4.1 Ecological niche differentiation in SDMs
The use of species distribution models (SDMs) in biodiversity
assessments primarily focuses on estimating habitat suitability at the
species level (Collart et al., 2021; Elith et al., 2010; Elith &
Leathwick, 2009). These species-level SDMs assume ”ecological niche
conservatism” and overlook within-species phylogenetic or functional
heterogeneity. However, recent studies have highlighted the importance
of considering population-level differences in sustainable management
systems, as they reveal variations in climate predictor responses within
species (Benito Garzón et al., 2019; Collart et al., 2021; Nielsen et
al., 2021; Song & Li, 2023). Using the Japanese crayfish
(Cambaroides japonicus ) as an example, researchers demonstrated
that by accounting for local adaptations in distinct populations, SDMs
with resolutions below the species level can more reliably forecast
changes in biodiversity (Zhang et al., 2021).
Our findings indicate intermediate niche differences (0.465) between the
EIOS and WPI lineages of T. maxima , suggesting the need for
population-level SDMs for this species (Fig. 1-2). While all our models
exhibited strong predictive performance and good model transferability
(Table 2), the species-level model projected larger range contractions
due to climate change compared to the lineage-level models (Table 3).
Incorporating possible local adaptations, population-level SDMs yield
different predictions regarding the effects of climate change.
Therefore, our distribution predictions were less pessimistic when using
lineage-level models, aligning with earlier research suggesting that
intraspecific variation may mitigate the impact of climate change on
species distribution (Chardon et al., 2020; Razgour et al., 2019).