Preserving for the future the - once widespread but now vanishing - knowledge on traditional pig grazing in forests and marshes (Sava-Bosut floodplain, Serbia).

BACKGROUND: Traditional knowledge is key for sustainability, but it is rapidly disappearing. Pig keeping in forests and marshes is an ancient, once widespread, now vanishing practice, with a major economic and ecological potential. The knowledge of pig keepers and the foraging activity of pigs are hardly documented. METHODS: We studied the knowledge of traditional pig keepers (svinjars) on wild plants and pig foraging on the Sava-Bosut forest-marsh complex in Serbia. We conducted picture-based interviews about 234 locally common and/or salient plant species, and participatory fieldwork (11 days) and visual observation (21 days) on pig foraging. RESULTS: 181 wild plant species were known by svinjars and 106 taxa were consumed by pigs. Svinjars knew well and could name most regularly foraged species. 98 species were reported by svinjars as foraged and 56 as not eaten. 28 species were observed by the authors as eaten regularly, while 21 were nibbled and 17 avoided. Contradictory information on foraging was rare both among svinjars (8 species) and between svinjars and researchers (7 species); several of these species were rare. Leaves of 92, fruits or seeds of 21 and 'roots' of 20 species were reported or observed as eaten, usually with high seasonality. Svinjars were overall observant, but knew little about some less salient species (e.g. Veronica, Circaea). The most common forages (reported and/or observed) were fruits (Quercus, fleshy fruits), grasses (Agrostis, Glyceria), herbs (Ranunculus ficaria, Circaea), nutritious 'roots' (Carex spp., Iris), young shrub leaves (Crataegus, Carpinus) and 'tame' plants growing in the sun (Persicaria dubia, Erigeron annuus). Traditional, now extinct pig breeds were reported as less selective and more 'knowledgeable' about plants, as they received less additional fodder. Svinjars learnt their knowledge since childhood, from community members, but long-term personal observations and everyday encounters with pigs were also important sources of knowledge. CONCLUSIONS: A deeper understanding of pig foraging could contribute to using pigs in nature conservation management, resource management and organic farming, and to a better understanding of wild boar foraging. The knowledge of svinjars is a disappearing intangible cultural heritage of European importance. Knowledge holders deserve recognition, and legal and financial support to continue this tradition.

European primary forest database v2.0.

Primary forests, defined here as forests where the signs of human impacts, if any, are strongly blurred due to decades without forest management, are scarce in Europe and continue to disappear. Despite these losses, we know little about where these forests occur. Here, we present a comprehensive geodatabase and map of Europe's known primary forests. Our geodatabase harmonizes 48 different, mostly field-based datasets of primary forests, and contains 18,411 individual patches (41.1 Mha) spread across 33 countries. When available, we provide information on each patch (name, location, naturalness, extent and dominant tree species) and the surrounding landscape (biogeographical regions, protection status, potential natural vegetation, current forest extent). Using Landsat satellite-image time series (1985-2018) we checked each patch for possible disturbance events since primary forests were identified, resulting in 94% of patches free of significant disturbances in the last 30 years. Although knowledge gaps remain, ours is the most comprehensive dataset on primary forests in Europe, and will be useful for ecological studies, and conservation planning to safeguard these unique forests.

Controlling invasive alien shrub species, enhancing biodiversity and mitigating flood risk: A win-win-win situation in grazed floodplain plantations.

The high nature conservation value of floodplain ecosystems is severely threatened by invasive alien species. Besides adversely affecting native biodiversity, these species also pose a major threat from a wider socio-ecological perspective (e.g. 'roughness' increases flood risk). Finding options to control dense shrub layers consisting of invasive alien species is therefore of high priority for multipurpose management. We studied cattle grazing impacts on the cover, composition and diversity of the herb and shrub layers in floodplain poplar plantations along the Tamis river, Serbia. Non-grazed, moderately grazed, intensively grazed and resting place stands were sampled in five locations in three sampling points. Non-grazed stands had substantially higher cover of invasive alien shrub species (on average 65%) than moderately and intensively grazed stands, and resting places (5.17, 0.02 and 0.00%, respectively), but without considerable differences between the grazing intensity categories. The number of invasive alien species in the shrub layer decreased considerably from non-grazed to intensively grazed stands. Species composition in the herb layer changed from non-grazed to intensively grazed stands, while resting places differed substantially from the other categories. Total species richness, richness of native generalist herbaceous grassland species, and the cover of palatable grasses were the highest in moderately and intensively grazed stands. Our results suggest that cattle grazing in floodplains is effective at controlling invasive alien shrub species. Furthermore, continuous moderate or intensive grazing would contribute to multifunctional management of invaded floodplains by enhancing local biodiversity, reducing flood risk, and providing additional grazing areas for the local community.

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.