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Loss of biological diversity is one of the greatest challenges that our civilization must face nowadays. Reaction to the diminishing biodiversity of agricultural landscapes is various measures promoting free-living organisms. The study deals with the vegetation composition and structure of agro-environmental-climatic measures applied on arable land in operating conditions (intensively farmed regions of the Czech Republic). Additional study focus was applied to a popular measure of the feeding bio-belts. Bio-belts are not only hiding places for free-living animals but can provide them a rich food offer in the period from the harvest of main crops until winter. Thanks to the bio-belts, the landscape gains in biodiversity, and sloping sites can be protected from soil erosion. The vegetation of land parts used as bio-belts was assessed using phytocoenological relevés. Dominant plant species sown in the bio-belts were Avena sativa, Panicum miliaceum, Brassica oleracea var. acephala, Fagopyrum esculentum, Phacelia tanacetifolia, and Pisum arvense. Apart from the sown plants, there were also weeds occurring in the bio-belts, of which the most abundant were Chenopodium album, Amaranthus retroflexus, Setaria verticillata, Cirsium arvense, Equisetum arvense, etc. Risks connected with the realization of feeding bio-belts in respect of weeds occurring on arable land are negligible. Weeds from bio-belts have only a limited potential to spread to adjacent arable land. A potential spreading of weeds from the bio-belts to adjacent arable land was not demonstrated. On the contrary, thanks to its composition, the vegetation of bio-belts has the potential to extend the food offer for animals. Thus, bio-belts are useful for supporting biodiversity in regions intensively used for agriculture.

Peatlands function as important global carbon sinks as peatlands store 30% to 40% of the total soil carbon even though peatlands only cover 3% of the Earth's terrestrial surface. However, drainage activities have damaged the ecosystem and caused many peatlands to function as carbon sources instead. Restoration projects aim to recover the hydrology and Sphagnum moss populations in peatlands by rewetting and removing trees, respectively. However, long-term studies on the recovery of restored bogs (a type of peatland) are scarce, and more so from a functional point of view. Here, the similarities of the environmental characteristics, and vegetation communities in terms of species composition and functionality (i.e., plant functional traits and functional diversity) between two restored bogs and the adjacent reference bogs (the two study sites ‘Anderstorp’ and ‘Store Mosse’) in southern Sweden were compared, eight years post-restoration. The pH significantly differed between areas (i.e., restored or reference) in both sites but the differences were small. The electrical conductivity (EC, i.e. concentration of ions in the water) was higher in the restored areas than in the reference areas, and Anderstorp had higher EC levels in general than Store Mosse. The effect of restoration on the water table depth (WTD) between the areas depended on the site. At Store Mosse, the WTD was closer to the surface in the restored area than the reference area. For both sites, the species composition was significantly different between areas and the Sphagnum moss coverages were higher in the natural areas than in the restored areas. In addition, no environmental variable (pH, EC or WTD) seemed to act as the dominant driver for the vegetation composition. The plant trait analyses were based on vascular bog plants and both sites showed similar trends between areas for 7 out of 8 traits, with a larger effect size at Store Mosse. For the traits seed mass, leaf dry matter content (LDMC), leaf

Peatlands function as important global carbon sinks as peatlands store 30% to 40% of the total soil carbon even though peatlands only cover 3% of the Earth's terrestrial surface. However, drainage activities have damaged the ecosystem and caused many peatlands to function as carbon sources instead. Restoration projects aim to recover the hydrology and Sphagnum moss populations in peatlands by rewetting and removing trees, respectively. However, long-term studies on the recovery of restored bogs (a type of peatland) are scarce, and more so from a functional point of view. Here, the similarities of the environmental characteristics, and vegetation communities in terms of species composition and functionality (i.e., plant functional traits and functional diversity) between two restored bogs and the adjacent reference bogs (the two study sites ‘Anderstorp’ and ‘Store Mosse’) in southern Sweden were compared, eight years post-restoration. The pH significantly differed between areas (i.e., restored or reference) in both sites but the differences were small. The electrical conductivity (EC, i.e. concentration of ions in the water) was higher in the restored areas than in the reference areas, and Anderstorp had higher EC levels in general than Store Mosse. The effect of restoration on the water table depth (WTD) between the areas depended on the site. At Store Mosse, the WTD was closer to the surface in the restored area than the reference area. For both sites, the species composition was significantly different between areas and the Sphagnum moss coverages were higher in the natural areas than in the restored areas. In addition, no environmental variable (pH, EC or WTD) seemed to act as the dominant driver for the vegetation composition. The plant trait analyses were based on vascular bog plants and both sites showed similar trends between areas for 7 out of 8 traits, with a larger effect size at Store Mosse. For the traits seed mass, leaf dry matter content (LDMC), leaf

Plant phenology provides information on the seasonal dynamics of plants, and changes herein are important for understanding the impact of climate change and human management on the biosphere. Land surface phenology is the study of plant phenology across large spatial scales estimated by satellite observations. However, satellite observations (pixels) are often composed of a mixture of vegetation types, like woody vegetation and herbaceous vegetation, having different phenological characteristics. Therefore, any changes in tree cover presumably impact land surface phenology, as trees usually have a different seasonal cycle compared to herbaceous vegetation. On the other hand, changes in land surface phenology are often interpreted as a result of climate change-induced impacts on the photosynthetic activity of vegetation. Therefore, it is important to better understand the role of changes in vegetation cover (here, the proportion between tree and short vegetation cover) in satellite-derived land surface phenology analysis. We studied the impact of changes in tree cover on satellite observed land surface phenology at a global scale over the past three decades. We found an extension of the growing season length in 36.6% of the areas where tree cover increased, whereas only 20.1% of the areas where tree cover decreased showed an increase in growing season length. Furthermore, the ratio between tree cover and short vegetation cover was found to affect changes in the length of the growing season, with the denser tree cover showing a more pronounced extension of the growing season length (especially in boreal forests). These results highlight the importance of changes in tree cover when analyzing the impact of climate change on vegetation phenology. Our study thereby addresses a critical knowledge gap for an improved understanding of changes in land surface phenology during recent decades in the context of climate and human-induced global land cover change.

Plant phenology provides information on the seasonal dynamics of plants, and changes herein are important for understanding the impact of climate change and human management on the biosphere. Land surface phenology is the study of plant phenology across large spatial scales estimated by satellite observations. However, satellite observations (pixels) are often composed of a mixture of vegetation types, like woody vegetation and herbaceous vegetation, having different phenological characteristics. Therefore, any changes in tree cover presumably impact land surface phenology, as trees usually have a different seasonal cycle compared to herbaceous vegetation. On the other hand, changes in land surface phenology are often interpreted as a result of climate change-induced impacts on the photosynthetic activity of vegetation. Therefore, it is important to better understand the role of changes in vegetation cover (here, the proportion between tree and short vegetation cover) in satellite-derived land surface phenology analysis. We studied the impact of changes in tree cover on satellite observed land surface phenology at a global scale over the past three decades. We found an extension of the growing season length in 36.6% of the areas where tree cover increased, whereas only 20.1% of the areas where tree cover decreased showed an increase in growing season length. Furthermore, the ratio between tree cover and short vegetation cover was found to affect changes in the length of the growing season, with the denser tree cover showing a more pronounced extension of the growing season length (especially in boreal forests). These results highlight the importance of changes in tree cover when analyzing the impact of climate change on vegetation phenology. Our study thereby addresses a critical knowledge gap for an improved understanding of changes in land surface phenology during recent decades in the context of climate and human-induced global land cover change.

