EFFECT OF DETRITUS INPUT CHANGE ON MICROORGANISMS IN FOREST SOILS

IN CENTRAL EUROPE

István FEKETE1*,2, Áron BÉNI3, Katalin JUHOS1 ,Zsolt KOTROCZÓ1

1Department of Soil Science and Water Management, Szent István University, 29-43 Villányi St., Budapest, 1118, Hungary, feketeistani@gmail.com; 2Institute of Environmental Science University of Nyíregyháza; 3Institute of Agricultural Chemistry and Soil Science, University of Debrecen;

Climate change often can cause alteration in detritus production. We examined the effects of litter input on soil dynamic processes in a Quercetum petraeae-cerris forest in northeastern

Hungary, at the Síkfőkút DIRT (Detritus Input and Removal Treatment) experimental site. The goal of the DIRT project is to assess how rates and sources of plant litter inputs might control

the accumulation and dynamics of organic matter and nutrients in forest soils over decadal time scales. Six treatments were applied in the experimental site. Beside the control (C), two

detritus addition (DL and DW) and three detritus removal (NL, NR and NI) treatments were applied in which aboveground and belowground detritus quantities were manipulated. The fungal

biomass showed more than five times higher values for litter doubling treatment (2 mg fungi/g soil ) than in the soils of NL (0.4 mg fungi/g soil).

Abstract

Site description and experimental design: We carried out

our investigation in the Síkfokút Experimental Forest } in

northeastern Hungary. The study area (27 ha) is located in

the southern part of the Bükk Mountains at an average

altitude of 325 m.a.s.l (47° 55’ N; 20° 26’ E). The area has

been protected and has been part of the Bükk National Park

since 1976. Mean annual temperature is 10 C and mean

annual precipitation is 553 mm. This forest (Quercetum

petraeae- cerris community) has had no active management

since 1976 (Jakucs, 1985), but has a legacy of intensive

forest management that occurred before that time. The

experimental aboveground and belowground litter

manipulation plots were established in November 2000. We

established one control and five litter manipulation treatments

each with three randomly located 7x7 m replicate plots

established under complete canopy cover (Fekete et al.,

2007). There were two types of detritus addition treatments

(Double Wood DW and Double Litter (DL). In three

treatments, detritus inputs were removed: No Litter (NL) No

Roots plots (NR) and No Inputs (NI) (Nadelhoffer et al., 2004;

Fekete et al. 2012).

Soil sampling and measurements: Soil samples

were collected randomly from 5 locations in every

site from 0 to 25 cm in three layers (0-5, 5-15, 15-

25 cm in 25 June 2014. The determination of soil

fungal biomass was based on the ergosterol

content measurement by HPLC method (Béni et al

2014). We study the number of bacteria and fungi

with MPN method (Reichart, 1991).

These parameters of the treatments were

compared by ANOVA and these were completed

with Tukey’s HSD test.

Financial support: Project no. 126478 and 125688 has been implemented with the

support provided by the National Research, Development and Innovation Fund of Hungary,

financed under the KH_17 funding scheme.

Soil microorganisms react most quickly to changes in environmental parameters in the

soil. In our detritus manipulation experiment we studied the amount of bacteria and

fungai with MPN method in 0-5 cm soil layer and fungi biomass in 0-5, 5-15 and 15-25

cm of 18 DIRT plots. These studies showed a significantly higher amount of bacteria in

case of detritus addition and control treatments than in detritus withdrawal treatments,

while in DL and DW treatments showed significantly higher values than in the detritus

withdrawal treatments for the amount of fungi with MPN method and fungal biomass.

We found the greatest difference between treatments in the fungal biomass in the top 5

cm layer than in deeper layers. In 0-5 cm layer DL was significantly higher than all

other treatments and DW and C are significantly higher than detritus withdrawal

treatments. The fungi biomass were significantly higer in detritus addition treatments

and control than detritus withdrawal treatments in 5-15 cm deep layer while in the 15-

25 deep layer the fungi biomass were significantly higer only in detritus addition

treatments than detritus withdrawal treatments.

According to our investigations, the lack of both leaf litter and live roots significantly

reduces the amount of soil microorganisms. However, doubling of leaf litter did not

cause a significant increase in the amount of bacteria or fungi compared to the control.

Figure 1 The bacteria of the MPN

numbers in reatments of Síkfőkút

DIRT site t in the upper 5 cm of

soil layer.

Figure 2

The fungi of the MPN number on

Síkfőkút DIRT site treatmyents,

in the upper 5 cm of soil laer.

Figure 3 Fungai biomass in

the upper 25cm (0-5, 5-15,

15-25 cm) of soil layers.

Material and methods

Result and Discussion

ReferencesAron, Beni ; Erzsebet, Soki ; Kate, Lajtha ; Istvan, Fekete 2014 An optimized HPLC method for soil fungal biomass determination

and its application to a detritus manipulation study JOURNAL OF MICROBIOLOGICAL METHODS 103 pp. 124-130.

Fekete, I., Kotroczó, Zs, Varga, Cs, Hargitai, R., Townsend, K., 2012. Variability of organic matter inputs affects soil moisture and

soil biological parameters in a European detritus manipulation experiment. Ecosystems 15, 792-803

Fekete, I., Varga, Cs, Kotroczó, Zs, Krakomperger, Zs, Tóth, J.A., 2007. The effect of temperature and moisture on enzyme

activity in Síkfokút Site. Cereal Research } Communications 35, 381-385.

Jakucs, P. (Ed.), 1985. Ecology of an Oak Forest in Hungary I. Akadémiai Kiadó, Budapest, pp. 23, 69.

Kotroczo, Z., Veres, Z., Fekete, I., Papp, M., & T oth, J. A. (2012). Effects of climate change on litter production in a Quercetum

petraeae-cerris forest in Hungary. Acta Silvatica et Lignaria Hungarica, 8, 31–38.

Nadelhoffer, K., Boone, R., Bowden, R.D., Canary, J., Kaye, J., Micks, P., Ricca, A., McDowell, W., Aitkenhead, J., 2004. The

DIRT experiment. In: Foster, D.R., Aber, D.J. (Eds.), Forests in Time. Yale University Press, Michigan.

Reichart O. (1991): Some remarks on the bias of the MPN method. International Journal of Food Microbiology. 13. 131-142.

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We carried out our investigation in

the Síkfokút Experimental Forest } in

northeastern Hungary.