Why forests and fields can matter more than temperature
Climate change is transforming ecosystems, but temperature is not the only pressure determining where wildlife survives. The surrounding habitat can be equally important, or even more influential, in explaining which species occur in a particular location.
A study published in Nature Communications on 14 October 2026 analysed biodiversity patterns across Finland and found that habitat composition was the strongest overall explanatory factor for the occurrence and abundance of many terrestrial animals.
Led by Emy Guilbault and colleagues, the research covered 503 species across birds, butterflies, moths, small mammals and large mammals. The observations extended over approximately two decades and across a north-to-south distance of roughly 1,100 kilometres.
The results do not suggest that climate change is unimportant. Instead, they show that habitat and climate influence different animals in different ways, with their relative importance changing across regions, years and ecological groups.
How the research was conducted
The researchers assembled more than three million ecological monitoring records collected across Finland between approximately 1999 and 2019. These observations described where animals were found and, where available, their abundance.
They combined these records with environmental information, including average annual temperature, cumulative precipitation and the number of snow days.
Habitat composition was measured through the proportions of different land-cover types around monitoring sites. These included forests, wetlands, cropland, urban environments and semi-natural open areas.
A separate set of variables described landscape configuration, such as fragmentation and the diversity of habitat types in an area.
The team applied an extended Bayesian joint species distribution model to investigate the relationships between animal distributions and these environmental factors.
This modelling approach allowed researchers to compare the relative explanatory contributions of climate, habitat composition and landscape configuration across species.
Because the environmental factors are interconnected, the results are best interpreted as associations in observational data rather than controlled demonstrations of cause and effect.
Habitat composition led the overall comparison
Across the complete analysis, the mix of habitats surrounding observation sites generally explained more variation in species occurrence and abundance than either climate or landscape configuration considered separately.
This result is relevant to land-use decisions involving forestry, agriculture, wetland protection and urban development. Each of these activities can alter the environments available to wildlife.
A species dependent on a particular forest structure may struggle when that forest is replaced with cropland or urban infrastructure, even when regional temperatures have changed little.
Likewise, protecting a variety of habitats may support species with different ecological needs, although the study did not experimentally test particular conservation interventions.
The authors emphasised that the importance of habitat was not identical for every animal. Several drivers often contributed to the observed patterns simultaneously.
Consequently, the finding should not be reduced to a claim that habitat always matters more than climate in every ecosystem.
Different animal groups responded differently
Habitat composition was especially influential for butterflies, birds and small mammals. These groups often depend on particular vegetation, food resources and local conditions.
For large mammals and moths, habitat and climate both played substantial explanatory roles.
Butterflies may rely on specific host plants during development, while birds can respond strongly to nesting opportunities, vegetation structure and feeding areas.
Small mammals can be sensitive to changes in ground cover and local habitat resources. Large mammals often range over larger territories and experience environmental pressures at broader spatial scales.
Moths comprise many species with different ecological requirements, which can make their responses difficult to summarise with a single environmental explanation.
The study identified broad differences between groups but did not establish that every species within a group responds in the same way.
This variation matters because a conservation strategy designed around one animal group may not adequately protect another.
Why geography changes the picture
The researchers found that environmental drivers behaved differently depending on the spatial and temporal scale of the analysis.
When comparing different biogeographical regions and years, climate often accounted for more variation. Within the same region and year, habitat composition was generally more influential.
This helps explain why climate and habitat can both be central to biodiversity research without being competing explanations.
Climate helps establish broad conditions under which species can survive. Habitat determines whether suitable resources and shelter are available within those broader climatic zones.
Two areas experiencing similar temperatures may support different animal communities because their vegetation, land cover and habitat structures differ.
The importance of climate also varied along Finland’s roughly 1,100-kilometre latitudinal gradient.
For butterflies and large mammals, climate tended to become relatively more influential at higher latitudes.
Birds showed a different pattern, with habitat becoming relatively more important toward northern regions. Moths did not show an equally clear north-to-south trend.
These differences argue against applying a single nationwide explanation to every species or region.
Species traits help explain vulnerability
The study also considered characteristics that might influence how animals respond to environmental change.
These included body size, the pace of a species’ life history and the extent to which it specialises in particular habitats or food resources.
