Agroforestry Practices Promote Biodiversity and Natural Resource Diversity in Atlantic Nicaragua

PLoS One. 2016 Sep 8;11(9):e0162529. doi: 10.1371/journal.pone.0162529. eCollection 2016.

Abstract

Tropical forest conversion to pasture, which drives greenhouse gas emissions, soil degradation, and biodiversity loss, remains a pressing socio-ecological challenge. This problem has spurred increased interest in the potential of small-scale agroforestry systems to couple sustainable agriculture with biodiversity conservation, particularly in rapidly developing areas of the tropics. In addition to providing natural resources (i.e. food, medicine, lumber), agroforestry systems have the potential to maintain higher levels of biodiversity and greater biomass than lower diversity crop or pasture systems. Greater plant diversity may also enhance soil quality, further supporting agricultural productivity in nutrient-limited tropical systems. Yet, the nature of these relationships remains equivocal. To better understand how different land use strategies impact ecosystem services, we characterized the relationships between plant diversity (including species richness, phylogenetic diversity, and natural resource diversity), and soil quality within pasture, agroforests, and secondary forests, three common land use types maintained by small-scale farmers in the Pearl Lagoon Basin, Nicaragua. The area is undergoing accelerated globalization following the 2007 completion of the region's first major road; a change which is expected to increase forest conversion for agriculture. However, farmer agrobiodiversity maintenance in the Basin was previously found to be positively correlated with affiliation to local agricultural NGOs through the maintenance of agroforestry systems, despite these farmers residing in the communities closest to the new road, highlighting the potential for maintaining diverse agroforestry agricultural strategies despite heightened globalization pressures. We found that agroforestry sites tended to have higher surface soil %C, %N, and pH relative to neighboring to secondary forest, while maintaining comparable plant diversity. In contrast, pasture reduced species richness, phylogenetic diversity, and natural resource diversity. No significant relationships were found between plant diversity and the soil properties assessed; however higher species richness and phylodiversity was positively correlated with natural resource diversity. These finding suggest that small, diversified agroforestry systems may be a viable strategy for promoting both social and ecological functions in eastern Nicaragua and other rapidly developing areas of the tropics.

MeSH terms

  • Agriculture*
  • Atlantic Ocean
  • Biodiversity*
  • Forestry*
  • Geography
  • Nicaragua
  • Soil
  • Species Specificity

Substances

  • Soil

Grants and funding

This work was supported by the U.S. National Socio-Environmental Synthesis Center (SESYNC), the Helmholtz Centre for Environmental Research (UFZ), and the German Center for Integrative Biodiversity Research (iDIV) Biodiversity and Ecosystem Services working group. SS was supported by the National Oceanic and Atmospheric Agency Climate and Global Change Postdoctoral Fellowship Program, administered by the University Corporation for Atmospheric Research. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.