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1.
Megan M. Wheeler Christopher Neill Elizabeth Loucks Annalisa Weiler Betsy Von Holle Matthew Pelikan Tom Chase 《Restoration Ecology》2015,23(5):539-547
Creating native‐species‐rich grasslands to replace agricultural grasslands can be an important strategy for supplementing the area of grasslands, which are in decline in many regions. In the northeastern United States, sandplain grasslands support a diverse plant community and rare plant and animal species that are declining because of reductions in historical disturbances such as fire and grazing. We designed an experiment on Martha's Vineyard, Massachusetts, to test methods of establishing native‐species‐rich coastal sandplain grassland on former agricultural land. We tested the efficacy of: (1) tilling, herbicide, hot foam, and plastic cover in removing initial nonnative vegetation, and (2) combinations of tilling and seeding for establishing native species. We measured native and nonnative species richness and percent cover before and for 5 years after treatment. Herbicide, plastic cover, and spring, summer, and fall tilling were about equally effective in reducing nonnative species cover and promoting native species cover. Tilling and seeding each increased native species richness and percent cover, and seeding and tilling together increased native species richness and cover more than either treatment alone. Combined seeding and disturbance also reduced the cover of nonnative species, but nonnative species cover remained higher than in adjacent reference sandplain grassland. Results indicated that native species establishment was enhanced by the availability of seeds and by reduction of initial nonnative plant cover. The most efficient method of converting coastal agricultural grasslands to sandplain grassland with a higher number and proportion of native species is a single season of plant removal and seeding. 相似文献
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Werner Ulrich Buntarou Kusumoto Simone Fattorini Yasuhiro Kubota 《Diversity & distributions》2020,26(6):769-778
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Understanding biodiversity changes in the Anthropocene (e.g. due to climate and land‐use change) is an urgent ecological issue. This important task is challenging because global change effects and species responses are dependent on the spatial scales considered. Furthermore, responses are often not immediate. However, both scale and time delay issues can be tackled when, at each study site, we consider dynamics in both observed and dark diversity. Dark diversity includes those species in the region that can potentially establish and thrive in the local sites’ conditions but are currently locally absent. Effectively, dark diversity connects biodiversity at the study site to the regional scales and defines the site‐specific species pool (observed and dark diversity together). With dark diversity, it is possible to decompose species gains and losses into two space‐related components: one associated with local dynamics (species moving from observed to dark diversity and vice versa) and another related to gains and losses of site‐specific species pool (species moving to and from the pool after regional immigration, regional extinction or change in local ecological conditions). Extinction debt and immigration credit are useful to understand dynamics in observed diversity, but delays might happen in species pool changes as well. In this opinion piece we suggest that considering both observed and dark diversity and their temporal dynamics provides a deeper understanding of biodiversity changes. Considering both observed and dark diversity creates opportunities to improve conservation by allowing to identify species that are likely to go regionally extinct as well as foreseeing which of the species that newly arrive to the region are more likely to colonize local sites. Finally, by considering temporal lags and species gains and losses in observed and dark diversity, we combine phenomena at both spatial and temporal scales, providing a novel tool to examine biodiversity change in the Anthropocene. 相似文献