Loss of biological diversity is one of the greatest challenges that our civilization must face nowadays. Reaction to the diminishing biodiversity of agricultural landscapes is various measures promoting free-living organisms. The study deals with the vegetation composition and structure of agro-environmental-climatic measures applied on arable land in operating conditions (intensively farmed regions of the Czech Republic). Additional study focus was applied to a popular measure of the feeding bio-belts. Bio-belts are not only hiding places for free-living animals but can provide them a rich food offer in the period from the harvest of main crops until winter. Thanks to the bio-belts, the landscape gains in biodiversity, and sloping sites can be protected from soil erosion. The vegetation of land parts used as bio-belts was assessed using phytocoenological relevés. Dominant plant species sown in the bio-belts were Avena sativa, Panicum miliaceum, Brassica oleracea var. acephala, Fagopyrum esculentum, Phacelia tanacetifolia, and Pisum arvense. Apart from the sown plants, there were also weeds occurring in the bio-belts, of which the most abundant were Chenopodium album, Amaranthus retroflexus, Setaria verticillata, Cirsium arvense, Equisetum arvense, etc. Risks connected with the realization of feeding bio-belts in respect of weeds occurring on arable land are negligible. Weeds from bio-belts have only a limited potential to spread to adjacent arable land. A potential spreading of weeds from the bio-belts to adjacent arable land was not demonstrated. On the contrary, thanks to its composition, the vegetation of bio-belts has the potential to extend the food offer for animals. Thus, bio-belts are useful for supporting biodiversity in regions intensively used for agriculture., info:eu-repo/semantics/openAccess

Loss of biological diversity is one of the greatest challenges that our civilization must face nowadays. Reaction to the diminishing biodiversity of agricultural landscapes is various measures promoting free-living organisms. The study deals with the vegetation composition and structure of agro-environmental-climatic measures applied on arable land in operating conditions (intensively farmed regions of the Czech Republic). Additional study focus was applied to a popular measure of the feeding bio-belts. Bio-belts are not only hiding places for free-living animals but can provide them a rich food offer in the period from the harvest of main crops until winter. Thanks to the bio-belts, the landscape gains in biodiversity, and sloping sites can be protected from soil erosion. The vegetation of land parts used as bio-belts was assessed using phytocoenological relevés. Dominant plant species sown in the bio-belts were Avena sativa, Panicum miliaceum, Brassica oleracea var. acephala, Fagopyrum esculentum, Phacelia tanacetifolia, and Pisum arvense. Apart from the sown plants, there were also weeds occurring in the bio-belts, of which the most abundant were Chenopodium album, Amaranthus retroflexus, Setaria verticillata, Cirsium arvense, Equisetum arvense, etc. Risks connected with the realization of feeding bio-belts in respect of weeds occurring on arable land are negligible. Weeds from bio-belts have only a limited potential to spread to adjacent arable land. A potential spreading of weeds from the bio-belts to adjacent arable land was not demonstrated. On the contrary, thanks to its composition, the vegetation of bio-belts has the potential to extend the food offer for animals. Thus, bio-belts are useful for supporting biodiversity in regions intensively used for agriculture., info:eu-repo/semantics/openAccess

About 21% of the African population directly depends on rangeland resources. As this number is predicted to grow, it is important to understand the response of African rangelands to global environmental change and formulate, in turn, better hypotheses on their capacity to support livelihoods. Here we used three decades of satellite data and a dynamic global vegetation model to study the response of rangeland vegetation to recent climate change and to describe changes in the vegetation structure accompanying greening and browning trends. Long-term climate change was the dominant driver of vegetation dynamics in ca. 2,495,000 km2 of African rangelands (22.7% of the total extent). Examples of these rangelands are in Mauritania, Senegal, Chad, Namibia, Botswana, and South Africa, where the vegetation greened up due to an overall increase in trees, shrubs, and short herbaceous vegetation. We further identified a more extended different type of rangeland (ca. 2,915,000 km2) where vegetation dynamics appeared to be largely unrelated to long-term climate variations. In these rangelands, we observed opposite trends between woody cover (trees and shrubs) and short vegetation (mostly representative of the herbaceous layer). Greening (West Africa, South Sudan) was associated with an overall increase in woody cover (+4.4%) and a concomitant decline in short vegetation (−3.4%), while browning (Angola, Mozambique) resulted from a decrease in woody cover (−2.6%) and an increase in short vegetation (+4.3%) (total per cent change average during 1982–2015). Our results offer a nuanced perspective to frame greening and browning trends in rangeland systems. While greening may mitigate climate change via higher carbon uptake, the encroachment of less palatable woody species reduces the resources available to pastoral communities. On the other hand, browning due to a reduction in the woody cover attenuates carbon sequestration rates, but the observed increase in s

Data on sedimentation, sediment grain size, vegetation composition and vegetation characteristics of a field experiment on a salt marsh in nature reserve the Slufter (Wadden island Texel, the Netherlands).

