%0 Journal Article
%T Air photo evidence of historical land cover change in the highlands: Wetlands and grasslands give way to crops and woodlots
%A Christian A. Kull
%J Madagascar Conservation & Development
%D 2012
%I Madagascar Wildlife Conservation, Jane Goodall Institute Switzerland
%X Madagascar¡¯s high plateau ¨C where people farm, graze cattle, and set periodic fire in a grass dominated landscape ¨C receives disproportionately little conservation attention. An aerial photograph-based analysis of land - cover change in the latter half of the 20th century, based on a stratified random sample of twenty eight sites, reveals dramatic trends associated with an increas-ing human population that is building a cultural landscape of villages and agro-ecosystems to assure its livelihoods. On average across the sample sites, about 23 % of grassland areas present in 1949¨C1950 were converted to crops fields, farm trees and built - up areas by the 1990s. Of all land - cover transitions, the most dramatic changes included the loss of approximately 60 % of wetlands and 37 % of riparian forests. These land covers, which are dispersed along the fine - grained dendritic stream network, are habitat for crayfish, frogs, and other fauna, yet are also prized locations in the rice - based Malagasy agricultural system. The results of this study suggest that attention be given to highland grassland, wetland and riparian forest ecosystem restoration and conservation; however, any on - the - ground initiatives should incorporate respect for local needs and allow sustainable use of these ecosystems, given their cultural and subsistence importance. R¨¦SUM¨¦Les hautes terres malgaches, domin¨¦es par une v¨¦g¨¦tation herbac¨¦e, sont des paysages fortement marqu¨¦s par la gestion productive qu¡¯y exerce l¡¯Homme ; qu¡¯il s¡¯agisse des pratiques culturales, de l¡¯¨¦levage ou de la manipulation des r¨¦gimes du feu. Cette r¨¦gion ne re oit g¨¦n¨¦ralement pas d¡¯int¨¦r¨ºt pour la conservation de la biodiversit¨¦. Cet article pr¨¦sente les r¨¦sultats d¡¯une ¨¦tude r¨¦gionale de changement d¡¯occupation des sols et des dynamiques des formations v¨¦g¨¦tales des hautes terres au cours de la deuxi¨¨me moiti¨¦ du XXe si¨¨cle. L¡¯¨¦tude est bas¨¦e sur l¡¯analyse de photographies a¨¦riennes prises entre 1949¨C1950 et 1990¨C1993 de 28 parcelles de 10 km2 s¨¦lectionn¨¦es dans un ¨¦chantillon al¨¦atoire et spatialement stratifi¨¦. Les r¨¦sultats confirment plusieurs tendances li¨¦es ¨¤ l¡¯implantation d¡¯une population agricole croissante : 23 pourcent du terrain qui ¨¦tait couvert de formations gramin¨¦ennes (herbeuses) en 1950 ont ¨¦t¨¦ remplac¨¦s par des champs pour l¡¯agriculture, des plantations arbor¨¦es et des zones r¨¦sidentielles. Mais la cat¨¦gorie de couverture v¨¦g¨¦tale qui a ¨¦t¨¦ transform¨¦e le plus fortement est les zones humides (les mar¨¦cages), dont la superficie a diminu¨¦ de 60 pourcent. De plus, 37 pourcent de la superficie
%K wetland conversion
%K land cover change
%K zones humides
%K paysages
%K hautes terres
%K Madagascar
%K zones herbeuses
%K cultures
%K geography
%K historical ecology
%K remote sensing
%U http://www.journalmcd.com/index.php/mcd/article/view/mcd.v7i3.7