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1. The increase of species richness with the area of the habitat sampled, that is the species–area relationship, and its temporal analogue, the species–time relationship (STR), are among the few general laws in ecology with strong conservation implications. However, these two scale‐dependent phenomena have rarely been considered together in biodiversity assessment, especially in freshwater systems. 2. We examined how the spatial scale of sampling influences STRs for a Central‐European stream fish assemblage (second‐order Bernecei stream, Hungary) using field survey data in two simulation‐based experiments. 3. In experiment one, we examined how increasing the number of channel units, such as riffles and pools (13 altogether), and the number of field surveys involved in the analyses (12 sampling occasions during 3 years), influence species richness. Complete nested curves were constructed to quantify how many species one observes in the community on average for a given number of sampling occasions at a given spatial scale. 4. In experiment two, we examined STRs for the Bernecei fish assemblage from a landscape perspective. Here, we evaluated a 10‐year reach level data set (2000–09) for the Bernecei stream and its recipient watercourse (third‐order Kemence stream) to complement results on experiment one and to explore the mechanisms behind the observed patterns in more detail. 5. Experiment one indicated the strong influence of the spatial scale of sampling on the accumulation of species richness, although time clearly had an additional effect. The simulation methodology advocated here helped to estimate the number of species in a diverse combination of spatial and temporal scale and, therefore, to determine how different scale combinations influence sampling sufficiency. 6. Experiment two revealed differences in STRs between the upstream (Bernecei) and downstream (Kemence) sites, with steeper curves for the downstream site. Equations of STR curves were within the range observed in other studies, predominantly from terrestrial systems. Assemblage composition data suggested that extinction–colonisation dynamics of rare, non‐resident (i.e. satellite) species influenced patterns in STRs. 7. Our results highlight that the determination of species richness can benefit from the joint consideration of spatial and temporal scales in biodiversity inventory surveys. Additionally, we reveal how our randomisation‐based methodology may help to quantify the scale dependency of diversity components (α, β, γ) in both space and time, which have critical importance in the applied context. 相似文献
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Anna Kvendi‐Jak Melinda Halassy Anik Csecserits Karl Hülber Katalin Szitr Thomas Wrbka Katalin Trk 《应用植被学》2019,22(1):138-149
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Seed germination and seedling establishment patterns have been used to classify species as shade tolerant or intolerant. The main objective of this research was to investigate, under controlled conditions, seed germination of species from different successional positions as well as to follow seed germination and seedling survival under natural shade in the field. The species studied were Solarium granuloso‐leprosum, Trema micrantha, Cecropia pachystachya, Croton piptocalyx, Bauhinia forficata subsp. pruinosa. Senna macranthera, Schizolobium parahyba, Piptadenia gonoacantha, Chorisia speciosa, Pseudobombax grandiflorum, Ficus guaranitica, Esenbeckia leiocarpa, Pachystroma longifolium, Myroxylon peruiferum, and Hymenaea courbaril. Field trials were carried out at Santa Genebra Municipal Reserve, Campinas, SP, Brazil, at the forest edge and in the understory. No significant correlations were detected between successional status and seed size or seed water content. Light‐regulated germination was present only in small‐seeded species. In field experiments, most species, including the light‐sensitive ones, were able to germinate under the canopy, where a low red/far‐red ratio predominates. Most species, mainly those of early‐ and intermediate successional positions, presented low seedling survival rates under shade. Myroxylon peruiferum was the most shade tolerant species, while 5. granuloso‐leprosum, C. speciosa, P. gonoacantha, F. guaranitica, T. micrantha, and 5. parahyba were the most shade intolerant. These latter species showed little or no survival under the shade conditions. 相似文献
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Rémy Beugnon;Nolwenn Le Guyader;Alexandru Milcu;Jonathan Lenoir;Jérémy Puissant;Xavier Morin;Stephan Hättenschwiler; 《Global Change Biology》2024,30(3):e17214
Changes in climate and biodiversity are widely recognized as primary global change drivers of ecosystem structure and functioning, also affecting ecosystem services provided to human populations. Increasing plant diversity not only enhances ecosystem functioning and stability but also mitigates climate change effects and buffers extreme weather conditions, yet the underlying mechanisms remain largely unclear. Recent studies have shown that plant diversity can mitigate climate change (e.g. reduce temperature fluctuations or drought through microclimatic effects) in different compartments of the focal ecosystem, which as such may contribute to the effect of plant diversity on ecosystem properties and functioning. However, these potential plant diversity-induced microclimate effects are not sufficiently understood. Here, we explored the consequences of climate modulation