| 1. |
- Borgström, Sara, 1977-
(författare)
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Urban shades of green : Current patterns and future prospects of nature conservation in urban landscapes
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Urban nature provides local ecosystem services such as absorption of air pollutants, reduction of noise, and provision of places for recreation, and is therefore crucial to urban sustainable development. Nature conservation in cities is also part of the global effort to halt biodiversity decline. Urban landscapes, however, display distinguishing social and ecological characteristics and therefore the implementation of nature conservation frameworks into cities, requires reconsideration of what nature to preserve, for whom and where. The aim of this thesis was to examine the current urban nature conservation with special focus on formally protected areas, and discuss their future role in the urban landscape. A social-ecological systems approach was used as framework and both quantitative and qualitative methods were applied. The studies were performed at local to regional scales in the southern part of Sweden. Four key questions were addressed: i) What are the characteristics of nature conservation in urban landscapes? ii) How does establishment of nature conservation areas affect the surrounding urban landscape? iii) In what ways are spatial and temporal scales recognized in practical management of nature conservation areas? and iv) How can the dichotomy of built up and nature conservation areas be overcome in urban planning? Nature reserves in urban, compared to rural landscapes were in general fewer, but larger and included a higher diversity of land covers. They were also based on a higher number and different kinds of objectives than rural nature reserves. Urbanisation adjacent to nature reserves followed the general urbanisation patterns in the cities and no additional increase in urban settlements could be detected. In general, there was a lack of social and ecological linkages between the nature conservation areas and the urban landscape and practical management showed a limited recognition of cross-scale interactions and meso-scales. Such conceptual and physical isolation risks decreasing the public support for nature conservation, cause biodiversity decline, and hence impact the generation of ecosystem services. A major future challenge is therefore to transform current conservation strategies to become a tool where urban nature is perceived, planned and managed as valuable and integrated parts of the city. To enable social-ecological synergies, future urban planning should address proactive approaches together with key components like active enhancement of multifunctional landscapes, cross-scale strategies and border zone management.
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| 2. |
- Auffret, Alistair
(författare)
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The role of past and present management in the seed dispersal of grassland plants in the rural landscape
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The destruction and fragmentation of semi-natural grasslands due toagricultural industrialisation during the past 150 years has had seriousconsequences for biodiversity in the rural landscape. Currently, plantcommunities are usually better explained by historical than by presentday landscape configurations, and the ability for plant species todisperse in space and in time, within and between remaining habitatfragments or to restoration sites will be an important factor in thefuture diversity in the landscape. Here, I present a landscape scaleseed bank and seed rain experiment covering semi-natural grasslands,pastures on former arable fields, abandoned grasslands and smallremnant habitats. The results suggest that in addition to grasslandspecialists remaining in the field layer of abandoned grasslands,remnant seed banks have the potential to be important contributors tothe future diversity of the rural landscape. However, unsuitablegrazing intensities in current pastures are limiting the potential fordispersal of target species across the landscape. Despite large changesin agricultural practice, there still exists the opportunity for human-mediated seed dispersal to increase functional connectivity infragmented landscapes, and I also present a review article in which Iassess past and present human-mediated seed dispersal vectors, andgive recommendations for management and further research.
