Artigo
Changes in tree size, not species diversity, underlie the low above-ground biomass in natural forest edges
Registro en:
SILVA, M. C.; MELO, F. P. L.; BERG, E. V. D. Changes in tree size, not species diversity, underlie the low above-ground biomass in natural forest edges. Journal of Vegetation Science, [S.I.], v. 32, n. 2, e13003, Mar./Apr. 2021. DOI: 10.1111/jvs.13003.
Autor
Silva, Mateus Cardoso
Melo, Felipe Pimentel Lopes
Berg, Eduardo van den
Institución
Resumen
Questions: Forest's above-ground biomass is an important component of the global
carbon cycle and, in forest fragments, it tends to decrease near the edges. This edge
effect on biomass can be due to the number and identity of species residing at edges
or due to the context of edges constraining plant functioning regardless of the species. Here, we took advantage of species-rich natural forest edges to test the role
of species richness, composition, and context dependency in explaining why forest
edges stock less above-ground biomass than interiors.
Location: Gallery forests in Brazilian savanna (latitude 21° S, longitude 44° W).
Methods: We tested the relationship between species richness and above-ground
biomass in 49 forest plots (10,142 trees). We used a novel adaptation of the Price
equation to calculate the impact of species composition (losses and gains) and context dependency on the differences of above-ground biomass between edges and
interiors.
Results: Differences in species richness and composition did not explain the lower
above-ground biomass of forest edges when compared to interiors. Biomass responses were context-dependent, in which the same species achieved smaller sizes
when it grew in the edge than in the interior.
Conclusions: Our study shows that edge effects on biomass may operate independently of biodiversity as edges and interiors had a similar number of species but distinct above-ground biomass. Indeed, in the studied natural forest patches, the edge
context itself limits plant size and, thus, the above-ground biomass stock. Beyond
unveiling the underlying causes of edge effects on forest biomass, our results call for
distinct policies to conserve both the carbon stocks in forest interiors but also the
unique diversity of natural edges.