| 1. |
- Hagenblad, Jenny, et al.
(author)
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Low genetic diversity despite multipleintroductions of the invasive plant species Impatiens glandulifera in Europe
- 2015
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In: BMC Genetics. - : Springer Science and Business Media LLC. - 1471-2156. ; 16:103
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Journal article (peer-reviewed)abstract
- Background: Invasive species can be a major threat to native biodiversity and the number of invasive plant speciesis increasing across the globe. Population genetic studies of invasive species can provide key insights into theirinvasion history and ensuing evolution, but also for their control. Here we genetically characterise populations ofImpatiens glandulifera, an invasive plant in Europe that can have a major impact on native plant communities. Wecompared populations from the species’ native range in Kashmir, India, to those in its invaded range, along alatitudinal gradient in Europe. For comparison, the results from 39 other studies of genetic diversity in invasivespecies were collated.Results: Our results suggest that I. glandulifera was established in the wild in Europe at least twice, from an areaoutside of our Kashmir study area. Our results further revealed that the genetic diversity in invasive populations ofI. glandulifera is unusually low compared to native populations, in particular when compared to other invasivespecies. Genetic drift rather than mutation seems to have played a role in differentiating populations in Europe. Wefind evidence of limitations to local gene flow after introduction to Europe, but somewhat less restrictions in thenative range. I. glandulifera populations with significant inbreeding were only found in the species’ native rangeand invasive species in general showed no increase in inbreeding upon leaving their native ranges. In Europe wedetect cases of migration between distantly located populations. Human activities therefore seem to, at leastpartially, have facilitated not only introductions, but also further spread of I. glandulifera across Europe.Conclusions: Although multiple introductions will facilitate the retention of genetic diversity in invasive ranges,widespread invasive species can remain genetically relatively invariant also after multiple introductions. Phenotypicplasticity may therefore be an important component of the successful spread of Impatiens glandulifera across Europe.
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| 2. |
- Jenny, Jean Philippe, et al.
(author)
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Scientists’ Warning to Humanity: Rapid degradation of the world's large lakes
- 2020
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In: Journal of Great Lakes Research. - : Elsevier BV. - 0380-1330. ; 46:4, s. 686-702
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Research review (peer-reviewed)abstract
- © 2020 The Authors Large lakes of the world are habitats for diverse species, including endemic taxa, and are valuable resources that provide humanity with many ecosystem services. They are also sentinels of global and local change, and recent studies in limnology and paleolimnology have demonstrated disturbing evidence of their collective degradation in terms of depletion of resources (water and food), rapid warming and loss of ice, destruction of habitats and ecosystems, loss of species, and accelerating pollution. Large lakes are particularly exposed to anthropogenic and climatic stressors. The Second Warning to Humanity provides a framework to assess the dangers now threatening the world's large lake ecosystems and to evaluate pathways of sustainable development that are more respectful of their ongoing provision of services. Here we review current and emerging threats to the large lakes of the world, including iconic examples of lake management failures and successes, from which we identify priorities and approaches for future conservation efforts. The review underscores the extent of lake resource degradation, which is a result of cumulative perturbation through time by long-term human impacts combined with other emerging stressors. Decades of degradation of large lakes have resulted in major challenges for restoration and management and a legacy of ecological and economic costs for future generations. Large lakes will require more intense conservation efforts in a warmer, increasingly populated world to achieve sustainable, high-quality waters. This Warning to Humanity is also an opportunity to highlight the value of a long-term lake observatory network to monitor and report on environmental changes in large lake ecosystems.
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| 3. |
- Reinecke, J., et al.
(author)
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Acido- and neutrophilic temperate forest plants display distinct shifts in ecological pH niche across north-western Europe
- 2016
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In: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 39:12, s. 1164-1175
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Journal article (peer-reviewed)abstract
- Ecological niches of organisms vary across geographical space, but niche shift patterns between regions and the underlying mechanisms remain largely unexplored. We studied shifts in the pH niche of 42 temperate forest plant species across a latitudinal gradient from northern France to boreo-nemoral Sweden. We asked 1) whether species restrict their niches with increasing latitude as they reach their northern range margin (environmental constraints); 2) whether species expand their niches with increasing latitude as regional plant species richness decreases (competitive release); and 3) whether species shift their niche position toward more acidic sites with increasing latitude as the relative proportion of acidic soils increases (local adaptation). Based on 1458 vegetation plots and corresponding soil pH values, we modelled species response curves using Huisman-Olff-Fresco models. Four niche measures (width, position, left and right border) were compared among regions by randomization tests. We found that with increasing latitude, neutrophilic species tended to retreat from acidic sites, indicating that these species retreat to more favorable sites when approaching their range margin. Alternatively, these species might benefit from enhanced nitrogen deposition on formerly nutrient-poor, acidic sites in southern regions or lag behind in post-glacial recolonization of potential habitats in northern regions. Most acidophilic species extended their niche toward more base-rich sites with increasing latitude, indicating competitive release from neutrophilic species. Alternatively, acidophilic species might benefit from optimal climatic conditions in the north where some have their core distribution area. Shifts in the niche position suggested that local adaptation is of minor importance. We conclude that shifts in the pH niche of temperate forest plants are the rule, but the directions of the niche shifts and possible explanations vary. Our study demonstrates that differentiating between acidophilic and neutrophilic species is crucial to identify general patterns and underlying mechanisms.
