TY  - JOUR
A1  - Klaus, Valentin H.
A1  - Hölzel, Norbert
A1  - Boch, Steffen
A1  - Müller, Jorg
A1  - Socher, Stephanie A.
A1  - Prati, Daniel
A1  - Fischer, Markus
A1  - Kleinebecker, Till
T1  - Direct and indirect associations between plant species richness and productivity in grasslands regional differences preclude simple generalization of productivity-biodiversity relationships
JF  - Preslia : the journal of the Czech Botanical Society
N2  - Plant species richness of permanent grasslands has often been found to be significantly associated with productivity. Concentrations of nutrients in biomass can give further insight into these productivity-plant species richness relationships, e.g. by reflecting land use or soil characteristics. However, the consistency of such relationships across different regions has rarely been taken into account, which might significantly compromise our potential for generalization. We recorded plant species richness and measured above-ground biomass and concentrations of nutrients in biomass in 295 grasslands in three regions in Germany that differ in soil and climatic conditions. Structural equation modelling revealed that nutrient concentrations were mostly indirectly associated with plant species richness via biomass production. However, negative associations between the concentrations of different nutrients and biomass and plant species richness differed considerably among regions. While in two regions, more than 40% of the variation in plant species richness could be attributed to variation in biomass, K, P. and to some degree also N concentrations, in the third region only 15% of the variation could be explained in this way. Generally, highest plant species richness was recorded in grasslands where N and P were co-limiting plant growth, in contrast to N or K (co-) limitation. But again, this pattern was not recorded in the third region. While for two regions land-use intensity and especially the application of fertilizers are suggested to be the main drivers causing the observed negative associations with productivity, in the third region the little variance accounted for, low species richness and weak relationships implied that former intensive grassland management, ongoing mineralization of peat and fluctuating water levels in fen grasslands have overruled effects of current land-use intensity and productivity. Finally, we conclude that regional replication is of major importance for studies seeking general insights into productivity-diversity relationships.
KW  - anthropogenic effect
KW  - Biodiversity Exploratories project
KW  - fen grasslands
KW  - generalizability
KW  - land-use history
KW  - nitrogen
KW  - phosphorus
KW  - potassium
KW  - plant species richness
KW  - structural equation modeling
Y1  - 2013
SN  - 0032-7786
VL  - 85
IS  - 2
SP  - 97
EP  - 112
PB  - Czech Botanical Soc.
CY  - Praha
ER  - 
TY  - JOUR
A1  - Neill, Christopher
A1  - Coe, Michael T.
A1  - Riskin, Shelby H.
A1  - Krusche, Alex V.
A1  - Elsenbeer, Helmut
A1  - Macedo, Marcia N.
A1  - McHorney, Richard
A1  - Lefebvre, Paul
A1  - Davidson, Eric A.
A1  - Scheffler, Raphael
A1  - Figueira, Adelaine Michela e Silva
A1  - Porder, Stephen
A1  - Deegan, Linda A.
T1  - Watershed responses to Amazon soya bean cropland expansion and intensification
JF  - Philosophical transactions of the Royal Society of London : B, Biological sciences
N2  - The expansion and intensification of soya bean agriculture in southeastern Amazonia can alter watershed hydrology and biogeochemistry by changing the land cover, water balance and nutrient inputs. Several new insights on the responses of watershed hydrology and biogeochemistry to deforestation in Mato Grosso have emerged from recent intensive field campaigns in this region. Because of reduced evapotranspiration, total water export increases threefold to fourfold in soya bean watersheds compared with forest. However, the deep and highly permeable soils on the broad plateaus on which much of the soya bean cultivation has expanded buffer small soya bean watersheds against increased stormflows. Concentrations of nitrate and phosphate do not differ between forest or soya bean watersheds because fixation of phosphorus fertilizer by iron and aluminium oxides and anion exchange of nitrate in deep soils restrict nutrient movement. Despite resistance to biogeochemical change, streams in soya bean watersheds have higher temperatures caused by impoundments and reduction of bordering riparian forest. In larger rivers, increased water flow, current velocities and sediment flux following deforestation can reshape stream morphology, suggesting that cumulative impacts of deforestation in small watersheds will occur at larger scales.
KW  - soya beans
KW  - watersheds
KW  - nitrogen
KW  - phosphorus
KW  - soil
Y1  - 2013
U6  - https://doi.org/10.1098/rstb.2012.0425
SN  - 0962-8436
SN  - 1471-2970
VL  - 368
IS  - 1619
PB  - Royal Society
CY  - London
ER  -