Why Do Agroforestry Systems Enhance Biodiversity? Evidence From Habitat Amount Hypothesis Predictions

Abstract

Considering the present ecological crisis, land use-biodiversity relationships have become a major topic in landscape planning, ecosystem management and ecological restoration. In this scope, consistent patterns of outstanding biodiversity have been identified in agroforestry systems within diverse biogeographic regions and types of management. Empirical work has revealed that agroforestry higher structural complexity, when compared with current simplified agricultural systems, might be partially responsible for the observed patterns. The recently developed Habitat Amount Hypothesis predicts diversity for a local habitat patch, from the amount of the same habitat within the local landscape. We have expanded the previous hypothesis to the landscape level, computing the influence of the dominant land uses on the diversity of coexisting guilds. As a case study, we have considered archetypal landscapes dominated (or co-dominated) by crops or trees, which were compared using normalized diversities. The results obtained show that agroforestry systems substantially increase functional diversity and overall biodiversity within landscapes. We highlight that the normalized values should be parametrized to real conditions where the type of crop, tree and agroecological management will make a difference. Most importantly, our findings provide additional evidence that agroforestry has a critical role in enhancing biodiversity in agricultural landscapes and, in this way, should be regarded as a priority measure in European Agri-environmental funding schemes.

The influence of agroforestry on the formation of the structure of forest ecosystems

“…Simultaneously, the precondition for the effectiveness of optimization measures is the updating of the regulatory framework and legal field in the field of agroforestry melioration ( Prakhovnik et al, 2022). This issue is developed in the works of modern scientists M. Santos et al (2022) and S. Sorge et al (2022). Researchers emphasize that with effective management regulation of the increase in PFP areas and the fundamental conceptual provisions of agroforestry melioration, significant ecological and economic effects can be achieved.…”

Policy challenges for agroforestry implementation in Europe

“…Regarding the important role of AF on biodiversity, several reports have been published (Rois-Díaz et al, 2006) as well as several books and book chapters and papers on the role of AF in the adaptation and mitigation of climate change in agricultural systems (Mosquera-Losada et al, 2005Nair et al, 2009;Rigueiro-Rodríguez et al, 2009;Howlett et al, 2011a,b;Mosquera-Losada and Prabhu, 2019;Santos et al, 2022).…”

“…The presence of a tree in a treeless land causes disturbances and generates microclimates within the treeless/tree plots (Rigueiro-Rodríguez et al, 2012). In fact, the tree/shrub modifies the main ecological factors (radiation, temperature, and humidity), creating microhabitats for different species that differ from those growing up in open areas, therefore, increasing biodiversity per unit of land (McAdam et al, 2009;Santos et al, 2022). The presence of animals also enhances AF due to the impact of different animals on different plant species selected, trampling, and feces (Rigueiro-Rodríguez et al, 2012).…”

“…Finding uses for both components (woody perennial and agricultural components in the understory) are essential to foster AF expansion in the EU. The advantages of AF production are based on the increased biodiversity (by comparison with polycultural and monocultural systems), which allows multipurpose use of land and optimize the use of the resources (radiation, temperature, water, and nutrients), if adequate components (tree/shrubs/crops/animals) are integrated and adequately managed by considering the positive interactions among them (Mosquera-Losada et al, 2016;Santos et al, 2022). Moreover, the woody perennials promote microhabitat…”

Carbon stocks in coffee farms and secondary forest systems in the Peruvian Amazon rainforest

“…Nautiyal et al (2019) highlighted the importance of glomalin in maintaining soil aggregation and its positive correlation with soil organic carbon (SOC) that not only increases total carbon stock, but also binds to soil organic matter (SOM), preventing soil erosion, and further improving its aggregation. Coffee agroforestry systems are considered to bene t the environment by ful lling an important role in carbon storage, at the same time AMF contributes to a greater extent to regulating glomalin and glomalin-related soil proteins (GRSP) content, which are an important indicator of SOC stock (Li et al 2020;Santos et al 2022), varying according to the type of agroforestry system (Santos et al 2022).…”