Intermediate levels of wood extraction may facilitate coexistence of an endemic arboreal marsupial and Indigenous communities

Abstract

Land-use change is a major driver of biodiversity loss. Large-scale disturbances such as habitat loss, fragmentation and degradation are known to have negative consequences for native biota, but the effects of small-scale disturbances such as selective logging are less well known. We compared three sites with different regimes of selective logging performed by Indigenous communities in the South American temperate rainforest, to assess effects on the density and habitat selection patterns of the Near Threatened endemic arboreal marsupial Dromiciops gliroides. We used structured interviews to identify patterns of wood extraction, which was 0.22–2.55 m3 per ha per year. In the less disturbed site only two tree species were logged, in the intermediately disturbed sites eight species were logged at low intensity, and in the most disturbed site seven species were logged intensively. The site with intermediate disturbance had the highest fleshy-fruited plant diversity and fruit biomass values as a result of the proliferation of shade-intolerant plants. This site also had the highest density of D. gliroides. These findings are consistent with Connell's intermediate disturbance hypothesis, suggesting that coexistence of people with nature is possible if wood extraction volumes are moderate, increasing plant diversity. Indigenous communities have sustainably used natural resources for centuries, but current rates of land-use change are becoming a significant threat to both them and their natural resources.

Effects of selective logging on genetic diversity and population structure of a keystone mistletoe

“…Distance among sampled plants ranged from 1 to 93 m (13.63 ± 1.75 m, mean ± SE). Site 1 was the one with the lowest logging intensity and Site 3 the one with the largest logging intensity (the same sites of González‐Ancin et al, 2022; Figure 1b). Logging intensity was estimated based on interviews to the local people within a 700‐m buffer from the center of each sampling site, calculating the annual wood volume extracted based on the information provided by the respondents (González‐Ancin et al, 2022).…”

“…Both outcomes are likely to derive from the seed dispersal process, as it largely determines plant spatial arrangement (García et al, 2009) and gene flow in the landscape (Fontúrbel et al, 2019), as it the base between T. corymbosus and D. gliroides. Therefore, an increased resource availability (Fontúrbel et al, 2017a(Fontúrbel et al, , 2017bGonz alez-Ancin et al, 2022) may result in shorter seed dispersal distances and higher host reinfection rates (Watson & Rawsthorne, 2013), as frugivores do not need to travel long distances searching for fruits, and therefore the probability of depositing seeds nearby parental plants increase when resources are abundant and spatially clumped. Along with seed dispersal, pollination may also be influencing the genetic patterns observed.…”

“…This rural area is inhabited by Mapuche‐Huilliche indigenous people, who traditionally exploit forest resources (mainly wood) for subsistence. The intensity of wood extraction largely varies among households, resulting in a heterogeneous mosaic of selective logging intensity (see González‐Ancin et al, 2022 for details).…”

“…In both cases, the effects on genetic diversity seem to be related to the mistletoe's seed disperser: the arboreal marsupial D. gliroides , which largely determines its spatial distribution (García et al, 2009). As a matter of fact, D. gliroides abundance increases with intermediate levels of selective logging, as extracting some large trees creates gaps that favor shade‐intolerant species that provide abundant fleshy fruits (González‐Ancin et al, 2022). Thus, D. gliroides is an important piece of the puzzle in understanding how T. corymbosus genetic diversity and population structure change due to anthropogenic actions.…”

Effects of landscape configuration on the occurrence and abundance of an arboreal marsupial from the Valdivian rainforest

“…Therefore, the occurrence and abundance of D. gliroides across landscapes with different disturbance levels may depend on a multi-scale process, in which local vegetation structure and landscape configuration are relevant to explain the occurrence patterns observed in this study. A mild local disturbance may increase the availability of food resources, with a positive effect on D. gliroides occurrence and abundance [41,61]. However, landscape-level processes are expected to have the opposite effect.…”