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| 3. |
- Kalumanga, Elikana, 1975-
(författare)
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How elephants utilize a miombo-wetland ecosystem in Ugalla landscape, Western Tanzania
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- African elephants are ‘keystone’ species with respect to biodiversity conservation in Africa since they maintain habitats that support several animal communities by changing vegetation structure through foraging and by dispersing seeds between landscapes. Elephants are also ‘flagship’ species because, given their impressive size, they can make people sympathetic and stimulate local and international concerns for their protection. Economically, elephants contribute to national revenues as tourists are willing to pay to watch them. Despite all these factors, little is known however about elephant movement and how they utilize resources, especially in miombo-wetland ecosystems. This thesis investigates how elephants utilize resources in a miombo-wetland ecosystem in the Ugalla landscape of Western Tanzania over different protected areas containing different resource users. Using Global Positioning System (GPS) collars fitted to six elephants, it was observed that some elephant families are not confined in one protected area in the Ugalla landscape. Rather, they moved readily between different protected areas. Elephant movements were restricted to areas near the rivers, especially the Ugalla River, during the dry season and were dispersed widely during the wet season. As they move, elephants in the miombo woodlands of Ugalla selected the most abundant woody plants for browsing. Common to many woody plants, the browsed plants were short of mineral nutrients (e.g., sodium, calcium). Elephants obtained additional minerals by eating soils from certain termite mounds. Soils from termite mounds are richer in mineral elements (e.g., sodium, calcium, iron) compared to soils from the surrounding flood plain or compared to the browsed plants. However, the recorded termite mounds from which elephants eat soils were not evenly distributed in the landscape but confined mainly to the flood plains in the Ugalla Game Reserve. The Ugalla River, which is the main source of water for the elephants and other animals and also supports fishing activities by the local people in Ugalla during the dry seasons, is infested by the water hyacinth (Eichhornia crassipes). Such infestation potentially limits access to these precious surface water supplies. In addition at the regional level, the Ugalla River is among the major rivers that flow into the Lake Tanganyika which is shared by the countries of Tanzania, Burundi, Democratic Republic of Congo and Zambia. Thus, the spread of water hyacinth if left unchecked threatens to impact Lake Tanganyika, affecting many countries and ecosystem services. This thesis highlights that sustainable conservation of biodiversity in different protected areas in the Ugalla landscape requires an integrated management approach that will embrace conservation of different interrelated landscape resources required by both wildlife and the rural poor populations for their livelihoods. Regular coordinated wildlife anti-poaching patrols should be initiated across the entire Ugalla landscape because the elephants, among other wildlife, utilize different protected areas in Ugalla. Local communities should also be engaged in conservation initiatives (e.g., controlling the spread of the water hyacinth) as these directly impact local livelihoods.
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| 4. |
- Kapás, Rozália E., 1988-
(författare)
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Grassland restoration : Connectivity, plant community change and cows
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The ecological significance of semi-natural grasslands is high because these habitats provide a home for a diverse flora and fauna and support a range of associated ecosystem services. Due to large-scale land-use changes the extent of grassland habitat has declined. Hence, restoration efforts to mitigate grassland losses are now being prioritized across the globe and there is an increasing need to understand the drivers behind the recovery of degraded habitats. Since many restoration initiatives rely on spontaneous dispersal of plant species from sources at both local- and landscape-scales, community assembly is influenced by a range of factors which interact both over time and across spatial scales. Given this complexity over the scales, gaps remain in our understanding of how post-restoration management can be designed to facilitate the effective dispersal and establishment of target species in restored grasslands.In this thesis, I examined colonization patterns in Swedish grasslands by comparing plant communities in both ancient and restored grasslands and under contrasting management regimes. At small spatial scales and over the short-term following restoration, I investigated species recruitment sources and their relative contribution to colonization and regeneration. At larger temporal and spatial scales, I examined how the composition of vegetation and seed bank communities is determined by local environmental factors together with distance to species pool and presence of grazing livestock.I found that species mostly colonized spatially from local species sources through seed rain. The seed bank contributed to species colonization to a greater extent in ancient grasslands than in restored grasslands. Management through livestock grazing and shorter distance to species pool were positively associated with the number of species found in grasslands. Grazing livestock facilitated target species establishment into restored sites and the differences between ancient and restored grassland communities were smaller when grazing was active, highlighting that ancient sites can provide a source of colonizing species for restored sites. I found that plant species associated with former land-use declined immediately following restoration, while the occurrence of target species generally increased. However, there was a high initial stochasticity in the establishment of the target species and communities in restored grasslands were still distinct from continuously managed sites even after several decades.These results demonstrate that species presence in nearby ancient grasslands and potential dispersal from the local seed sources drives species colonization in restored and ancient grasslands. Livestock grazing was shown to be an important driver of grassland recovery, either by mediating spatial dispersal of seeds or improving site conditions for establishment. Target species are able to accumulate in the vegetation and seed bank over the long-term, as restored grasslands age. This accumulation will ensure an increasing resilience of grassland communities against future disturbances or changes in the climate. However this depends upon active management, for example by implementing management plans which include continued livestock grazing, and upon conserving remaining ancient grasslands as hotspots for biodiversity within the wider landscape.
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| 5. |
- Reimark, Josefin, 1962-
(författare)
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How has time and space affected plant biodiversity in the Hjälmö-Lådna archipelago?
