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Selecting replacements for invasive plants to support frugivores in highly modified sites: A case study focusing on Lantana camara 总被引：1，自引：0，他引：1
Summary Invasive plants are regarded as a major threat to biodiversity worldwide. Yet, in some cases, invasive plants now perform important ecological functions. For example, fleshy‐fruited invasive plants provide food that supports indigenous frugivore populations. How can the disparate goals of conservation versus invasive weed control be managed? We suggest using the fruit characteristics of the invasive plant to select replacement indigenous plants that are functionally similar from the perspective of frugivores. These could provide replacement food resources at sites where plants with these characteristics are part of the goal plant community and where such plants would not otherwise regenerate. Replacement plants could also redirect seed dispersal processes to favour indigenous, rather than invasive, plant species. We investigated the utility of this approach by ranking all indigenous fleshy‐fruited plant species from a region using a simple model that scored species based upon measures of fruit phenology, morphology, conspicuousness and accessibility relative to a target invasive species, Lantana (Lantana camara). The model successfully produced high scores for indigenous plant species that were used by more of the frugivores of Lantana than a random selection of plants, suggesting that this approach warrants further investigation. 相似文献
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João Vitor S. Messeder Tadeu J. Guerra Wesley Dáttilo Fernando A. O. Silveira 《Biotropica》2020,52(5):857-870
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Following defaunation, the loss of interactions with mutualists such as pollinators or seed dispersers may be compensated through increased interactions with remaining mutualists, ameliorating the negative cascading impacts on biodiversity. Alternatively, remaining mutualists may respond to altered competition by reducing the breadth or intensity of their interactions, exacerbating negative impacts on biodiversity. Despite the importance of these responses for our understanding of the dynamics of mutualistic networks and their response to global change, the mechanism and magnitude of interaction compensation within real mutualistic networks remains largely unknown. We examined differences in mutualistic interactions between frugivores and fruiting plants in two island ecosystems possessing an intact or disrupted seed dispersal network. We determined how changes in the abundance and behavior of remaining seed dispersers either increased mutualistic interactions (contributing to “interaction compensation”) or decreased interactions (causing an “interaction deficit”) in the disrupted network. We found a “rich‐get‐richer” response in the disrupted network, where remaining frugivores favored the plant species with highest interaction frequency, a dynamic that worsened the interaction deficit among plant species with low interaction frequency. Only one of five plant species experienced compensation and the other four had significant interaction deficits, with interaction frequencies 56–95% lower in the disrupted network. These results do not provide support for the strong compensating mechanisms assumed in theoretical network models, suggesting that existing network models underestimate the prevalence of cascading mutualism disruption after defaunation. This work supports a mutualist biodiversity‐ecosystem functioning relationship, highlighting the importance of mutualist diversity for sustaining diverse and resilient ecosystems. 相似文献
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F. Encinas‐Viso T. A. Revilla E. van Velzen R. S. Etienne 《Journal of evolutionary biology》2014,27(2):313-324
Animal seed dispersal provides an important ecosystem service by strongly benefiting plant communities. There are several theoretical studies on the ecology of plant–animal seed–disperser interactions, but few studies have explored the evolution of this mutualism. Moreover, these studies ignore plant life history and frugivore foraging behaviour. Thus, it remains an open question what the conditions for the diversification of fruit traits are, in spite of the multitude of empirical studies on fruit trait diversity. Here, we study the evolution of fruit traits using a spatially explicit individual‐based model, which considers the costs associated with adaptations inducing dispersal by frugivory, as well as frugivore foraging behaviour and abundance. Our model predicts that these costs are the main determinants of the evolution of fruit traits and that when the costs are not very high, the evolution of larger fruit traits (e.g. fleshy/colourful fruits) is controlled by the choosiness and response thresholds of the frugivores as well as their numerical abundance. 相似文献
