Reviewing historical traditional knowledge for innovative conservation management: A re-evaluation of wetland grazing.

Wetlands are fragile, dynamic systems, transient at larger temporal scales and strongly affected by long-term human activities. Sustaining at least some aspects of human management, particularly traditional grazing, would be especially important as a way of maintaining the "necessary" disturbances for many endangered species. Traditional ecological knowledge represents an important source of information for erstwhile management practices. Our objective was to review historical traditional knowledge on wetland grazing and the resulting vegetation response in order to assess their relevance to biodiversity conservation. We studied the Pannonian biogeographic region and its neighborhood in Central Europe and searched ethnographic, local historical, early botanical, and agrarian sources for historical traditional knowledge in online databases and books. The findings were analyzed and interpreted by scientist, nature conservationist and traditional knowledge holder (herder) co-authors alike. Among the historical sources reviewed, we found 420 records on traditional wetland grazing, mainly from the period 1720-1970. Data showed that wetlands in the region served as basic grazing areas, particularly for cattle and pigs. We found more than 500 mentions of habitat categories and 383 mentions of plants consumed by livestock. The most important reasons for keeping livestock on wetlands were grazing, stock wintering, and surviving forage gap periods in early spring or mid-late summer. Besides grazing, other commonly mentioned effects on vegetation were trampling and uprooting. The important outcomes were vegetation becoming patchy and remaining low in height, tall-growing dominant species being suppressed, litter being removed, and microhabitats being created, such as open surfaces of mud and water. These historical sources lay firm foundations for developing innovative nature conservation management methods. Traditional herders still holding wetland management knowledge could contribute to this process when done in a participatory way, fostering knowledge co-production.