The relationship between tree biodiversity and biomass dynamics changes with tropical forest succession

Abstract

Theory predicts shifts in the magnitude and direction of biodiversity effects on ecosystem function (BEF) over succession, but this theory remains largely untested. We studied the relationship between aboveground tree biomass dynamics (Δbiomass) and multiple dimensions of biodiversity over 8-16 years in eight successional rainforests. We tested whether successional changes in diversity-Δbiomass correlations reflect predictions of niche theories. Diversity-Δbiomass correlations were positive early but weak later in succession, suggesting saturation of niche space with increasing diversity. Early in succession, phylogenetic diversity and functional diversity in two leaf traits exhibited the strongest positive correlations with Δbiomass, indicating complementarity or positive selection effects. In mid-successional stands, high biodiversity was associated with greater mortality-driven biomass loss, i.e. negative selection effects, suggesting successional niche trade-offs and loss of fast-growing pioneer species. Our results demonstrate that BEF relationships are dynamic across succession, thus successional context is essential to understanding BEF in a given system.

Successional dynamics in Neotropical forests are as uncertain as they are predictable

“…Our model further reveals previously unexplored patterns, such as the relationship between species density and rates of change in stem density and basal area. As these associations were only observed in a few sites, further work may help to disentangle the mechanisms through which species diversity affects biomass dynamics and thereby ecosystem function (26). Overall, the strength of these processes differed widely among sites, which may reflect sitespecific characteristics related to species composition, stand age distribution, and environmental and landscape factors.…”

“…Despite the high levels of uncertainty detected, we might be able to elucidate the underlying processes behind the patterns observed, and to anticipate ecosystem change through the further development of high-dimensional models (28). Other metrics, such as species and functional dominance could also provide critical insights about the dynamic relation between functional traits and biomass accumulation (26). A challenging goal remains to model multidimensional variables such as species or functional composition.…”

A Review of Processes Behind Diversity—Productivity Relationships in Forests

“…Nevertheless, recruitment and mortality will influence the structural diversity of a forest and can themselves be correlated with the structural and species diversities [10]. Very few studies have examined DPRs in forests with recruitment, or quantified the contribution of the recruited cohort, the original cohort, and mortality, to tree species or size diversity-productivity relationships in forests [10,[65][66][67].…”

Predictores antropogénicos y biofísicos de deforestación en la Amazonia: hacia la integración de actividades REDD+

“…Sin embargo, aunque es evidente la disminución de la biodiversidad a nivel mundial (Strassburg et al 2010), no se conoce cuál es el impacto sobre la pérdida de funciones ecosistémicas (Oliver et al 2015), y menos sobre las tendencias futuras de demanda de bienes y servicios a escala regional. La mayoría de los estudios sobre mecanismos BEF se han enfocado principalmente en la productividad de biomasa vegetal, debido a que el carbono acumulado en la vegetación es determinante en el balance global con la atmósfera (Lasky et al 2014, Brienen et al 2015. Por este motivo, comprender el papel de la biodiversidad en el mantenimiento de las funciones ecosistémicas bajo diferentes niveles de degradación generados por un complejo sistema socioecológico en Amazonas (figura 1), es fundamental para establecer medidas de conservación y estrategias efectivas REDD+.…”

“…Se ha demostrado como los rasgos funcionales de especies arbóreas pueden ser buenos predictores de la producción de biomasa durante diferentes etapas de sucesión secundaria (Lasky et al 2014), sobre la dinámica de la relación biodiversidad-carbono que es dependiente de la escala espacial (Pooter et al 2015), incluso en sistemas agroforestales (Ali y Mattsson 2017). Sin embargo, es poco lo que se conoce sobre el efecto que tienen las especies más dominantes en estos procesos ecosistémicos.…”