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全面认识和理解生态系统服务的形成机制是维持其持续供给的前提。植物功能性状直接参与多种生态系统过程, 影响生态系统服务供给, 探讨植物功能性状与生态系统服务的关系是揭示生态系统服务形成机制的重要途径。该文采用系统的文献综述方法, 分析了植物功能性状与生态系统服务关系的研究特点, 总结了影响不同生态系统服务的主要植物功能性状, 阐述了可能的影响途径。结果表明: 植物功能性状与生态系统服务关系研究以草地和森林等自然生态系统为主; 大部分研究集中在生态系统供给服务和支持服务, 包括生物量、净初级生产力、土壤肥力等; 根据植物功能性状对不同生态系统服务的影响程度, 植物功能性状可以聚类为土壤保持服务相关性状、水分循环相关性状、多功能相关性状、产品提供服务与养分循环相关性状以及授粉与生物控制服务相关性状; 并阐述了植物功能性状指标影响不同的生态系统服务途径。围绕植物功能性状对生态系统服务的影响, 今后尚需进一步探讨生态系统多功能性、植物功能性状相关性、气候变化和人类活动不确定性、时空尺度差异等因素对二者关系的影响。 相似文献
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Little is known about how mutualistic interactions affect the distribution of species richness on broad geographic scales. Because mutualism positively affects the fitness of all species involved in the interaction, one hypothesis is that the richness of species involved should be positively correlated across their range, especially for obligate relationships. Alternatively, if mutualisms involve multiple mutualistic partners, the distribution of mutualists should not necessarily be related, and patterns in species distributions might be more strongly correlated with environmental factors. In this study, we compared the distributions of plants and vertebrate animals involved in seed‐dispersal mutualisms across the United States and Canada. We compiled geographic distributions of plants dispersed by frugivores and scatter‐hoarding animals, and compared their distribution of richness to the distribution in disperser richness. We found that the distribution of animal dispersers shows a negative relationship to the distribution of the plants that they disperse, and this is true whether the plants dispersed by frugivores or scatter‐hoarders are considered separately or combined. In fact, the mismatch in species richness between plants and the animals that disperse their seeds is dramatic, with plants species richness greatest in the in the eastern United States and the animal species richness greatest in the southwest United States. Environmental factors were corelated with the difference in the distribution of plants and their animal mutualists and likely are more important in the distribution of both plants and animals. This study is the first to describe the broad‐scale distribution of seed‐dispersing vertebrates and compare the distributions to the plants they disperse. With these data, we can now identify locations that warrant further study to understand the factors that influence the distribution of the plants and animals involved in these mutualisms. 相似文献
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种子传播将母株生殖周期的末端与它们后代种群的建立连结了起来,广泛认为,其对植被结构具有深刻的影响。种子传播的整个过程称为种子传播循环。研究表明,杂草种子传播的因子多种多样,包括仅依赖自身来完成的主动传播,以及依赖风、水、动物、人类等外界媒介的被动传播。其中,人类传播杂草种子是影响最广泛的一种,对现代植物的分布格局产生了深刻的影响。杂草种子的传播,对杂草种子库的数量和空间动态影响很大。研究种子传播的主要方法有荧光染料标记法、放射性同位素标记法、稳定同位素分析、分子遗传标记等。结合近几年国内外的研究进展,作者就杂草种子传播对种子库数量和空间动态影响的精确直接研究、杂草种子传播的过程及传播后的命运、杂草种子适应传播的机理、生态控草措施研究、外来杂草入侵蔓延与其种子传播的关系等方面提出了展望。 相似文献
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Rosa Menéndez;Geoff B. Monteith;Penny van Oosterzee;Noel D. Preece; 《Restoration Ecology》2024,32(4):e14104
With less than half of the world's tropical forests remaining, ecological restoration is urgently needed to halt biodiversity loss. However, the efficacy of different active reforestation methods remains largely untested particularly with respect to the recovery of fauna during the early years of restoration. Here, we present the results of a long-term restoration project in the Australian Wet Tropics after 6 years of planting. Using dung beetles as bioindicators of restoration success, we investigated how the diversity and density of trees in experimental plots influence the recovery of dung beetle diversity and their ecological functions (dung removal and secondary seed dispersal). We found that after only 6 years since planting, a native dung beetle community, representing around 41% of the species found in the adjacent rainforest, has colonized the experimental plots. Plots with the highest diversity of trees (24 species planted) showed higher dung beetle diversity, dung removal, and seed dispersal but only when the density of trees on the plots was low. These plots also have higher species richness, diversity, and abundance of rainforest species, while the opposite trend was found for open-habitat species. Therefore, planting a higher diversity of trees appears to be the best method for the early recovery of rainforest dung beetle communities and their functions. This is particularly crucial at low tree density, which is a common issue in active restoration projects as tree mortality is relatively high in the early years. 相似文献
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鸟类传播种子对于植物种群自然更新及群落演替具有重要的生态意义,鸟类栖息的树木具有富集种子雨功能,在山体滑坡区及废弃矿区等干扰生境中人工设置鸟类栖木,可以增加鸟类传播的种子雨输入,丰富土壤种子库,尤其食果鸟类可以传播那些处于群落演替中期至后期的乔、灌木树种,能够促进受干扰地区森林植被的演替进程.5·12汶川大地震对地震灾区造成了大面积的山体滑坡和严重的植被破坏,在地震灾区森林植被的生态恢复工作中,一些地区可以采用人工设置鸟类栖木方法,充分利用山体滑坡区周围残余森林的丰富种子源及众多食果鸟类,促进灾区森林植被的自然恢复. 相似文献