- 2011
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Traditionally European farmland management has declined during the last century, mainlydue to abandonment or intensification. When traditional management is replaced by newmethods many species are negatively affected and often threatened with extinction. In thisthesis, the Stockholm archipelago is used as a platform to study the effects of land use changeover time. The overall aim is to examine how time and space affects plant biodiversity in arural landscape, with focus on heterogeneous pastures.Historical records and maps were interpreted together with aerial photos and used to constructfour time-layers of land use: reflecting the landscape 200 years ago, 100 years ago, 50 yearsago and present. Investigations of plant species richness was conducted in seven habitats; 1)grazed fields, 2) grazed forest edges, 3) grazed forest interior, 4) former grazed fields, 5)former grazed forest edges, 6) former grazed forest interior, and 7) historical pasture islands,on 35 islands in Hjälmö-Lådna archipelago on the east-coast of Sweden. Plant speciesrichness was measured for all plant species and for grassland specialist species at three scales:i) fine-scale diversity (α div), ii) large-scale diversity (γ div ), and iii) spatial turnover (β div).Using Structural Equation Models (SEM) the variation in species diversity and plantcommunity composition was investigated in relation to landscape context, space andmanagement history.The land use change in the Hjälmö-Lådna archipelago followed the general trends on themainland in Sweden and the rest of Europe with loss of traditional managed habitats, such asmeadows or wooded pastures. However, no intensification and large-scale agriculture hasdeveloped on the islands, mainly because of physical limitations, but also because ofeconomical and conservation reasons. Surprisingly, the grazing pressure on the remaininggrazed habitats had not changed notable over the last century; although the study area was notparticularly species rich (highest average was 15 species/ m2 in grazed fields). Adjacenthabitats; field and wood pasture, showed a higher similarity in community composition thanexpected compared to random pairs. Grazing and proportion of openness had a positiveinfluence on species richness and especially on grassland specialists. The variation of totaldiversity at the landscape scale was best explained by the heterogeneity of grazed forest edgesand the local species diversity in fields.The results from the study suggest that grazing is important also in species-poor landscapes,and that it can aid in protecting and promote species-richness also in other types of speciespoorlandscapes. To prevent further loss of biodiversity it is necessary to keep fields andforest edges open with continuous management. To maintain values of high biodiversity andculture in the archipelago it is therefore important that farmers are subsidised by EU tocontinue to grazie heterogeneous habitats and pastures with many trees.
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| 6. |
- Waldén, Emelie, 1984-
(författare)
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Restoration of semi-natural grasslands : Impacts on biodiversity, ecosystem services and stakeholder perceptions
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Humans play a major role shaping the living conditions for not only ourselves, but also all other species on Earth. In fact, some species-rich habitat types require human management to uphold the biodiversity and related ecosystem services. One of the world’s most biodiverse habitats on small spatial scales, semi-natural grasslands, have been formed over the course of centuries through extensive grazing and mowing. However, due to political and economic reasons, up to 90% of the European semi-natural grasslands have been lost during the 20th century. To counteract these drastic losses, restoration actions are implemented in environmental policies across Europe. Yet, knowledge of the long-term restoration effects on biodiversity and ecosystem services is still limited. The vast need for future restoration also requires a better understanding of how different pre-conditions affect the restoration outcome, as well as how stakeholders perceive restoration, to be able to prioritise between sites and recognise the limitations of the restoration process. In this thesis, I examine restoration outcomes in Swedish semi-natural grasslands, in terms of plant diversity, associated ecosystem services and from the farmers’ and land-owners’ perspective. The outcome is also analysed in relation to environmental factors at the local and landscape scale. I found that the overall community composition recovered to resemble intact reference communities, but it took relatively long time (12-20 years). Moreover, the reference sites still had higher species richness both at large and small spatial scales, more grassland specialist species and a higher abundance of plant species important to the five tested ecosystem services (meat production, pollination, water retention, temperature regulation and cultural heritage). My results show that prioritising large, unfertilised, newly abandoned grasslands situated in landscapes containing a large grassland specialist species pool and high amounts of intact and remnant semi-natural grasslands, could speed up the plant recovery. However, prioritising fast results does not necessarily ensure long-term success at a larger spatial scale. Since restoration success can be interpreted differently depending on evaluation measure used, pre-defined, clear and realistic goals are essential. While the surveyed farmers and landowners overall perceived the restoration as successful, 40% were unsure whether the grasslands will be managed in the future. Low profitability still poses a threat to their maintenance and thus, also to the coupled biodiversity and ecosystem services. Policy changes are therefore urgently needed to facilitate incentives for sustained management of restored and intact European semi-natural grasslands in a long-term perspective.
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