【个人简介】Dr. Elise Pendall is a Professor of Soil Science at Western Sydney University’s Hawkesbury Institute for the Environment. She has three decades of interdisciplinary experience studying multifunctional soil and ecosystem responses to climate change and land-use alteration in grasslands, shrublands and forests. Her insights into rhizosphere soil-plant-microbe interactions inform biogeochemical modeling of processes regulating carbon inputs, metabolism, stabilization and nutrient balance and their potential feedbacks to climate change. She has published nearly 200 papers in international journals including Nature, Proceedings of the National Academy of Science, Science Advances, etc.

【报告题目】The existential challenge of soil carbon - climate feedbacks 

【报告摘要】Feedbacks between soil carbon (C) and the climate system lead to vexing challenges in predicting rates of future climate change, and to developing potential mitigation options based on natural climate solutions. This talk synthesizes results from climate gradients, Free-Air CO2 Enrichment systems, ecosystem warming and drought experiments to reveal areas of uncertainty in mechanistic understanding of soil carbon-climate feedbacks. 

We measure changes in soil C pools in response to rising atmospheric CO2 concentrations in grassland; analyse soil organic matter (SOM) decomposition rates and temperature sensitivity in forest, grassland and wetland ecosystems, at local and continental scales; evaluate the “priming effect” of SOM decomposition; and participate in global synthesis and modelling studies to synthesize mechanistic understanding. 

Rising atmospheric CO2 stimulated photosynthesis and C storage in biomass, but at the expense of C storage in soils. This effect appears to be mediated by plant nutrient uptake, and particularly by mycorrhizal associations that differ by ecosystem type. The tradeoff between plant and soil C may neutralize the CO2 fertilization effect to some degree. In productive and nutrient-rich forests, soil C may continue being stored if productivity increases and microbes prefer fresh SOM substrates. Soils from cold climates exhibit higher temperature sensitivity than those from warmer regions, potentially worsening the rate of climate change as high latitude areas experience rapid warming. Moreover, temperature sensitivity of SOM decomposition may be higher at depth than at the surface. 

Our research has revealed major uncertainties related to the stimulation of SOM decomposition by plant C inputs, temperature sensitivity of soil C, and trade-offs between aboveground and belowground C storage. Future research needs to investigate mechanisms explaining these critical feedback processes, and then to integrate the mechanisms into next-generation land surface models.

【个人简介】复旦大学特聘教授、博士生导师，入选教育部“长江学者”特聘教授、国家海外高层次青年人才、上海优秀学术带头人等；任复旦大学生命科学学院副院长、“上海长江河口湿地生态系统国家野外科学观测研究站”副站长等职务；担任中国生态学会理事。近年来，在科技部重大研发课题与基金委重大研究计划集成项目等资助下，聚焦湿地生态系统碳源汇格局与趋势，研发地表过程监测与预警技术，研究兼顾湿地保护修复与增汇的协同增效途径，提高“碳中和”目标下全球变化预估可靠性与气候变化应对能力。已发表SCI论文100余篇，包括以第一或通讯作者在Nature Climate Change、Nature Ecology & Evolution、Nature Communications、Ecology Letters等国际期刊发表论文。

【报告题目】土壤微生物呼吸的热适应性

【报告摘要】热适应性是指微生物分解功能对温度变化的适应性，即气候增加后微生物降低生理活性以提高其在高温环境中的适宜度，从而减缓碳分解速率，可显著改变未来的气候变化趋势。本报告将从种群、群落到生态系统三个层面介绍土壤微生物呼吸热适应性的形成机理，并介绍气候变化下其对土壤碳分解的影响强度。