through microclimate modification by plant diversity for ecosystem functioning as a potential mechanism contributing to the widely documented biodiversity–ecosystem functioning (BEF) relationships, using a combination of theoretical and simulation approaches. We focused on a diverse set of response variables at various levels of integration ranging from ecosystem-level carbon exchange to soil enzyme activity, including population dynamics and the activity of specific organisms. Here, we demonstrated that a vegetation layer composed of many plant species has the potential to influence ecosystem functioning and stability through the modification of microclimatic conditions, thus mitigating the negative impacts of climate extremes on ecosystem functioning. Integrating microclimatic processes (e.g. temperature, humidity and light modulation) as a mechanism contributing to the BEF relationships is a promising avenue to improve our understanding of the effects of climate change on ecosystem functioning and to better predict future ecosystem structure, functioning and services. In addition, microclimate management and monitoring should be seen as a potential tool by practitioners to adapt ecosystems to climate change. 相似文献
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Julian Schrader Christian Knig Soetjipto Moeljono Meelis Prtel Holger Kreft 《植被学杂志》2019,30(4):599-609
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Licong Dai Xiaowei Guo Xun Ke Fawei Zhang Yikang Li Cuoji Peng Kai Shu Qian Li Li Lin Guangmin Cao Yangong Du 《Ecology and evolution》2019,9(16):9395-9406
Grazing is an important modulator of both plant productivity and biodiversity in grassland community, yet how to determine a suitable grazing intensity in alpine grassland is still controversy. Here, we explore the effects of different grazing intensities on plant biomass and species composition, both at community level and functional group level, and examines the productivity–species richness relationship under four grazing patterns: no grazing (CK), light grazing (LG), moderate grazing, (MG) and heavy grazing (HG), attempt to determine a suitable grazing intensity in alpine grassland. The results were as follows. The total aboveground biomass (AGB) reduced with increasing grazing intensity, and the response of plant functional groups was different. AGB of both sedges and legumes increased from MG to HG, while the AGB of forbs reduced sharply and the grass AGB remained steady. There was a significant positive relationship between productivity and species richness both at community level and functional group level. In contrast, the belowground biomass (BGB) showed a unimodal relationship from CK to HG, peaking in MG (8,297.72 ± 621.29 g/m2). Interestingly, the grassland community tends to allocate more root biomass to the upper soil layer under increasing grazing intensities. Our results suggesting that moderate levels of disturbance may be the optimal grassland management strategy for alpine meadow in terms of root production. 相似文献
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Gunnar Keppel Thomas W. Gillespie Paul Ormerod Geoffrey A. Fricker 《Journal of Biogeography》2016,43(12):2332-2342
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- Helichrysum microphyllum subsp. tyrrhenicum (Asteraceae) is an endemic taxon of Sardinia and Corsica, where it grows at different altitudes. The objective of this study was to investigate the seed traits and germination behaviour of four Sardinian populations of this taxon located at different altitudes.
- Seed traits were evaluated, and germination tests were carried out by incubating seeds at a range of constant (5–30 °C) and alternating (25/10 °C) temperatures. The dry after‐ripening (DAR) pre‐treatment was also applied by storing seed in dry conditions for 3 months at 25 °C. Seed traits and germination behaviour data were statistically analysed to identify if there was a correlation with altitude.
- Differences in seed size, area and mass among populations were recorded, however, no relationship was found with altitude. High germination percentages were obtained in all populations, both in untreated and DAR seeds, and were positively affected by alternating temperatures. The final germination percentage and time required to reach 50% final germination (T50) showed no relationship with altitude.
- The differences in seed traits and germination detected among the studied populations of H. microphyllum subsp. tyrrhenicum were not correlated with altitude. This study provides new and important knowledge for this taxon. H. microphyllum subsp. tyrrhenicum is characterised by high germination percentages and low T50 values and does not seem to require any dormancy‐breaking treatment. This species represents a high‐potential native plant species that should be considered within environmental management plans.
