Demographic legacies of fire history in an African savanna

Fire is a key determinant of woody vegetation structure in savanna ecosystems, acting both independently and synergistically through interactions with herbivores. Fire influences biodiversity and ecological functioning, but quantifying its effects on woody structure is challenging at both species and community scales. Deeper insight into fire effects, and fire-herbivore interactions, can be gained through the examination of species-specific demographic and dynamic changes occurring across areas with different fire regimes in the presence of large herbivores. We used the Carnegie Airborne Observatory (an integrated LiDAR and imaging spectroscopy system) to map woody tree structure, species and dynamics over a four-year interval across two adjacent savanna landscapes with contrasting fire histories in Kruger National Park, South Africa. A history of higher fire frequency was associated with reduced woody canopy cover (17% vs. 23%) and an increased overall rate of treefall (27% vs. 18%). T...

火是稀树草原生态系统中木本植被结构的关键决定因子，既可独立发挥作用，也可通过与草食动物的相互作用产生协同效应。火会影响生物多样性与生态系统功能，但无论在物种尺度还是群落尺度，量化其对木本植被结构的影响均颇具挑战。通过对存在大型草食动物的不同火制度区域内的物种特异性种群统计特征与动态变化展开研究，能够更深入地理解火的影响效应以及火与草食动物的相互作用。本研究借助卡内基机载天文台（集成激光雷达（LiDAR）与成像光谱系统），在南非克鲁格国家公园内两处火历史迥异的相邻稀树草原景观中，以四年为时间间隔，对木本树木的结构、物种组成与动态变化进行了测绘。火频度更高的火历史区域，其木本冠层盖度更低（17% vs. 23%），整体树木倒伏率更高（27% vs. 18%）。（文本未完）