Integrating remote sensing and in-situ data to determine climate diversity and variability in cocoa systems in the provinces of Jaén and San Ignacio, Cajamarca (NW Perú)

Abstract

The lack of information on the geographic distribution of cocoa systems, along with species diversity and the influence of climatic factors on yields, presents challenges for the agronomic management of these plantations and the implementation of more effective agricultural policies. The objective of this study was to map cocoa area, species diversity and their response to historical climate variability in the provinces of Jaén and San Ignacio, Cajamarca, Peru.

For this purpose, PlanetScope and Sentinel-1 data, chosen for their high spatial resolution, were processed in Google Earth Engine using the Random Forest (RF) classification algorithm. Species diversity was determined by selecting 15 cocoa plots distributed in three altitudinal ranges. In each plot, all individuals with a diameter at breast height greater than 2.5 cm were registered within four 10 m x 20 m transects. A total of 4,338.6 ha of cocoa monocultures and agroforestry systems (AFS) distributed in valleys and in the proximity of water networks were mapped; overall thematic precision was 0.85 and a kappa index of 0.81. On the other hand, Musa sp. predominates at lower altitudes, while Inga edulis showed greater dominance at higher altitudes. The application of climatic and cocoa yield data allowed the calculation of the standardized anomaly index, which showed a remarkable impact of rainfall on cocoa yield, especially in 2021 and 2022, when it reached values above 0.94 MT/ha. Consequently, this integrated approach provides a deeper understanding of cocoa AFS, establishing a solid basis for decision-making aimed at optimizing yield through agricultural practices adapted to specific climatic conditions and promoting biodiversity by incorporating native species. Additionally, the findings have practical implications for agricultural policies, such as improving productivity, enhancing biodiversity, and adapting cocoa systems to climate change, promoting their sustainability and resilience.