| 1. |
- Hagenblad, Jenny, et al.
(författare)
-
Low genetic diversity despite multipleintroductions of the invasive plant species Impatiens glandulifera in Europe
- 2015
-
Ingår i: BMC Genetics. - : Springer Science and Business Media LLC. - 1471-2156. ; 16:103
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 2. |
- Lemke, Isgard H., et al.
(författare)
-
Patterns of phenotypic trait variation in two temperate forest herbs along a broad climatic gradient
- 2015
-
Ingår i: Plant Ecology. - : Springer Science and Business Media LLC. - 1385-0237 .- 1573-5052. ; 216:11, s. 1523-1536
-
Tidskriftsartikel (refereegranskat)abstract
- Phenotypic trait variation plays a major role in the response of plants to global environmental change, particularly in species with low migration capabilities and recruitment success. However, little is known about the variation of functional traits within populations and about differences in this variation on larger spatial scales. In a first approach, we therefore related trait expression to climate and local environmental conditions, studying two temperate forest herbs, Milium effusum and Stachys sylvatica, along a similar to 1800-2500 km latitudinal gradient. Within each of 9-10 regions in six European countries, we collected data from six populations of each species and recorded several variables in each region (temperature, precipitation) and population (light availability, soil parameters). For each plant, we measured height, leaf area, specific leaf area, seed mass and the number of seeds and examined environmental effects on within-population trait variation as well as on trait means. Most importantly, trait variation differed both between and within populations. Species, however, differed in their response. Intrapopulation variation in Milium was consistently positively affected by higher mean temperatures and precipitation as well as by more fertile local soil conditions, suggesting that more productive conditions may select for larger phenotypic variation. In Stachys, particularly light availability positively influenced trait variation, whereas local soil conditions had no consistent effects. Generally, our study emphasises that intra-population variation may differ considerably across larger scales-due to phenotypic plasticity and/or underlying genetic diversity-possibly affecting species response to global environmental change.
|
|
| 3. |
- Lindborg, Regina, et al.
(författare)
-
Investigating biodiversity trajectories using scenarios – Lessons from two contrasting agricultural landscapes
- 2009
-
Ingår i: Journal of Environmental Management. - : Elsevier BV. - 0301-4797 .- 1095-8630. ; 91:2, s. 499-508
-
Tidskriftsartikel (refereegranskat)abstract
- Agriculture is the major land use at a global scale. In addition to food production, multifunctionality of landscapes, including values and ecosystem services like biodiversity, recreation and culture, is now focus for management. This study explores how a scenario approach, involving different stakeholders, may help to improve landscape management for biodiversity conservation. Local farmers and executives at the County Administrative Board were invited to discuss rural development and conditions for farmland biodiversity in two Swedish landscapes. The potential biodiversity for three future land use scenarios for the two landscapes was discussed: nature conservation, outdoor recreation and energy production, and compared with current and historical landscapes in each region. Analyses of habitat areas, connectedness and landscape diversity suggested that the energy and recreation scenarios had a negative impact on farmland biodiversity, whereas the nature conservation scenario, the current and historically reconstructed landscapes had a higher potential for biodiversity. The farmers appreciated the nature conservation scenario, but also the energy production scenario and they highlighted the need of increased subsidies for management of biodiversity. The farmers in the high production area were less interested in nature quality per se. The executives had similar opinions as the farmers, but disagreed on the advantages with energy production, as this would be in conflict with the high biodiversity and recreational values. The local physical and socio-economical conditions differ between landscapes and potentially shaped the stakeholders emotional attachment to the local environment, their opinions and decisions on how to manage the land. We stress the importance of incorporating local knowledge, visions and regional prerequisites for different land uses in conservation, since site and landscape specific planning for biodiversity together with a flexible subsidy system are necessary to reach the conservation goals within EU.
|
|
| 4. |
- Plue, Jan, et al.
