Citation: Vandvik, V., I. E. Må ren, H. J. Ndangalasi, J. Taplin, F. Mbago, and J. C. Lovett. 201... more Citation: Vandvik, V., I. E. Må ren, H. J. Ndangalasi, J. Taplin, F. Mbago, and J. C. Lovett. 2014. Back to Africa: monitoring post-hydropower restoration to facilitate reintroduction of an extinct-in-the-wild amphibian. Ecosphere 5(8):95. http://dx. Abstract. Monitoring of the ecological efficiency of different restoration and mitigation measures is important to inform decision-making but can be challenging, especially in remote and low-resource settings. Species composition of the vegetation is sensitive to environmental variation, and can thus be used in restoration assessment, but this requires statistical approaches that can accommodate multivariate responses. We use principal response curves (PRC) to assess the efficiency of post-hydropower mitigation measures installed to secure the reintroduction of an extinct-in-the-wild amphibian back into its only native habitat. The endemic ovoviviparous Kihansi spray toad Nectophrynoides asperginis is only known from a wetland in the Lower Kihansi River Gorge in the Eastern Arc Mountains in Tanzania. River flow was diverted from the gorge for hydropower production in 1999, causing the spray wetland to desiccate, consequently threatening the toad and other plant and animal species dependent on the spray-zone habitat. To mitigate the toad population collapse, a sprinkler system was installed over a limited section of the original spray-zone wetlands to mimic the waterfall spray and toads were taken to the USA for ex situ breeding. The decline, extinction, ex situ breeding, and planned reintroduction of the species has driven substantial research on Kihansi spray toad biology. In contrast, the efficiency of the mitigation measures in restoring the spray-zone wetland habitat required for its successful reintroduction has not been formally evaluated. Here, we analyze re-sampled vegetation data from the spray-zone wetland over a period of eight years by means of principal response curves to investigate if the post-hydropower mitigation measures have successfully restored the pre-hydropower ecosystem. The results show that the spray-zone vegetation is recovering. The wetland flora and especially species important to the Kihansi spray toad have increased and the restored ecosystem has stabilized, favoring the reintroduction of the Kihansi spray toad to its native habitat. However, the wetland ecosystem is not restored entirely and continued mitigation measures are needed. Continued monitoring is essential to support evidence-based restoration, and we conclude that assessment based on vegetation monitoring coupled with principal response curve analyses provides a cost-effective and efficient monitoring tool for such projects.
SUMMARY In a 7-year field experiment undertaken in western Norway, the efficiency of four bracken... more SUMMARY In a 7-year field experiment undertaken in western Norway, the efficiency of four bracken control measures on a heathland was investigated: applicati on of two herbicides i) Asulox®- and ii) Gratil®- with follow-up annual cutting; iii) annual cutting; and iv) biannual cutting. Assessments were also made as to what extent the characteristic species c omposition and vegetation structure of heathlands were restored, and effects of the herbicides on non -target plant species commonly found on heaths. Fastest reduction in bracken cover resulted from herbicide application, but cutting proved equally efficient in the longer term; Asulox and biannual c utting both reduced bracken cover from over 70% to below 10% in 2 years, while annual cutting achieved this in 5 years. Gratil failed to have long-term effects. Species composition progressed towards a d esirable heathland vegetation community, but successional trajectories differed, and Asulox had minor unintended effects on a number...
Background / Purpose: Individual components of fragmentation – decreased patch size, increased di... more Background / Purpose: Individual components of fragmentation – decreased patch size, increased distance from source populations, increased patch disturbance and impermeability of intervening matrix – rarely occur in isolation. We compared bird community composition in forest fragments around the Budongo Forest Reserve in western Uganda. Our prediction was that some guilds would be more affected by certain aspects of fragmentation than others. Main conclusion: We found that different fragmentation impacts have something of a cumulative effect, especially on certain guilds. Species richness and diversity measures do not show fragmentation effects.
The challenges of developing legal regimes for sustainable management of ecosystems and natural r... more The challenges of developing legal regimes for sustainable management of ecosystems and natural resources, capable of meeting the enormous pressure from an increasing world population and the demands on higher standard of living, and from the effects of climate change, is enormous. Traditional protection of ecosystems and areas, have to be combined with use and exploitation of land, forests and other biological resources in order to meet the needs of the population. To achieve this, traditional regulation and protection probably has to be substituted by more flexible, incentive based regulation stimulating innovation and higher standard of ecosystem management than one can achieve by regulation and traditional sanctions alone. Globalization has made the traditional regulation on national basis less effective as a response to the challenge and the need to develop an ecosystem management that are social equitable as well as environmentally sustainable are evident. New models for manag...
