Forest ecology

森林生态学
  • 文章类型: Journal Article
    洪泛区为提供陆地生态系统服务做出了重大贡献,但也是全世界最脆弱和退化的生态系统之一。洪泛区性质的异质性是由特定河流洪水状况的变化引起的,流域特征,和山谷形态,影响季节性洪水森林的分类学,功能,和系统发育多样性。这项研究解决了洪泛区生态学中持续存在的知识差距,专注于季节性干燥的热带地区。我们探索洪水制度之间的关系,环境条件,植被组成,功能和系统发育多样性,以及环境变量对地上生物量(AGB)和生态策略的影响。该研究横跨巴西东南部主要流域的六条河流:里奥格兰德河和圣弗朗西斯科河。我们根据洪水状况确定了每个洪泛区的五个生态单元,并调查了每个生态单元的六个地块。我们测量了DBH>5cm的树木,并收集了功能性状,连同详细的土壤,气候,水位数据。我们计算了地块级植物区系组成,分类学,功能,和系统发育多样性,木材密度,和AGB。分析了功能和系统发育差异,以及气候的影响,土壤,水文变量使用广义线性混合模型进行量化。我们展示了洪水频率和持续时间如何影响整个洪泛区的植物区系组成。分类学和系统发育多样性响应气候,土壤,和水文变量,虽然功能多样性主要响应水文变量,强调环境过滤的作用。水文季节性,土壤肥力,在研究的季节性洪水泛滥的热带森林中,洪水制度成为影响群落结构和生态策略的关键因素。地块水平的AGB对磷有反应,但对气候或水文变量没有反应。该研究还强调了生态单位和盆地之间的功能和系统发育差异,表明潜在的气候变化影响。
    Floodplains contribute significantly to terrestrial ecosystem service provision but are also among the most vulnerable and degraded ecosystems worldwide. Heterogeneity in floodplain properties arises from variations in river-specific flood regimes, watershed characteristics, and valley morphology, influencing seasonally flooded forests\' taxonomic, functional, and phylogenetic diversity. This study addresses persisting knowledge gaps in floodplain ecology, focusing on the seasonally dry tropics. We explore the relationships between flood regime, environmental conditions, vegetation composition, functional and phylogenetic diversity, and the impact of environmental variables on above-ground biomass (AGB) and ecological strategies. The study spans six rivers in southeastern Brazil\'s main river basins: Rio Grande and São Francisco. We identified five eco-units in each floodplain based on flooding regimes and surveyed six plots per eco-unit. We measured trees with DBH > 5 cm and collected functional traits, along with detailed soil, climate, and water level data. We calculated plot-level floristic composition, taxonomic, functional, and phylogenetic diversity, wood density, and AGB. Functional and phylogenetic dissimilarity were analyzed, and the effects of climate, soil, and hydrological variables were quantified using generalized linear mixed models. We show how flood frequency and duration affect floristic composition across the floodplains. Taxonomic and phylogenetic diversity responded to climate, soil, and hydrological variables, while functional diversity responded primarily to hydrological variables, emphasizing the role of environmental filtering. Hydrological seasonality, soil fertility, and flood regime emerged as key factors shaping community structure and ecological strategies in the studied seasonally flooded tropical forests. Plot-level AGB responded to phosphorus but not to climate or hydrological variables. The study also highlights functional and phylogenetic dissimilarities among eco-units and basins, indicating potential climate change impacts.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    北纬高纬度随北极在纬度森林梯度上的扩大而变化,表明树木和灌木的存在向增加转变。变化的持续可能取决于未来的气候情景和当前状态,和网站历史,森林结构。这里,我们通过将当前的森林模式与最近的树木覆盖趋势以及到2100年的冠层高度的未来模型估计值联系起来,探索了北方地区基于梯度的变化的持久性。结果表明,从北方森林到针叶林-苔原过渡带的结构梯度上的预测潜在高度变化。高度的积极潜在变化集中在过渡森林中,在最近封面出现积极变化的地方,而北方森林的潜在变化是高度可变的。不同气候情景的结果是一致的,揭示了北美2100年持续的生物群落转移集中在过渡景观中,无论气候情景如何。
