ch. 9 communities. community characteristics many!
TRANSCRIPT
![Page 1: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/1.jpg)
Ch. 9 Communities
![Page 2: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/2.jpg)
Community Characteristics• Many!
![Page 3: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/3.jpg)
• Mechanism: Opening occurs– Trees die: damage by ice (winter), drying (summer)
• Wave moves 1-3 m/yr (cycle 60 yr)
Disturbances
![Page 4: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/4.jpg)
• Elements cycle• Communities differ in
rates, where nutrients located
Nutrient Cycles
![Page 5: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/5.jpg)
• Ex: • Tropical rain forest
– C in
– Litter decay weeks
Nutrient Cycles
?
![Page 6: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/6.jpg)
• Ex: • Tropical rain forest
– C in
– Litter decay weeks
• Subalpine forest– C in
– Decay 1/2 life 10 yr
Nutrient Cycles
![Page 7: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/7.jpg)
• Standing biomass: aboveground dry – desert 100 kg/ha– rain forest 500,000 kg/ha
Productivity
![Page 8: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/8.jpg)
• Net primary productivity: energy to biomass/ Productivity
![Page 9: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/9.jpg)
• Desert: • Mangrove forest, marsh, swamp:
Net primary productivity (Pn)
B=standingbiomass (tons/ha)
Pn=net primary productivity(metric tonsper ha/yr)
![Page 10: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/10.jpg)
• Energy conversion efficiency: % incoming • Note small values
– Rain forest _____ efficiency desert!
Energy Conversion
![Page 11: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/11.jpg)
Community Characteristics• Change through time......
![Page 12: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/12.jpg)
Community Characteristics• Change through time......• Succession: will discuss later• Stability: response community to
disturbance/stress• Several components:
– Resistance: ability remain unchanged during stress
– Resilience: rate return to normal
– Persistence: extent community unchanged over time
Only resistance not worth effort to quantify. WHY??
![Page 13: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/13.jpg)
Community Characteristics• Change through time......
![Page 14: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/14.jpg)
Community Characteristics• Change through time......• Succession: will discuss later
![Page 15: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/15.jpg)
Community Characteristics• Change through time......• Succession: will discuss later• Stability: response community to
disturbance/stress• Several components:
– Resistance: ability remain unchanged during stress
– Resilience: rate return to normal
– Persistence: extent community unchanged over time
Only resistance not worth effort to quantify. WHY??
![Page 16: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/16.jpg)
Community Characteristics• Resistance is futile.....
![Page 17: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/17.jpg)
Classification of communities
And now, for something completely different....
![Page 18: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/18.jpg)
Classification of communities• Data collection (sampling) covered in lab lectures
![Page 19: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/19.jpg)
Classification of communities• Data collection (sampling) covered: lab lectures• Recall…….• Association: more formal and precise unit
– basic unit plant community classification
– composed of stands (stand: particular member association)
– taxonomic analogy: association = species, stands = individuals
• How decide which stands belong to same association?
![Page 20: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/20.jpg)
Classification of communities
• 4 major approaches:• 1) Tabular methods• 2) Cluster analysis• 3) Association analysis• 4) Ordination methods
![Page 21: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/21.jpg)
Tabular methods
Tables…….
![Page 22: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/22.jpg)
Tabular methods• American approach: based on “dominance”
(physiognomic)– Rel. cover, density, basal area, biomass
– Importance
Plant Ecology
![Page 23: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/23.jpg)
Tabular methods• Association based on (layers)
– Ex, Pinus ponderosa/Agropyron spicatum woodland
• Samples: some
![Page 24: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/24.jpg)
Tabular methods• European approach: based • Braun-Blanquet technique (relevé technique)
Sounds French
![Page 25: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/25.jpg)
Tabular methods• Braun-Blanquet technique (relevé technique)• Sample called relevé
– 1) Get
– 2) Choose
– 3) Compile
– 4) Do sp.-area
– 5) Place 1 (relevé) subjectively
– 6) Data: sp.
![Page 26: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/26.jpg)
Tabular methods• Classification: table method. • Sort species: discard widespread & rare,
Cover, sociability (dispersion)
![Page 27: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/27.jpg)
Tabular methods• Differentiated table has differential species: characteristic
of – Have hi fidelity: few stands
– Have hi constancy: most stands
![Page 28: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/28.jpg)
Tabular methods• Note: • 1) • 2) differential sp.
– Ex, moss sp. on trees
Olympic National Park,Washington
![Page 29: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/29.jpg)
Cluster analysis• Expresses ____________ of stands graphically (2 D)• Similarity? Coefficient of Community (CC)• CC: how
![Page 30: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/30.jpg)
Cluster analysis• 2 major indices:
– Jaccard’s Index – Sorensen’s Index
• Presence or cover (“weighted by cover”)• Values: from 100 (same) to 0 (no sp. in common)
![Page 31: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/31.jpg)
Cluster analysis• Generate dendrogram (tree diagram ________________)• Y axis = “resolving power”: 40 great power, 0 no power,
to distinguish diffs.
![Page 32: Ch. 9 Communities. Community Characteristics Many!](https://reader035.vdocument.in/reader035/viewer/2022062217/56649f275503460f94c3f26d/html5/thumbnails/32.jpg)
Cluster analysis• Decide level similarity:
– CC = 10 (threshold III): 2 associations– CC = 20 (threshold II): 7 associations– CC = 30 (threshold I): 15 associations
• Result: associations based