SUMMARY In a 7-year field experiment undertaken in western Norway, the efficiency of four bracken... more SUMMARY In a 7-year field experiment undertaken in western Norway, the efficiency of four bracken control measures on a heathland was investigated: applicati on of two herbicides i) Asulox®- and ii) Gratil®- with follow-up annual cutting; iii) annual cutting; and iv) biannual cutting. Assessments were also made as to what extent the characteristic species c omposition and vegetation structure of
Citation: Vandvik, V., I. E. Må ren, H. J. Ndangalasi, J. Taplin, F. Mbago, and J. C. Lovett. 201... more Citation: Vandvik, V., I. E. Må ren, H. J. Ndangalasi, J. Taplin, F. Mbago, and J. C. Lovett. 2014. Back to Africa: monitoring post-hydropower restoration to facilitate reintroduction of an extinct-in-the-wild amphibian. Ecosphere 5(8):95. http://dx. Abstract. Monitoring of the ecological efficiency of different restoration and mitigation measures is important to inform decision-making but can be challenging, especially in remote and low-resource settings. Species composition of the vegetation is sensitive to environmental variation, and can thus be used in restoration assessment, but this requires statistical approaches that can accommodate multivariate responses. We use principal response curves (PRC) to assess the efficiency of post-hydropower mitigation measures installed to secure the reintroduction of an extinct-in-the-wild amphibian back into its only native habitat. The endemic ovoviviparous Kihansi spray toad Nectophrynoides asperginis is only known from a wetland in the Lower Kihansi River Gorge in the Eastern Arc Mountains in Tanzania. River flow was diverted from the gorge for hydropower production in 1999, causing the spray wetland to desiccate, consequently threatening the toad and other plant and animal species dependent on the spray-zone habitat. To mitigate the toad population collapse, a sprinkler system was installed over a limited section of the original spray-zone wetlands to mimic the waterfall spray and toads were taken to the USA for ex situ breeding. The decline, extinction, ex situ breeding, and planned reintroduction of the species has driven substantial research on Kihansi spray toad biology. In contrast, the efficiency of the mitigation measures in restoring the spray-zone wetland habitat required for its successful reintroduction has not been formally evaluated. Here, we analyze re-sampled vegetation data from the spray-zone wetland over a period of eight years by means of principal response curves to investigate if the post-hydropower mitigation measures have successfully restored the pre-hydropower ecosystem. The results show that the spray-zone vegetation is recovering. The wetland flora and especially species important to the Kihansi spray toad have increased and the restored ecosystem has stabilized, favoring the reintroduction of the Kihansi spray toad to its native habitat. However, the wetland ecosystem is not restored entirely and continued mitigation measures are needed. Continued monitoring is essential to support evidence-based restoration, and we conclude that assessment based on vegetation monitoring coupled with principal response curve analyses provides a cost-effective and efficient monitoring tool for such projects.
SUMMARY In a 7-year field experiment undertaken in western Norway, the efficiency of four bracken... more SUMMARY In a 7-year field experiment undertaken in western Norway, the efficiency of four bracken control measures on a heathland was investigated: applicati on of two herbicides i) Asulox®- and ii) Gratil®- with follow-up annual cutting; iii) annual cutting; and iv) biannual cutting. Assessments were also made as to what extent the characteristic species c omposition and vegetation structure of heathlands were restored, and effects of the herbicides on non -target plant species commonly found on heaths. Fastest reduction in bracken cover resulted from herbicide application, but cutting proved equally efficient in the longer term; Asulox and biannual c utting both reduced bracken cover from over 70% to below 10% in 2 years, while annual cutting achieved this in 5 years. Gratil failed to have long-term effects. Species composition progressed towards a d esirable heathland vegetation community, but successional trajectories differed, and Asulox had minor unintended effects on a number...
Background / Purpose: Individual components of fragmentation – decreased patch size, increased di... more Background / Purpose: Individual components of fragmentation – decreased patch size, increased distance from source populations, increased patch disturbance and impermeability of intervening matrix – rarely occur in isolation. We compared bird community composition in forest fragments around the Budongo Forest Reserve in western Uganda. Our prediction was that some guilds would be more affected by certain aspects of fragmentation than others. Main conclusion: We found that different fragmentation impacts have something of a cumulative effect, especially on certain guilds. Species richness and diversity measures do not show fragmentation effects.
The challenges of developing legal regimes for sustainable management of ecosystems and natural r... more The challenges of developing legal regimes for sustainable management of ecosystems and natural resources, capable of meeting the enormous pressure from an increasing world population and the demands on higher standard of living, and from the effects of climate change, is enormous. Traditional protection of ecosystems and areas, have to be combined with use and exploitation of land, forests and other biological resources in order to meet the needs of the population. To achieve this, traditional regulation and protection probably has to be substituted by more flexible, incentive based regulation stimulating innovation and higher standard of ecosystem management than one can achieve by regulation and traditional sanctions alone. Globalization has made the traditional regulation on national basis less effective as a response to the challenge and the need to develop an ecosystem management that are social equitable as well as environmentally sustainable are evident. New models for manag...
SUMMARY In a 7-year field experiment undertaken in western Norway, the efficiency of four bracken... more SUMMARY In a 7-year field experiment undertaken in western Norway, the efficiency of four bracken control measures on a heathland was investigated: applicati on of two herbicides i) Asulox®- and ii) Gratil®- with follow-up annual cutting; iii) annual cutting; and iv) biannual cutting. Assessments were also made as to what extent the characteristic species c omposition and vegetation structure of
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