    High northern latitude changes with Arctic amplification across a latitudinal forest gradient suggest a shift towards an increased presence of trees and shrubs. The persistence of change may depend on the future scenarios of climate and on the current state, and site history, of forest structure. Here, we explore the persistence of a gradient-based shift in the boreal by connecting current forest patterns to recent tree cover trends and future modeled estimates of canopy height through 2100. Results show variation in the predicted potential height changes across the structural gradient from the boreal forest through the taiga-tundra ecotone. Positive potential changes in height are concentrated in transitional forests, where recent positive changes in cover prevail, while potential change in boreal forest is highly variable. Results are consistent across climate scenarios, revealing a persistent biome shift through 2100 in North America concentrated in transitional landscapes regardless of climate scenario.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    相关系数被广泛用于识别和量化代理档案中的气候信号。树木气候学家通常会使用树木年轮年代学与气象测量之间的显着关系来区分或多或少相关的气候变化以形成年轮。虽然在寒冷季节的月份中通常发现微不足道的生长-气候相关性,我们认为,与夏季高温的弱关系并不一定证明它们对木制品发育的重要性。这里,我们使用斯堪的纳维亚北部和西班牙南部之间十个树线站点的最大晚木密度记录,以证明当植被时间变得更长和更温暖时,每月的生长-气候相关性如何从狭窄的单峰季节变化到宽的双峰季节。当最低温度超过5°C左右的“生物零”时,就会发生统计上有意义的关系。我们得出的结论是,没有证据表明树木生长与地中海地区最暖的夏季温度之间具有统计学意义,这并不是缺乏生理重要性的证据夏季高温对环形成的重要性。因为相关性永远不应该与因果关系混淆,统计值需要机械理解,对于生长季节内外的无关紧要的相关性,需要不同的解释。
    Correlation coefficients are widely used to identify and quantify climate signals in proxy archives. Significant relationships between tree-ring chronologies and meteorological measurements are typically applied by dendroclimatologists to distinguish between more or less relevant climate variation for ring formation. While insignificant growth-climate correlations are usually found with cold season months, we argue that weak relationships with high summer temperatures not necessarily disprove their importance for xylogenesis. Here, we use maximum latewood density records from ten treeline sites between northern Scandinavia and southern Spain to demonstrate how monthly growth-climate correlations change from narrow unimodal to wide bimodal seasons when vegetation periods become longer and warmer. Statistically meaningful relationships occur when minimum temperatures exceed \'biological zero\' at around 5° C. We conclude that the absence of evidence for statistical significance between tree growth and the warmest summer temperatures at Mediterranean sites is no evidence of absence for the physiological importance of high summer temperatures for ring formation. Since correlation should never be confused with causation, statistical values require mechanistic understanding, and different interpretations are needed for insignificant correlations within and outside the growing season.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    我们研究了两种同胞小袋鼠的发生,红脖子的pademelon(Thylogalethetis)和红腿的pademelon(T.污名)在新南威尔士州东北部,澳大利亚与结构栖息地属性的关系。在我们的研究现场,这两个物种都栖息在封闭的森林环境中,并且分布重叠,但是T.thetis在晚上离开森林以放牧相邻的草林边缘,而T.stigmatica仍留在森林中并浏览森林植被。研究的目的是调查两种森林类型的结构属性,潮湿的硬叶林和雨林,与森林环境中这两种小袋鼠物种的精细规模有关。