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Summary Bush regeneration programmes aim to restore native plant communities by interventions designed to assist natural recovery, supplemented by planting or direct seeding where necessary. The present study compared ground-dwelling ant communities and rates of seed removal by ants in weed-infested, regenerating and undamaged urban bushland in northern Sydney. Three replicate dry sclerophyll sites on sandstone were studied, each containing zones of weed-infested, regenerating and undamaged bushland. Canopy cover, midstorey cover, ground cover and litter depth were measured at each site. Each zone type showed distinctive vegetation and cover characteristics, particularly at the ground level. Ground foraging ants were sampled with pitfall traps, sorted to morphospecies and placed in functional groups. There were no significant differences in ant abundance, number of genera or number of morphospecies between site types. Ant diversity and equitability was highest in the undamaged zones, followed by regenerating zones, then weedy zones. There was a significant difference between zone types in the proportion of ant species in different functional groups. Weedy zones were dominated by Opportunist species whereas regenerating zones had a high proportion of Dominant Dolichoderinae. At undamaged zones, the distribution of ants across functional groups was more even. Differences in the ant communities between the three zone types were reflected by differences in interactions between ants and seeds. Seed removal rates of both native and exotic seeds were significantly lower at weedy zones than at undamaged zones, with the regenerating zones having intermediate rates. Sites subject to regeneration 4–10 years previously were intermediate between undamaged and weedy zones for ground cover, litter depth, ant species diversity and equitability, proportion of Opportunist ant species, and seed removal rates. Thus, the regeneration techniques used have been at least partially successful in restoring some aspects of the invertebrate fauna and ecological interactions typical of undamaged dry sclerophyll bushland. 相似文献
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Interactions among animals and plants are key to understanding seed dispersal, plant regeneration and plant community patterns. These interactions can be dynamic, with changes of species and functional roles across space and time. Despite fluctuations in species abundances and resources over time being the rule in natural communities, most studies approach plant–frugivore interactions as temporally static. We documented changes in bird and ant species in interactions with plants producing carbohydrate- (Miconia rubiginosa) or lipid-rich diaspores (Xylopia aromatica) comparing two fruiting seasons 15 years apart in a savanna in southeastern Brazil. We tested if abundance and body size of dispersal vectors (birds and ants) affected the frequency of interactions and the quantitative effectiveness of seed dispersal (QTC). Rich bird (26 species) and ant (18 genera) assemblages interacted with the diaspores. A core of bird and ant taxa was temporally consistent, and responsible for most seed removal across the two years for both plants. Temporal transience was more common for sporadic partners of interactions, and for species with similar functional roles. Abundance and body size of birds affected the interspecific contributions to QTC. Large-bodied birds dispersed large quantities of seeds of our relatively small-seeded plants, even if their visits were sporadic. For ants, variations in temperature and rainfall across time seems more important in driving variations in the contributions to QTC. The combined effect of birds and ants in the same system helps to stabilize the temporal fluctuations in the amount of seeds dispersed. However, ants alone are unlikely to replace the functional roles of vertebrate dispersers. Even though species in the assemblage change either their quantitative contribution to seed dispersal or their presence or absence in the interaction network, species persisting in interaction over time are the most important quantitative partners for plants. 相似文献
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Weta are giant, flightless orthopterans that are endemic to New Zealand. Although they are known to consume fleshy fruits and disperse seeds after gut passage, which is unusual among insects, their effectiveness as seed dispersal mutualists is debated. We conducted a series of laboratory experiments on alpine scree weta (Deinacrida connectens) and mountain snowberries (Gaultheria depressa) to investigate how fruit consumption rates, the proportion of ingested seeds dispersed intact and weta movement patterns vary with weta body sizes. On average weta dispersed 252 snowberry seeds nightly and travelled at a rate of 4 m min?1. However, seed dispersal effectiveness varied over three orders of magnitude and was strongly associated with body sizes. Smaller weta consumed few snowberry seeds and acted primarily as seed predators. On the other hand, the largest weta consumed and dispersed thousands of seeds each night and appear to be capable of transporting seeds over large distances. Overall results indicate that scree weta shift from being weakly interacting seed predators to strongly interacting, effective seed dispersers as they increase in size. 相似文献
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生态补偿标准的确定是生态补偿机制建立的重点和难点.以南水北调东线水源地保护一期生态建设工程的补偿为例,探讨生态建设的补偿标准.从工程投资和机会成本的角度分析生态建设的总成本为1.46亿元/年,通过生态系统服务价值评价并结合专家咨询赋权,计算出生态建设工程成功实施后,建设区域所增加的生态服务效益为0.83亿元/年,外部区域所增加的生态服务效益为2.13亿元/年;综合生态建设成本和生态效益,提出了根据生态服务效益分担生态建设成本的补偿标准分析思路,并由此计算得到外部区域对建设区域的补偿标准为1.11亿元/年. 相似文献
