loading page

Climate and habitat loss interactively restructure trait composition and covariance across a human-modified landscape
  • Meghna Krishnadas
Meghna Krishnadas
Centre for Cellular and Molecular Biology CSIR

Corresponding Author:[email protected]

Author Profile


Species traits influence their response to environmental conditions and the match between phenotypes and environment mediates spatial changes in species composition. These trait-environment linkages can be disrupted in human-modified landscapes. Human land-use creates habitat fragments where dispersal limitation or edge effects can exclude species that may otherwise suit a given macro-scale environment. Furthermore, stressful micro-environments in fragments may limit viable trait combinations resulting in stronger trait covariance compared to contiguous forest, especially in harsher macroenvironments. In a wet tropical forest landscape in the Western Ghats Biodiversity Hotspot of peninsular India, I compared fragments with adjacent contiguous forest for signatures of trait-mediated assembly of tree communities along macroenvironmental gradients. Using four key plant traits—seed size, specific leaf area (SLA), wood density, and maximum height—I evaluated changes in trait-mediated abundances and trait covariance across environmental gradients. Trait-mediated abundances primarily changed along the elevation gradient in contiguous forest, smaller-seeded, shorter, thinner-leaved species increased at higher elevations. In fragments, higher SLA species increased in more seasonal climate and decreased with higher precipitation, and larger seeds decreased at warmer sites. However, traits only weakly predicted abundances and only contiguous forests experienced significant compositional change via traits, driven by trait syndromes varying along a composite environmental gradient defined by elevation, water deficit, and soil C:N ratio. Covariance of seed size and maximum height along gradients of precipitation and temperature revealed divergent constraints on viable phenotypes in fragments and contiguous forest. Notably, local biotic conditions (functional diversity) had stronger effects than environment in explaining trait covariance. Overall, the results imply that trait syndromes and trait covariance, rather than single traits, determine the phenotypes best suited to different macroenvironmental conditions and should inform management or restoration goals in fragments.
21 Sep 2021Submitted to Ecology and Evolution
23 Sep 2021Submission Checks Completed
23 Sep 2021Assigned to Editor
26 Sep 2021Reviewer(s) Assigned
22 Oct 2021Review(s) Completed, Editorial Evaluation Pending
01 Nov 2021Editorial Decision: Revise Minor
17 Jan 20221st Revision Received
18 Jan 2022Submission Checks Completed
18 Jan 2022Assigned to Editor
18 Jan 2022Review(s) Completed, Editorial Evaluation Pending
25 Jan 2022Reviewer(s) Assigned
18 Mar 2022Editorial Decision: Revise Minor
07 May 20222nd Revision Received
07 May 2022Submission Checks Completed
07 May 2022Assigned to Editor
07 May 2022Review(s) Completed, Editorial Evaluation Pending
10 May 2022Editorial Decision: Revise Minor
15 May 20223rd Revision Received
16 May 2022Submission Checks Completed
16 May 2022Assigned to Editor
16 May 2022Review(s) Completed, Editorial Evaluation Pending
18 May 2022Editorial Decision: Accept