    我们收集了48个相机陷阱站的发生数据,这些相机陷阱站平均分配给雨林和湿硬叶林。在每个摄像机点上,我们还测量了一系列结构栖息地属性,以确定两种Thylogale物种的栖息地隶属关系。主成分分析用于描述栖息地的主要趋势,并使用广义线性模型来描述变量在预测每个物种栖息地发生方面的功效。
    Thylogalethetis的发生次数明显大于T.stimatica的发生次数,这是由潮湿的硬叶林中T.thetis的发生率明显增加所驱动的。这两个物种之间存在空间和时间上的划分;在单个相机上,这两个物种的发生有显着差异,而在湿叶树森林中,病斑T.thetis的活动时间表与T.thetis的活动时间表不同,后者达到了最大的发生率。在更精细的(摄像机站)尺度上,T.thetis的发生率随着靠近道路和草地边缘以及岩石较少,陡峭程度较低的地点而增加。在葡萄藤等雨林元素的存在下,棕榈和蕨类植物,更多的地面覆盖和树木落差,以及新兴桉树较少的地点。
    我们的发现对管理这些行星及其栖息地具有启示意义。T.thetis是一种常见的物种,比T.signatica更常遇到,它对路边和草地边缘等人为干扰做出了积极的反应,大概是因为这些地区提供了良好的放牧机会。相比之下,T.污名病是一种受威胁的物种,它对自然干扰做出了反应,比如横向覆盖更大的落树间隙,热带雨林食物植物可能更丰富。我们的研究结果表明,因此,保护受威胁的T.stimatica需要保护完整的雨林。
    UNASSIGNED: We studied the occurrence of two sympatric wallabies, the red-necked pademelon (Thylogale thetis) and the red-legged pademelon (T. stigmatica) in northeastern New South Wales, Australia in relation to structural habitat attributes. At our study site, both species inhabit closed forest environments and have overlapping distributions, but T. thetis leaves the forest at night to graze adjacent grassy forest edges whereas T. stigmatica remains within the forest and browses forest vegetation. The objectives of the study were to investigate how structural attributes of two forest types, wet sclerophyll forest and rainforest, relate to the fine-scale occurrence of these two wallaby species within the forested environment.
    UNASSIGNED: We gathered occurrence data from 48 camera trap stations divided equally between rainforest and wet sclerophyll forest. At each camera point, we also measured a range of structural habitat attributes to determine habitat affiliations for the two Thylogale species. Principal component analyses were used to describe major trends in habitat, and generalised linear models were used to describe the efficacy of the variables in predicting habitat occurrence of each species.
    UNASSIGNED: The number of occurrences of Thylogale thetis was significantly greater than occurrences of T. stigmatica, which was driven by significantly greater occurrences of T. thetis in wet sclerophyll forest. There was both spatial and temporal partitioning between the two species; there was a significant difference in the occurrences of the two species at individual cameras and T. stigmatica had a different activity schedule than T. thetis in wet sclerophyll forest, where the latter reached its greatest rate of occurrence. At a finer (camera station) scale, occurrences of T. thetis increased with proximity to roads and grassy edges and at sites that were less rocky and less steep. T. stigmatica occurrence increased in the presence of rainforest elements like vines, palms and ferns, more ground-level cover and tree-fall gaps and at sites with fewer emergent eucalypts.
