Trade‐offs between biodiversity and agriculture are moving targets in dynamic landscapes

Abstract

1. Understanding how biodiversity responds to intensifying agriculture is critical to mitigating the trade-offs between them. These trade-offs are particularly strong in tropical and subtropical deforestation frontiers, yet it remains unclear how changing landscape context in such frontiers alters agriculture-biodiversity trade-offs. 2. We focus on the Argentinean Chaco, a global deforestation hotspot, to explore how landscape context shapes trade-off curves between agricultural intensity and avian biodiversity. We use a space-for-time approach and integrate a large field dataset of bird communities (197 species, 234 survey plots), three agricultural intensity metrics (meat yield, energy yield and profit) and a range of environmental covariates in a hierarchical Bayesian occupancy framework. 3. Woodland extent in the landscape consistently determines how individual bird species, and the bird community as a whole, respond to agricultural intensity. Many species switch in their fundamental response, from decreasing occupancy with increased agricultural intensity when woodland extent in the landscape is low (loser species), to increasing occupancy with increased agricultural intensity when woodland extent is high (winner species). 4. This suggests that landscape context strongly mediates who wins and loses along agricultural intensity gradients. Likewise, where landscapes change, such as in deforestation frontiers, the very nature of the agriculture-biodiversity trade-offs can change as landscapes transformation progresses. 5. Synthesis and applications. Schemes to mitigate agriculture-biodiversity trade-offs, such as land sparing or sharing, must consider landscape context. Strategies that are identified based on a snapshot of data risk failure in dynamic landscapes, particularly where agricultural expansion continues to reduce natural habitats. Rather than a single, fixed strategy, adaptive management of agriculture-biodiversity | 2055 Journal of Applied Ecology MACCHI et Al.

Proximity to forest mediates trade‐offs between yields and biodiversity of birds in oil palm smallholdings

“…These data support previous studies highlighting a need to account for the effects of isolation from natural habitat when considering agricultural policies for biodiversity protection (Batáry et al, 2011;Gilroy et al, 2014;Macchi et al, 2020;Zhang et al, 2017) and underline that in tropical regions, failing to account for the importance of large tracts of natural habitat within the landscape may lead to incorrect conclusions about the biodiversity benefits of land-sharing agriculture and hence to inappropriate land management strategies.…”

Fading opportunities for mitigating agriculture-environment trade-offs in a South American deforestation hotspot

“…On the other hand, there is considerable doubt if silvopastoral systems, as currently practiced, will maintain environmental values in the long-term; with evidence that they rapidly loose trees and carbon (Fernández et al, 2020). Likewise, biodiversity found in silvopastures might heavily depend on nearby forests (Macchi et al, 2020), and silvopastures might constitute sink habitat as hunting pressure on them can be high (Romero-Muñoz et al, 2020). All this cautions against a widespread expansion of silvopasture into remaining forests (as encouraged by the current zoning), and our results suggest rather that areas currently under intense agricultural land systems are converted to silvopasture.…”

“…forest, cropland, pasture, natural grasslands, and other). Silvopastoral systems were identified as pastures with 12-30% woody cover (Macchi et al, 2020).…”

Concentrating vs. spreading our footprint: how to meet humanity's needs at least cost to nature

“…Beyond these studies, one abundance‐based analysis (lacking yield data) has concluded sparing probably outperforms sharing for birds in a Bornean forest/oil palm landscape (Edwards et al ., 2010). Two more recent studies that have used density measures have highlighted the value, within agricultural landscapes, of retaining forest blocks (Karp et al ., 2019) or woodlands (Macchi et al ., 2020), but do not consider the consequences (if these are to be safeguarded while production is to be sustained) of maintaining high yields elsewhere.…”