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| 4. |
- De Frenne, Pieter, et al.
(author)
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Interregional variation in the floristic recovery of post-agricultural forests
- 2011
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In: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745. ; 99:2, s. 600-609
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Journal article (peer-reviewed)abstract
- 1. Worldwide, the floristic composition of temperate forests bears the imprint of past land use for decades to centuries as forests regrow on agricultural land. Many species, however, display significant interregional variation in their ability to (re)colonize post-agricultural forests. This variation in colonization across regions and the underlying factors remain largely unexplored. 2. We compiled data on 90 species and 812 species x study combinations from 18 studies across Europe that determined species' distribution patterns in ancient (i.e. continuously forested since the first available land use maps) and post-agricultural forests. The recovery rate (RR) of species in each landscape was quantified as the log-response ratio of the percentage occurrence in post-agricultural over ancient forest and related to the species-specific life-history traits and local (soil characteristics and light availability) and regional factors (landscape properties as habitat availability, time available for colonization, and climate). 3. For the herb species, we demonstrate a strong (interactive) effect of species' life-history traits and forest habitat availability on the RR of post-agricultural forest. In graminoids, however, none of the investigated variables were significantly related to the RR. 4. The better colonizing species that mainly belonged to the short-lived herbs group showed the largest interregional variability. Their recovery significantly increased with the amount of forest habitat within the landscape, whereas, surprisingly, the time available for colonization, climate, soil characteristics and light availability had no effect. 5. Synthesis. By analysing 18 independent studies across Europe, we clearly showed for the first time on a continental scale that the recovery of short-lived forest herbs increased with the forest habitat availability in the landscape. Small perennial forest herbs, however, were generally unsuccessful in colonizing post-agricultural forest even in relatively densely forested landscapes. Hence, our results stress the need to avoid ancient forest clearance to preserve the typical woodland flora.
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| 5. |
- Wasof, Safaa, et al.
(author)
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Ecological niche shifts of understorey plants along a latitudinal gradient of temperate forests in north-western Europe
- 2013
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In: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 22:10, s. 1130-1140
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Journal article (peer-reviewed)abstract
- Aim In response to environmental changes and to avoid extinction, species may either track suitable environmental conditions or adapt to the modified environment. However, whether and how species adapt to environmental changes remains unclear. By focusing on the realized niche (i.e. the actual space that a species inhabits and the resources it can access as a result of limiting biotic factors present in its habitat), we here examine shifts in the realized-niche width (i.e. ecological amplitude) and position (i.e. ecological optimum) of 26 common and widespread forest understorey plants across their distributional ranges. Location Temperate forests along a ca. 1800-km-long latitudinal gradient from northern France to central Sweden and Estonia. Methods We derived species' realized-niche width from a -diversity metric, which increases if the focal species co-occurs with more species. Based on the concept that species' scores in a detrended correspondence analysis (DCA) represent the locations of their realized-niche positions, we developed a novel approach to run species-specific DCAs allowing the focal species to shift its realized-niche position along the studied latitudinal gradient while the realized-niche positions of other species were held constant. Results None of the 26 species maintained both their realized-niche width and position along the latitudinal gradient. Few species (9 of 26: 35%) shifted their realized-niche width, but all shifted their realized-niche position. With increasing latitude, most species (22 of 26: 85%) shifted their realized-niche position for soil nutrients and pH towards nutrient-poorer and more acidic soils. Main conclusions Forest understorey plants shifted their realized niche along the latitudinal gradient, suggesting local adaptation and/or plasticity. This macroecological pattern casts doubt on the idea that the realized niche is stable in space and time, which is a key assumption of species distribution models used to predict the future of biodiversity, hence raising concern about predicted extinction rates.
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