TY  - JOUR
A1  - Schwarzer, Christian
A1  - Heinken, Thilo
A1  - Luthardt, Vera
A1  - Joshi, Jasmin Radha
T1  - Latitudinal shifts in species interactions interfere with resistance of southern but not of northern bog-plant communities to experimental climate change
JF  - The journal of ecology
N2  - The persistence of species under changed climatic conditions depends on adaptations and plastic responses to these conditions and on interactions with their local plant community resulting in direct and indirect effects of changed climatic conditions. Populations at species' range margins may be especially crucial in containing a gene pool comprising adaptations to extreme climatic conditions. Many species of northern European bog ecosystems reach their southern lowland range limit in central Europe. In a common-garden experiment, we experimentally assessed the impact of projected climatic changes on five bog-plant species (including peat moss Sphagnum magellanicum) sampled along a latitudinal gradient of 1400km from Scandinavia to the marginal lowland populations in Germany. Populations were cultivated in monocultures and in experimental communities composed of all five species from their local community, and exposed to five combinations of three climate treatments (warming, fluctuating water-tables, fertilization) in a southern common garden. Whereas most monocultures showed a decreasing biomass production from southern to northern origins under southern environmental conditions, in the experimental mixed-species communities, an increasing biomass production towards northern communities was observed together with a shift in interspecific interactions along the latitudinal gradient. While negative dominance effects prevailed in southern communities, higher net biodiversity effects were observed in northern subarctic communities. The combined effects of climate treatments increased biomass production in monocultures of most origins. In communities, however, overall the treatments did not result in significantly changed biomass production. Among individual treatments, water-table fluctuations caused a significant decrease in biomass production, but only in southern communities, indicating higher vulnerability to changed climatic conditions. Here, negative effects of climate treatments on graminoids were not compensated by the slightly increased growth of peat moss that benefited from interspecific interactions only in northern communities.Synthesis. We conclude that shifting interactions within multispecies communities caused pronounced responses to changed climatic conditions in wetland communities of temperate southern marginal, but not of northern subarctic origin. Therefore, future models investigating the impacts of climate change on plant communities should consider geographical variation in species interactions an important factor influencing community responses to changed climatic conditions.
KW  - additive partitioning of biodiversity effects
KW  - biodiversity
KW  - ecosystem services
KW  - ecosystem stability
KW  - intraspecific divergence
KW  - multifactorial environmental change
KW  - nitrogen deposition
KW  - northern peatlands
KW  - Sphagnum magellanicum
KW  - wetland ecosystems
Y1  - 2013
U6  - https://doi.org/10.1111/1365-2745.12158
SN  - 0022-0477
SN  - 1365-2745
VL  - 101
IS  - 6
SP  - 1484
EP  - 1497
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -