Global environmental change is a growing threat to biodiversity

Global environmental change is a growing threat to biodiversity, driving biological
change at the molecular, individual, population, community and ecosystem levels, and
often leading to irreversible species losses . In the Anthropocene era,
direct and indirect global change drivers affecting biodiversity are typically
grouped into five categories: climate change, invasive species, land use change, natural
resource use and exploitation, and pollution . These human-induced
pressures can additionally act in synergy with each other , and unfold
with differing severity across the globe.

For instance, cold climate regions are especially prone to increased numbers of extreme climatic events and warming.
Cold climate regions are defined by the ‘E’ class in Peel et al. (2007) and correspond to Arctic-, Antarctic-, sub-Arctic-, sub-Antarctic-, and alpine regions and the Tibetan Plateau (known as the ‘Third Pole’). Many – but not all – cold regions have faced little pressure from GCD relating to direct exploitation of natural resources, pollution, land use, and human pressure in general, relative to other global systems. This partly explains why cold climate regions are among the most pristine areas globally, hosting unique fauna and flora assemblages, which have evolved and persisted under cold climatic conditions. Yet, other GCD are being exacerbated in cold regions, especially climate change.

Parts of these regions are now warming more rapidly than elsewhere (IPCC 2021), driving rapid changes in biodiversity, sometimes at levels similar to other regions globally (Chown and Brooks
2019). Locally and regionally, changes in biodiversity of cold climate regions may
critically affect global nutrient cycling, soil fertility, and ecosystem stability, within these
geographic zones and beyond (Kunfu et al. 2021). At the global scale, cold climate
regions are thus both sentinels and magnifiers of climate change, with melting of polar
ice sheets affecting sea levels and altering oceanographic circulation, and thawing of
permafrost, in combination with shrub expansion, reducing albedo and acting as a
positive feedback to warming climates (Thackeray & Hall 2019).

The ecosystems of cold climate regions are often species-poor, with component
species that have a low competitive ability and thus, low resistance to invasions (Convey
1996, Frenot et al. 2005). Despite the historically low incidence of biological invasions
compared to more densely populated regions of the globe, cold climate regions are now
at high risk of invasion as both climatic and transportation barriers are reduced (Frenot
et al. 2015; Hughes et al. 2015, 2020; Pyšek et al. 2017). Human influence is indeed
increasing (e.g. Leihy et al., 2020), as more Arctic, sub-Antarctic and alpine systems
become of interest for resource exploitation, while all areas are also facing increasing
tourism, which can transport non-native species propagules (McDougall et al. 2011,
Hulme et al. 2012, Vila et al. 2016, Sisneros-Kidd et al. 2019). This pressure changes
native communities and increases their vulnerability to significant impacts of invasive
non-native species, which can occupy empty niches (Mathakutha et al. 2019; Daly et al.
2023).

Cold regions require urgent attention due to their relatively pristine but fragile
status and the very rapid effects of GCD (e.g., glacial retreat, invasional load). However,
to date, biodiversity data across cold regions remain inadequate both in terms of
taxonomic and geographic coverage, owing to their remoteness, low human population densities and provisioning services, and lacking or highly complex governance (Pertierra
& Hughes 2019, Pertierra et al. 2022). Nevertheless, cold climate regions create valuable
opportunities to evaluate biodiversity changes related to climate shifts and biological
invasions because of few additional confounding anthropogenic drivers (Bergstrom and
Chown 1999). To better understand these intensifying disturbances, we here examine
the range of effects of GCD on the biodiversity of cold environments and the concurrent
threat to their stability and functionality.

We evaluate the effects of GCD on biodiversity and their cascading consequences at three levels of impact: individual (altered physiology), population (altered size and genetics), and species (altered distributions and interactions). In this context, we also discuss the challenges (uncertainties, biases, representativeness) that must be overcome when studying biodiversity loss in cold
regions.

Diode production is helping you to communicate about your research projets.