Nedovoljno je informacija o strukturnim promenama vegetacije šumo pašnjaka, uključujući i njihovu vezu sa abiotičkim faktorima. U ovom radu stavljen je akcenat na vezu između različitih stadijuma ciklusa šumo pašnjaka i važnih sredinskih varijabli sa ciljem razumevanja dinamičnosti ovog odnosa i procesa koji dovode do degradacije šumo pašnjaka. Istorijske promene vegetacijske strukture na Krčedinskoj adi u protekle 44 godine identifikovane su pomoću analize avio i satelitskih snimaka. Stvarni podaci sa terena (24 vegetacijska plota) i CCA analiza korišteni su kako bi se analizirala veza između biljnih zajednica i prisutnih sredinskih faktora. Odabrana su tri dominantna strukturna tipa vegetacije: GR (grazing) - plotovi pod ispašom; WC (woody cover) - plotovi šikarastog tipa sa dominacijom visokog žbunja i drvenastih vrsta čija visina premašuje 2 m; TR (transitional) - prelazna forma između livadske i drvenaste vegetacije sa trnovitim žbunjem visine manje od 2 m. Odabran je sledeći set sredinskih parametara: GI (intenzitet ispaše), Ind učestalost plavljenja), E (nadmorska visina), i zemljišni parametri: TN (ukupni azot), AP (dostupni fosfor), K (kalijum), Mg (magnezijum), Ca (kalcijum), pH, C/N (odnos ugljenika i azota) i NB (nitrificirajuće bakterije).Klasifikacija biljnih vrsta iz različtih sukcesivnih stadijuma prema CSR Grime-ovom modelu dodatno je doprinela razumevanju dinamičnosti vegetacijskih sukcesija a analiza uticaja invazivnih biljnih vrsta na zemljišne parametre doprinela je razumevanju fluktuacija zemljišnih parametara i usmeravanju restauracijskih mera. Analiza promena zemljišnog pokrivača pomoću satelitskih snimakapokazala je da su u prošlosti biljne zajednice na Krčedinskoj adi bile sa većom populacijom zeljastih vrsta i očuvanih šuma vrbe bez prisustva degradiranih sastojina. Ove zajednice velikim delom su zamenjene dominantn, There is insufficient information on structural changes within wood-pasture, including their relationship with abiotic influences. This thesis addresses the links between important environmental variables and different stages of the wood- pasture cycle, with the aim of understanding fluctuations in this relationship and processes that follow wood-pasture degradation. Satellite and aerial image interpretation was used to identify structural vegetation shifts over 44 years under significantly declining livestock numbers and ground truthing data of 24 plots to assess the current field scenario. Canonical correspondence analysis (CCA) was employed to evaluate the relationship between plant communities and invironmental influences. Three dominant structural vegetation types – grazing plots (GR), transitional habitats with thorny shrubs (TR) and woody encroachment (WC) - were surveyed and the following set of variables was chosen: grazing intensity (GI), inundation frequency (Ind), elevation (E), soil total nitrogen (TN), soil available phosphorus (AP), soil potassium (K), soil magnesium (Mg), soil calcium (Ca), soil pH (pH), soil carbon to nitrogen ratio (C/N) and soil nitrifying bacteria (NB). Classification of plants from different succession stages according to Grimes CSR model, gave its contribution to understand vegetation dynamics while the analysis of invasive plant species influence on soil variables helped to understand the fluctuations of soil variables and to advice on restoration measures.Interpretation of satellite images revealed dominance of wood-pasture habitats in the past,which alternated structurally between more open and more closed physiognomies i.e. indicates progressive succession pathway which is in accordance with CSR plant species categorization which revealed that the main succes

Aims: Litter decomposition is an important driver of soil carbon and nutrient cycling in nutrient-limited Arctic ecosystems. However, climate change is expected to induce changes that directly or indirectly affect decomposition. We examined the direct effects of long-term warming relative to differences in soil abiotic properties associated with vegetation type on litter decomposition across six subarctic vegetation types. Methods: In six vegetation types, rooibos and green tea bags were buried for 70–75 days at 8 cm depth inside warmed (by open-top chambers) and control plots that had been in place for 20–25 years. Standardized initial decomposition rate and stabilization of the labile material fraction of tea (into less decomposable material) were calculated from tea mass losses. Soil moisture and temperature were measured bi-weekly during summer and plant-available nutrients were measured with resin probes. Results: Initial decomposition rate was decreased by the warming treatment. Stabilization was less affected by warming and determined by vegetation type and soil moisture. Soil metal concentrations impeded both initial decomposition rate and stabilization. Conclusions: While a warmer Arctic climate will likely have direct effects on initial litter decomposition rates in tundra, stabilization of organic matter was more affected by vegetation type and soil parameters and less prone to be affected by direct effects of warming.

Aims: Litter decomposition is an important driver of soil carbon and nutrient cycling in nutrient-limited Arctic ecosystems. However, climate change is expected to induce changes that directly or indirectly affect decomposition. We examined the direct effects of long-term warming relative to differences in soil abiotic properties associated with vegetation type on litter decomposition across six subarctic vegetation types. Methods: In six vegetation types, rooibos and green tea bags were buried for 70–75 days at 8 cm depth inside warmed (by open-top chambers) and control plots that had been in place for 20–25 years. Standardized initial decomposition rate and stabilization of the labile material fraction of tea (into less decomposable material) were calculated from tea mass losses. Soil moisture and temperature were measured bi-weekly during summer and plant-available nutrients were measured with resin probes. Results: Initial decomposition rate was decreased by the warming treatment. Stabilization was less affected by warming and determined by vegetation type and soil moisture. Soil metal concentrations impeded both initial decomposition rate and stabilization. Conclusions: While a warmer Arctic climate will likely have direct effects on initial litter decomposition rates in tundra, stabilization of organic matter was more affected by vegetation type and soil parameters and less prone to be affected by direct effects of warming.

Aims: Litter decomposition is an important driver of soil carbon and nutrient cycling in nutrient-limited Arctic ecosystems. However, climate change is expected to induce changes that directly or indirectly affect decomposition. We examined the direct effects of long-term warming relative to differences in soil abiotic properties associated with vegetation type on litter decomposition across six subarctic vegetation types. Methods: In six vegetation types, rooibos and green tea bags were buried for 70–75 days at 8 cm depth inside warmed (by open-top chambers) and control plots that had been in place for 20–25 years. Standardized initial decomposition rate and stabilization of the labile material fraction of tea (into less decomposable material) were calculated from tea mass losses. Soil moisture and temperature were measured bi-weekly during summer and plant-available nutrients were measured with resin probes. Results: Initial decomposition rate was decreased by the warming treatment. Stabilization was less affected by warming and determined by vegetation type and soil moisture. Soil metal concentrations impeded both initial decomposition rate and stabilization. Conclusions: While a warmer Arctic climate will likely have direct effects on initial litter decomposition rates in tundra, stabilization of organic matter was more affected by vegetation type and soil parameters and less prone to be affected by direct effects of warming.

Aims: Litter decomposition is an important driver of soil carbon and nutrient cycling in nutrient-limited Arctic ecosystems. However, climate change is expected to induce changes that directly or indirectly affect decomposition. We examined the direct effects of long-term warming relative to differences in soil abiotic properties associated with vegetation type on litter decomposition across six subarctic vegetation types. Methods: In six vegetation types, rooibos and green tea bags were buried for 70–75 days at 8 cm depth inside warmed (by open-top chambers) and control plots that had been in place for 20–25 years. Standardized initial decomposition rate and stabilization of the labile material fraction of tea (into less decomposable material) were calculated from tea mass losses. Soil moisture and temperature were measured bi-weekly during summer and plant-available nutrients were measured with resin probes. Results: Initial decomposition rate was decreased by the warming treatment. Stabilization was less affected by warming and determined by vegetation type and soil moisture. Soil metal concentrations impeded both initial decomposition rate and stabilization. Conclusions: While a warmer Arctic climate will likely have direct effects on initial litter decomposition rates in tundra, stabilization of organic matter was more affected by vegetation type and soil parameters and less prone to be affected by direct effects of warming.

