TY - JOUR
T1 - Vegetation structure is as important as climate for explaining ecosystem function across patagonian rangelands
AU - Gaitán, Juan J.
AU - Oliva, Gabriel E.
AU - Bran, Donaldo E.
AU - Maestre, Fernando T.
AU - Aguiar, Martín R.
AU - Jobbágy, Esteban G.
AU - Buono, Gustavo G.
AU - Ferrante, Daniela
AU - Nakamatsu, Viviana B.
AU - Ciari, Georgina
AU - Salomone, Jorge M.
AU - Massara, Virginia
N1 - Publisher Copyright:
© 2014 The Authors. Journal of Ecology © 2014 British Ecological Society.
PY - 2014/11/1
Y1 - 2014/11/1
N2 - 1. Drylands cover about 41% of Earth's land surface, and 65% of their area supports domestic livestock that depends on the above-ground net primary productivity (ANPP) of natural vegetation. Thus, understanding how biotic and abiotic factors control ANPP and related ecosystem functions can largely help to create more sustainable land-use practices in rangelands, particularly in the context of ongoing global environmental change. 2. We used 311 sites across a broad natural gradient in Patagonian rangelands to evaluate the relative importance of climate (temperature and precipitation) and vegetation structure (grass and shrub cover, species richness) as drivers of ANPP, precipitation-use efficiency (PUE) and precipitation marginal response (PMR). 3. Climatic variables explained 60%, 52% and 12% of the variation in grass cover, shrub cover and species richness, respectively. Shrub cover increased in areas with warmer, drier and winter rainfall climates, while the response observed for both grass cover and species richness was the opposite. Climate and vegetation structure explained 70%, 60% and 29% of the variation in ANPP, PUE and PMR, respectively. These three variables increased with increasing vegetation cover, particularly grass cover. Species richness also increased with ANPP, PUE and PMR. ANPP increased, and PUE decreased with increasing mean annual precipitation, whereas PMR increased with the proportion of precipitation falling in spring-summer. Temperature had a strong negative effect on ANPP and PUE, and a positive direct effect on PMR. Standardized total effects from structural equation modelling showed that vegetation structure and climate had similar strengths as drivers of ecosystem functioning. Grass cover had the highest total effect on ANPP (0.58), PUE (0.55) and PMR (0.41). Among the climatic variables, mean annual precipitation had the strongest total effect on ANPP (0.51) and PUE (-0.41), and the proportion of the precipitation falling in spring-summer was the most influential on PMR (0.36). 4. Synthesis. Vegetation structure is as important as climate in shaping ecosystem functioning Patagonian rangelands. Maintaining and enhancing vegetation cover and species richness, particularly in grasses, could reduce the adverse effects of climate change on ecosystem functioning in these ecosystems.
AB - 1. Drylands cover about 41% of Earth's land surface, and 65% of their area supports domestic livestock that depends on the above-ground net primary productivity (ANPP) of natural vegetation. Thus, understanding how biotic and abiotic factors control ANPP and related ecosystem functions can largely help to create more sustainable land-use practices in rangelands, particularly in the context of ongoing global environmental change. 2. We used 311 sites across a broad natural gradient in Patagonian rangelands to evaluate the relative importance of climate (temperature and precipitation) and vegetation structure (grass and shrub cover, species richness) as drivers of ANPP, precipitation-use efficiency (PUE) and precipitation marginal response (PMR). 3. Climatic variables explained 60%, 52% and 12% of the variation in grass cover, shrub cover and species richness, respectively. Shrub cover increased in areas with warmer, drier and winter rainfall climates, while the response observed for both grass cover and species richness was the opposite. Climate and vegetation structure explained 70%, 60% and 29% of the variation in ANPP, PUE and PMR, respectively. These three variables increased with increasing vegetation cover, particularly grass cover. Species richness also increased with ANPP, PUE and PMR. ANPP increased, and PUE decreased with increasing mean annual precipitation, whereas PMR increased with the proportion of precipitation falling in spring-summer. Temperature had a strong negative effect on ANPP and PUE, and a positive direct effect on PMR. Standardized total effects from structural equation modelling showed that vegetation structure and climate had similar strengths as drivers of ecosystem functioning. Grass cover had the highest total effect on ANPP (0.58), PUE (0.55) and PMR (0.41). Among the climatic variables, mean annual precipitation had the strongest total effect on ANPP (0.51) and PUE (-0.41), and the proportion of the precipitation falling in spring-summer was the most influential on PMR (0.36). 4. Synthesis. Vegetation structure is as important as climate in shaping ecosystem functioning Patagonian rangelands. Maintaining and enhancing vegetation cover and species richness, particularly in grasses, could reduce the adverse effects of climate change on ecosystem functioning in these ecosystems.
KW - Above-ground net primary productivity
KW - Drylands
KW - Ecosystem services
KW - Grass-shrub balance
KW - Mean annual precipitation
KW - Precipitation marginal response
KW - Precipitation-use efficiency
KW - Species richness
UR - http://www.scopus.com/inward/record.url?scp=84925265790&partnerID=8YFLogxK
U2 - 10.1111/1365-2745.12273
DO - 10.1111/1365-2745.12273
M3 - Article
AN - SCOPUS:84925265790
SN - 0022-0477
VL - 102
SP - 1419
EP - 1428
JO - Journal of Ecology
JF - Journal of Ecology
IS - 6
ER -