    UNASSIGNED: Our findings have implications for managing these pademelons and their habitats. T. thetis is a common species that was encountered more often than T. stigmatica, and it responded positively to human disturbance like roadsides and grassy edges, presumably because these areas provided good grazing opportunities. By comparison, T. stigmatica is a threatened species, and it responded to natural disturbance like tree-fall gaps where lateral cover was greater, and where rainforest food plants may be more abundant. Our results suggest, therefore, that conservation of the threatened T. stigmatica requires the preservation of intact rainforest.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    气候变化导致的生物多样性和生态系统健康下降引起了人们的迫切关注。作为回应,正在实施大规模的多物种监测计划,这些计划越来越多地采用基于传感器的方法,例如声学记录。这些方法严重依赖生态数据科学。然而,开发用于处理基于传感器的数据的可靠算法在很大程度上依赖于足够质量和数量的标记数据集。我们提供了1,575个黎明合唱音景录音数据集,141被完全注释(n=32,994注释)与鸟类,哺乳动物和两栖动物发声。包括其余的录音以促进新颖的研究应用。这些录音与48个站点级别的气候条件配对,森林结构和地形协变量。该数据集为开发声学分类算法或研究生物多样性和野生动物行为及其与环境梯度的关系的研究人员提供了宝贵的资源。黎明合唱录音是作为长期北方斑点猫头鹰监测计划的一部分收集的;这表明了利用现有监测工作来加强生物多样性采样的补充价值。
    这个黎明合唱音景录音数据集是为数不多的带有非生物和种间(跨物种)和种内(物种内)鸟类注释的开放式声学数据集之一,哺乳动物和两栖动物的子型和第一个与气候配对,在记录器位置提取的森林结构和地形协变量。这使其成为研究黎明合唱及其与环境关系的研究人员的宝贵资源。
    UNASSIGNED: Declines in biodiversity and ecosystem health due to climate change are raising urgent concerns. In response, large-scale multispecies monitoring programmes are being implemented that increasingly adopt sensor-based approaches such as acoustic recording. These approaches rely heavily on ecological data science. However, developing reliable algorithms for processing sensor-based data relies heavily on labelled datasets of sufficient quality and quantity. We present a dataset of 1,575 dawn chorus soundscape recordings, 141 being fully annotated (n = 32,994 annotations) with avian, mammalian and amphibian vocalisations. The remaining recordings were included to facilitate novel research applications. These recordings are paired with 48 site-level climatic, forest structure and topographic covariates. This dataset provides a valuable resource to researchers developing acoustic classification algorithms or studying biodiversity and wildlife behaviour and its relationship to environmental gradients. The dawn chorus recordings were collected as part of a long-term Northern Spotted Owl monitoring program; this demonstrates the complementary value of harnessing existing monitoring efforts to strengthen biodiversity sampling.
    UNASSIGNED: This dataset of dawn chorus soundscape recordings is one of the few open-access acoustic datasets annotated with non-biotic and both interspecific (across species) and intraspecific (within species) bird, mammal and amphibian sonotypes and the first that is paired with climatic, forest structure and topographical covariates extracted at recorder locations. This makes it a valuable resource for researchers studying the dawn chorus and its relationship to the environment.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    地球上的大多数树木都依赖于外生菌根真菌(EcMF)释放并提供的关键土壤养分,地球上所有的陆地植物都与帮助它们在自然界中生存的细菌联系在一起。然而,我们对EcMF的存在如何改变土壤细菌群落的理解,土壤食物网,根化学需要直接的实验证据来理解EcMF可能在地下植物微生物组中产生的影响。为此,我们在接种了EcMF和本地森林细菌群落或仅本地细菌群落的土壤中种植了松树植物。然后我们分析了土壤细菌群落,应用代谢组学和脂质组学,和链接的组学数据集,以了解EcMF的存在如何改变地下生物地球化学,细菌群落结构,以及它们的功能潜力。我们发现EcMF(i)的存在会富集与自然界中植物生长增强有关的土壤细菌,(ii)改变脂质和非脂质土壤代谢物的数量和组成,和(iii)改变植物根系化学以抑制病原体,酶促保守,和活性氧清除。使用这种多才多艺的方法,因此,我们表明,这种广泛的真菌共生可能是构建土壤食物网的常见因素。重要的是了解土壤微生物之间的相互作用以及它们的寄主植物将帮助我们对抗气候变化对陆地生态系统的负面影响。不幸的是,我们缺乏清楚的了解外生菌根真菌(EcMF)的存在-地球上最主要的土壤微生物群之一-形状低于地面有机资源和细菌群落的组成。为了解决这个知识差距,我们对土壤和植物根部的脂质和非脂质代谢物进行了分析,以土壤细菌群落为特征,并比较了有或没有EcMF的改良土壤。我们的结果表明,EcMF的存在改变了土壤有机资源的有效性,影响不同细菌群落的增殖(在类型和潜在功能方面),并启动植物根系化学以抑制病原体和节约能源。因此,我们的发现为两个最主要的土壤微生物群之间以及与宿主植物之间的相互作用提供了急需的见解。