Aims: Litter decomposition is an important driver of soil carbon and nutrient cycling in nutrient-limited Arctic ecosystems. However, climate change is expected to induce changes that directly or indirectly affect decomposition. We examined the direct effects of long-term warming relative to differences in soil abiotic properties associated with vegetation type on litter decomposition across six subarctic vegetation types. Methods: In six vegetation types, rooibos and green tea bags were buried for 70–75 days at 8 cm depth inside warmed (by open-top chambers) and control plots that had been in place for 20–25 years. Standardized initial decomposition rate and stabilization of the labile material fraction of tea (into less decomposable material) were calculated from tea mass losses. Soil moisture and temperature were measured bi-weekly during summer and plant-available nutrients were measured with resin probes. Results: Initial decomposition rate was decreased by the warming treatment. Stabilization was less affected by warming and determined by vegetation type and soil moisture. Soil metal concentrations impeded both initial decomposition rate and stabilization. Conclusions: While a warmer Arctic climate will likely have direct effects on initial litter decomposition rates in tundra, stabilization of organic matter was more affected by vegetation type and soil parameters and less prone to be affected by direct effects of warming.

Land abandonment followed by natural revegetation constitutes the main land‐use change in the Mediterranean mountains, affecting soil quality and soil organic carbon (SOC) stocks; however, there are few studies analysing the effects of cropland abandonment on soils in mid‐mountains. In the Leza Valley (Spain), 43.2% of the area was cultivated but abandoned during the 20th‐century. Natural revegetation gave rise to five land uses (LULCs): pastures (5 years), shrubs (Cistus laurifolius, 20–35 years), bushes (Juniperus communis, 35–50 years), young forests (Quercus pyrenaica) and old forests (>70 years). The aim of this research was to study the effects of natural revegetation of abandoned fields on physico‐chemical soil quality and SOC in various LULCs. In each of the LULCs, soil samples were collected every 10 cm, down to 40 cm depth, at three points, with a total of 60 samples being analysed (12 per LULC). In addition, plant species inventories were carried out. The results indicated (a) significant differences in physico‐chemical soil quality between the first years of abandonment and forests; (b) the SOC content increased with revegetation duration and decreased with increase in soil depth; (c) the highest SOC and TN stocks were found in the first 10 cm; (d) the results of the principal component analysis with all the data differentiate forests from shrubs and pastures. This study confirms the need to be aware of the effects of land abandonment and natural revegetation processes on the soil, in order to promote management strategies to preserve ecosystem services that agricultural marginal lands can provide.

Aims: Litter decomposition is an important driver of soil carbon and nutrient cycling in nutrient-limited Arctic ecosystems. However, climate change is expected to induce changes that directly or indirectly affect decomposition. We examined the direct effects of long-term warming relative to differences in soil abiotic properties associated with vegetation type on litter decomposition across six subarctic vegetation types. Methods: In six vegetation types, rooibos and green tea bags were buried for 70–75 days at 8 cm depth inside warmed (by open-top chambers) and control plots that had been in place for 20–25 years. Standardized initial decomposition rate and stabilization of the labile material fraction of tea (into less decomposable material) were calculated from tea mass losses. Soil moisture and temperature were measured bi-weekly during summer and plant-available nutrients were measured with resin probes. Results: Initial decomposition rate was decreased by the warming treatment. Stabilization was less affected by warming and determined by vegetation type and soil moisture. Soil metal concentrations impeded both initial decomposition rate and stabilization. Conclusions: While a warmer Arctic climate will likely have direct effects on initial litter decomposition rates in tundra, stabilization of organic matter was more affected by vegetation type and soil parameters and less prone to be affected by direct effects of warming.

Islands are vulnerable ecosystems worldwide, increasingly exposed to human pressure, global climate change and invasive species. Thus, understanding island species diversity is key for nature conservation. Recent studies on insular plant communities indicated that habitat-specific species composition and richness might largely affect diversity patterns observed at the island scale. In consequence, habitat-based approaches are needed to (i) estimate how environmental changes at the habitat scale may affect island diversity, and to (ii) estimate the contribution of different patches of the same habitat to island diversity with respect to habitat-specific environmental constraints. In the present study, we tested these habitat-to-island diversity relationships for shoreline habitats (brackish reeds, salt marsh, rocky shore, tall herbs) and island interior habitats (rocks, semi-natural grassland, pioneer forest, coniferous forest, mixed forest) using 108 islands of three Baltic archipelagos in Sweden. These islands differed in terms of island-scale variables describing effects of island configuration and distance, and habitat-scale variables representing the effects of habitat area, abiotic environment and land-use. The studied habitats differed in their contribution to island species diversity, called habitat specificity. Shoreline habitats shared many common specialist species adapted to extreme conditions like sea salt or bird grazing, while habitats of the island interior harbored mainly species adapted to the specific conditions of a single habitat. We found high variability in habitat specificity as a consequence of habitat-specific environmental factors. Variability was highest for grasslands, where it was related to abandonment and soil fertility, stressing the importance of grassland management for maintaining island biodiversity. Habitats with high habitat specificity through either high species richness or many habitat-specific specialists should be the prima

The paper deals with plant species richness - diversity relationship along the rising elevation in a semi-disturbed tree line ecotone in upper Bhaderwah, a part of lesser Himalaya. 253 plant species distributed over 170 genera and 62 families were recorded during the intensive field surveys carried during May 2014 to September 2016. These included 11 trees, 29 shrubs and 213 herb species with 247 angiosperms and 6 gymnosperms. Family Asteraceae with 37 species dominated the study area. Maximum richness (179) was observed at sub-alpine zone (Site IV) while the trees (H'=1.74) and shrubs (H'=2.48) revealed maximum diversity at Site III and herbs at Site IV (H'=4.60). The maximum evenness for trees, shrubs and herbs was exhibited by sites III (J'=0.79), V (J'=0.87) and VI (J'=0.94), respectively. The diversity and evenness showed an incremental rise along the rising elevation reaching maxima at the mid elevation with Site-IV being the species rich and Site-VII species deficit, which implies that sub-alpine and alpine forests need effective monitoring and conservation.

Historical contingency is the impact of past events, like the timing and order of species arrival, on community assembly, and can sometimes result in alternative stable states of ecological communities. Large herbivores, wild and domestic, can cause profound changes in the structure and functioning of plant communities and therefore probably influence historical contingency; however, little empirical data on the stability of such shifts or subsequent drivers of stability are available. We studied the centennial legacy of reindeer (Rangifer tarandus) pressure on arctic tundra vegetation by considering historical milking grounds (HMGs): graminoid- and forb-dominated patches amid shrub-dominated tundra, formed by historical Sami reindeer herding practices that ended approximately 100 years ago. Our results show that the core areas of all studied HMGs remained strikingly stable, being hardly invaded by surrounding shrubs. Soil nitrogen concentrations were comparable to heavily grazed areas. However, the HMGs are slowly being reinvaded by vegetative growth of shrubs at the edges, and the rate of ingrowth increased with higher mineral N availability. Furthermore, our data indicate that several biotic feedbacks contribute to the stability of the HMGs: increased nutrient turnover supporting herbaceous vegetation, strong interspecific competition preventing invasion and herbivore damage to invading shrubs. In particular, voles and lemmings appear to be important, selectively damaging shrubs in the HMGs. We concluded that HMGs provide clear evidence for historical contingency of herbivore effects in arctic ecosystems. We showed that several biotic feedbacks can contribute to subsequent vegetation stability, but their relative importance will vary in time and space., Originnally included in thesis in manuscript form