(författare)
-
Green infrastructure can promote plant functional connectivity in a grassland species around fragmented semi-natural grasslands in NW-Europe
- 2022
-
Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 2022:10
-
Tidskriftsartikel (refereegranskat)abstract
- Species may benefit from green infrastructure, i.e. the network of natural and anthropogenic habitat remnants in human-dominated landscapes, if it helps isolated populations in remaining habitat patches to be functionally connected. The importance of green infrastructure is therefore increasingly emphasized in conservation policy to counter biodiversity loss. However, there is limited evidence, particularly in plants, that green infrastructure promotes functional connectivity, i.e. supports the colonization of habitat patches across a landscape. We applied landscape genetics to test whether the green infrastructure supports structural and functional connectivity in the grassland perennial Galium verum, in 35 landscapes in Belgium, Germany and Sweden. We used multivariate genetic clustering techniques, nestedness analyses and conditional inference trees to examine landscape-scale patterns in genetic diversity and structure of plant populations in the green infrastructure surrounding semi-natural grasslands. Inferred functional connectivity explained genetic variation better than structural connectivity, yielding positive effects on genetic variation. The road verge network, a major structural component of the green infrastructure and its functional connectivity, most effectively explained genetic diversity and composition in G. verum. Galium verum ramets occupying the surrounding landscape proved to be genetic subsets of focal grassland populations, shaping a nested landscape population genetic structure with focal grasslands, particularly ancient ones, harbouring unique genetic diversity. This nested pattern weakened as road network density increased, suggesting road verge networks enable high landscape occupancy by increased habitat availability and facilitates gene flow into the surrounding landscape. Our study proposes that green infrastructure can promote functional connectivity, providing that a plant species can survive outside of core habitat patches. As this often excludes habitat specialist species, conservation practice and policy should primarily focus on ancient, managed semi-natural grasslands. These grasslands both harbour unique genetic diversity and act as primary gene and propagule sources for the surrounding landscape, highlighting their conservation value.
|
|
| 5. |
- Caron, M. M., et al.
(författare)
-
Latitudinal variation in seeds characteristics of Acer platanoides and A. pseudoplatanus
- 2014
-
Ingår i: Plant Ecology. - : Springer Science and Business Media LLC. - 1385-0237 .- 1573-5052. ; 215:8, s. 911-925
-
Tidskriftsartikel (refereegranskat)abstract
- Climate change will likely affect population dynamics of numerous plant species by modifying several aspects of the life cycle. Because plant regeneration from seeds may be particularly vulnerable, here we assess the possible effects of climate change on seed characteristics and present an integrated analysis of seven seed traits (nutrient concentrations, samara mass, seed mass, wing length, seed viability, germination percentage, and seedling biomass) of Acer platanoides and A. pseudoplatanus seeds collected along a wide latitudinal gradient from Italy to Norway. Seed traits were analyzed in relation to the environmental conditions experienced by the mother trees along the latitudinal gradient. We found that seed traits of A. platanoides were more influenced by the climatic conditions than those of A. pseudoplatanus. Additionally, seed viability, germination percentage, and seedling biomass of A. platanoides were strongly related to the seed mass and nutrient concentration. While A. platanoides seeds were more influenced by the environmental conditions (generally negatively affected by rising temperatures), compared to A. pseudoplatanus, A. platanoides still showed higher germination percentage and seedling biomass than A. pseudoplatanus. Thus, further research on subsequent life-history stages of both species is needed. The variation in seed quality observed along the climatic gradient highlights the importance of studying the possible impact of climate change on seed production and species demography.
|
|
| 6. |
- Lindborg, Regina, et al.
(författare)
-
A landscape perspective on conservation of semi-natural grasslands.
- 2008
-
Ingår i: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809. ; 125:1-4, s. 213-222
-
Tidskriftsartikel (refereegranskat)abstract
- Current agri-environmental schemes and subsidies for conservation and restoration of semi-natural grasslands do not explicitly assess land use changes affecting whole landscapes, but have so far focused on single objects and small areas. In this paper, we discuss a landscape perspective versus a “single object” perspective when conserving semi-natural grassland in agricultural landscapes. The focus is on the values biodiversity, cultural heritage, a vital countryside, and effects on economy when land use changes. We conclude that when land use change in the landscape surrounding an object, important additional effects on the different values are found. For example, a countryside where animals graze former arable fields and where marginal habitats are managed will have a positive effect, not only on the biodiversity associated to semi-natural grasslands, but also for the image of a vital and dynamic landscape. An increased number of roads, on the other hand, may negatively affect cultural heritage and decrease biodiversity in grasslands, leading to negative effects on the value of common goods through isolation. Placing objects in a larger spatial context and combining several different aspects into a landscape perspective, will improve long-term preservation of values associated to semi-natural grasslands.
|
|
| 7. |
- Maes, Sybryn L., et al.
