| 1. |
- De Frenne, P., et al.
(författare)
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Atmospheric nitrogen deposition on petals enhances seed quality of the forest herb Anemone nemorosa
- 2018
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Ingår i: Plant Biology. - : Wiley. - 1435-8603 .- 1438-8677. ; 20:3, s. 619-626
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Tidskriftsartikel (refereegranskat)abstract
- Elevated atmospheric input of nitrogen (N) is currently affecting plant biodiversity and ecosystem functioning. The growth and survival of numerous plant species is known to respond strongly to N fertilisation. Yet, few studies have assessed the effects of N deposition on seed quality and reproductive performance, which is an important life-history stage of plants. Here we address this knowledge gap by assessing the effects of atmospheric N deposition on seed quality of the ancient forest herb Anemone nemorosa using two complementary approaches. By taking advantage of the wide spatiotemporal variation in N deposition rates in pan-European temperate and boreal forests over 2years, we detected positive effects of N deposition on the N concentration (percentage N per unit seed mass, increased from 2.8% to 4.1%) and N content (total N mass per seed more than doubled) of A.nemorosa seeds. In a complementary experiment, we applied ammonium nitrate to aboveground plant tissues and the soil surface to determine whether dissolved N sources in precipitation could be incorporated into seeds. Although the addition of N to leaves and the soil surface had no effect, a concentrated N solution applied to petals during anthesis resulted in increased seed mass, seed N concentration and N content. Our results demonstrate that N deposition on the petals enhances bioaccumulation of N in the seeds of A.nemorosa. Enhanced atmospheric inputs of N can thus not only affect growth and population dynamics via root or canopy uptake, but can also influence seed quality and reproduction via intake through the inflorescences.
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| 2. |
- De Frenne, P, et al.
(författare)
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Significant effects of temperature on the reproductive output of the forest herb Anemone nemorosa L.
- 2010
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 259:4, s. 809-817
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Tidskriftsartikel (refereegranskat)abstract
- Climate warming is already influencing plant migration in different parts of the world.Numerous modelshave been developed to forecast future plant distributions. Few studies, however, have investigated thepotential effect of warming on the reproductive output of plants. Understorey forest herbs in particular,have received little attention in the debate on climate change impacts.This study focuses on the effect of temperature on sexual reproductive output (number of seeds, seedmass, germination percentage and seedling mass) of Anemone nemorosa L., a model species for slowcolonizing herbaceous forest plants. We sampled seeds of A. nemorosa in populations along a 2400 kmlatitudinal gradient from northern France to northern Sweden during three growing seasons (2005, 2006and 2008). This study design allowed us to isolate the effects of accumulated temperature (GrowingDegree Hours; GDH) from latitude and the local abiotic and biotic environment. Germination and seedsowing trials were performed in incubators, a greenhouse and under field conditions in a forest. Finally,we disentangled correlations between the different reproductive traits of A. nemorosa along thelatitudinal gradient.We found a clear positive relationship between accumulated temperature and seed and seedlingtraits: reproductive output of A. nemorosa improved with increasing GDH along the latitudinal gradient.Seedmass and seedling mass, for instance, increased by 9.7% and 10.4%, respectively, for every 1000 8C hincrease in GDH.Wealso derived strong correlations between several seed and seedling traits both underfield conditions and in incubators. Our results indicate that seed mass, incubator-based germinationpercentage (Germ%Inc) and the output of germinable seeds (product of number of seeds and Germ%Incdivided by 100) from plants grown along a latitudinal gradient (i.e. at different temperature regimes)provide valuable proxies to parameterize key population processes in models.We conclude that (1) climate warming may have a pronounced positive impact on sexualreproduction of A. nemorosa and (2) climate models forecasting plant distributions would benefit fromincluding the temperature sensitivity of key seed traits and population processes.
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| 3. |
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| 4. |
- De Frenne, P, et al.
(författare)
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Unraveling the effects of temperature, latitude and local environment on the reproduction of six forest herbs.
