Report on the Sino-German-Swiss Symposium

“Linking Chinese and German Biodiversity Ecosystem Functioning research in forests”

Biodiversity researcher from China, Germany and Switzerland met from 04.-10. May in Halle and Tübingen to exchange their experience in Biodiversity-Ecosystem Functioning (BEF)-experiments, which have been conducted in China or Germany. The symposium was organized by Prof. Helge Bruelheide (Martin Luther University Halle Wittenberg) and Prof. Ma Keping (Institute of Botany, Chinese Academy of Sciences) and had the aim to present and discuss the results from the different platforms.

Participants of the symposium

Fig. 1: Participants of the symposium in the Botanical Garden of the Institute of Biology / Geobotany of Martin Luther Universität Halle Wittenberg

In total, there were 43 participants in the symposium, among them 15 from China and 25 from Germany as well as researchers from Switzerland and USA. Beside an intensive exchange about the possibilities of multidisciplinary synthesis across the different experimente and observational studies, there was the opportunity to see the German Biodiversity platforms. Thus, they visited the Global Change Experimental Facilities (GCEF) and the tree diversity experiment in Kreinitz (Sachsen) of the Helmholtz Centre for Environmental Research UFZ as well as the German Centre of integrative biodiversity research (iDiv) of the universities Halle, Jena und Leipzig.

The Jena experiment

Fig. 2: Prof. Dr. Nico Eisenhauer explains the trait-based diversity experiment of the Jena experiment

The symposium took place at the Martin Luther Universität Halle Wittenberg and at the Eberhards Karl University Tübingen. This allowed to visit the experiments both in East and South Germany, such as the Jena experiment on grassland diversity, the BIOTREE tree BEF-experiment in Bechstedt (Thuringia) und the German Biodiversity Exploratories in the Schwäbische Alb. Thus, within the few days of the symposium the participants could acquire a profound knowledge on the central initiatives of DFG-funded German biodiversity research.

German Biodiversity Exploratories

Fig. 3: Soil sampling in one of the forest plots of the German Biodiversity Exploratories in the Schwäbischen Alb

A central result of the symposium were novel research ideas for future biodiversity experiments, which will be the backbone for a common proposal for a new German-Swiss Research Unit. Furthermore, all participants agreed that the amount of results already obtained on the different platforms meanwhile allows the compilation of synthesis data sets across all different experiments. The first steps in this direction and a discussion on publication ideas arising from these data sets were taken on this workshop.

The BEF-China Project

The joint Chinese-German-Swiss research project “BEF-China” (FOR 891) integrates more than 15 German, Swiss, and Chinese universities and institutes into 13 collaborative subprojects. The project was funded in the first phase from 2008-2011 and is now in the third phase, 2014-2016.

In 2009 and 2010, the BEF-China project established a large forest biodiversity–ecosystem functioning (BEF) experiment at the subtropical forest site Xingangshan in Jiangxi Province, China. The BEF-China project is the first BEF forest experiment in the highly species-rich subtropics.

The present research concentrates on measuring ecosystem functions in the experimental plots, namely primary productivity, carbon and nitrogen storage, nutrient cycling, and prevention of soil erosion. The latter process is an ecosystem service which has until now never been studied in an experimental biodiversity manipulation, but has prominent importance in this region. An additional research focus will be interactions with other trophic levels and strata (herb layer, soil macrofauna, herbivores, decomposers, mycorrhiza, soil microorganisms). To meet these objectives, a wide range of scientists contribute to the BEF-China project, involving groups focusing on tree growth allometries, plant functional traits, plant-insect interactions, wood decomposition, phosphorus cycling and erosion potential.

As in the first phase, the project continues to be carried out in close collaboration between Chinese and European researchers with complementary knowledge and skills. In addition, the measurements in the CSPs are continuing. The joint synthesis of the data gathered in both phases of BEF-China will help to resolve one of the most central issues in ecology and global change biology: how plant diversity may maintain vital services in forest ecosystems.

Site A was planted for the experiment from March to the end of April 2009.

Fig. 1: Site A kml

Digital elevation model of site A

Fig. 2: Digital elevation model of site A

Plots at site A: tree richness

Fig. 3: Plots at site A: tree richness

Plots at site A: shrub richness

Fig. 4: Plots at site A: shrub richness

Site B was planted for the experiment from March to the end of April 2010.

Fig. 1: Site B kml

Digital elevation model of site B

Fig. 2: Digital elevation model of site B

Plots at site B: tree richness

Fig. 3: Plots at site B: tree richness

Plots at site B: shrub richness

Fig. 4: Plots at site B: shrub richness

In a parallel observational approach, a total of 27 Comparative Study Plots (CSPs) were set up in existing forests in an adjacent Gutianshan National Nature Reserve (Zhejiang Province) in 2008.

The selection of CSPs followed a comparative design, employing a stratification of successional age. The CSPs address the impact of successional age on ecosystem functioning, providing a basis for assessing the successional processes at work across tree species diversity in the Main Experiment. Since the Main Experiment was planted with saplings, the first years of the project will reflect the conditions of young successional stages with respect to microclimate, food web structure and nutrient fluxes and pools.

Gutianshan National Nature Reserve (S. Both)

Fig. 1: Gutianshan National Nature Reserve (S. Both)

These observational investigations of existing highly diverse species assemblages in the CSP will serve as a later reference for a comparison with the experimental results. For this reason, all subprojects of the Research Unit focused on the CSPs in the first three years of the project (2008-2011), and several analyses are ongoing.