Biomass resilience of Neotropical secondary forests

Abstract

Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha(-1)), corresponding to a net carbon uptake of 3.05 Mg C ha(-1) yr(-1), 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha(-1)) across sites, and this recovery increased with water availability (higher local rainfall and lower climatic water deficit). We present a biomass recovery map of Latin America, which illustrates geographical and climatic variation in carbon sequestration potential during forest regrowth. The map will support policies to minimize forest loss in areas where biomass resilience is naturally low (such as seasonally dry forest regions) and promote forest regeneration and restoration in humid tropical lowland areas with high biomass resilience.

Estimating Aboveground Biomass and Carbon Stocks in Periurban Andean Secondary Forests Using Very High Resolution Imagery

“…The AGB and carbon stock mapping estimates for a mid-successional stage secondary forest in the test area (ca. 6-51 Mg¨ha´1) were within the range reported by other studies of secondary forests in the Neotropics (e.g., [74]). We identified significant analytical relationships between vegetation indices extracted from multiple Geoeye-1 and Pleiades-1A VHR imagery and AGB values estimated using field measurements and allometric equations.…”

Gross changes in forest area shape the future carbon balance of tropical forests

“…The uncertainty of bookkeeping models partly arises from data used to define response curves (usually from local data) and their representativeness for application to large regions. Here, we compare biomass recovery curves derived from a recent synthesis of secondary forest plots in Latin America by Poorter et al (2016) with the curves used previously in bookkeeping models from Houghton (1999) and Hansis et al (2015). We find that the two latter models overestimate the long-term (100 years) vegetation carbon density of secondary forest by about 25 %.…”

“…Even though carbon densities have a high spatial variability in the real world, the same response curve measured at one location is often applied in bookkeeping models over large regions. A recent study of the biomass resilience of secondary forests in the neotropics provides new biomass recovery curves from 45 secondary forest sites (Poorter et al, 2016). These new data are valuable to revisit the response curves for the regrowth of secondary forest in the Amazon area, an important region with a large E LULCC .…”

“…In this study, we first aim to compare the recent biomass regrowth curves from Poorter et al (2016) with the ones used in two bookkeeping models (Hansis et al, 2015;Houghton, 1999) for their implications in E LULCC . Second, we demonstrate that because of the asymmetry between carbon loss from deforestation and carbon gain from regrowth, even when the net forest area change is positive, a large initial gross forest area change can still cause E LULCC to be a source of CO 2 to the atmosphere on multi-decadal horizons.…”

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

“…Sin embargo, todavía es poco conocida la relación existente de estos procesos ecosistémicos con la biodiversidad y sobre todo, su repercusión en el funcionamiento de los ecosistemas de acuerdo a los predictores biofísicos de cada localidad. Poorter et al (2016) demostraron que los bosques secundarios neotropicales, incluyendo los de la Amazonía, difieren drásticamente en su capacidad de recuperación de biomasa (promedio de 66 años para recuperar 90 % de la biomasa aérea), principalmente impulsado por la variación en la disponibilidad de agua, debido a que las altas precipitaciones y el bajo déficit hídrico, permiten extender la temporada de crecimiento e incrementar la producción de biomasa. Así mismo, explican que la fertilidad de suelos tiene un efecto positivo significativo en la recuperación relativa de biomasa, pero ningún efecto sobre la recuperación absoluta debido a que las grandes diferencias con el macroclima pueden anular efectos más sutiles de la fertilidad del suelo.…”