- 2009
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 18:6, s. 641-651
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Tidskriftsartikel (refereegranskat)abstract
- Aim To investigate the effect of temperature, latitude and local environment on the reproductive traits of widespread perennial forest herbs to better understand the potential impacts of rising temperatures on their population dynamics and colonization capacities.Location Six regions along a latitudinal gradient from France to Sweden.Methods Within each region, we collected data from three to five populations of up to six species. For each species, several variables were recorded in each region (temperature, latitude) and population (local abiotic and biotic environmental variables), and seed production and germination were estimated. Resource investment in reproduction (RIR) was quantified as seed number × seed mass, while germinable seed output (GSO) was expressed as seed number × germination percentage. We performed linear regression and mixed effect models to investigate the effects of temperature (growing degree hours), latitude and local abiotic and biotic environment on RIR and GSO.Results Temperature and latitude explained most of the variation in RIR and GSO for early flowering species with a northerly distribution range edge (Anemone nemorosa, Paris quadrifolia and Oxalis acetosella). Reproduction of the more southerly distributed species (Brachypodium sylvaticum, Circaea lutetiana and Primula elatior), in contrast, was independent of temperature/latitude. In the late summer species, B. sylvaticum and C. lutetiana, variation in RIR and GSO was best explained by local environmental variables, while none of the investigated variables appeared to be related to reproduction in P. elatior.Main conclusions We showed that reproduction of only two early flowering, northerly distributed species was related to temperature. This suggests that the potential reproductive response of forest herbs to climate warming partly depends on their phenology and distribution, but also that the response is to some extent species dependent. These findings should be taken into account when predictions about future shifts in distribution range are made.
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| 5. |
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| 6. |
- Reinecke, J., et al.
(författare)
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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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Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 39:12, s. 1164-1175
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Tidskriftsartikel (refereegranskat)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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| 7. |
- De Frenne, P., et al.
(författare)
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A latitudinal gradient in seed nutrients of the forest herb Anemone nemorosa
- 2011
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Ingår i: Plant Biology. - : Wiley. - 1435-8603 .- 1438-8677. ; 13:3, s. 493-501
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Tidskriftsartikel (refereegranskat)abstract
- The nutrient concentration in seeds determines many aspects of potential success of the sexual reproductive phase of plants, including the seed predation probability, efficiency of seed dispersal and seedling performance. Despite considerable research interest in latitudinal gradients of foliar nutrients, a similar gradient for seeds remains unexplored. We investigated a potential latitudinal gradient in seed nutrient concentrations within the widespread European understorey forest herb Anemone nemorosa L. We sampled seeds of A. nemorosa in 15 populations along a 1900-km long latitudinal gradient at three to seven seed collection dates post-anthesis and investigated the relative effects of growing degree-hours > 5 degrees C, soil characteristics and latitude on seed nutrient concentrations. Seed nitrogen, nitrogen:phosphorus ratio and calcium concentration decreased towards northern latitudes, while carbon:nitrogen ratios increased. When taking differences in growing degree-hours and measured soil characteristics into account and only considering the most mature seeds, the latitudinal decline remained particularly significant for seed nitrogen concentration. We argue that the decline in seed nitrogen concentration can be attributed to northward decreasing seed provisioning due to lower soil nitrogen availability or greater investment in clonal reproduction. This pattern may have large implications for the reproductive performance of this forest herb as the degree of seed provisioning ultimately co-determines seedling survival and reproductive success.
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| 8. |
- De Frenne, Pieter, et al.
(författare)
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Microclimate moderates plant responses to macroclimate warming
- 2013
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 110:46, s. 18561-18565
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Tidskriftsartikel (refereegranskat)abstract
- Recent global warming is acting across marine, freshwater, and terrestrial ecosystems to favor species adapted to warmer conditions and/or reduce the abundance of cold-adapted organisms (i.e., thermophilization of communities). Lack of community responses to increased temperature, however, has also been reported for several taxa and regions, suggesting that climatic lags may be frequent. Here we show that microclimatic effects brought about by forest canopy closure can buffer biotic responses to macroclimate warming, thus explaining an apparent climatic lag. Using data from 1,409 vegetation plots in European and North American temperate forests, each surveyed at least twice over an interval of 12-67 y, we document significant thermophilization of ground-layer plant communities. These changes reflect concurrent declines in species adapted to cooler conditions and increases in species adapted to warmer conditions. However, thermophilization, particularly the increase of warm-adapted species, is attenuated in forests whose canopies have become denser, probably reflecting cooler growing-season ground temperatures via increased shading. As standing stocks of trees have increased in many temperate forests in recent decades, local microclimatic effects may commonly be moderating the impacts of macroclimate warming on forest understories. Conversely, increases in harvesting woody biomass-e.g., for bioenergy-may open forest canopies and accelerate thermophilization of temperate forest biodiversity.