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Michael J. O'Brien Francisco I. Pugnaire Cristina Armas Susana Rodríguez‐Echeverría Christian Schöb 《Ecology and evolution》2017,7(7):2441-2448
The stress‐gradient hypothesis predicts a higher frequency of facilitative interactions as resource limitation increases. Under severe resource limitation, it has been suggested that facilitation may revert to competition, and identifying the presence as well as determining the magnitude of this shift is important for predicting the effect of climate change on biodiversity and plant community dynamics. In this study, we perform a meta‐analysis to compare temporal differences of species diversity and productivity under a nurse plant (Retama sphaerocarpa) with varying annual rainfall quantity to test the effect of water limitation on facilitation. Furthermore, we assess spatial differences in the herbaceous community under nurse plants in situ during a year with below‐average rainfall. We found evidence that severe rainfall deficit reduced species diversity and plant productivity under nurse plants relative to open areas. Our results indicate that the switch from facilitation to competition in response to rainfall quantity is nonlinear. The magnitude of this switch depended on the aspect around the nurse plant. Hotter south aspects under nurse plants resulted in negative effects on beneficiary species, while the north aspect still showed facilitation. Combined, these results emphasize the importance of spatial heterogeneity under nurse plants for mediating species loss under reduced precipitation, as predicted by future climate change scenarios. However, the decreased water availability expected under climate change will likely reduce overall facilitation and limit the role of nurse plants as refugia, amplifying biodiversity loss. 相似文献
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《Journal of Plant Ecology》2025,18(2)
The stability mechanisms of ecosystem functions have been a hot topic in ecology. However, in wetland ecosystems, the mechanisms by which biotic and abiotic factors interact to affect ecosystem stability in changing environments remain largely unclear. This study investigated the key factors and underlying mechanisms that regulate the spatial variability of wetland productivity by measuring community productivity, multiple components of biodiversity (i.e. species diversity, community functional composition and diversity) and environmental factors along a well-characterized gradient of wetland degradation in the lower reaches of the Yellow River. The results showed that the spatial variability of productivity in wetlands increased with intensified degradation. The spatial variability of wetland productivity was not related to species richness but was mainly affected by changes in community functional composition and diversity. Furthermore, degradation-induced changes in soil nutrients drove the spatial variability of productivity to increase with shifts in functional composition towards more conservative traits (i.e. higher leaf dry matter content and root tissue density), and to decrease with higher functional trait diversity. These findings reveal the driving mechanism of spatial variability in wetland productivity under degradation, and suggest that reduced nutrient availability, by altering plant resource strategies, can affect the spatial reliability of key ecosystem functions in wetlands. 相似文献
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Wenhong Ma Jin‐Sheng He Yuanhe Yang Xiangping Wang Cunzhu Liang Mohammat Anwar Hui Zeng Jingyun Fang Bernhard Schmid 《Global Ecology and Biogeography》2010,19(2):233-243
Aim Our objective was to document the general relationship between plant species richness (SR) and above‐ground net primary productivity (ANPP) at different spatial scales and the environmental influence on this relationship. Location Temperate and alpine grasslands of China. Methods We investigated SR and ANPP at 321 field sites (1355 plots) across the widely distributed temperate and alpine grasslands of China. Ordinary least squares (OLS) regressions were used to test SR–ANPP relationships among site means. Plot‐level data of SR and ANPP were analysed with general linear models (GLMs) and the correlation between SR and ANPP was decomposed into covariance components to test the influence of climatic variables, region, vegetation type and remaining variation among sites on SR, ANPP and their relationship. Results We found positive linear relationships between SR and ANPP among sites in both the alpine and temperate grassland regions and in different grassland vegetation types of these biomes. Environmental gradients such as growing‐season precipitation affected both SR and ANPP in parallel. However, after removing the among‐site environmental variation, residual SR and ANPP were no longer correlated at the pooled within‐site level. Main conclusions The positive SR–ANPP relationship across large‐scale environmental gradients among sites was most likely the result of climatic variables influencing SR and ANPP in parallel. Our results suggest that in China's natural grasslands there is no direct relationship between SR and ANPP, presumably because the pool of available species for local community assembly is large, in contrast to experiments where species pools are artificially reduced. 相似文献
