Topographical characteristics of sites in the Ankeniheny Zahamena forest corridor, Madagascar

Full materials and methods available from Supporting Information (Manual_1_Classical_Survey)

In order to represent the whole studied Ankeniheny Zahamena Forest Corridor, the biophysical workpackages (Biodiversity, Carbon and Hydrology) contributed to the definition of a sampling design strategy to locate some zones to focus all works. The zones of interest (ZOI) were then identified after discussion between WPs by taking into account different criterias such as:

- Biophysical criterias : altitude, slope and other biophysical criterias as bioclimate zone, length of dry season, soil type

- The deforestation history

- The access

According to these criterias, four (4) ZOIs considered as representative and including all the principal existing conditions of the CAZ area were selected.

- ZOI1 in Lakato

- ZOI2 in Andasibe

- ZOI3 in Anjahamana/Ambalarondra

- ZOI4 in Didy

Sites identification

For the carbon workpackage (WP4) field activities. Site is defined as a unit of sampling where field activities were done. The criterias to be considered when selecting the sites are presented in the following.

Land use classification

The land use characterization is based on the study of Styger and al. (2007). Four land uses were identified in different villages, with for each land uses four (4) replicates, the land uses are:

- Closed canopy

- Tree fallow

- Shrub fallow

- Tany maty or degraded grassland

In addition to these land uses, another land use type was the reforestation. They were identified by the other workpackages through interviews with Non-government Organizations (NGOs) and community groups.

Criteria for the site identification

Each site should fulfill some criterias defined by biophysical workpackages. As there are some specific requirements for the WP2 (Hydrology workpackage) & WP5 (biodiversity workpackage), the criteria retained for the site selection were

- Slope of site should be less than 45 degrees.

- Transects must be located as near to the centre of a patch of habitat as possible to avoid edge effects

- Each site must be superior or equal to 120m by 120m

- Avoid areas of unusual disturbances, such as mining sites

- Transects should not be laid across or along streams

- Distance between sites are at least 500m each other.

Number and location of sites

In each ZOI, there are three or four campsites which are formed by a set of sites. For a good sampling, biophysical WPs choose a number of 16 plots to be surveyed in each ZOI. To be more specific, the 16 plots are obtained as follow: 4LU x 4 replicates.

Particularly for WP4, because of the need to apprehend the variability of carbon stock, some extra plots were surveyed within each ZOI. In total 28 sites were surveyed in ZOI1 Lakato, 48 sites in ZOI2 Andasibe, 28 sites in ZOI3 Anjahamana, and 28 sites in ZOI4 Didy.

The sites locations are identified by remote sensing carried out by CI team. One site corresponds to one land use.

This dataset is included in the following collections

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