| 1. |
- Govaert, Sanne, et al.
(författare)
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Edge influence on understorey plant communities depends on forest management
- 2020
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Ingår i: Journal of Vegetation Science. - : Wiley. - 1100-9233 .- 1654-1103. ; 31:2, s. 281-292
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Tidskriftsartikel (refereegranskat)abstract
- Questions: Does the influence of forest edges on plant species richness and composition depend on forest management? Do forest specialists and generalists show contrasting patterns?Location: Mesic, deciduous forests across Europe.Methods: Vegetation surveys were performed in forests with three management types (unthinned, thinned 5-10 years ago and recently thinned) along a macroclimatic gradient from Italy to Norway. In each of 45 forests, we established five vegetation plots along a south-facing edge-to-interior gradient (n = 225). Forest specialist, generalist and total species richness, as well as evenness and proportion of specialists, were tested as a function of the management type and distance to the edge while accounting for several environmental variables (e.g. landscape composition and soil characteristics). Magnitude and distance of edge influence were estimated for species richness per management type.Results: Greatest total species richness was found in thinned forests. Edge influence on generalist plant species richness was contingent on the management type, with the smallest decrease in species richness from the edge-to-interior in unthinned forests. In addition, generalist richness increased with the proportion of forests in the surrounding landscape and decreased in forests dominated by tree species that cast more shade. Forest specialist species richness, however, was not affected by management type or distance to the edge, and only increased with pH and increasing proportion of forests in the landscape.Conclusions: Forest thinning affects the plant community composition along edge-to-interior transects of European forests, with richness of forest specialists and generalists responding differently. Therefore, future studies should take the forest management into account when interpreting edge-to-interior because both modify the microclimate, soil processes and deposition of polluting aerosols. This interaction is key to predict the effects of global change on forest plants in landscapes characterized by the mosaic of forest patches and agricultural land that is typical for Europe.
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| 2. |
- Meeussen, Camille, et al.
(författare)
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Structural variation of forest edges across Europe
- 2020
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 462
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Tidskriftsartikel (refereegranskat)abstract
- Forest edges are interfaces between forest interiors and adjacent land cover types. They are important elements in the landscape with almost 20% of the global forest area located within 100 m of the edge. Edges are structurally different from forest interiors, which results in unique edge influences on microclimate, functioning and biodiversity. These edge influences have been studied for multiple decades, yet there is only limited information available on how forest edge structure varies at the continental scale, and which factors drive this potential structural diversity. Here we quantified the structural variation along 45 edge-to-interior transects situated along latitudinal, elevational and management gradients across Europe. We combined state-of-the-art terrestrial laser scanning and conventional forest inventory techniques to investigate how the forest edge structure (e.g. plant area index, stem density, canopy height and foliage height diversity) varies and which factors affect this forest edge structural variability. Macroclimate, management, distance to the forest edge and tree community composition all influenced the forest edge structural variability and interestingly we detected interactive effects of our predictors as well. We found more abrupt edge-to-interior gradients (i.e. steeper slopes) in the plant area index in regularly thinned forests. In addition, latitude, mean annual temperature and humidity all affected edge-to-interior gradients in stem density. We also detected a simultaneous impact of both humidity and management, and humidity and distance to the forest edge, on the canopy height and foliage height diversity. These results contribute to our understanding of how environmental conditions and management shape the forest edge structure. Our findings stress the need for site-specific recommendations on forest edge management instead of generalized recommendations as the macroclimate substantially influences the forest edge structure. Only then, the forest edge microclimate, functioning and biodiversity can be conserved at a local scale.
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| 3. |
- Plue, Jan, et al.
(författare)
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Biological flora of the British Isles:Poa nemoralis
- 2020
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Ingår i: Journal of Ecology. - : WILEY. - 0022-0477 .- 1365-2745. ; 108:4, s. 1750-1774
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This account presents information on all aspects of the biology ofPoa nemoralisL. (Wood Meadow-grass) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of theBiological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history, and conservation. The grassPoa nemoralisis widespread and frequent to locally common across the British Isles, except for western and central Ireland, and northern Scotland. In both its native Eurasian range and introduced ranges in, for example, the Americas, its main habitat comprises temperate (mixed) deciduous woodland. The species finds important secondary habitats in hedgerows, as well as in non-woodland vegetation such as on cliffs, screes and walls or sporadically in grassland and heathland. Although not always taxonomically or morphologically distinct units, the species is suspected to comprise many cytological races and hybrid polyploid populations with variable morphology. Morphological variation amongP. nemoralispopulations may also be a sign of local environmental adaptation or a result of introgressive hybridization with other, morphologically variable members ofPoasectionStenopoasuch asP. glauca,P. compressaorP. pratensis. Poa nemoralisis a small-statured, loosely caespitose grass, with populations ranging from a few individual tufts to those visually defining the aspect of the herbaceous understorey. The species tolerates moderate to deep shade on the forest floor, yet it tends to forage for available light, occurring more and growing taller in canopy gaps, forest edges and hedgerows. The amount of light is central to its survival and reproductive ecology, being important for flower induction, seed production and seed germination. The species produces large quantities of small, light seeds which facilitate spatial and temporal dispersal. The species occupies a wide range of soil pH (3-7) and nutrient conditions (C/N ratio ranges between 10 and 25), though it clearly prefers moderately acid and somewhat drier soils with limited litter thickness, avoiding soils with mor humus types.Poa nemoralisdisplays distinct small-scale acidifuge responses, being absent in areas of low soil pH (<3). Poa nemoralisis a moderately strong indicator of ancient woodland: it can quickly colonize recently established wooded areas adjacent to ancient woodland when it is not hindered by dispersal limitation and elevated nutrient levels. Nonetheless, dispersal limitation impedes rapid colonization of isolated, recently established woodlands, in spite of ample records of zoochorous seed dispersal. While currently frequent to locally common, the species is at risk if ancient woodlands continue to decline in its native Eurasian range. Across N.W. Europe, it is already in moderate decline in temperate deciduous ancient woodlands because of acidification, eutrophication and darkening of the forest understorey. In its introduced ranges, it is considered invasive.