1. Herbivory can drive vegetation into different states of productivity and community composition, and these changes may be stable over time due to historical contingency effects. Interactions with abiotic and biotic soil components can contribute to such long-term legacies in plant communities through stabilizing positive feedbacks. 2. We studied the role of plant-soil feedbacks in maintaining vegetation changes caused by historical (similar to 1350-1900 AD) reindeer herding in northern Sweden. These historical milking grounds (HMGs) consist of meadow plant communities formed in naturally nutrient-poor heath or naturally nutrient-rich shrub-dominated vegetation and are still clearly visible in the landscape, a century after active use ceased. 3. We selected two phytometer species: the forb Potentilla crantzii as representative of HMG vegetation, and the dwarf shrub Betula nana, as representative of control vegetation. We grew both species under glasshouse conditions on soils derived from replicated HMG and paired control plots, using live soils and sterilized (-radiation)-inoculated soils, to separate between biotic and abiotic soil effects. 4. A net negative plant-soil feedback for B.nana biomass in its home (i.e., control) soil and a net positive feedback for P.crantzii in its home (i.e., HMG) soil in heath habitat was partly driven by the soil biotic community. However, abiotic differences in mineral nitrogen (N) concentrations between control and HMG soils were a stronger driver of differences in plant growth. Positive feedbacks maintaining a high mineral nutrient availability are thus important, especially in nutrient-poor habitats. 5. The positive plant responses to higher soil mineral N concentrations, combined with positive biotic plant-soil feedbacks, might shift the competitive balance in favour of typical HMG plant species, thereby contributing to stability of HMG plant communities. Our data indicate that herbivore-driven changes in the interactions betw, Originally included in thesis in manuscript form.

Historical contingency is the impact of past events, like the timing and order of species arrival, on community assembly, and can sometimes result in alternative stable states of ecological communities. Large herbivores, wild and domestic, can cause profound changes in the structure and functioning of plant communities and therefore probably influence historical contingency; however, little empirical data on the stability of such shifts or subsequent drivers of stability are available. We studied the centennial legacy of reindeer (Rangifer tarandus) pressure on arctic tundra vegetation by considering historical milking grounds (HMGs): graminoid- and forb-dominated patches amid shrub-dominated tundra, formed by historical Sami reindeer herding practices that ended approximately 100 years ago. Our results show that the core areas of all studied HMGs remained strikingly stable, being hardly invaded by surrounding shrubs. Soil nitrogen concentrations were comparable to heavily grazed areas. However, the HMGs are slowly being reinvaded by vegetative growth of shrubs at the edges, and the rate of ingrowth increased with higher mineral N availability. Furthermore, our data indicate that several biotic feedbacks contribute to the stability of the HMGs: increased nutrient turnover supporting herbaceous vegetation, strong interspecific competition preventing invasion and herbivore damage to invading shrubs. In particular, voles and lemmings appear to be important, selectively damaging shrubs in the HMGs. We concluded that HMGs provide clear evidence for historical contingency of herbivore effects in arctic ecosystems. We showed that several biotic feedbacks can contribute to subsequent vegetation stability, but their relative importance will vary in time and space., Originnally included in thesis in manuscript form

Historical contingency is the impact of past events, like the timing and order of species arrival, on community assembly, and can sometimes result in alternative stable states of ecological communities. Large herbivores, wild and domestic, can cause profound changes in the structure and functioning of plant communities and therefore probably influence historical contingency; however, little empirical data on the stability of such shifts or subsequent drivers of stability are available. We studied the centennial legacy of reindeer (Rangifer tarandus) pressure on arctic tundra vegetation by considering historical milking grounds (HMGs): graminoid- and forb-dominated patches amid shrub-dominated tundra, formed by historical Sami reindeer herding practices that ended approximately 100 years ago. Our results show that the core areas of all studied HMGs remained strikingly stable, being hardly invaded by surrounding shrubs. Soil nitrogen concentrations were comparable to heavily grazed areas. However, the HMGs are slowly being reinvaded by vegetative growth of shrubs at the edges, and the rate of ingrowth increased with higher mineral N availability. Furthermore, our data indicate that several biotic feedbacks contribute to the stability of the HMGs: increased nutrient turnover supporting herbaceous vegetation, strong interspecific competition preventing invasion and herbivore damage to invading shrubs. In particular, voles and lemmings appear to be important, selectively damaging shrubs in the HMGs. We concluded that HMGs provide clear evidence for historical contingency of herbivore effects in arctic ecosystems. We showed that several biotic feedbacks can contribute to subsequent vegetation stability, but their relative importance will vary in time and space., Originnally included in thesis in manuscript form

Historical contingency is the impact of past events, like the timing and order of species arrival, on community assembly, and can sometimes result in alternative stable states of ecological communities. Large herbivores, wild and domestic, can cause profound changes in the structure and functioning of plant communities and therefore probably influence historical contingency; however, little empirical data on the stability of such shifts or subsequent drivers of stability are available. We studied the centennial legacy of reindeer (Rangifer tarandus) pressure on arctic tundra vegetation by considering historical milking grounds (HMGs): graminoid- and forb-dominated patches amid shrub-dominated tundra, formed by historical Sami reindeer herding practices that ended approximately 100 years ago. Our results show that the core areas of all studied HMGs remained strikingly stable, being hardly invaded by surrounding shrubs. Soil nitrogen concentrations were comparable to heavily grazed areas. However, the HMGs are slowly being reinvaded by vegetative growth of shrubs at the edges, and the rate of ingrowth increased with higher mineral N availability. Furthermore, our data indicate that several biotic feedbacks contribute to the stability of the HMGs: increased nutrient turnover supporting herbaceous vegetation, strong interspecific competition preventing invasion and herbivore damage to invading shrubs. In particular, voles and lemmings appear to be important, selectively damaging shrubs in the HMGs. We concluded that HMGs provide clear evidence for historical contingency of herbivore effects in arctic ecosystems. We showed that several biotic feedbacks can contribute to subsequent vegetation stability, but their relative importance will vary in time and space., Originnally included in thesis in manuscript form

Historical contingency is the impact of past events, like the timing and order of species arrival, on community assembly, and can sometimes result in alternative stable states of ecological communities. Large herbivores, wild and domestic, can cause profound changes in the structure and functioning of plant communities and therefore probably influence historical contingency; however, little empirical data on the stability of such shifts or subsequent drivers of stability are available. We studied the centennial legacy of reindeer (Rangifer tarandus) pressure on arctic tundra vegetation by considering historical milking grounds (HMGs): graminoid- and forb-dominated patches amid shrub-dominated tundra, formed by historical Sami reindeer herding practices that ended approximately 100 years ago. Our results show that the core areas of all studied HMGs remained strikingly stable, being hardly invaded by surrounding shrubs. Soil nitrogen concentrations were comparable to heavily grazed areas. However, the HMGs are slowly being reinvaded by vegetative growth of shrubs at the edges, and the rate of ingrowth increased with higher mineral N availability. Furthermore, our data indicate that several biotic feedbacks contribute to the stability of the HMGs: increased nutrient turnover supporting herbaceous vegetation, strong interspecific competition preventing invasion and herbivore damage to invading shrubs. In particular, voles and lemmings appear to be important, selectively damaging shrubs in the HMGs. We concluded that HMGs provide clear evidence for historical contingency of herbivore effects in arctic ecosystems. We showed that several biotic feedbacks can contribute to subsequent vegetation stability, but their relative importance will vary in time and space., Originnally included in thesis in manuscript form

