Abstract

ROLDAN, Mateo; CARMINATI, Alejandra; BIGANZOLI, Fernando  and  PARUELO, José M. Are private refuges effective for conserving ecosystem properties?. Ecol. austral [online]. 2010, vol.20, n.2, pp.185-199. ISSN 1667-782X.

To evaluate the contribution to conservation of private refuges, we compared the ecosystem functioning of this type of conservation (Refuge) with contiguous national parks (Park) and rural ranches and farms under traditional management (Traditional). We assume the Park as the reference situation, in as much they constitute the areas with the lowest human intervention. The analysis was based on three descriptors of the seasonal dynamics of the carbon gains, derived from spectral data provided by the MODIS sensor: the Normalized Difference Vegetation Index integral (NDVI-I), a spectral index related to the total carbon gains of the ecosystem; the relative range [RRel: (maximum NDVI-minimum NDVI)/(NDVI-I)], and the month of occurrence of the maximum value of NDVI (MMax). These last two attributes characterize the seasonality and phenology of vegetation. We worked on three contrasting biogeographic regions of Argentina [Paranaense forest (Misiones province), Mesopotamic Pampa (Entre Ríos province), Interior Pampa (Córdoba province)]. In the Paranaense forest, the Refuge presented a lower NDVI-I value than the Park, but higher than the Traditional (P<0.05). The seasonality of the vegetation carbon gains (RRel) was lower on the Park than for the other two managements. In the Mesopotamic Pampa, the gallery forests were the most productive unit (higher NDVI-I). The Refuge presented an intermediate behavior. Grasslands presented the highest NDVI-I on the Refuge (P<0.05). The emblematic vegetation of this region (the palm savannas), did not differ among managements. The seasonality was lower in the gallery forests of the Park. In the Interior Pampa, the differences between Refuge and Traditional, both in NDVI-I and RRel, were not significantly different among vegetation types or managements. The MMax did not differ between managements for any of the regions studied. Our results showed that for most of the ecosystem attributes considered, the Refuge presented values more similar to those of the reference situation (the Park) than to the traditional management alternatives. Private conservation therefore has being efficient for the conservation and maintenance of the ecosystemic processes and services bounded to the dynamic of the vegetation carbon gains.

Keywords : Private land conservation; Remote sensing; Ecosystem functioning; Paranaense forest; Mesopotamic Pampa; Interior Pampa.

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