Changes in plant diversity in a water-limited and isolated high-mountain range (Sierra Nevada, Spain)

Abstract

Climate change impacts are of a particular concern in small mountain ranges, where cold-adapted plant species have their optimum zone in the upper bioclimatic belts. This is commonly the case in Mediterranean mountains, which often harbour high numbers of endemic species, enhancing the risk of biodiversity losses. This study deals with shifts in vascular plant diversity in the upper zones of the Sierra Nevada, Spain, in relation with climatic parameters during the past two decades. We used vegetation data from permanent plots of three surveys of two GLORIA study regions, spanning a period of 18 years (2001–2019); ERA5 temperature and precipitation data; and snow cover durations, derived from on-site soil temperature data. Relationships between diversity patterns and climate factors were analysed using GLMMs. Species richness showed a decline between 2001 and 2008, and increased thereafter. Species cover increased slightly but significantly, although not for endemic species. While endemics underwent cover losses proportional to non-endemics, more widespread shrub species increased. Precipitation tended to increase during the last decade, after a downward trend since 1960. Precipitation was positively related to species richness, colonisation events, and cover, and negatively to disappearance events. Longer snow cover duration and rising temperatures were also related to increasing species numbers, but not to cover changes. The rapid biotic responses of Mediterranean alpine plants indicate a tight synchronisation with climate fluctuations, especially with water availability. Thus, it rather confirms concerns about biodiversity losses, if projections of increasing temperature in combination with decreasing precipitation hold true.

The Diversity and Community Assembly Process of Wetland Plants from Lakeshores on the Qinghai-Tibetan Plateau

“…Zhang et al [73] also indicated that both MAT and MAP influenced species richness and phylogenetic diversity of alpine steppe plants on the QTP. In line with this, several studies found that precipitation was a primary contributor to species richness [74,75]. Similarly, the research in the Tabu River basin of Inner Mongolia has revealed that the heterogeneity of MAT and MAP were the strongest predictors of alpha diversity patterns [76].…”

Spatial heterogeneity and temporal stability characterize future climatic refugia in Mediterranean Europe

“…For the high mountains of the Mediterranean, warming patterns are expected to be coupled with a decline in precipitation patterns, a shift from snowfall to rainfall, and a reduction in snow cover (Bravo et al, 2008; Pérez‐Palazón et al, 2018). Consequently, even a contemporary increase in species richness, due to the upward range shifts of species, would not counterbalance the projected risk for globally important biodiversity hotspots (Kazakis et al, 2021; Lamprecht et al, 2021; Pauli et al, 2012). While higher mountains and mountain ranges are subjected to harsh conditions, species are often able to survive extended periods of extreme climate.…”

Plant Phenology Dynamics and Pollination Networks in Summits of the High Tropical Andes: A Baseline for Monitoring Climate Change Impacts

“…Long-term research within the framework of monitoring networks such as the Global Observation Research Initiative in Alpine Environment (GLORIA) has shown that global warming is affecting community structure (Steinbauer et al, 2019). For example, in European mountains, climate warming and changes in precipitation are having contrasting effects on the summit floras, increasing species richness in boreal-temperate summits but decreasing richness in Mediterranean sites, probably because of increased drought severity in the European south (Pauli et al, 2012;Lamprecht et al, 2021). Monitoring within the GLORIA-Andes network in northwestern Argentina has shown an increase in the abundance of small herbs and disperse grasses (Carilla et al, 2017).…”