Local traditional ecological knowledge about hay management practices in wetlands of the Biebrza Valley, Poland.

BACKGROUND: The Biebrza Valley is one of the largest complexes of wetlands (floodplain and percolation mire) and conservation sites in Central Europe. Local communities have managed the area extensively for subsistence and farming purposes for centuries; nonetheless, since the 1960s, hand mowing and livestock grazing have been gradually ceasing due to the intensification of farming, and wetlands have undergone natural succession. Currently, the protection of this vast ecosystem is challenging. Despite its remarkable cultural origin, the complexity of the traditional practices and knowledge of local people have never been studied comprehensively. Therefore, we found it urgent to explore if traditional ecological knowledge that could be used in conservation management of the area still exists among the local community. METHODS: We interviewed 42 inhabitants of seven villages located in the Lower Basin of the Biebrza Valley (NE-Poland) in the consecutive years 2018-2020. We applied semi-structured, repeated interviews with farmers (aged 29-89), each lasting several hours. By using different ethnoecological methods (visual stimuli, walks in wetlands, co-mapping of the area), we explored traditional knowledge on the plants, landscape and traditional management of wetlands. RESULTS: Farmers from the oldest generation, who used to manage wetlands with scythes, shared the deepest ecological knowledge. Local people divided wetlands into zones differentiated by vegetation type and hay quality. Depending on plant composition, people managed wetlands under a mixed regime: mowing once or twice a year during periods that ensured good hay quality and pasturing various livestock: cattle, horses, sheep, pigs and fowl. We identified at least 50 plant ethnospecies, which were described exhaustively by their habitat, morphological features, and mowing and grazing value. CONCLUSIONS: The local community in the Biebrza Valley shared a deep traditional ecological knowledge and had a good memory of traditional farming practices. Research confirmed the unquestionable cultural origin of the local ecosystem, therefore in conservation endeavours the area should be treated first and foremost as a cultural landscape. The documented exceptional local perception of the wetland landscape, elements of traditional knowledge and complex farming practices should be considered for inclusion into conservation management, and cooperation with the local community should also be taken into account.

Minimal temperature of pollen germination controls species distribution along a temperature gradient.

BACKGROUND AND AIMS: Although plant distribution patterns are well documented, our understanding of the ecophysiological mechanisms that control the geographical ranges of plant species remains poor. We used a largely ignored method, the performance of the male gametophyte in vitro, to assess whether the thermal range of pollen germination and tube growth controls species distribution ranges, in this case along an elevational gradient. METHODS: Using in vitro pollen germination experiments, we obtained cardinal temperatures (minimal, optimal and maximal) of pollen germination and pollen tube growth for 25 herbaceous species along a mean annual temperature gradient of about 5 °C. These temperatures were correlated with temperatures of the sites where the species were collected. The presence of a phylogenetic signal in the data set as well as an effect of species flowering phenology were also estimated. KEY RESULTS AND CONCLUSIONS: We found a strong positive relationship between temperature conditions at our collection sites and the minimum temperature for both pollen germination and pollen tube growth. In addition, a significant correlation between maximum temperature of pollen tube growth and temperature of flowering month was apparent. We conclude that the restriction of pollen germination and growth by low temperatures is an important contributor to the climatic restriction of plant species distributions. Improved knowledge of this thermal precursor to seed production could, from a functional perspective, enhance our understanding of species distributions along climatic gradients and our ability to predict how anthropogenic climate change might affect plant community composition.

Variation of sesquiterpene lactone contents in different Arnica montana populations: influence of ecological parameters.

In ten grassland or heathland sites along a geographic (north to south) and climatic gradient in Germany, flowerheads of Arnica montana were collected, and the total content of sesquiterpene lactones (SLs) as well as the content of the detected single compounds were determined. The ratios of helenalin (H)- and corresponding 11 alpha,13-dihydrohelenalin(DH)-type compounds were calculated. All habitats were characterised concerning the climatic and soil conditions, and the values obtained were correlated with SL contents according to univariate statistical analyses. All populations showed very similar and constant ratios of helenalin ( 1)/11 alpha,13-dihydrohelenalin ( 2) at around 1.5-2/1 irrespective of different ecological parameters. The ratio of helenalin/11 alpha,13-dihydrohelenalin esters was several fold higher in all samples, but it was nearly identical in every habitat among each other, except for the helenalin/11 alpha,13-dihydrohelenalin 2-methylbutyrate pair ( 5/ 11), which showed a constantly twofold higher H/DH ratio. However, the 6- O-isovalerylhelenalin content ( 6) showed highly significant correlations to climatic factors.