As a consequence of global warming and associated climate change, the drought events and frequents was predicted to increase in the future. These changes will showed great impacts on grasslands structure and functions, as precipitation is the main driver for plant growth and development in this region. Therefore, understanding how plant species respond to drought has been a key issue for both plant physiologists and ecologists. As nitrogen (N) and phosphorus (P) are the two most important essential nutrients that limit plant growth, maintenance, and reproduction in terrestrial ecosystems, the responses of N and P to drought can be used to partly explain the population dynamics and ecosystem functioning under drought conditions.
Dr. LUO Wentao, researcher of Institute of Applied Ecology, CAS. We investigates both short- and long-term drought effects on canopy N and P concentrations, using drought manipulations along a natural drought gradient in grasslands of northern China. Drought manipulation along climatic gradients is a developing research field for understanding vegetation responses to short- and long-term drought and climate change, and each new publication contributes to the expansion of knowledge in this field. Most research in this field has concentrated on productivity and species diversity; therefore, the current manuscript contributes important knowledge by using this approach to study changes in plant canopy nutrient concentrations.
Accurate models of biotic responses to climate change require comparable methods to estimate how plant communities shift with increasing drought. Experimentally altering precipitation inputs is a direct way to mechanistically identify single vs. multiple variables and to project forward outcomes to novel environmental conditions for which the natural gradient approach offers no comparisons.
To project experimental results, we must first assume that experimental results matched changes observed in natural conditions, where single sites were, to some extent, representative of the entire biome, i.e., the experimental results were coherent among different sites within the grassland biome.
However, different plant canopy nutrient concentrations in response to water shortage were shown between the manipulative experiments and natural gradient approaches, as well as among different sites within the studied arid and semiarid grassland biome. “Such differences highlighted uncertainties that would occur in biogeochemical models that are informed solely by single-site experimental data or natural gradient information. We suggest that plant community responses to drought conditions that are predicted using these models should be re-evaluated”, the researcher said.
The study, entitled “Differential responses of canopy nutrients to experimental drought along a natural aridity gradient” has been published in Ecology.
The study is financially supported by the National Natural Science Foundation of China and the National Key Research and Development Program of China.