(författare)
-
Effects of enhanced nitrogen inputs and climate warming on a forest understorey plant assessed by transplant experiments along a latitudinal gradient
- 2014
-
Ingår i: Plant Ecology. - : Springer Science and Business Media LLC. - 1385-0237 .- 1573-5052. ; 215:8, s. 899-910
-
Tidskriftsartikel (refereegranskat)abstract
- Global warming and enhanced nitrogen (N) inputs are two key global-change drivers affecting temperate forest ecosystems simultaneously. Interactive effects of multiple drivers might cause species responses to differ from those in single-factor experiments; therefore, there is an urgent need for more multi-factor studies. Here, we assessed the growth and reproductive performance of multiple populations of a widespread grass of deciduous forests (Milium effusum) sampled along a latitudinal gradient and subjected to experimental manipulations of temperature and nitrogen availability. Common garden transplant experiments along the latitudinal gradient were used to manipulate temperatures and combined with experimental N addition to assess intraspecific responses of the study species to global-change drivers as well as to determine local adaptation. The total biomass, number of seeds and seedling emergence time of M. effusum increased when transplanted in the southern common garden. Apart from effects on the seed mass, the species did not respond to N addition alone. Yet, interactive effects between warming and N addition were found: N addition led to increased biomass growth but only in the northern common garden. Significant home-site advantages were apparent, most likely because of increased mycorrhizal colonization of roots of local transplants. We show that multiple global-change drivers may alter dynamics in understorey communities of temperate forests. Our study reinforces the need to increase our understanding of plant responses to future environmental changes by expanding the multi-factor research framework.
|
|
| 8. |
- Ehrmann, Steffen, et al.
(författare)
-
Habitat properties are key drivers of Borrelia burgdorferi (s.l.) prevalence in Ixodes ricinus populations of deciduous forest fragments
- 2018
-
Ingår i: Parasites & Vectors. - : Springer Science and Business Media LLC. - 1756-3305. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe tick Ixodes ricinus has considerable impact on the health of humans and other terrestrial animals because it transmits several tick-borne pathogens (TBPs) such as B. burgdorferi (sensu lato), which causes Lyme borreliosis (LB). Small forest patches of agricultural landscapes provide many ecosystem services and also the disservice of LB risk. Biotic interactions and environmental filtering shape tick host communities distinctively between specific regions of Europe, which makes evaluating the dilution effect hypothesis and its influence across various scales challenging. Latitude, macroclimate, landscape and habitat properties drive both hosts and ticks and are comparable metrics across Europe. Therefore, we instead assess these environmental drivers as indicators and determine their respective roles for the prevalence of B. burgdorferi in I. ricinus.MethodsWe sampled I. ricinus and measured environmental properties of macroclimate, landscape and habitat quality of forest patches in agricultural landscapes along a European macroclimatic gradient. We used linear mixed models to determine significant drivers and their relative importance for nymphal and adult B. burgdorferi prevalence. We suggest a new prevalence index, which is pool-size independent.ResultsDuring summer months, our prevalence index varied between 0 and 0.4 per forest patch, indicating a low to moderate disservice. Habitat properties exerted a fourfold larger influence on B. burgdorferi prevalence than macroclimate and landscape properties combined. Increasingly available ecotone habitat of focal forest patches diluted and edge density at landscape scale amplified B. burgdorferi prevalence. Indicators of habitat attractiveness for tick hosts (food resources and shelter) were the most important predictors within habitat patches. More diverse and abundant macro and microhabitat had a diluting effect, as it presumably diversifies the niches for tick-hosts and decreases the probability of contact between ticks and their hosts and hence the transmission likelihood.ConclusionsDiluting effects of more diverse habitat patches would pose another reason to maintain or restore high biodiversity in forest patches of rural landscapes. We suggest classifying habitat patches by their regulating services as dilution and amplification habitat, which predominantly either decrease or increase B. burgdorferi prevalence at local and landscape scale and hence LB risk. Particular emphasis on promoting LB-diluting properties should be put on the management of those habitats that are frequently used by humans. In the light of these findings, climate change may be of little concern for LB risk at local scales, but this should be evaluated further.
|
|
| 9. |
- Plue, Jan, et al.