There is insufficient available information on structural changes within wood-pastures including their relationship to abiotic influences such as livestock grazing, flooding and available soil nutrients. In this paper, we address the links between important environmental variables and different stages of the wood-pasture cycle, with the aim of understanding fluctuations in this relationship and processes that follow changes in wood-pasture condition. We used satellite and aerial image interpretation to identify structural vegetation shifts over 44 years under significantly declining livestock numbers. We used ground truthing of 24 plots to assess the current field scenario and employed canonical correspondence analysis (CCA) to evaluate the relationship between plant communities and environmental influences. Three dominant structural vegetation types grassland, transitional vegetation with thorny shrubs and woody encroachment were surveyed and the following set of variables was chosen: grazing intensity, inundation frequency, elevation, soil total nitrogen, soil available phosphorus, soil potassium, soil magnesium, soil calcium, soil pH and soil carbon to nitrogen ratio. Interpretation of satellite images revealed dominance of wood-pasture in the past, which alternated structurally between more open and more closed physiognomies. CCA with ground truthing data and forward selection revealed grazing intensity as the predominant ecological driver modifying vegetation structure, as well as transitioning vegetation patterns between open herbaceous and closed woody cover. Each structural vegetation type demonstrated a collective distribution pattern and a close relationship to certain abiotic drivers, indicating strong interactions between soil parameters, grazing pressure and vegetation composition.

Historical contingency is the impact of past events, like the timing and order of species arrival, on community assembly, and can sometimes result in alternative stable states of ecological communities. Large herbivores, wild and domestic, can cause profound changes in the structure and functioning of plant communities and therefore probably influence historical contingency; however, little empirical data on the stability of such shifts or subsequent drivers of stability are available. We studied the centennial legacy of reindeer (Rangifer tarandus) pressure on arctic tundra vegetation by considering historical milking grounds (HMGs): graminoid- and forb-dominated patches amid shrub-dominated tundra, formed by historical Sami reindeer herding practices that ended approximately 100 years ago. Our results show that the core areas of all studied HMGs remained strikingly stable, being hardly invaded by surrounding shrubs. Soil nitrogen concentrations were comparable to heavily grazed areas. However, the HMGs are slowly being reinvaded by vegetative growth of shrubs at the edges, and the rate of ingrowth increased with higher mineral N availability. Furthermore, our data indicate that several biotic feedbacks contribute to the stability of the HMGs: increased nutrient turnover supporting herbaceous vegetation, strong interspecific competition preventing invasion and herbivore damage to invading shrubs. In particular, voles and lemmings appear to be important, selectively damaging shrubs in the HMGs. We concluded that HMGs provide clear evidence for historical contingency of herbivore effects in arctic ecosystems. We showed that several biotic feedbacks can contribute to subsequent vegetation stability, but their relative importance will vary in time and space., Originnally included in thesis in manuscript form

Early agriculture can be detected in palaeovegetation records, but quantification of the relative importance of climate and land use in influencing regional vegetation composition since the onset of agriculture is a topic that is rarely addressed. We present a novel approach that combines pollen-based REVEALS estimates of plant cover with climate, anthropogenic land-cover and dynamic vegetation modelling results. This is used to quantify the relative impacts of land use and climate on Holocene vegetation at a sub-continental scale, i.e. northern and western Europe north of the Alps. We use redundancy analysis and variation partitioning to quantify the percentage of variation in vegetation composition explained by the climate and land-use variables, and Monte Carlo permutation tests to assess the statistical significance of each variable. We further use a similarity index to combine pollen based REVEALS estimates with climate-driven dynamic vegetation modelling results. The overall results indicate that climate is the major driver of vegetation when the Holocene is considered as a whole and at the sub-continental scale, although land use is important regionally. Four critical phases of land-use effects on vegetation are identified. The first phase (from 7000 to 6500 BP) corresponds to the early impacts on vegetation of farming and Neolithic forest clearance and to the dominance of climate as a driver of vegetation change. During the second phase (from 4500 to 4000 BP), land use becomes a major control of vegetation. Climate is still the principal driver, although its influence decreases gradually. The third phase (from 2000 to 1500 BP) is characterised by the continued role of climate on vegetation as a consequence of late-Holocene climate shifts and specific climate events that influence vegetation as well as land use. The last phase (from 500 to 350 BP) shows an acceleration of vegetation changes, in particular during the last century, caused by new farming practic

Climate warming is faster in the Arctic than the global average. Nutrient availability in the tundra soil is expected to increase by climate warming through (i) accelerated nutrient mobilization in the surface soil layers, and (ii) increased thawing depths during the growing season which increases accessibility of nutrients in the deeper soil layers. Both processes may initiate shifts in tundra vegetation composition. It is important to understand the effects of these two processes on tundra plant functional types. We manipulated soil thawing depth and nutrient availability at a Northeast-Siberian tundra site to investigate their effects on above- and below-ground responses of four plant functional types (grasses, sedges, deciduous shrubs and evergreen shrubs). Seasonal thawing was accelerated with heating cables at c. 15 cm depth without warming the surface soil, whereas nutrient availability was increased in the surface soil by adding slow-release NPK fertilizer at c. 5 cm depth. A combination of these two treatments was also included. This is the first field experiment specifically investigating the effects of accelerated thawing in tundra ecosystems. Deep soil heating increased the above-ground biomass of sedges, the deepest rooted plant functional type in our study, but did not affect biomass of the other plant functional types. In contrast, fertilization increased above-ground biomass of the two dwarf shrub functional types, both of which had very shallow root systems. Grasses showed the strongest response to fertilization, both above- and below-ground. Grasses were deep-rooted, and they showed the highest plasticity in terms of vertical root distribution, as grass root distribution shifted to deep and surface soil in response to deep soil heating and surface soil fertilization respectively. Synthesis. Our results indicate that increased thawing depth can only benefit deep-rooted sedges, while the shallow-rooted dwarf shrubs, as well as flexible-rooted grasses