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| 9. |
- De Frenne, Pieter, et al.
(författare)
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Plant movements and climate warming : intraspecific variation in growth responses to nonlocal soils
- 2014
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 202:2, s. 431-441
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Tidskriftsartikel (refereegranskat)abstract
- Most range shift predictions focus on the dispersal phase of the colonization process. Because moving populations experience increasingly dissimilar nonclimatic environmental conditions as they track climate warming, it is also critical to test how individuals originating from contrasting thermal environments can establish in nonlocal sites. We assess the intraspecific variation in growth responses to nonlocal soils by planting a widespread grass of deciduous forests (Milium effusum) into an experimental common garden using combinations of seeds and soil sampled in 22 sites across its distributional range, and reflecting movement scenarios of up to 1600km. Furthermore, to determine temperature and forest-structural effects, the plants and soils were experimentally warmed and shaded. We found significantly positive effects of the difference between the temperature of the sites of seed and soil collection on growth and seedling emergence rates. Migrant plants might thus encounter increasingly favourable soil conditions while tracking the isotherms towards currently colder' soils. These effects persisted under experimental warming. Rising temperatures and light availability generally enhanced plant performance. Our results suggest that abiotic and biotic soil characteristics can shape climate change-driven plant movements by affecting growth of nonlocal migrants, a mechanism which should be integrated into predictions of future range shifts.
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| 10. |
- Plue, Jan, et al.
(författare)
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Buffering effects of soil seed banks on plant community composition in response to land use and climate
- 2020
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 30:1, s. 128-139
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Tidskriftsartikel (refereegranskat)abstract
- AimClimate and land use are key determinants of biodiversity, with past and ongoing changes posing serious threats to global ecosystems. Unlike most other organism groups, plant species can possess dormant life‐history stages such as soil seed banks, which may help plant communities to resist or at least postpone the detrimental impact of global changes. This study investigates the potential for soil seed banks to achieve this.Location Europe.Time period 1978–2014.Major taxa studied Flowering plantsMethodsUsing a space‐for‐time/warming approach, we study plant species richness and composition in the herb layer and the soil seed bank in 2,796 community plots from 54 datasets in managed grasslands, forests and intermediate, successional habitats across a climate gradient.ResultsSoil seed banks held more species than the herb layer, being compositionally similar across habitats. Species richness was lower in forests and successional habitats compared to grasslands, with annual temperature range more important than mean annual temperature for determining richness. Climate and land‐use effects were generally less pronounced when plant community richness included seed bank species richness, while there was no clear effect of land use and climate on compositional similarity between the seed bank and the herb layer.Main conclusionsHigh seed bank diversity and compositional similarity between the herb layer and seed bank plant communities may provide a potentially important functional buffer against the impact of ongoing environmental changes on plant communities. This capacity could, however, be threatened by climate warming. Dormant life‐history stages can therefore be important sources of diversity in changing environments, potentially underpinning already observed time‐lags in plant community responses to global change. However, as soil seed banks themselves appear, albeit less, vulnerable to the same changes, their potential to buffer change can only be temporary, and major community shifts may still be expected.
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| 11. |
- Auffret, Alistair G., et al.
