The positive carbon stocks–biodiversity relationship in forests: co‐occurrence and drivers across five subclimates

Abstract

Carbon storage in forests and its ability to offset global greenhouse gas emissions, as well as biodiversity and its capacity to support ecosystem functions and services, are often considered separately in landscape planning. However, the potential synergies between them are currently poorly understood. Identifying the spatial patterns and factors driving their co-occurrence across different climatic zones is critical to more effectively conserve forest ecosystems at the regional level. Here, we integrated information of National Forest Inventories and Breeding Bird Atlases across Europe and North America (Spain and Quebec, respectively), covering five subclimates (steppe, dry Mediterranean, humid Mediterranean, boreal, and temperate). In particular, this study aimed to (1) determine the spatial patterns of both forest carbon stocks and biodiversity (bird richness, tree richness, and overall biodiversity) and the factors that influence them; (2) establish the relationships between forest carbon stocks and biodiversity; and (3) define and characterize the areas of high (hotspots) and low (coldspots) values of carbon and biodiversity, and ultimately quantify their spatial overlap. Our results show that the factors affecting carbon and biodiversity vary between regions and subclimates. The highest values of carbon and biodiversity were found in northern Spain (humid Mediterranean subclimate) and southern Quebec (temperate subclimate) where there was more carbon as climate conditions were less limiting. High density and structural diversity simultaneously favored carbon stocks, tree, and overall biodiversity, especially in isolated and mountainous areas, often associated with steeper slopes and low accessibility. In addition, the relationship between carbon stocks and biodiversity was positive in both regions and all subclimates, being stronger where climate is a limiting factor for forest growth. The spatial overlap between hotspots of carbon and biodiversity provides an excellent opportunity for landscape planning to maintain carbon stocks and conserve biodiversity. The variables positively affecting carbon and biodiversity were also driving the hotspots of both carbon and biodiversity, emphasizing the viability of "win-win" solutions. Our results highlight the need to jointly determine the spatial patterns of ecosystem services and biodiversity for an effective and sustainable planning of forest landscapes that simultaneously support conservation and mitigate climate change.

Trade‐offs between carbon stocks and biodiversity in European temperate forests

“…Even if living and dead wood constitute the substrate for many forest species (Hatanaka, Wright, Loyn, & Mac Nally, 2011;Lassauce, Paillet, Jactel, & Bouget, 2011;Stokland, Siitonen, & Jonsson, 2012), the carbon contained in these forest features is only indirectly related to biodiversity (Hatanaka et al, 2011). Typically based on coarsegrained data, recent evidence supports a positive correlation between above-ground live carbon and biodiversity at broader extents (Di Marco et al, 2018;Lecina-Diaz et al, 2018;Strassburg et al, 2010). The shape of the carbon-biodiversity relationship, however, remains unclear for smaller extents such as individual landscapes or stands (Ferreira et al, 2018;Pichancourt et al, 2014).…”

“…Large uncertainties also remain on how this relationship varies across biogeographical regions (Di Marco et al, 2018;Lecina-Diaz et al, 2018;Potter & Woodall, 2014;Xian et al, 2015). For the tropics, there is evidence for a positive relationship between biodiversity and above-ground live carbon stocks, both across stands (Cavanaugh et al, 2014;Deere et al, 2018;Magnago et al, 2015), and within stands (Sullivan et al, 2017), especially for disturbed sites (Ferreira et al, 2018).…”

“…In temperate forests, research has traditionally focused on carbon sequestration and productivity (Huang et al, 2018;Ratcliffe et al, 2017). Although recent work highlighted the importance of carbon quality, or complexity, for bird biodiversity (Hatanaka et al, 2011;Lecina-Diaz et al, 2018), studies relating carbon quantity to biodiversity remain rare and mostly refer to tree diversity only (Potter & Woodall, 2014;Xian et al, 2015).…”

“…The carbon-biodiversity relationship may also vary across taxonomic groups (Di Marco et al, 2018;Ferreira et al, 2018;Lecina-Diaz et al, 2018). Even in the tropics, most research to date has focused on either vertebrates (Beaudrot et al, 2016;Deere et al, 2018;Sollmann et al, 2017), or tree species richness only (Cavanaugh et al, 2014;Magnago et al, 2015;Sullivan et al, 2017), while research comparing the fine-scale carbon-biodiversity relationship across groups of organisms remains rare (Ferreira et al, 2018).…”

Water availability drives aboveground biomass and bird richness in forest restoration plantings to achieve carbon and biodiversity cobenefits

“…However, variation in the species planted, proportions of trees and shrubs (structural diversity), planting density, patch shape, and stand age can influence rates of aboveground biomass accumulation, as well as the quality of potential habitat for native fauna (Paul, Cunningham, et al, 2016;Paul, Roxburgh, England, et al, 2015). Aboveground biomass stores up to 50% carbon (Martin & Thomas, 2011) and is widely used as a measure of forest productivity and carbon stocks (Duffy et al, 2017;Lecina-Diaz et al, 2018). Rates of aboveground biomass accumulation depend on climate and nutrient availability (Duffy et al, 2017;Ratcliffe et al, 2017;Vilà et al, 2013) and also vary among planting types.…”