关键词: 惰性有机碳, 常绿阔叶林, 城市化, 珠江三角洲, 活性有机碳

Abstract: Alpine meadows occur in low temperature environments and are highly sensitive to climate warming. The response of alpine meadows to climate warming will help predict the possible impact of future climate change on alpine ecosystems. To deepen understanding of the mechanisms of alpine ecosystem responses to climate change, from the individual plant level, the community level, and in relation to the physical, chemical and biological properties of soil, we reviewed the effects of warming on vegetationsoil system of alpine meadow. We identified uncertainties in recent studies on the influences of climate warming on alpine meadow ecosystems and set out guidelines for future research on these issues. Rising temperature can promote the growth and development of alpine meadow plants. Plant photosynthetic and respiration rates, biomass and species diversity increase under moderate warming. However, different plant species have different physiological structures and ecological niches, which interact with the amplitude and duration of increasing temperature. This can result in variations of plant photosynthesis and respiration intensity, biomass allocation and phenological phases. Excessive temperature rises tend to simplify alpine meadow ecosystems and ultimately cause a reduction in species diversity, which influence community succession. Rising air temperature increases soil temperature, reduces soil moisture and has a mixed effect on soil organic carbon. Under shortterm warming, soil carbon and enzyme activity increase, raising the soil respiration rate. Over time, the soil respiration rate shows an adaptation to temperature rise. The response models to temperature vary according to their different components and the life processes of species in alpine meadow ecosystems. This leads to large uncertainties in the effects of climate warming on various components of plant and soil ecosystems in alpine meadows. We suggest to find a quantified threshold for the positive and negative effects on alpine meadow vegetation and soil system components under different amplitudes and durations of warming, and to address the response mechanisms from viewpoint of ecologicalmolecular biology.

Key words: evergreen broad-leaved forest, recalcitrant organic carbon, Pearl River Delta, urbanization, active organic carbon