"Disused railway lines make excellent vehicles to study ecological processes being linear, of fixed width, constructed in the same way, with potential vegetation influences such as time since abandonment and climate being easy to discover. Moreover they are rarely studied. Thus the current study fills a gap in the literature. Samples were taken from a total of 176 releves across 35 sites on 22 different railway lines within England and Wales. The communities were analysed using the standard UK phytosociological method, the National Vegetation Classification (NVC). Few similarities were found with published NVC communities. A large number of communities had affinities with MG1 Arrhenatherum elatius grassland but with un-described sub-communities, with ruderal species or wood and scrub species as major components. Similarly, a number of communities had affinities to OV communities but with different constant species. Hence it is difficult to apply the NVC to synanthropic habitats and that there are ruderal communities in existence that are not described in the NVC. A modified Braun-Blanquet approach to analysing the vegetation data was also undertaken. Hierarchical analysis identified seven clusters equating to communities. Species characteristic of each community were identified using Indicator Values, although these species rarely had both high fidelity and exclusivity. The potential contribution of environmental, temporal and edaphic variables to the development of these communities was assessed. This was underpinned by the theoretical question of succession. Is it an ordered progression through to a climax community or is the process much more stochastic ? There is no simple relationship between time since abandonment and any measure of successional progress. However CCA analysis showed that some factors, primarily abiotic, were significantly associated with community composition. Time since abandonment only becomes significant when it is combined

1.Climate warming is faster in the Arctic than the global average. Nutrient availability in the tundra soil is expected to increase by climate warming through 1) accelerated nutrient mobilization in the surface soil layers, and 2) increased thawing depths during the growing season which increases accessibility of nutrients in the deeper soil layers. Both processes may initiate shifts in tundra vegetation composition. It is important to understand the effects of these two processes on tundra plant functional types. 2.We manipulated soil thawing depth and nutrient availability at a Northeast-Siberian tundra site to investigate their effects on above and belowground responses of four plant functional types (grasses, sedges, deciduous shrubs and evergreen shrubs). Seasonal thawing was accelerated with heating cables at ~15 cm depth without warming the surface soil, whereas nutrient availability was increased in the surface soil by adding slow-release NPK fertilizer at ~5 cm depth. A combination of these two treatments was also included. This is the first field experiment specifically investigating the effects of accelerated thawing in tundra ecosystems. 3.Deep soil heating increased the aboveground biomass of sedges, the deepest-rooted plant functional type in our study, but did not affect biomass of the other plant functional types. In contrast, fertilization increased aboveground biomass of the two dwarf shrub functional types, which both had very shallow root systems. Grasses showed the strongest response to fertilization, both above and belowground. Grasses were deep-rooted, and they showed the highest plasticity in terms of vertical root distribution, as grass root distribution shifted to deep and surface soil in response to deep soil heating and surface soil fertilization, respectively. 4.Synthesis - Our results indicate that increased thawing depth can only benefit deep-rooted sedges, while the shallow-rooted dwarf shrubs as well as flexible-rooted grasses take a

There is a wealth of studies dealing with the reconstruction of past environmental changes and their effects on vegetation composition in NW Iberia, but none of them have focused specifically on the post-disturbance dynamics (i.e. the type of response) of the vegetation at different space and time scales. To fill this gap, we analysed the record of pollen and non-pollen palynomorphs (NPP) of a 235-cm thick colluvial sequence spanning the last ~13,900years. The aims were to detect the changes in vegetation, identify the responsible drivers and determine the type of responses to disturbance. To extract this information we applied multivariate statistical techniques (constrained cluster analysis and principal components analysis on transposed matrices, PCA tr) to the local (hydro-hygrophytes and NPP) and regional (land pollen) datasets separately. In both cases the cluster analysis resulted in eight local and regional assemblage zones, while five (local types) and four (regional types) principal components were obtained by PCA tr to explain 94.1% and 96.6% of the total variance, respectively. The main drivers identified were climate change, grazing pressure, fire events and cultivation. The vegetation showed gradual, threshold and elastic responses to these drivers, at different space (local vs. regional) and time scales, revealing a complex ecological history. Regional responses to perturbations were sometimes delayed with respect to the local response. The results also showed an ecosystem resilience, such as the persistence of open Betula-dominated vegetation community for ~1700years after the onset of the Holocene, and elastic responses, such as the oak woodland to the 8200calyr BP dry/cold event. Our results support the notion that palaeoecological research is a valuable tool to investigate ecosystem history, their responses to perturbations and their ability to buffer them. This knowledge is critical for modelling the impact of future environmental change and to h

Interactions between aboveground vertebrate herbivores and subterranean yellow meadow ants (Lasius flavus) can drive plant community patterns in grassland ecosystems. Here, we study the relative importance of the presence of ants (L. flavus) and ant mounds under different simulated grazing regimes for biomass production and species composition in plant communities. We set up a greenhouse experiment using intact soil cores with their associated vegetation.We found that plant biomass production in the short term was affected by an interaction between simulated grazing (clipping) and ant mound presence. Clipping homogenized production on and off mounds, while in unclipped situations production was higher off than on mounds. During the experiment, these differences in unclipped situations disappeared, because production on unclipped mounds increased. Plant species richness was on average higher in clipped treatments and patterns did not change significantly over the experimental period. Plant community composition was mainly affected by clipping, which increased the cover of grazing-tolerant plant species. The actual presence of yellow meadow ants did not affect plant community composition and production.We conclude that the interaction between ant mounds and clipping determined plant community composition and biomass production, while the actual presence of ants themselves was not important. Moreover, clipping can overrule effects of ant mounds on biomass production. Only shortly after the cessation of clipping biomass production was affected by ant mound presence, suggesting that only under low intensity clipping ant mounds may become important determining plant production. Therefore, under low intensity grazing ant mounds may drive the formation of small-scale plant patches.

Whether diversity and composition of avian communities is determined primarily by responses of species to the floristic composition or to the structural characteristics of habitats has been an ongoing debate, at least since the publication of MacArthur and MacArthur (1961). This debate, however, has been hampered by two problems: 1) it is notoriously time consuming to measure the physiognomy of habitat, particularly in forests, and 2) rigorous statistical methods to predict the composition of bird assemblages from assemblages of plants have not been available. Here we use airborne laser scanning (lidar) to measure the habitat (vegetation) structure of a montane forest across large spatial extents with a very fine grain. Furthermore, we use predictive co-correspondence and canonical correspondence analyses to predict the composition of bird communities from the composition and structure of another community (i.e. plants). By using these new techniques, we show that the physiognomy of the vegetation is a significantly more powerful predictor of the composition of bird assemblages than plant species composition in the field and as well in the shrub/tree layer, both on a level of p < 0.001. Our results demonstrate that ecologists should consider remote sensing as a tool to improve the understanding of the variation of bird assemblages in space and time. Particularly in complex habitats, such as forests, lidar is a valuable and comparatively inexpensive tool to characterize the structure of the canopy even across large and rough terrain.

