Belowground carbon stock data in the Ankeniheny Zahamena forest corridor, Madagascar
(ESPA P4GES)

Full materials and methods available from Supporting Information (Manual_2_Belowground_Root_Survey)

A survey was conducted in humid tropical forest in Ankeniheny-Zahamena corridor (CAZ), located on the eastern Madagascar. This area, extends over 370,032 hectares (ha), is located between 48° 49' to 49°03 ' East and 17° 30' to 17° 43' south. Four zones of interest (ZOIs) were selected for the purposes of this study: Lakato (ZOI1), Andasibe (ZOI2), Anjahamana (ZOI3) and Didy (ZOI4). The selection of four zones was based on a range of biophysical criterias: altitude, slope and other biophysical criterias as bioclimate zone, length of dry season, soil type. Moreover, others criterias were considered such as the deforestation history and access.

In each zone, some sites were selected. Site is defined as a unit of sampling where field activities were done. The selection of sites was based on a number of criterias including:

- Land use characterization: closed canopy, tree fallow, shrub fallow and tany maty or degraded grassland

- Other criteria defined by biophysical workpackages (WP2 (Hydrology workpackage) &WP5 (biodiversity workpackage)): Slope of site should be less than 45 degrees.

The Voronoi polygon is the polygon of occupancy and the elementary space which is formed by the intersection of the perpendicular lines that pass through the midpoints of the lines connecting the center of the sampled tree to the center of the nearest neighboring trees. Here a simplified voronoi was used because of tropical forest complexity, where trees have different ages and different dimensions. Large trees are neighbours of small trees.

In order to estimate the root biomass around the trees, we carried out an excavation of the roots in pits neighbouring the target tree where there is no tree.

This dataset is included in the following collections

Can Paying for Global Ecosystem Services reduce poverty? (P4GES)