A social-ecological approach to identify and quantify biodiversity tipping points in South America's seasonal dry ecosystems

Abstract

<p><strong>Abstract.</strong> Tropical dry forests and savannas harbour unique biodiversity and provide critical ES, yet they are under severe pressure globally. We need to improve our understanding of how and when this pressure provokes tipping points in biodiversity and the associated social-ecological systems. We propose an approach to investigate how drivers leading to natural vegetation decline trigger biodiversity tipping and illustrate it using the example of the Dry Diagonal in South America, an understudied deforestation frontier.</p> <p>The Dry Diagonal represents the largest continuous area of dry forests and savannas in South America, extending over three million km² across Argentina, Bolivia, Brazil, and Paraguay. Natural vegetation in the Dry Diagonal has been undergoing large-scale transformations for the past 30 years due to massive agricultural expansion and intensification. Many signs indicate that natural vegetation decline has reached critical levels. Major research gaps prevail, however, in our understanding of how these transformations affect the unique and rich biodiversity of the Dry Diagonal, and how this affects the ecological integrity and the provisioning of ES that are critical both for local livelihoods and commercial agriculture.</p> Inspired by social-ecological systems theory, our approach helps to explain:</br> (i) how drivers of natural vegetation decline affect the functioning of ecosystems, and thus ecological integrity,</br> (ii) under which conditions, where, and at which scales the loss of ecological integrity may lead to biodiversity tipping points, and </br> (iii) how these biodiversity tipping points may impact human well-being. </br> Implementing such an approach with the greater aim of furthering more sustainable land use in the Dry Diagonal requires a transdisciplinary collaborative network, which in a first step integrates extensive observational data from the field and remote sensing with advanced ecosystem and biodiversity models. Secondly, it integrates knowledge obtained from dialogue processes with local and regional actors as well as meta-models describing the actor network. The co-designed methodological framework can be applied not only to define, detect, and map biodiversity tipping points across spatial and temporal scales, but also to evaluate the effects of tipping points on ES and livelihoods. This framework could be used to inform policy making, enrich planning processes at various levels of governance, and potentially contribute to prevent biodiversity tipping points in the Dry Diagonal and beyond.</p>

Pastoralists’ perceptions on the future of cattle farming amidst rangeland degradation: A case study from Namibia's semiarid communal areas

“…34 Drought occurs in most arid and semiarid regions. [35][36][37] Droughts understood as the "prolonged absence or marked…”

“…Drought occurs in most arid and semiarid regions. 35-37 Droughts understood as the “prolonged absence or marked deficiency of precipitation.” 38 This leads to soil water deficit, which affects grass growth, and reduces the water availability for livestock and humans. Many areas in Namibia have experienced a decrease in precipitation since the middle of the 20th century, and the mean annual rainfall is projected to decrease further.…”

Evaluating the effectiveness of mitigation measures in environmental impact assessments: A comprehensive review of development projects in Korea

“…In this study, we applied the Biodiversity Tipping Point (BD-TP) framework, as introduced by Ref. [ 20 ], to dynamically assess the impacts of development projects on biodiversity. This innovative framework is designed to evaluate structural, compositional, and functional changes in ecosystems that result from habitat loss due to disturbances, while also integrating the interactions between ecological and social systems [ 20 ].…”

“…In this study, we employed the Biodiversity Tipping Point framework to evaluate the effectiveness of mitigation plans. This framework allows for a precise understanding and prediction of the non-linear changes in ecological responses due to urbanization, and it classifies the extent of impact changes before and after development based on tipping points [ 20 ]. Notably, the framework enables the analysis of how sensitively ecological responses react to mitigation measures, using ‘tipping points' as a benchmark.…”

“…Using the biodiversity tipping point (BD-TP) framework proposed by Ref. [ 20 ], we categorized the effects of mitigation measures on biodiversity into four levels (very high, high, low, and very low) and analyzed their effectiveness.…”