    Most of Earth\'s trees rely on critical soil nutrients that ectomycorrhizal fungi (EcMF) liberate and provide, and all of Earth\'s land plants associate with bacteria that help them survive in nature. Yet, our understanding of how the presence of EcMF modifies soil bacterial communities, soil food webs, and root chemistry requires direct experimental evidence to comprehend the effects that EcMF may generate in the belowground plant microbiome. To this end, we grew Pinus muricata plants in soils that were either inoculated with EcMF and native forest bacterial communities or only native bacterial communities. We then profiled the soil bacterial communities, applied metabolomics and lipidomics, and linked omics data sets to understand how the presence of EcMF modifies belowground biogeochemistry, bacterial community structure, and their functional potential. We found that the presence of EcMF (i) enriches soil bacteria linked to enhanced plant growth in nature, (ii) alters the quantity and composition of lipid and non-lipid soil metabolites, and (iii) modifies plant root chemistry toward pathogen suppression, enzymatic conservation, and reactive oxygen species scavenging. Using this multi-omic approach, we therefore show that this widespread fungal symbiosis may be a common factor for structuring soil food webs.IMPORTANCEUnderstanding how soil microbes interact with one another and their host plant will help us combat the negative effects that climate change has on terrestrial ecosystems. Unfortunately, we lack a clear understanding of how the presence of ectomycorrhizal fungi (EcMF)-one of the most dominant soil microbial groups on Earth-shapes belowground organic resources and the composition of bacterial communities. To address this knowledge gap, we profiled lipid and non-lipid metabolites in soils and plant roots, characterized soil bacterial communities, and compared soils amended either with or without EcMF. Our results show that the presence of EcMF changes soil organic resource availability, impacts the proliferation of different bacterial communities (in terms of both type and potential function), and primes plant root chemistry for pathogen suppression and energy conservation. Our findings therefore provide much-needed insight into how two of the most dominant soil microbial groups interact with one another and with their host plant.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    保护区越来越多地提高其固碳能力,生物多样性的好处。然而,我们对它们是否有效减少森林砍伐和退化的了解有限,或促进植被生长,以及这对地上木质碳储量变化的影响。在这里,我们提供了一个新的基于卫星雷达的南部非洲林地植被碳变化图,并将其与匹配方法相结合,以评估保护区对碳动态的影响。我们证明了保护对地上碳有积极的影响,与未受保护的可比土地(每年+0.08%)相比,保护区的存量增长更快(每年+0.53%)。保护的积极影响反映了较低的森林砍伐率(-39%)和退化率(-25%),以及受保护土地内植被生长的患病率更高(12%)。在控制了位置差异后,受到严格保护的区域与其他类型的保护具有相似的结果,效果评分因国家而异,以及威胁的程度。这些结果突出了保护区封存地上碳的潜力,尽管我们警告说,在某些地区,这可能会对生物多样性产生负面影响,和人类福祉。
    Protected areas are increasingly promoted for their capacity to sequester carbon, alongside biodiversity benefits. However, we have limited understanding of whether they are effective at reducing deforestation and degradation, or promoting vegetation growth, and the impact that this has on changes to aboveground woody carbon stocks. Here we present a new satellite radar-based map of vegetation carbon change across southern Africa\'s woodlands and combine this with a matching approach to assess the effect of protected areas on carbon dynamics. We show that protection has a positive effect on aboveground carbon, with stocks increasing faster in protected