Conservation on the Frontier: Understanding and Influencing How Cattle Production Impacts Avian Diversity in the Dry Chaco Forests of Argentina
Authors:   , Mastrangelo Matias Enrique 
Published: November 2021

<p>This thesis combines the identification of land-use strategies that provide high yields and high biodiversity with the identification of the psycho-social drivers of land-use decisions in an agricultural landscape. I visited 116 landholdings in two agricultural landscapes of the Dry Chaco region in Argentina. In 27 landholdings producing beef cattle in production systems of different land-use intensity, I collected empirical information on: (i) cattle yields, (ii) avian diversity, density and composition, and (iii) structural attributes of habitat in the agricultural matrix. The Chaco avifauna responded non-linearly to increasing cattle production intensification as bird species richness was relatively unchanged from forests to intermediate-intensity silvopastoral systems and decreased sharply at high-intensity pasture systems. This pattern indicated the presence of a threshold in habitat quality for birds when native tree cover falls below 30%. The concave trade-off function suggests that land-sharing through the integration of native trees and pastures in silvopastoral systems has more potential than land-sparing to simultaneously provide high cattle yields and high bird diversity. Intermediate-intensity silvopastoral systems may represent a matrix type of high habitat quality for most bird species due to the lower frequency and intensity of disturbances resulting from agricultural management, compared to high-intensity systems. Bird functional groups responded differently to agricultural intensification and habitat modification. Forest-restricted and fruit-eating bird species occurred at low density in intermediate-intensity silvopastoral systems and disappeared from high-intensity pasture systems. Therefore, low-intensity systems and forest fragments (larger than 1000 ha) should be maintained in the landscape to provide habitat for species of high conservation concern and potentially contributing to forest regeneration.  In 89 landholdings varying in landholding size and land tenure condition, I interviewed landholders and collected information about their beliefs, values and perceptions regarding conservation of remnant forest fragments. Based on this information, I tested the ability of three social psychological models and nine psycho-social constructs to explain landholders’ conservation intentions. The Theory of Planned behaviour provided a parsimonious and plausible explanatory model of landholders’ intentions to conserve remnant forest fragments in their landholdings. A model integrating self-interest and pro-social motives as proximal predictors and self-identity as the ultimate predictor explained 42% of the variance in landholders’ conservation intentions. The perceived pressure from relevant others to conserve forests (i.e. social norms) and the tendency to value forests favourably or unfavourably (i.e. attitudes) directly and significantly influenced landholders’ willingness to set-aside remnant forests in their landholdings. Landholders’ self-identity and their level of awareness of the scale and consequences of deforestation underlay the effects of social norms and attitudes on conservation intentions. Policy interventions aimed at influencing the behaviour of landholders towards more conservation-oriented outcomes would be more effective if tailored to the characteristics of landholder identity groups. Influencing conservation intentions of high-intensity, productivist landholders may require policy incentives and regulations that link better environmental performance with agricultural production outcomes and can become peer-enforced in the long-term. Conservation and development outcomes can be jointly enhanced for low-intensity, pre-productivist landholders through policies that secure their land tenure and facilitate the implementation of silvopastoral systems.</p>