Impacts of Climate Change and Human Activities on Plant Species α-Diversity across the Tibetan Grasslands

Abstract

Plant species α-diversity is closely correlated with ecosystem structures and functions. However, whether climate change and human activities will reduce plant species α-diversity remains controversial. In this study, potential (i.e., potential species richness: SRp, Shannonp, Simpsonp and Pieloup) and actual plant species α-diversity (i.e., actual species richness: SRa, Shannona, Simpsona and Pieloua) during 2000–2020 were quantified based on random forests in grasslands on the Tibetan Plateau. Overall, climate change had positive influences on potential plant species α-diversity across all the grassland systems. However, more than one-third areas showed decreasing trends for potential plant species α-diversity. Climate change increased the SRp at rates of 0.0060 and 0.0025 yr−1 in alpine steppes and alpine meadows, respectively. Temperature change predominated the variations of Shannonp and Simpsonp, and radiation change predominated the variations of SRp and Pieloup. Geography position, local temperature, precipitation and radiation conditions regulated the impacts of climate change on potential species α-diversity. On average, human activities caused 1% plant species loss but elevated the Shannon, Simpson and Pielou by 26%, 4% and 5%, respectively. There were 46.51%, 81.08%, 61.26% and 61.10% areas showing positive effects of human activities on plant species richness, Shannon, Simpson and Pielou, respectively. There were less than 48% areas showing increasing trends of human activities’ impacts on plant species α-diversity. Human activities increased plant species richness by 2% in alpine meadows but decreased plant species richness by 1% in alpine steppes. Accordingly, both the impacts of climate change and human activities on plant species α-diversity were not always negative and varied with space and grassland types. The study warned that both climate change and human activities may not cause as much species loss as expected. This study also cautioned that the impacts of radiation change on plant species α-diversity should be at least put on the same level as the impacts of climate warming and precipitation change on plant α-diversity.

Assessing the suitability and dynamics of three medicinal Sambucus species in China under current and future climate scenarios

“…Notably, the impact of human activities on plant species distribution cannot be overlooked, as they have become increasingly influential in shaping suitable habitats for animals and plants ( Xu et al., 2019 ). Specifically, the impact of human activities on the diversity and distribution of plant communities can be either positive or negative ( Wang et al., 2022 ; Huang and Fu, 2023 ). Moreover, the structure and function of different plant communities show considerable variation in response to human activities ( Sun et al., 2021b ; Zha et al., 2022 ).…”

The Relative Effects of Climate Change and Phenological Change on Net Primary Productivity Vary with Grassland Types on the Tibetan Plateau

“…In recent decades, the TP has experienced unprecedented warming, resulting in various effects on its delicate ecosystems, including fluctuations in ecosystem productivity [19,31,32]. Alpine grassland, as the dominant vegetation type in the TP, represents a substantial portion of the carbon pool within the alpine ecosystems [21,33]. The response of alpine grassland ecosystems to global change is a key scientific issue in the field of global change ecology, with profound implications for the conservation and management of alpine ecosystems [12,33].…”

“…Alpine grassland, as the dominant vegetation type in the TP, represents a substantial portion of the carbon pool within the alpine ecosystems [21,33]. The response of alpine grassland ecosystems to global change is a key scientific issue in the field of global change ecology, with profound implications for the conservation and management of alpine ecosystems [12,33]. Although several studies have examined the effects of climate change and vegetation phenology on alpine grassland ecosystems in the TP, ambiguities still persist [2,31].…”

Effects of Climate Change and Fencing on Forage Nutrition Quality of Alpine Grasslands in the Northern Tibet

“…Increasing protein content and decreasing cellulose content are important ways to improve forage nutrition quality [ 10 , 11 , 12 ]. Global warming is widely recognized as an indisputable fact, and meanwhile global precipitation has changed significantly [ 13 , 14 , 15 ]. Fencing, as one of the most common human constructions, is considered an important way of restoring degraded grasslands [ 16 , 17 ].…”

“…These diverse alpine grassland ecosystems are important components of global alpine ecosystems [ 20 , 30 ]. Alpine grasslands in the Northern Tibet have suffered and will continue to suffer from both climate change and human activities [ 1 , 13 ]. On one hand, the Northern Tibet, as one sensitive region to climate change, has been becoming and will continue to become warmer and wetter [ 13 ].…”