areas (+0.53% per year) compared to comparable lands not under protection (+0.08% per year). The positive effect of protection reflects lower rates of deforestation (-39%) and degradation (-25%), as well as a greater prevalence of vegetation growth (+12%) inside protected lands. Areas under strict protection had similar outcomes to other types of protection after controlling for differences in location, with effect scores instead varying more by country, and the level of threat. These results highlight the potential for protected areas to sequester aboveground carbon, although we caution that in some areas this may have negative impacts on biodiversity, and human wellbeing.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    仅气候驱动因素并不能充分解释整个欧洲落叶林中萌芽时间的区域变化。stand-levelfactors,如树种丰富度,可能会通过在同一地点的宏观气候下创造不同的微气候来影响爆发时间。我们评估了春季物候的不同阶段(开始,中点,结束,四个重要的欧洲树种(Betulapendula,FagusSylvatica,Quercusrobur和Tiliacordata)在2021年和2022年在比利时(FORBIO)进行的普通花园树木生物多样性实验的单一栽培和四种混合林分。林分之间在芽冷却方面的微气候差异,温度强迫,土壤温度相当高,在春季,四种混合物通常比单一栽培更冷,但不是在冬天。在2021年较冷的春天,在看台上,萌芽期的结束提前了,它的整体持续时间缩短了,在四种混合物中。在物种层面,这种反应对于F.sylvatica是显著的。在2022年较温暖的春季,在F.sylvatica和,不太明显,在B.pendula中,但在立场上没有一般反应。Q.robur在2021年的四种混合物中显示出特定的模式,延迟了萌芽的开始,而在2022年,所有林分的萌芽持续时间都很短。单一栽培和四种物种混合物之间的物候差异与光照而不是温度的微气候差异有关,因为即使相对较冷的微气候也显示出先进的物候。与天气条件相比,树种丰富度对萌芽时间的影响较小,但是这种影响对关键物种如F.sylvatica和较冷的泉水很重要。这些结果表明,森林生物多样性可以影响萌芽物候,具有更广泛的含义,特别是森林和陆地表面模型。
    Climatic drivers alone do not adequately explain the regional variation in budburst timing in deciduous forests across Europe. Stand-level factors, such as tree species richness, might affect budburst timing by creating different microclimates under the same site macroclimate. We assessed different phases of the spring phenology (start, midpoint, end, and overall duration of the budburst period) of four important European tree species (Betula pendula, Fagus sylvatica, Quercus robur and Tilia cordata) in monocultures and four-species mixture stands of a common garden tree biodiversity experiment in Belgium (FORBIO) in 2021 and 2022. Microclimatic differences between the stands in terms of bud chilling, temperature forcing, and soil temperature were considerable, with four-species mixtures being generally colder than monocultures in spring, but not in winter. In the colder spring of 2021, at the stand level, the end of the budburst period was advanced, and its overall duration shortened, in the four-species mixtures. At species level, this response was significant for F. sylvatica. In the warmer spring of 2022, advances in spring phenology in four-species stands were observed again in F. sylvatica and, less markedly, in B. pendula but without a general response at the stand level. Q. robur showed specific patterns with delayed budburst start in 2021 in the four-species mixtures and very short budburst duration for all stands in 2022. Phenological differences between monocultures and four-species mixtures were linked to microclimatic differences in light availability rather than in temperature as even comparatively colder microclimates showed an advanced phenology. Compared to weather conditions, tree species richness had a lower impact on budburst timing, but this impact can be of importance for key species like F. sylvatica and colder springs. These results indicate that forest biodiversity can affect budburst phenology, with wider implications, especially for forest- and land surface models.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    重要的是要有关于存在/缺席的可靠信息,人口结构,和自然范围内动物的密度。检测小生物,然而,例如Nearctic树树干编织蜘蛛DrapetiscaalterandaChamberlin1909(Araneae:Linyphiidae),由于其小型化和神秘的性质,提出了挑战。我们使用捕获/重新捕获研究来确定该蜘蛛的检测和重新捕获概率,该方法使用了用于测量树干的标准拍片技术。蜘蛛在3种不同的树种上释放,这些树种提供了一系列的微栖息地,包括可变的树皮表面积和沟槽深度/宽度。微生境特征在蜘蛛重新捕获的时间中起着很小的作用(即,随着开沟的增加,重新捕获的速度较慢)。然而,我们的结果表明,在大多数情况下,重复实验和个体重新捕获概率超过90%的100%检测,在树种之间和树木周长方面没有观察到显着的重新捕获差异。此外,我们表明,大多数蜘蛛可以在围绕树干的2次采样旋转内被重新捕获,收集雄性和雌性蜘蛛的可能性没有差异(尽管它们的大小明显不同)。最后,我们发现刷子之间没有区别,支持这种方法可在收藏家和研究中复制的观点。总的来说,我们对通过这种技术获得的生态知识建立了信心,并鼓励其在类似物种和系统中的应用。
