Bondaruk V F, Xu C, Wilfahrt P, Yahdjian L, Yu Q, Borer E T, Jentsch A, Seabloom E W, Smith M D, Alberti J, Oñatibia G R, Dieguez H, Carbognani M, Kübert A, Power S A, Eisenhauer N, Isbell F, Auge H, Chandregowda M H, Churchill A C, Daleo P, Forte T, Greenville A C, Koerner S E, Ohlert T, Peri P, Petraglia A, Salesa D, Tedder M, Valdecantos A, Verhoeven E, Wardle G M, Werner C, Wheeler G R, An H, Biancari L, Diao H J, Gutknecht J, Han L B, Ke Y G, Liu J L, Maziko Y, Tian D S, Tissue D, Wanke S, Wei C Z, Wilkins K, Wu H H, Young A L, Zhang F W, Zhang B, Zhu J T, Zong N, Zuo X A, Hautier Y
Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina.
Facultad de Agronomía, Departamento de Recursos Naturales y Ambiente, Cátedra de Ecología, Universidad de Buenos Aires, Buenos Aires, Argentina.
Nat Ecol Evol. 2025 May 19. doi: 10.1038/s41559-025-02705-8.
Plant biomass tends to increase under nutrient addition and decrease under drought. Biotic and abiotic factors influence responses to both, making the combined impact of nutrient addition and drought difficult to predict. Using a globally distributed network of manipulative field experiments, we assessed grassland aboveground biomass response to both drought and increased nutrient availability at 26 sites across nine countries. Overall, drought reduced biomass by 19% and nutrient addition increased it by 24%, resulting in no net impact under combined drought and nutrient addition. Among the plant functional groups, only graminoids responded positively to nutrients during drought. However, these general responses depended on local conditions, especially aridity. Nutrient effects were stronger in arid grasslands and weaker in humid regions and nitrogen-rich soils, although nutrient addition alleviated drought effects the most in subhumid sites. Biomass responses were weaker with higher precipitation variability. Biomass increased more with increased nutrient availability and declined more with drought at high-diversity sites than at low-diversity sites. Our findings highlight the importance of local abiotic and biotic conditions in predicting grassland responses to anthropogenic nutrient and climate changes.
在添加养分的情况下，植物生物量往往会增加，而在干旱条件下则会减少。生物和非生物因素会影响对这两种情况的反应，使得添加养分和干旱的综合影响难以预测。我们利用一个全球分布的控制性田间试验网络，评估了九个国家26个地点的草地地上生物量对干旱和养分有效性增加的反应。总体而言，干旱使生物量减少了19%，添加养分使生物量增加了24%，因此在干旱和添加养分共同作用下没有净影响。在植物功能组中，只有禾本科植物在干旱期间对养分有正向反应。然而，这些一般反应取决于当地条件，尤其是干旱程度。在干旱草原中养分效应更强，而在湿润地区和富氮土壤中则较弱，不过在亚湿润地区添加养分对干旱效应的缓解作用最大。降水变率越高，生物量反应越弱。与低多样性地点相比，在高多样性地点，随着养分有效性增加生物量增加得更多，而随着干旱生物量下降得更多。我们的研究结果凸显了当地非生物和生物条件在预测草地对人为养分和气候变化反应方面的重要性。
