Assessment of structure and function in metal polluted grasslands using Terrestrial Model Ecosystems.
Ecosystem effects of metal pollution in field situations are hard to predict, since metals occur often in mixtures and links between structural (organisms) and functional endpoints (ecosystem processes) are not always that clear. In grasslands, both structure and functioning was suspected to be affected by a mixture of copper, lead, and zinc. Therefore, the structural and functional variables were studied simultaneously using Terrestrial Model Ecosystems (TMEs). Comparing averages of low- and high-polluted soil, based on total metal concentrations, did not show differences in structural and functional variables. However, nematode community structure (Maturity Index) negatively correlated with metal concentrations. Next to that, multivariate statistics showed that enchytraeid, earthworm and, to lesser extent, nematode diversity decreased with increasing metal concentrations and a lower pH in the soil. Bacterial CFU and nematode biomass were positively related with decomposer activity and nitrate concentrations. Nitrate concentrations were negatively related to ammonium concentrations. Earthworm biomass, CO(2) production and plant yield were not related to metal concentrations. The most metal-sensitive endpoint was enchytraeid biomass. In all analyses, soil pH was a significant factor, indicating direct effects on organisms, or indicating indirect effects by influencing metal availability. In general, structural diversity seemed more positively related to functional endpoints than structural biomass. TMEs proved valuable tools to assess the structure and function in metal polluted field situations. The outcome feeds modeling effort and direct future research.
Vrije Universiteit, Department of Animal Ecology, De Boelelaan 1085 NL-1081 HV Amsterdam, The Netherlands; Grontmij|AquaSense, Amsterdam, P.O. Box 95125, NL-1090 HC Amsterdam, The Netherlands. Electronic address: stefan.kools@grontmij.nl.
Stefan A E
SAE
Kools
Vrije Universiteit, Department of Animal Ecology, De Boelelaan 1085 NL-1081 HV Amsterdam, The Netherlands; National Institute for Public Health and the Environment (RIVM), P.O. Box 1 NL-3720 BA Bilthoven, The Netherlands.
Marie-Elène Y
MY
Boivin
Wageningen University and Research Center, Laboratory of Nematology, P.O. Box 8123 NL-6700 ES Wageningen, The Netherlands.
André W G
AWG
Van Der Wurff
Vrije Universiteit, Department of Animal Ecology, De Boelelaan 1085 NL-1081 HV Amsterdam, The Netherlands.
Matty P
MP
Berg
Vrije Universiteit, Department of Animal Ecology, De Boelelaan 1085 NL-1081 HV Amsterdam, The Netherlands.
Cornelis A M
CAM
Van Gestel
Vrije Universiteit, Department of Animal Ecology, De Boelelaan 1085 NL-1081 HV Amsterdam, The Netherlands.
Nico M
NM
Van Straalen
D000818:Animals; D044822:Biodiversity; D018533:Biomass; D002980:Climate; D017753:Ecosystem; D004787:Environmental Pollution; D008670:Metals / Q000032:analysis / Q000633:toxicity*; D008954:Models, Biological; D009348:Nematoda / Q000187:drug effects; D009426:Netherlands; D009835:Oligochaeta / Q000187:drug effects; D063245:Plant Development; D010944:Plants / Q000187:drug effects; D006109:Poaceae / Q000187:drug effects*; D013054:Spectrophotometry, Atomic / Q000379:methods; D015032:Zinc / Q000032:analysis / Q000633:toxicity
D008670:Metals; D015032:Zinc