Browsing by Subject "VEGETATION CHANGE"

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  • Etongo, Daniel; Djenontin, Ida Nadia S.; Kanninen, Markku; Glover, Edinam K. (2017)
    Empirical ethnobotanical studies in Burkina Faso and the Sahel apply unmodified use-value methods, which often fail to capture uses of plants within and across categories. These methods mask both the relative uses and local people's 'true' knowledge of plant species. This study addresses these methodological weaknesses by assessing plant use-values within and across eight use categories for livelihood values and their potentials for environmental protection among 48 informants, selected through a stratified random technique. The research is twofold: (1) to document and identify the conservation status of plant species and (2) to assess local knowledge and perceived importance of the most easily found plant species in relation to informant's age, gender, ethnicity, and location. Seventy-three plant species belonging to 24 families were recorded on fields, fallows, and forests. The most easily found 30 species belonged to 14 families of which Combretaceae, Mimosodeae, Caesalpinioideae, and Anacardiaceae dominated. Results show that Adansonia digitata, Parkia biglobosa, Vitellaria paradoxa, and Balanites aegyptiaca were more valued for livelihood benefits, while A. digitata, Tamarindus indica, and Ficus thonningii received more value for their potentials in environmental protection. Local knowledge was unevenly distributed and showed significant differences at the 0.01 % level among gender, age, ethnicity, and study village. The relative importance of plant uses goes beyond nutrition and potentials in environmental protection and can provide valuable information for creating local markets for such goods. Three species belonging to different families were identified as vulnerable and considered priority for conservation. The design of conservation and development projects should consider creating opportunities for knowledge sharing that will not only improve knowledge but provide better understanding of local priorities based on sociocultural and economic factors.
  • Koskinen, Markku; Maanavilja, Liisa Maria; Nieminen, Mika; Minkkinen, Kari; Tuittila, Eeva-Stiina (2016)
    Forestry-drained peatlands in the boreal region are currently undergoing restoration in order to bring these ecosystems closer to their natural (undrained) state. Drainage affects the methane (CH4) dynamics of a peatland, often changing sites from CH4 sources to sinks. Successful restoration of a peatland would include restoration of not only the surface vegetation and hydrology, but also the microbial populations and thus CH4 dynamics. As a pilot study, CH4 emissions were measured on two pristine, two drained and three restored boreal spruce swamps in southern Finland for one growing season. Restoration was successful in the sense that the water table level in the restored sites was significantly higher than in the drained sites, but it was also slightly higher than in the pristine sites. The restored sites were surprisingly large sources of CH4 (mean emissions of 52.84 mg CH4 m(-2) d(-1)), contrasting with both the pristine (1.51 mg CH4 m(-2) d(-1)) and the drained sites (2.09 mg CH4 m-(2) d(-1)). More research is needed to assess whether the high CH4 emissions observed in this study are representative of restored spruce mires in general.
  • Zhang, Hui; Gallego-Sala, Angela V.; Amesbury, Matthew J.; Charman, Dan J.; Piilo, Sanna Riikka; Väliranta, Minna Maria (2018)
    Northern peatlands have accumulated large carbon (C) stocks since the last deglaciation and during past millennia they have acted as important atmospheric C sinks. However, it is still poorly understood how northern peatlands in general and Arctic permafrost peatlands in particular will respond to future climate change. In this study, we present C accumulation reconstructions derived from 14 peat cores from four permafrost peatlands in northeast European Russia and Finnish Lapland. The main focus is on warm climate phases. We used regression analyses to test the importance of different environmental variables such as summer temperature, hydrology, and vegetation as drivers for nonautogenic C accumulation. We used modeling approaches to simulate potential decomposition patterns. The data show that our study sites have been persistent mid- to late-Holocene C sinks with an average accumulation rate of 10.80-32.40g C m(-2) year(-1). The warmer climate phase during the Holocene Thermal Maximum stimulated faster apparent C accumulation rates while the Medieval Climate Anomaly did not. Moreover, during the Little Ice Age, apparent C accumulation rates were controlled more by other factors than by cold climate per se. Although we could not identify any significant environmental factor that drove C accumulation, our data show that recent warming has increased C accumulation in some permafrost peatland sites. However, the synchronous slight decrease of C accumulation in other sites may be an alternative response of these peatlands to warming in the future. This would lead to a decrease in the C sequestration ability of permafrost peatlands overall.
  • Urbanova, Zuzana; Straková, Petra; Kastovska, Eva (2018)
    Various peatland restoration strategies developed during the last two decades have aimed to stop degradation and bring back the original hydrology, biodiversity and other peatland functions. This study evaluated progress 6-15 years after rewetting in vegetation development, physicochemical properties of peat, soil organic matter (SOM) quality and microbial activity in previously long-term drained bogs and spruce swamp forests (SSF) in comparison with pristine and long-term drained sites in the Bohemian Forest, Czech Republic. Long-term drainage led to overall ecosystem degradation, indicated by a change in vegetation composition, reduced decomposability of peat, with high content of recalcitrant compounds and decreased pH, and reduced soil microbial biomass and activity. The degradation was more pronounced in SSF, while bogs seemed to be relatively resistant to environmental changes caused by drainage. Post-rewetting progress has occurred with regard to vegetation composition, peat pH, microbial biomass and potential anaerobic CO2 and CH4 production, all of which tending towards characteristics of the pristine sites. However, overall SOM quality has not yet responded significantly, indicating that some peat properties and functions, such as C accumulation, need much longer periods of time to return to the original level.
  • Aubriot, Xavier; Knapp, Sandra; Syfert, Mindy; Poczai, Péter; Buerki, Sven (2018)
    • While brinjal eggplant (Solanum melongena L.) is the second most important solanaceaous vegetable crop, we lack firm knowledge of its evolutionary relationships. This in turn limits efficient use of crop wild relatives in eggplant improvement. Here, we examine the hypothesis of linear step-wise expansion of the eggplant group from Africa to Asia. • We use museum collections to generate nuclear and full-plastome data for all species of the eggplant clade. We combine a phylogenomic approach with distribution data to infer a biogeographic scenario for the clade. • The eggplant clade has Pleistocene origins in northern Africa. Dispersions to tropical Asia gave rise to Solanum insanum, the wild progenitor of the eggplant, and to Africa distinct lineages of widespread and southern-African species. Results suggest that spread of species to southern Africa is recent and was likely facilitated by large mammal herbivores feeding on Solanum fruits (African elephant, impala). • Rather than a linear ‘Out Of Africa’ sequence, our results are more consistent with an initial event into Asia, and subsequent wide dispersion and differentiation across Africa driven by large mammalian herbivores. Our evolutionary results will impact future work on eggplant domestication and use of wild relatives in breeding of this increasingly important solanaceous crop.