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| 4. |
- Vanneste, Thomas, et al.
(författare)
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Contrasting microclimates among hedgerows and woodlands across temperate Europe
- 2020
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Ingår i: Agricultural and Forest Meteorology. - : Elsevier BV. - 0168-1923 .- 1873-2240. ; 281
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Tidskriftsartikel (refereegranskat)abstract
- Hedgerows have the potential to facilitate the persistence and migration of species across landscapes, mostly due to benign microclimatic conditions. This thermal buffering function may become even more important in the future for species migration under climate change. Unfortunately, there is a lack of empirical studies quantifying the microclimate of hedgerows, particularly at broad geographical scales. Here we monitored sub-canopy temperatures using 168 miniature temperature sensors distributed along woodland-hedgerow transects, and spanning a 1600-km macroclimatic gradient across Europe. First, we assessed the variation in the temperature offset (that is, the difference between sub-canopy and corresponding macroclimate temperatures) for minimum, mean and maximum temperatures along the woodland-hedgerow transects. Next, we linked the observed patterns to macroclimate temperatures as well as canopy structure, overstorey composition and hedgerow characteristics. The sub-canopy versus macroclimate temperature offset was on average 0.10 degrees C lower in hedgerows than in woodlands. Minimum winter temperatures were consistently lower by 0.10 degrees C in hedgerows than in woodlands, while maximum summer temperatures were 0.80 degrees C higher, albeit mainly around the woodland-hedgerow ecotone. The temperature offset was often negatively correlated with macroclimate temperatures. The slope of this relationship was lower for maximum temperatures in hedgerows than in woodlands. During summer, canopy cover, tree height and hedgerow width had strong cooling effects on maximum mid-day temperatures in hedgerows. The effects of shrub height, shrub cover and shade-casting ability, however, were not significant. To our knowledge, this is the first study to quantify hedgerow microclimates along a continental-scale environmental gradient. We show that hedgerows are less efficient thermal insulators than woodlands, especially at high ambient temperatures (e.g. on warm summer days). This knowledge will not only result in better predictions of species distribution across fragmented landscapes, but will also help to elaborate efficient strategies for biodiversity conservation and landscape planning.
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| 5. |
- Vanneste, Thomas, et al.
(författare)
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Plant diversity in hedgerows and road verges across Europe
- 2020
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 57:7, s. 1244-1257
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Tidskriftsartikel (refereegranskat)abstract
- Linear landscape elements such as hedgerows and road verges have the potential to mitigate the adverse effects of habitat fragmentation and climate change on species, for instance, by serving as a refuge habitat or by improving functional connectivity across the landscape. However, so far this hypothesis has not been evaluated at large spatial scales, preventing us from making generalized conclusions about their efficacy and implementation in conservation policies. Here, we assessed plant diversity patterns in 336 vegetation plots distributed along hedgerows and road verges, spanning a macro-environmental gradient across temperate Europe. We compared herb-layer species richness and composition in these linear elements with the respective seed-source (core) habitats, that is, semi-natural forests and grasslands. Next, we assessed how these differences related to several environmental drivers acting either locally, at the landscape level or along the studied macro-ecological gradient. Across all regions, about 55% of the plant species were shared between forests and hedgerows, and 52% between grasslands and road verges. Habitat-specialist richness was 11% lower in the linear habitats than in the core habitats, while generalist richness was 14% higher. The difference in floristic composition between both habitat types was mainly due to species turnover, and not nestedness. Most notably, forest-specialist richness in hedgerows responded positively to tree cover, tree height and the proportion of forests in the surrounding landscape, while generalist richness was negatively affected by tree height and buffering effect of trees on subcanopy temperatures. Grassland and road verge diversity was mainly influenced by soil properties, with positive effects of basic cation levels on the number of specialists and those of bioavailable soil phosphorus on generalist diversity. Synthesis and applications. We demonstrate that linear landscape elements provide a potential habitat for plant species across Europe, including slow-colonizing specialists. Additionally, our results stress the possibility for land managers to modify local habitat features (e.g. canopy structure, subcanopy microclimate, soil properties, mowing regime) through management practices to enhance the colonization success of specialists in these linear habitats. These findings underpin the management needed to better conserving the biodiversity of agricultural landscapes across broad geographical scales.
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