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The fire avoidance hypothesis proposes that a benefit of seed dispersal by ants (myrmecochory) is to protect seeds from being killed during fire and to facilitate post‐fire germination of seeds that require heat shock to break their physical dormancy. The aim of this study was to quantify the effect of fire and seed burial by a predominant seed‐dispersing ant, Rhytidoponera metallica (subfamily: Ectatomminae) on germination levels of three ant‐dispersed legume species (Pultenaea daphnoides, Acacia myrtifolia and Acacia pycnantha). Experimental burial of seeds within aluminium cans at a site prior to being burnt and at an adjacent unburnt site showed that fire increased germination levels, particularly for seeds buried at 1‐ and 2‐cm deep and that overall, germination levels differed among the three plant species. To quantify seed burial depths and post‐fire germination levels facilitated by R. metallica ants, seeds were fed to colonies prior to fire at the burnt and unburnt sites. Of the seeds buried within nests that were recovered, between 45% and 75% occurred within the upper 6 cm of the soil profile, although unexpectedly, greater percentages of seeds were recovered from the upper 0–2 cm of nests in the unburnt site compared with nests in the burnt site. Germination levels of buried seeds associated with R. metallica nests ranged from 21.2% to 29.5% in the burnt site compared with 3.1–14.8% in the unburnt site. While increased seed germination levels were associated with R. metallica nests following fire, most seeds were buried at depths below those where optimal temperatures for breaking seed dormancy occurred during the fire. We suggest that R. metallica ants may provide fire avoidance benefits to myrmecochorous seeds by burying them at a range of depths within a potential germination zone defined by intra‐ and inter‐fire variation in levels of soil heating. 相似文献
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Seed dispersal is a central process in plant ecology with consequences for species composition and habitat structure. Some bird species are known to disperse the seeds they ingest, whereas others, termed ‘seed predators’, digest them and apparently play no part in dispersal, but it is not clear if these are discrete strategies or simply the ends of a continuum. We assessed dispersal effectiveness by combining analysis of faecal samples and bird density. The droppings of seed dispersers contained more entire seeds than those of typical seed predators, but over a quarter of the droppings of seed predators contained whole seeds. This effect was further magnified when bird density was taken into account, and was driven largely by one frequent interaction: the Chaffinch Fringilla coelebs, a typical seed predator and the most abundant bird species in the area and dispersed seeds of Leycesteria formosa, a non‐native plant with berry‐like fruits. These results suggest the existence of a continuum between seed predators and seed dispersers. 相似文献
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The role of mutualisms in contributing to species invasions is rarely considered, inhibiting effective risk analysis and management options. Potential ecological consequences of invasion of non‐native pollinators include increased pollination and seed set of invasive plants, with subsequent impacts on population growth rates and rates of spread. We outline a quantitative approach for evaluating the impact of a proposed introduction of an invasive pollinator on existing weed population dynamics and demonstrate the use of this approach on a relatively data‐rich case study: the impacts on Cytisus scoparius (Scotch broom) from proposed introduction of Bombus terrestris. Three models have been used to assess population growth (matrix model), spread speed (integrodifference equation), and equilibrium occupancy (lattice model) for C. scoparius. We use available demographic data for an Australian population to parameterize two of these models. Increased seed set due to more efficient pollination resulted in a higher population growth rate in the density‐independent matrix model, whereas simulations of enhanced pollination scenarios had a negligible effect on equilibrium weed occupancy in the lattice model. This is attributed to strong microsite limitation of recruitment in invasive C. scoparius populations observed in Australia and incorporated in the lattice model. A lack of information regarding secondary ant dispersal of C. scoparius prevents us from parameterizing the integrodifference equation model for Australia, but studies of invasive populations in California suggest that spread speed will also increase with higher seed set. For microsite‐limited C. scoparius populations, increased seed set has minimal effects on equilibrium site occupancy. However, for density‐independent rapidly invading populations, increased seed set is likely to lead to higher growth rates and spread speeds. The impacts of introduced pollinators on native flora and fauna and the potential for promoting range expansion in pollinator‐limited ‘sleeper weeds’ also remain substantial risks. 相似文献