A habitat specialist may have fewer alternatives when its preferred environment disappears, whereas a generalist can potentially use a wider range of settings.
Body size and life history may also shape how animals respond to climate variability and environmental disruption.
In the Finnish analysis, larger mammals tended to be less sensitive to climate variability than smaller mammals.
Bird and mammal species with faster life histories also tended to show lower sensitivity to climate variability in the comparisons reported.
These are group-level statistical patterns, not rules that can predict the fate of an individual species with certainty.
The findings suggest that ecological traits can help identify potentially vulnerable species, but local evidence remains essential.
Climate and land use interact
An important complication is that climate and habitat do not change independently. Warming can alter vegetation, while forestry, agriculture and urban development reshape land cover.
The researchers found that some of the explanatory effects attributed to climate, habitat composition and landscape configuration were shared or correlated.
This makes it difficult to interpret the relative importance of one variable as though every other environmental condition had been held constant.
The model can identify patterns across extensive observational records, but it cannot isolate every causal mechanism behind a species’ distribution.
Conservation policy should therefore avoid treating habitat protection and climate action as alternatives.
Both pressures can influence biodiversity, and their effects may reinforce or modify each other.
A practical strategy needs to consider how land management decisions interact with long-term changes in temperature, precipitation and seasonal conditions.
What conservation authorities can learn
The findings place habitat management at the centre of biodiversity planning, especially where land-use change is rapid.
Maintaining suitable forests, wetlands and other ecosystems can help preserve resources that species need to survive and reproduce.
Restoring habitat connections may also be relevant where landscapes are fragmented, although this particular study did not measure the outcomes of specific restoration projects.
Management priorities should reflect the species being protected and the environmental pressures affecting them in each region.
For some animal groups, local habitat changes may be particularly consequential. For others, regional climate conditions may exert comparable influence.
Long-term monitoring is valuable because short observation periods may miss changes in the relative importance of these factors.
The researchers did not calculate the cost-effectiveness of particular conservation policies, so their findings should guide further assessment rather than serve as a universal policy formula.
Why the findings matter outside Finland
Although the analysis focused on boreal environments, the challenge of distinguishing climate pressures from habitat change is relevant worldwide.
Countries with very different ecosystems, including South Africa, must also make decisions about land conversion, habitat fragmentation and climate adaptation.
The Finnish results cannot determine which pressures dominate for South African wildlife, because those species and landscapes were not included in the study.
They do, however, demonstrate the value of collecting local biodiversity records alongside detailed information about land use and climate.
Planning based solely on broad climate projections may overlook important habitat conditions that determine whether animals can persist in a particular place.
The study supports evidence tailored to the species, location and time period rather than a single explanation applied to all ecosystems.
Limitations and future research
The research drew on observational monitoring programmes, which can reveal associations but cannot independently prove that particular environmental changes caused the observed biodiversity patterns.
Monitoring methods and coverage differed between animal groups, creating additional uncertainty despite the researchers’ modelling efforts.
The environmental variables could not capture every influence on wildlife, such as disease, predation or fine-scale differences in habitat quality.
The findings also describe Finnish ecosystems during the study period; future conditions and other biomes may produce different relationships.
Further research could test the framework in tropical forests, grasslands and arid regions, and examine how restoration interventions affect species over time.
Such studies could help translate statistical associations into more direct evidence about conservation outcomes.
A more complete view of biodiversity change
Across 503 terrestrial animal species and more than three million records, the researchers found that habitat composition was the leading overall explanatory factor for biodiversity patterns in Finland.
Climate nevertheless remained important, particularly when comparing different regions and years, and its influence varied considerably between animal groups.
Species traits and geographic context further shaped these relationships, showing why a single environmental explanation is rarely sufficient.
The central message is that protecting wildlife requires understanding the actual landscapes animals inhabit while also responding to climate change.
Conservation strategies that consider habitat, climate and their interactions are better aligned with the complexity documented by this research.
Source Information
Study: Shifting balance between habitat and climate in boreal biodiversity patterns across space, time and taxa.
Authors: Emy Guilbault, Laura H. Antão, Andrea Santangeli and colleagues.
Journal: Nature Communications.
Published: 14 October 2026.
Methods: More than three million records for 503 species across approximately 20 years and 1,100 kilometres in Finland, analysed using Bayesian joint species distribution modelling.
