Implications of landscape configuration on herbaceous forage production in native forests openings

TRINCO, FABIO D.; RUSCH, VERÓNICA E.; HOWISON, RUTH A.; GARIBALDI, LUCAS A.; TITTONELL, PABLO A.

AGROFORESTRY SYSTEMS

SPRINGER

Lugar: Berlin; Año: 2021

0167-4366

Sound management of native forests used for cattle ranching require understanding the dynamics of forage productivity in the openings. Despite their importance, forage productivity drivers in highly heterogeneous forested landscapes, or their variability over the year, are still unclear. The aim of this work is to find predictors of Normalized Difference Vegetation Index (NDVI) variation in the openings of native temperate forests, and to evaluate whether the effect of these predictors change within the growing season. We used high-resolution remote sensing imagery from NW Patagoniato separate forest openings from tree dense canopy. We obtained data of each opening related with herbaceous forage productivity and calculated landscape metrics. We estimated a multiple linear regression model for predicting NDVI in each season. Beyond known variables related with forage production (altitude, precipitation, etc.), the shape of forest? openings appeared as relevant in predicting NDVI. The amount of forest border of the opening was related with a decrease of NDVI in spring when soil water content is not limiting, and conversely with an increase of NDVI in summer when water is limiting growth. Also, the similarity of the opening with a circle resulted in higher NDVI over all the growing period. These results suggest that forage productivity drivers such as temperature and soil moisture inside the opening, and competition or facilitation process between trees and grasses are mediated by the shape of the opening. Management of heterogeneous native forests for cattle raising require taking into account the shape of the openings.