(författare)
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More warm-adapted species in soil seed banks than in herb layer plant communities across Europe
- 2023
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Ingår i: Journal of Ecology. - : John Wiley & Sons. - 0022-0477 .- 1365-2745. ; 111:5, s. 1009-1020
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Tidskriftsartikel (refereegranskat)abstract
- Responses to climate change have often been found to lag behind the rate of warming that has occurred. In addition to dispersal limitation potentially restricting spread at leading range margins, the persistence of species in new and unsuitable conditions is thought to be responsible for apparent time-lags. Soil seed banks can allow plant communities to temporarily buffer unsuitable environmental conditions, but their potential to slow responses to long-term climate change is largely unknown. As local forest cover can also buffer the effects of a warming climate, it is important to understand how seed banks might interact with land cover to mediate community responses to climate change. We first related species-level seed bank persistence and distribution-derived climatic niches for 840 plant species. We then used a database of plant community data from grasslands, forests and intermediate successional habitats from across Europe to investigate relationships between seed banks and their corresponding herb layers in 2763 plots in the context of climate and land cover. We found that species from warmer climates and with broader distributions are more likely to have a higher seed bank persistence, resulting in seed banks that are composed of species with warmer and broader climatic distributions than their corresponding herb layers. This was consistent across our climatic extent, with larger differences (seed banks from even warmer climates relative to vegetation) found in grasslands. Synthesis. Seed banks have been shown to buffer plant communities through periods of environmental variability, and in a period of climate change might be expected to contain species reflecting past, cooler conditions. Here, we show that persistent seed banks often contain species with relatively warm climatic niches and those with wide climatic ranges. Although these patterns may not be primarily driven by species’ climatic adaptations, the prominence of such species in seed banks might still facilitate climate-driven community shifts. Additionally, seed banks may be related to ongoing trends regarding the spread of widespread generalist species into natural habitats, while cool-associated species may be at risk from both short- and long-term climatic variability and change.
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| 12. |
- Demey, A., et al.
(författare)
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Hemiparasitic litter additions alter gross nitrogen turnover in temperate semi-natural grassland soils
- 2014
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Ingår i: Soil Biology & Biochemistry. - : Elsevier BV. - 0038-0717. ; 68, s. 419-428
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Tidskriftsartikel (refereegranskat)abstract
- Hemiparasitic plants accumulate nutrients in their leaves and therefore produce high-quality litter with faster decomposition and nutrient release rates compared to non-parasitic litter. Higher levels of plant-available nitrogen (N) in the presence of hemiparasitic plants have been attributed to this 'litter effect', but effects on N dynamics in the soil remain unstudied. We tested the hypothesis that litter of Rhinanthus angustifolius and Pedicularis sylvatica increases N transformation rates in the soil more than non-parasitic litter of a species mix from the same communities. We expected the litter effect to be higher in the oligotrophic Pedicularis soil compared to the mesotrophic Rhinanthus soil. Gross N transformation rates were quantified using a N-15 tracing modeling approach. Differentially N-15 labeled NH4Cl + KNO3 was added to two soils with three treatments (control, soil amended with non-parasitic litter, soil amended with Rhinanthus or Pedicularis litter) in a laboratory incubation experiment. The concentration and 15N enrichment of NH4+ and NO3 in the soil were measured at six time points within one or two weeks (depending on the soil) after label addition. Hemiparasitic litter addition increased the overall cycling of N more compared to the addition of non-parasitic litter. Relative to the non-parasitic litter, addition of Rhinanthus litter increased the net flux from organic N to NH4+ by 61% and net (autotrophic) nitrification by 80%. Addition of Pedicularis litter increased the net flux from organic N to NH4+ by 28% relative to addition of non-parasitic litter, while there was no effect on nitrification. Surprisingly, gross mineralization of organic N to NH4+ decreased with litter addition for the Rhinanthus soil (control soil > nonparasitic litter > Rhinanthus litter), while it increased with litter addition in the Pedicularis soil (control soil < non-parasitic litter < Pedicularis litter). Our results support the hypothesis that litter from hemiparasitic plants increases soil N availability more than non-parasitic litter, but contradicts the expectation that the hemiparasitic litter effect would be more pronounced in an oligotrophic as compared to a mesotrophic system. This litter-induced augmentation in soil fertility provides in addition to the parasitic suppression of hosts a second potentially important pathway by which hemiparasitic plants impact on plant community composition. However, future research on P and K return via hemiparasitic litter should be considered. (C) 2013 Elsevier Ltd. All rights reserved.
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| 13. |
- Plue, Jan, et al.
