

r



Study Area

Taia Rivers

Kori Chiefdom

Moyamba District


0

50

100

150

200

250

7ndash12

13ndash1

819

ndash24

25ndash3

031

ndash36

37ndash4

243

ndash48

49ndash5

455

ndash60

61ndash6

667

ndash72

73ndash7

879

ndash84

85ndash9

091

ndash96

97ndash1

02lt1

02

Num

ber o

f tre

es

Dbh class







0

10

20

30

40

50

60

0 20 40 60 80 100 120

Hei

ght (

m)


y = 02628x + 14225R2 = 02927


ndash2ndash1

012345

0 2 4 6 8 10 12 14 16 18



y = ndash1943ln(x) + 46139R2 = 09374


050

100150200250300

lt5

6ndash10

11ndash

15

16ndash2

0

21ndash2

5

26ndash3

0

31ndash3

5

36ndash4

0

41ndash4

5

46ndash5

0

51ndash5

5

56ndash6

0

Num

ber o

f tre

esHeight class











5 Conclusion



Data Availability




Acknowledgments


References











































































































SHDI minus 1113944S





i1P2i (3)



Jprime Hprime

Log(S) (4)
















(5)

3 Results





4 Discussion












Mimosaceae 2

Albizia Ferruginea




Caesalpiniaceae 3

Afzelia Africana








Moraceae 3

Ficus mucoso





Dracaenaceae 1

Dracaena alliotii






Table 3 Continued









Moyamba

Taia

Rive

r



Study Area

Taia Rivers

Kori Chiefdom

Moyamba District


0

50

100

150

200

250

7ndash12

13ndash1

819

ndash24

25ndash3

031

ndash36

37ndash4

243

ndash48

49ndash5

455

ndash60

61ndash6

667

ndash72

73ndash7

879

ndash84

85ndash9

091

ndash96

97ndash1

02lt1

02

Num

ber o

f tre

es

Dbh class







0

10

20

30

40

50

60

0 20 40 60 80 100 120

Hei

ght (

m)


y = 02628x + 14225R2 = 02927


ndash2ndash1

012345

0 2 4 6 8 10 12 14 16 18



y = ndash1943ln(x) + 46139R2 = 09374


050

100150200250300

lt5

6ndash10

11ndash

15

16ndash2

0

21ndash2

5

26ndash3

0

31ndash3

5

36ndash4

0

41ndash4

5

46ndash5

0

51ndash5

5

56ndash6

0

Num

ber o

f tre

esHeight class











5 Conclusion



Data Availability




Acknowledgments


References












































































































(5)

3 Results





4 Discussion












Mimosaceae 2

Albizia Ferruginea




Caesalpiniaceae 3

Afzelia Africana








Moraceae 3

Ficus mucoso





Dracaenaceae 1

Dracaena alliotii






Table 3 Continued









Moyamba

Taia

Rive

r



Study Area

Taia Rivers

Kori Chiefdom

Moyamba District


0

50

100

150

200

250

7ndash12

13ndash1

819

ndash24

25ndash3

031

ndash36

37ndash4

243

ndash48

49ndash5

455

ndash60

61ndash6

667

ndash72

73ndash7

879

ndash84

85ndash9

091

ndash96

97ndash1

02lt1

02

Num

ber o

f tre

es

Dbh class







0

10

20

30

40

50

60

0 20 40 60 80 100 120

Hei

ght (

m)


y = 02628x + 14225R2 = 02927


ndash2ndash1

012345

0 2 4 6 8 10 12 14 16 18



y = ndash1943ln(x) + 46139R2 = 09374


050

100150200250300

lt5

6ndash10

11ndash

15

16ndash2

0

21ndash2

5

26ndash3

0

31ndash3

5

36ndash4

0

41ndash4

5

46ndash5

0

51ndash5

5

56ndash6

0

Num

ber o

f tre

esHeight class











5 Conclusion



Data Availability




Acknowledgments


References









































































































Mimosaceae 2

Albizia Ferruginea




Caesalpiniaceae 3

Afzelia Africana








Moraceae 3

Ficus mucoso





Dracaenaceae 1

Dracaena alliotii






Table 3 Continued









Moyamba

Taia

Rive

r



Study Area

Taia Rivers

Kori Chiefdom

Moyamba District


0

50

100

150

200

250

7ndash12

13ndash1

819

ndash24

25ndash3

031

ndash36

37ndash4

243

ndash48

49ndash5

455

ndash60

61ndash6

667

ndash72

73ndash7

879

ndash84

85ndash9

091

ndash96

97ndash1

02lt1

02

Num

ber o

f tre

es

Dbh class







0

10

20

30

40

50

60

0 20 40 60 80 100 120

Hei

ght (

m)


y = 02628x + 14225R2 = 02927


ndash2ndash1

012345

0 2 4 6 8 10 12 14 16 18



y = ndash1943ln(x) + 46139R2 = 09374


050

100150200250300

lt5

6ndash10

11ndash

15

16ndash2

0

21ndash2

5

26ndash3

0

31ndash3

5

36ndash4

0

41ndash4

5

46ndash5

0

51ndash5

5

56ndash6

0

Num

ber o

f tre

esHeight class











5 Conclusion



Data Availability




Acknowledgments


References


































































































Table 3 Continued









Moyamba

Taia

Rive

r



Study Area

Taia Rivers

Kori Chiefdom

Moyamba District


0

50

100

150

200

250

7ndash12

13ndash1

819

ndash24

25ndash3

031

ndash36

37ndash4

243

ndash48

49ndash5

455

ndash60

61ndash6

667

ndash72

73ndash7

879

ndash84

85ndash9

091

ndash96

97ndash1

02lt1

02

Num

ber o

f tre

es

Dbh class







0

10

20

30

40

50

60

0 20 40 60 80 100 120

Hei

ght (

m)


y = 02628x + 14225R2 = 02927


ndash2ndash1

012345

0 2 4 6 8 10 12 14 16 18



y = ndash1943ln(x) + 46139R2 = 09374


050

100150200250300

lt5

6ndash10

11ndash

15

16ndash2

0

21ndash2

5

26ndash3

0

31ndash3

5

36ndash4

0

41ndash4

5

46ndash5

0

51ndash5

5

56ndash6

0

Num

ber o

f tre

esHeight class











5 Conclusion



Data Availability




Acknowledgments


References




































































































0

10

20

30

40

50

60

0 20 40 60 80 100 120

Hei

ght (

m)


y = 02628x + 14225R2 = 02927


ndash2ndash1

012345

0 2 4 6 8 10 12 14 16 18



y = ndash1943ln(x) + 46139R2 = 09374


050

100150200250300

lt5

6ndash10

11ndash

15

16ndash2

0

21ndash2

5

26ndash3

0

31ndash3

5

36ndash4

0

41ndash4

5

46ndash5

0

51ndash5

5

56ndash6

0

Num

ber o

f tre

esHeight class











5 Conclusion



Data Availability




Acknowledgments


References








































































































5 Conclusion



Data Availability




Acknowledgments


References
































































































species diversity, growth, status, and biovolume of taia

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