Biodiversity transformations in the global ocean: A climate change and conservation management perspective

The complex dynamics of ecological communities and populations and the resulting patterns of temporal and spatial variation of biodiversity have been a central focus of ecology but still are not well understood

The complex dynamics of ecological communities and populations and the resulting patterns of temporal and spatial variation of biodiversity have been a central focus of ecology but still are not well understood.
The biological diversity of different communities is an emergent property influenced by a reticulate web including different templates such as abiotic constraints on local and regional scales, biotic interactions on local scales, connection of interacting communities in meta-communities, and evolution. These templates are interwoven in feedback and reciprocal connections, and climate change may affect these feedback. Both directly and indirectly via species range shifts.
The difficulty of predicting responses of complex systems to multiple stressors constitutes a major challenge for evaluating risks to biological sustainability in a time of rapid environmental change.
A key challenge is to understand how temporal and spatial variation in the earth's abiotic environment affects the ecology and distribution of organisms. Predictions of species distribution shifts are typically either correlative (i.e., based on statistical association between occurrence and current environmental variables, for example, Hodapp et al., 2023) or process-based (i.e., based on an independent, mechanistic model describing the physiological basis for species biogeographic distribution, for example, Deutsch et al., 2020). A deeper understanding of the mechanistic underpinnings for species biogeographic boundaries may lead to better predictions into novel conditions. However, such analyses are often limited to species with experimental data to estimate some aspect of thermal performance.
Moreover, even for data rich species, there is a logistical limit to how many variables one can vary experimentally, and therefore, it is dif- In their analyses, Hodapp et al. (2023) show that while species shift their distributional ranges to track their climate niche, the net effect is still a loss in total habitat area (specifically, the area of habitats with an occurrence probability larger than .5). Likely this is due to the overall loss of suitable habitat within the habitat range outpacing range shifts. This result illustrates the importance of evaluating the spatial heterogeneity of biodiversity change in addition to aggregate metrics such as distributional edges. The importance of spatial heterogeneity also becomes apparent in their finding that species distributions near the equator may become more discontinuous and fragmented, with implications for population dynamics. Lastly, the finding that marine ecosystems get reconfigured when predators change their distribution, and that this effect is very strong near the poles, illustrates that we need to understand impacts of biodiversity redistribution from a food web context.
Transgressing levels of biological organization and scales is not only a scientific challenge but also critical if predictions about climate change will be possible because such predictions will also concern multiple temporal and spatial scales. Predicting changes in the abundance and distribution of organisms due to large-scale abiotic fluctuations will require appropriate community theories (Hawkins et al., 2003;Huxman et al., 2004;Thomas et al. 2004). Remaining challenges include understanding how species interactions affect community assembly under novel environmental conditions (Tekwa et al., 2022), and how that shapes higher order patterns in species diversity (Solè et al., 2002) This study will inspire more research into the spatial heterogeneity of climate impacts on biodiversity and food web structure and promote a transdisciplinary approach to understand biodiversity transformations in the ocean (Convey & Peck, 2019;Sumaila et al., 2019), providing solutions and actions to mitigate climate change (Marquet et al., 2019).

DATA AVA I L A B I L I T Y S TAT E M E N T
Data sharing not applicable to this article as no datasets were generated or analysed for this commentary.