21 6 Cattle herder, 5321 Kunmadaras, Széchenyi u. 7., Hungary 22 7 Shepherd, 4251 Hajdúsámson, Liszt Ferenc u. 9., Hungary 23 Abstract 29Wetlands are fragile, dynamic systems, transient at larger temporal scales and strongly affected 30 by long-term human activities. Sustaining at least some aspects of human management, particularly 31 traditional grazing, would be especially important as a way of maintaining the "necessary" 32 disturbances for many endangered species. Traditional ecological knowledge represents an important 33 source of information for erstwhile management practices. Our objective was to review historical 34 traditional knowledge on wetland grazing and the resulting vegetation response in order to assess 35 their relevance to biodiversity conservation. 36 We studied the Pannonian biogeographic region and its neighborhood in Central Europe and 37 searched ethnographic, local historical, early botanical, and agrarian sources for historical traditional 38 knowledge in online databases and books. The findings were analyzed and interpreted by scientist, 39 nature conservationist and traditional knowledge holder (herder) co-authors alike. 40 Among the historical sources reviewed, we found 420 records on traditional wetland grazing, 41 mainly from the period 1720-1970. Data showed that wetlands in the region served as basic grazing 42 areas, particularly for cattle and pigs. We found more than 500 mentions of habitat categories and 43 383 mentions of plants consumed by livestock. The most important reasons for keeping livestock on 44 wetlands were grazing, stock wintering, and surviving forage gap periods in early spring or mid-late 45 summer. Besides grazing, other commonly mentioned effects on vegetation were trampling and 46 uprooting. The important outcomes were vegetation becoming patchy and remaining low in height, 47 tall-growing dominant species being suppressed, litter being removed, and microhabitats being 48 created such as open surfaces of mud and water. 49 These historical sources lay firm foundations for developing innovative nature conservation 50 management methods. Traditional herders still holding wetland management knowledge could 51 contribute to this process when done in a participatory way, fostering knowledge co-production. 52 53 3 Keywords: effect of livestock grazing, knowledge gap, knowledge co-production, traditional 54 ecological knowledge, vegetation structure 55 56