English: Bush fallow under shifting cultivation is the most common practised subsistence farming system in southern Mozambique. This system is likely to persist due to the existence of large areas sparsely inhabited coupled with financial limitations preventing small scale farmers from buying fertilizers. The bush fallow is intended to recover naturally the productive capacities of soils lost during cropping. This study was conducted therefore to gain a better understanding on the composition and biomass of bush fallow vegetation, climatic factors affecting leaf litter decay of an important tree species and the dynamics of some soil fertility indicators. Five agroecosystems representing rainfall regions of <400 mm (AE6), 400-600 mm (AE5), 600-800 mm (AE3), 800-1000 mm (AE2), >1000 mm (AE1) and a transitional agroecosystem of 400-800 mm (AE4) were selected. Within each agroecosystem, five land uses (virgin, cultivated, < 5 years fallow, 5-15 years fallow and >15 years fallow) were identified. Descriptions and comparisons of vegetation were performed between land uses within agroecosystems and similar land uses across agroecosystems, except in cultivated land; effects of soil water content and soil temperature on decomposition of Brachystegia spiciformis leaf litter were evaluated in recently abandoned agricultural fields cleared of any vegetation (Bare) and in >15 years fallow fields (15F) at sites in a transect that covered AE2 to AE6; and at every combination of agroecosystem and land use the dynamics of organic C, total N, CEC, pH, P, Ca, Mg and K were determined in the 0-50 mm, 50-100 mm and 100-200 mm soil layers. A total of 204 species that including N-fixing species, belonging to 141 genera and 50 families divided into tree, shrub and herbaceous layers were identified. The tree layer was only found in virgin fields and in fields abandoned to bush fallow >15 years, whereas shrub and herbaceous layers occurred in all fields. The tree species in bush fallow field, Afrikaans: Bosbraak onder verskuiwende verbouing is die mees algemene bestaansboererystelsel wat in suidelike Mosambiek toegepas word. Die stelsel sal waarskynlik voortgaan weens die groot ylbevolkte areas en kleinboere se beperkte finansiële vermoëns om kunsmis te koop. Die bosbraak het ten doel om die produksievermoë van gronde, wat met gewasverbouing verlore gaan, natuurlik te herstel. Hierdie studie is dus gedoen om ‘n beter begrip te kry van die samestelling en biomassa van bosbraakplantegroei, klimaatfaktore wat die afbraak van ‘n belangrike boomspesie beïnvloed en die dinamika van sekere grondvrugbaarheidsindikatore. Vyf agro-ekosisteme wat reënvalstreke van <400 mm (AE6), 400-600 mm (AE5), 600- 800 mm (AE3), 800-1000 mm (AE2) en >1000 mm (AE1) en ‘n oorgangsagroekosisteem van 400-800 mm (AE4) is geselekteer. Binne elke agro-ekosisteem is vyf landsgebruike (onversteurde, bewerkte, <5 jaar braak, 5-15 jaar braak en >15 jaar braak) geïdentifiseer. Beskrywings en vergelykings van die plantegroei tussen landgebruike binne agro-ekosisteme en soortgelyke landgebruike oor agro-ekosisteme is gedoen; effekte van grondwaterinhoud en grondtemperatuur op die afbraak van Brachystecia spiciformis blaarreste is in bewerkte lande sonder enige plantegroei en wat onlangs vir bosbraak gelos is (Kaal), en in >15 jaar braaklande (>15F) by lokaliteite wat ‘n deursnit vanaf AE2 tot AE6 dek, geëvalueer; en by elke kombinasie van agroekosisteem en landgebruik is die dinamika van organiese C, totale N, KUK, pH, P, Ca, Mg en K in die 0-50 mm, 50-100 mm en 100-200 mm grondlae bepaal. ‘n Totaal van 204 spesies wat N-bindende spesies in sluit en tot 141 genera en 50 families behoort, is geïdentifiseer en in ‘n boom-, struik- en kruidlaag verdeel. Die boomlaag is slegs in onbewerkte en >15 jaar bosbraaklande gevind, terwyl die struiken kruidlae in alle lande voorkom. Die boomspesies in bosbraaklande van die kus en natter AE1, AE2 en AE3 (gedomineer deur B. Spiciformis and Julbernaldia glob, Sida/SAREC

Hyperspectral canopy reflectance was used to predict sub-surface water nutrients, vegetation composition, and canopy nutrients, which could lead to more useful means for assessing the status of wetlands. Thirty field quadrats at two tidal freshwater marsh sites on the Nanticoke River (Maryland) were treated with five nitrogen levels. During the 2004-05 growing seasons, hyperspectral canopy reflectance was measured using a spectroradiometer with 1nm resolution across the visible and near - infrared spectrum (350-1075 nm), water samples were collected using lysimeters, species cover was quantified, and biomass was collected and analyzed for canopy nutrients. ANOVA was used to determine whether nitrogen affected reflectance, species composition, canopy N and P, and partial least squares regression was used to develop reflectance models predictive of these ecosystem properties. Results indicated that hyperspectral radiometry could be used as a remote sensing tool for quantifying sub-surface water nitrogen, vegetation composition, and canopy nutrients in tidal freshwater marshes.

Spontananeous distribution and survival in experimental plots of four marsh orchids ( Dactylorhiza spp.) in a hay-meadow complex were related to mineral composition of groundwater, soil nutrient availability and species composition of the vegetation. Differences in Ca2+ contents of the groundwater pointed to the discharge of various groundwater flows in the meadow. Soil fertility and extent of N limitation, measured with the phytometer Cirsium palustre, varied with position on the gradient. Total N content of the soil and levels of exchangable K+ and NH4+ were correlated to organic matter content. Highest total P levels were found in areas with a pronounced discharge of mineral-rich groundwater. Concentration of available P was higher in wet than in drier sites. Natural abundance and survival of introduced Dactylorhiza maculata (L.) Soo plantlets was highest in Juncus acutiflorus-dominated transitions between meadows and Parvocaricetea marsh. These were characterized by the occurrence of a water type of intermediate mineral content and by low soil fertility, limited by N and P. Survival of D. praetermissa (Druce) Soo showed exactly the opposite pattern to that of D. maculata. It had its optimal spontaneous abundance in more fertile parts of the meadow influenced by discharge of groundwater with an intermediate mineral content. D. majalis (Rchb. f.) Hunt & Summerh. also occurred in the more fertile parts of the meadow, but showed an optimum in drier stands associated with discharge of highly calcareous groundwater. The phosphorus-pool of these soils was high, but the availability of phosphate was low. The soil fertility of D. majalis site was limited by N. D. incarnata (L.) Soo occurred mainly in transitions between basiphilous small sedge vegetation and productive hay meadow stands. The species occurred at fertile but waterlogged soils with high concentrations of NH4+. The presence of base-rich groundwater with a high pH apparently prevents the species from ammonium

Die vorliegende Masterarbeit hatte zum Ziel, Auswirkungen von einmaliger und wiederkehrender Dürre auf die Vegetationsgemeinschaft, funktionellen Gruppen und phänologischen Muster in einer Bergwiese zu untersuchen., This master’s thesis laid special focus on drought-related changes in vegetation composition, functional groups and phenological events on an alpine meadow., by Sonja Pirchmoser, BSC, Masterarbeit University of Innsbruck 2019

Die vorliegende Masterarbeit hatte zum Ziel, Auswirkungen von einmaliger und wiederkehrender Dürre auf die Vegetationsgemeinschaft, funktionellen Gruppen und phänologischen Muster in einer Bergwiese zu untersuchen., This master’s thesis laid special focus on drought-related changes in vegetation composition, functional groups and phenological events on an alpine meadow., by Sonja Pirchmoser, BSC, Masterarbeit University of Innsbruck 2019