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Haiyan Ren Friedhelm Taube Claudia Stein Yingjun Zhang Yongfei Bai Shuijin Hu 《Ecology and evolution》2018,8(1):231-241
Many biodiversity experiments have demonstrated that plant diversity can stabilize productivity in experimental grasslands. However, less is known about how diversity–stability relationships are mediated by grazing. Grazing is known for causing species losses, but its effects on plant functional groups (PFGs) composition and species asynchrony, which are closely correlated with ecosystem stability, remain unclear. We conducted a six‐year grazing experiment in a semi‐arid steppe, using seven levels of grazing intensity (0, 1.5, 3.0, 4.5, 6.0, 7.5, and 9.0 sheep per hectare) and two grazing systems (i.e., a traditional, continuous grazing system during the growing period (TGS), and a mixed one rotating grazing and mowing annually (MGS)), to examine the effects of grazing system and grazing intensity on the abundance and composition of PFGs and diversity–stability relationships. Ecosystem stability was similar between mixed and continuous grazing treatments. However, within the two grazing systems, stability was maintained through different pathways, that is, along with grazing intensity, persistence biomass variations in MGS, and compensatory interactions of PFGs in their biomass variations in TGS. Ecosystem temporal stability was not decreased by species loss but rather remain unchanged by the strong compensatory effects between PFGs, or a higher grazing‐induced decrease in species asynchrony at higher diversity, and a higher grazing‐induced increase in the temporal variation of productivity in diverse communities. Ecosystem stability of aboveground net primary production was not related to species richness in both grazing systems. High grazing intensity weakened the temporal stabilizing effects of diversity in this semi‐arid grassland. Our results demonstrate that the productivity of dominant PFGs is more important than species richness for maximizing stability in this system. This study distinguishes grazing intensity and grazing system from diversity effects on the temporal stability, highlighting the need to better understand how grazing regulates ecosystem stability, plant diversity, and their synergic relationships. 相似文献
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Tom R. Bishop Mark P. Robertson Berndt J. van Rensburg Catherine L. Parr 《Journal of Biogeography》2014,41(12):2256-2268
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Fletcher W. Halliday Robert W. Heckman Peter A. Wilfahrt Charles E. Mitchell 《Global Change Biology》2020,26(9):4854-4867
Host and parasite richness are generally positively correlated, but the stability of this relationship in response to global change remains poorly understood. Rapidly changing biotic and abiotic conditions can alter host community assembly, which in turn, can alter parasite transmission. Consequently, if the relationship between host and parasite richness is sensitive to parasite transmission, then changes in host composition under various global change scenarios could strengthen or weaken the relationship between host and parasite richness. To test the hypothesis that host community assembly can alter the relationship between host and parasite richness in response to global change, we experimentally crossed host diversity (biodiversity loss) and resource supply to hosts (eutrophication), then allowed communities to assemble. As previously shown, initial host diversity and resource supply determined the trajectory of host community assembly, altering post‐assembly host species richness, richness‐independent host phylogenetic diversity, and colonization by exotic host species. Overall, host richness predicted parasite richness, and as predicted, this effect was moderated by exotic abundance—communities dominated by exotic species exhibited a stronger positive relationship between post‐assembly host and parasite richness. Ultimately, these results suggest that, by modulating parasite transmission, community assembly can modify the relationship between host and parasite richness. These results thus provide a novel mechanism to explain how global environmental change can generate contingencies in a fundamental ecological relationship—the positive relationship between host and parasite richness. 相似文献