Diversity and carbon storage across the tropical forest biome

Abstract

Tropical forests are global centres of biodiversity and carbon storage. Many tropical countries aspire to protect forest to fulfil biodiversity and climate mitigation policy targets, but the conservation strategies needed to achieve these two functions depend critically on the tropical forest tree diversity-carbon storage relationship. Assessing this relationship is challenging due to the scarcity of inventories where carbon stocks in aboveground biomass and species identifications have been simultaneously and robustly quantified. Here, we compile a unique pan-tropical dataset of 360 plots located in structurally intact old-growth closed-canopy forest, surveyed using standardised methods, allowing a multi-scale evaluation of diversity-carbon relationships in tropical forests. Diversity-carbon relationships among all plots at 1 ha scale across the tropics are absent, and within continents are either weak (Asia) or absent (Amazonia, Africa). A weak positive relationship is detectable within 1 ha plots, indicating that diversity effects in tropical forests may be scale dependent. The absence of clear diversity-carbon relationships at scales relevant to conservation planning means that carbon-centred conservation strategies will inevitably miss many high diversity ecosystems. As tropical forests can have any combination of tree diversity and carbon stocks both require explicit consideration when optimising policies to manage tropical carbon and biodiversity.

Mapped aboveground carbon stocks to advance forest conservation and recovery in Malaysian Borneo

“…In contrast, logging-free forests harbor much higher aboveground carbon stocks averaging 200 Mg C ha −1 (Fig. 5b), a value observed in ground-based studies (Slik et al, 2010;Sullivan et al, 2017). Although unlogged forests have a wide distribution of natural carbon densities, the difference in distributions clearly indicates that logged forests have a greatly suppressed amount of carbon stock above ground (Berry et al, 2010).…”

“…These areas alone contain about 151 Tg (million metric tons), or 38%, of State's total forest aboveground carbon that could be protected. High carbon stock forests such as these may or may not harbor high levels of biological diversity (Ashton and Hall, 1992;Sullivan et al, 2017). This possibility must be carefully tested and entered into the narrative on evaluating remaining forests for conservation.…”

“…Mapping and monitoring of ACD has become increasingly routine (Asner et al, 2012a;Zolkos et al, 2013), and now offers to accelerate efforts to conserve forests in the context of climate change mitigation by identifying areas of high-biomass, old growth canopies and/or areas deemed ecologically viable for recovery (Lindenmayer et al, 2013;Smith et al, 2000;UNFCCC, 2009). Carbon stock mapping may also complement other types of mapping for decision-making, such as for biodiversity protection, although high carbon stocks are not always correlated with high species diversity (Sullivan et al, 2017).…”

Species Diversity, Stand Structure, and Species Distribution across a Precipitation Gradient in Tropical Forests in Myanmar

“…For example, a negative relationship has been found between latitude and the annual net primary productivity of forests [22]. Tropical forests are rich in biodiversity and contain a significant proportion of global biodiversity [23,24], and they vary geographically depending on evolutionary history and climate [7,23,24]. Thus, knowledge of how the diversity, distribution, and structure of tropical forests varies between rainfall regions is critical for tropical ecology.…”

Big data of tree species distributions: how big and how good?

“…Therefore, data on tree species distributions, even when available, may be highly heterogeneous. The result is that most insights on the role of biodiversity in forest ecosystems come from certain well-studied regions (Ruiz-Benito et al 2014) or concentrate on certain biomes for which research collaboration networks are in place (ter Steege et al 2006;Sullivan et al 2017).…”