Protected areas within multifunctional landscapes: Squeezing out intermediate land use intensities in the tropics?

A protected area (PA) tends to be designated in an area where tracts of primary forest remain, often with poor accessibility due to terrain features and yet with some exposure to threats. Typically, a PA is at the start of a ‘forest transition’ gradient. The establishment of a PA influences the whole gradient. We analyzed the temporal patterns of land-use change inside and outside four PAs, with one located in each of Laos, Indonesia, Madagascar and Cameroon. In Laos, in the Viengkham landscape, the rates of conversion of natural forest increased after the designation of the PA and were higher than the spatial baseline predicted. In the three other landscapes, the policies associated with the implementation of PAs increased the conversion rate immediately outside the boundary of the PAs. In Indonesia, in the Bungo landscape, forms of land-use associated with multifunctional agroforestry activities involving rubber trees land-use became the target for conversion to oil palm and monoculture rubber tree crops when the rules on the protection of the remaining natural forest were tightened. We tested a new metric for the degree of integration of forest in multifunctional landscapes which recognizes the surrounding matrix, both as surrogate habitat and as a corridor for tree species. Two important findings were: (i) a ‘leakage’ zone of influence of at least 10 km around a PA needs to be included for quantification of the deforestation and degradation changes that may be due to forest protection inside the PA and (ii) agroforest and other mixed tree cover can maintain or increase the degree of integration of forest in the multifunctional landscape for biodiversity maintenance and conservation, while providing a source of livelihood for the local people.

► Protection Area (PA) establishment increases vegetation contrast by slowing tree cover loss inside the PA and increasing it outside.
► Using this contrast to estimate PA effectiveness produces negative ‘leakage’ effects at least 10 km around a PA.
► Agroforestry systems surrounding a PA tend to disappear through conversion to more intensive land-use practices.
► Tree cover contrasts imply loss of ecological connectivity and the loss of agroforests induces an ‘island effect’.
► Forest gradient management can achieve conservation and development goals.