Buffering effects of soil seed banks on plant community composition in response to land use and climate

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 Europe. Time period 1978–2014. Major taxa studied Flowering plants. Methods Using 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. 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

More warm‐adapted species in soil seed banks than in herb layer plant communities across Europe

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

A comparison of fuzzy logic and cluster renewal approaches for heat transfer modeling in a 1296 t/h CFB boiler with low level of flue gas recirculation

The interrelation between fuzzy logic and cluster renewal approaches for heat transfer modeling in a circulating fluidized bed (CFB) has been established based on a local furnace data. The furnace data have been measured in a 1296 t/h CFB boiler with low level of flue gas recirculation. In the present study, the bed temperature and suspension density were treated as experimental variables along the furnace height. The measured bed temperature and suspension density were varied in the range of 1131–1156 K and 1.93–6.32 kg/m3, respectively. Using the heat transfer coefficient for commercial CFB combustor, two empirical heat transfer correlation were developed in terms of important operating parameters including bed temperature and also suspension density. The fuzzy logic results were found to be in good agreement with the corresponding experimental heat transfer data obtained based on cluster renewal approach. The predicted bed-to-wall heat transfer coefficient covered a range of 109–241 W/(m2K) and 111–240 W/(m2), for fuzzy logic and cluster renewal approach respectively. The divergence in calculated heat flux recovery along the furnace height between fuzzy logic and cluster renewal approach did not exceeded ±2%

The impact of bed particle size in heat transfer to membrane walls of supercritical CFB boiler

Experimental research has been carried out in a supercritical circulating fluidized bed combustor in order to indicate the effect of the bed particle size on bed-to-wall heat transfer coefficient. The bed inventory used were 0.219, 0.246 and 0.411 mm Sauter mean particles diameter. The operating parameters of a circulating fluidized bed combustor covered a range from 3.13 to 5.11 m/s for superficial gas velocity, 23.7 to 26.2 kg/(m2s) for the circulation rate of solids, 0.33 for the secondary air fraction and 7500 to 8440 Pa pressure drop. Furthermore, the bed temperature, suspension density and the main parameters of cluster renewal approach were treated as experimental variables along the furnace height. The cluster renewal approach was used in order to predict the bed-to-wall heat transfer coefficient. A simple semi-empirical method was proposed to estimate the overall heat transfer coefficient inside the furnace as a function of particle size and suspension density. The computationally obtained results were compared with the experimental data of this work

Soil seed bank and herb layer diversity within secondary oak forest in the Kozubowski Landscape Park

The research concerned the evaluation of the soil seed bank and herb layer diversity in the 60−year old secondary oak forest growing in the Kozubowski Landscape Park (Nida Basin, southern Poland). The aim of the studies was to determine the diversity, similarity and species structure of herb layer and soil seed bank within plots situated at different distances from the forest edge as well as to discuss the obtained data with the results of analogous research which were conducted in the natural oak forest in Białowieża (north−eastern Poland). 12 plots 20×20 m were situated in three zones from edge to the centre of the forest (P, S and L; fig. 1). A total of 134 species of vascular plants were recorded in the analysed herb layer (4800 m2). It was found that in the plots closest to the forest edge, both the Shannon’s diversity index and the average density of the herb layer species were significantly higher than on these located deeper in forest (fig. 2, 3). The soil seed bank contained a total of 2820 seeds belonging to 45 species. The density of the seed bank ranged from 1406/m2 (P) to 1061/m2 and 1057/m2 (S and L, respectively). The seed bank species richness showed a constant decrease from zone P to L (fig. 4). The Sörensen species similarity coefficient between the herb layer and the seed bank for the entire forest was 0.43. Although nearly 90% of the seeds of the whole bank belonged to the species present in the herb layer, the species structure of the above ground vegetation was clearly different from that recorded in the bank. It was found that over 66% of all seeds in the bank belonged to Poa nemoralis. A comparative analysis of the studied oak forest and natural oak forest of Białowieża showed: a similar number of forest species in herb layer per 100 m2, similarly high proportion of ancient forest species in the herb layer, much lower species richness of the seed bank as well as its density in the secondary forest. Our results also point to several times lower values of H’ Shannon−Wiener’s biodiversity index, both in the herb layer and the seed bank in comparison to the undisturbed Białowieża oak forest

Buffering effects of soil seed banks on plant community composition in response to land use and climate.

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: Europe. Time period: 1978–2014. Major taxa studied: Flowering plants. Methods: Using 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. 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

European soil seed bank communities across a climate and land-cover gradient.

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. Europe Time period. 1978 – 2014 Major taxa studied. Flowering plants Methods. 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.Please 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. Funding provided by: Natural Environment Research CouncilCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100000270Award Number: NE/D00036X/1Funding provided by: Norges ForskningsrådCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100005416Award Number: 184912,73758/410,156325/530Funding provided by: Svenska Forskningsrådet FormasCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001862Award Number: 2015‐1065,2018‐00961Funding provided by: VetenskapsrådetCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100004359Funding provided by: ÖstersjöstiftelsenCrossref Funder Registry ID: http://dx.doi.org/10.13039/100009050This 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