(författare)
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European soil seed bank communities across a climate and land-cover gradient
- 2020
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Annan publikationabstract
- This is the data set used for the publication Buffering effects of soil seed banks on plant community composition in response to land use and climate, published in the journal Global Ecology and Biogeography.Aim.Climate and land use are key determinants of biodiversity, with past and ongoing changes posing serious threats to global ecosystems. Unlike most other organism groups, plant species can possess dormant life-history stages such as soil seed banks, which may help plant communities to resist or at least postpone the detrimental impact of global changes. This study investigates the potential for soil seed banks to achieve this.Location. EuropeTime period. 1978 – 2014Major taxa studied. Flowering plantsMethods.Using a space-for-time/warming approach, we study plant species richness and composition in the herb layer and the soil seed bank in 2796 community plots from 54 datasets in managed grasslands, forests and intermediate, successional habitats across a climate gradient.Results.Soil seed banks held more species than the herb layer, being compositionally similar across habitats. Species richness was lower in forests and successional habitats compared to grasslands, with annual temperature range more important than mean annual temperature for determining richness. Climate and land use effects were generally less pronounced when plant community richness included seed bank species richness, while there was no clear effect of land use and climate on compositional similarity between the seed bank and the herb layer.Main conclusions.High seed bank diversity and compositional similarity between the herb layer and seed bank plant communities may provide a potentially important functional buffer against the impact of ongoing environmental changes on plant communities. This capacity could, however, be threatened by climate warming. Dormant life-history stages can therefore be important sources of diversity in changing environments, potentially underpinning already observed time-lags in plant community responses to global change. However, as soil seed banks themselves appear, albeit less, vulnerable to the same changes, their potential to buffer change can only be temporary, and major community shifts may still be expected.MethodsThis dataset is a collection of 41 published and 5 unpublished data sets, consisting of 2796 plots with corresponding seed bank and herb layer community data. Sampling effort varied across data sets, but involved sampling of the soil and subsequent germination trials in a greenhouse to determine seed bank composition. Herb layer communities were determined by the identification of plants in relevés. Please consult the readme file and published paper for further details.Usage NotesPlease contact database or individual data set authors for further information and collaboration when using the data set or any of its component parts. Please also note that some of these data sets have already been published alongside their orginal papers. Finally, please cite data and datasets according to community standards.
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| 14. |
- Vellend, Mark, et al.
(författare)
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Homogenization of forest plant communities and weakening of species–environment relationships via agricultural land use
- 2007
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Ingår i: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745. ; 95, s. 565-573
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Tidskriftsartikel (refereegranskat)abstract
- 1Disturbance may cause community composition across sites to become more or less homogenous, depending on the importance of different processes involved in community assembly. In north-eastern North America and Europe local (alpha) diversity of forest plants is lower in forests growing on former agricultural fields (recent forests) than in older (ancient) forests, but little is known about the influence of land-use history on the degree of compositional differentiation among sites (beta diversity).2Here we analyse data from 1446 sites in ancient and recent forests across 11 different landscapes in north-eastern North America and Europe to demonstrate decreases in beta diversity and in the strength of species–environment relationships in recent vs. ancient forests.3The magnitude of environmental variability among sites did not differ between the two forest types. This suggests the difference in beta diversity between ancient and recent forests was not due to different degrees of environmental heterogeneity, but rather to dispersal filters that constrain the pool of species initially colonizing recent forests.4The observed effects of community homogenization and weakened relationships between species distributions and environmental gradients appear to persist for decades or longer. The legacy of human land-use history in spatial patterns of biodiversity may endure, both within individual sites and across sites, for decades if not centuries.
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| 15. |
- Verheyen, Kris, et al.
(författare)
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201 Combining Biodiversity Resurveys across Regions to Advance Global Change Research
- 2017
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Ingår i: BioScience. - : Oxford University Press (OUP). - 0006-3568 .- 1525-3244. ; 67:1, s. 73-83
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Tidskriftsartikel (refereegranskat)abstract
- More and more ecologists have started to resurvey communities sampled in earlier decades to determine long-term shifts in community composition and infer the likely drivers of the ecological changes observed. However, to assess the relative importance of and interactions among multiple drivers, joint analyses of resurvey data from many regions spanning large environmental gradients are needed. In this article, we illustrate how combining resurvey data from multiple regions can increase the likelihood of driver orthogonality within the design and show that repeatedly surveying across multiple regions provides higher representativeness and comprehensiveness, allowing us to answer more completely a broader range of questions. We provide general guidelines to aid the implementation of multiregion resurvey databases. In so doing, we aim to encourage resurvey database development across other community types and biomes to advance global environmental change research.
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