(författare)
-
Where does the community start, and where does it end? Including the seed bank to reassess forest herb layer responses to the environment
- 2017
-
Ingår i: Journal of Vegetation Science. - : Wiley. - 1100-9233 .- 1654-1103. ; 28:2, s. 424-435
-
Tidskriftsartikel (refereegranskat)abstract
- QuestionBelow-ground processes are key determinants of above-ground plant population and community dynamics. Still, our understanding of how environmental drivers shape plant communities is mostly based on above-ground diversity patterns, bypassing below-ground plant diversity stored in seed banks. As seed banks may shape above-ground plant communities, we question whether concurrently analysing the above- and below-ground species assemblages may potentially enhance our understanding of community responses to environmental variation. LocationTemperate deciduous forests along a 2000km latitudinal gradient in NW Europe. MethodsHerb layer, seed bank and local environmental data including soil pH, canopy cover, forest cover continuity and time since last canopy disturbance were collected in 129 temperate deciduous forest plots. We quantified herb layer and seed bank diversity per plot and evaluated how environmental variation structured community diversity in the herb layer, seed bank and the combined herb layer-seed bank community. ResultsSeed banks consistently held more plant species than the herb layer. How local plot diversity was partitioned across the herb layer and seed bank was mediated by environmental variation in drivers serving as proxies of light availability. The herb layer and seed bank contained an ever smaller and ever larger share of local diversity, respectively, as both canopy cover and time since last canopy disturbance decreased. Species richness and -diversity of the combined herb layer-seed bank community responded distinctly differently compared to the separate assemblages in response to environmental variation in, e.g. forest cover continuity and canopy cover. ConclusionsThe seed bank is a below-ground diversity reservoir of the herbaceous forest community, which interacts with the herb layer, although constrained by environmental variation in e.g. light availability. The herb layer and seed bank co-exist as a single community by means of the so-called storage effect, resulting in distinct responses to environmental variation not necessarily recorded in the individual herb layer or seed bank assemblages. Thus, concurrently analysing above- and below-ground diversity will improve our ecological understanding of how understorey plant communities respond to environmental variation.
|
|
| 10. |
- Valdés, Alicia, et al.
(författare)
-
The contribution of patch-scale conditions is greater than that of macroclimate in explaining local plant diversity in fragmented forests across Europe
- 2015
-
Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 24:9, s. 1094-1105
-
Tidskriftsartikel (refereegranskat)abstract
- AimMacroclimate is a major determinant of large-scale diversity patterns. However, the influence of smaller-scale factors on local diversity across large spatial extents is not well documented. Here, we quantify the relative importance of local (patch-scale), landscape-scale and macroclimatic drivers of herbaceous species diversity in small forest patches in agricultural landscapes across Europe. LocationDeciduous forest patches in eight regions along a macroclimatic gradient from southern France to central Sweden and Estonia. MethodsThe diversity of forest specialists and generalists at three levels (whole forest patch, sampling plots within patches and between scales) was related to patch-scale (forest area, age, abiotic and biotic heterogeneity), landscape-scale (amount of forest, grasslands and hedgerows around the patch, patch isolation) and macroclimatic variables (temperature and precipitation) using generalized linear mixed models and variation partitioning for each group of variables. ResultsThe total amount of explained variation in diversity ranged from 8% for plot-scale diversity of generalists to 54% for patch-scale diversity of forest specialists. Patch-scale variables always explained more than 60% of the explained variation in diversity, mainly due to the positive effect of within-patch heterogeneity on patch-scale and between-scale diversities and to the positive effect of patch age on plot-scale diversity of forest specialists. Landscape-scale variables mainly contributed to the amount of explained variation in plot-scale diversity, being more important for forest specialists (21%) than for generalists (18%). Macroclimatic variables contributed a maximum of 11% to the plot-scale diversity of generalists. Main conclusionsMacroclimate poorly predicts local diversity across Europe, and herbaceous diversity is mainly explained by habitat features, less so by landscape structure. We show the importance of conserving old forest patches as refugia for typical forest species, and of enhancing the landscape context around the patches by reducing the degree of disturbance caused by agriculture.
|
|