    It is important to have reliable information on the presence/absence, population structure, and density of animals across their natural range. Detecting small organisms, however, such as the Nearctic tree trunk sheetweaver spider Drapetisca alteranda Chamberlin 1909 (Araneae: Linyphiidae), presents challenges due to its diminutive size and cryptic nature. We used a capture/recapture study to determine the detection and recapture probabilities of this spider using a standard beat sheet technique adopted for surveying tree trunks. Spiders were released on 3 different tree species that provided a range of microhabitats, including variable bark surface area and furrow depth/width. Microhabitat features played a small role in the timing of spider recapture (i.e., slower rate of recapture as furrowing increased). However, our results demonstrated 100% detection across replicate experiments and individual recapture probabilities exceeding 90% in most situations, with no significant differences in recapture observed among tree species and with respect to tree circumference. Furthermore, we show that most spiders could be recaptured within 2 sampling revolutions around the tree trunk, and there was no difference in the probability of collecting male and female spiders (although they differ markedly in size). Finally, we found no difference among brushers, supporting the idea that this method is replicable across collectors and studies. Collectively, we establish confidence in the ecological knowledge obtained with this technique and encourage its application with similar species and systems.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    气候变化可能会增加特有树种的栖息地丧失,并推动山区森林的森林转化。高程梯度提供了预测此类变化可能后果的机会。虽然已经沿着海拔梯度研究了各种分类单元的物种组成,关于土壤生物营养变化的数据很少。这里,我们调查了长白山北坡Collembola群落的营养变化,中国。我们在七个海拔(800-1700masl)的原始森林中采样了Collembola。我们在物种水平上测量了个体体长和总体稳定同位素。我们进一步将Collembola物种分类为生命形式。随着海拔的增加,Colembola群落的Δ15N和Δ13C值以及最小Δ15N值和同位素唯一性的群落加权均值增加,而Δ15N值的范围减小。Δ13C值的最大值和最小值在海拔之间有所不同,但没有线性趋势。Further,在所有海拔高度上出现的Collembola物种的Δ15N值随海拔高度的增加而增加。Δ15N值随海拔的变化在半叶物种中最为明显,而Δ13C值随着Euedaphic物种的升高而增加最强。Δ15N值随着半叶和松叶物种的体型减小而增加。总的来说,结果表明,在较低海拔地区充当初级分解者的Collembola物种向在较高海拔森林中充当次级分解者,甚至是捕食者或清道夫的转变。结果进一步表明,获得替代食物资源取决于Collembola的生命形式以及体型,并且在生态系统之间有所不同。
    Climate change will likely increase habitat loss of endemic tree species and drives forest conversion in mountainous forests. Elevation gradients provide the opportunity to predict possible consequences of such changes. While species compositions of various taxa have been investigated along elevation gradients, data on trophic changes in soil-dwelling organisms are scarce. Here, we investigated trophic changes of the Collembola communities along the northern slope of Changbai Mountain, China. We sampled Collembola in primary forests at seven elevations (800-1700 m asl). We measured individual body lengths and bulk stable isotopes on species level. We further categorized Collembola species into life forms. The community-weighted means of Δ15N and Δ13C values as well as minimum Δ15N values and isotopic uniqueness of Collembola communities increased with increasing elevation, while the range of Δ15N values decreased. Maximum and minimum of Δ13C values differed between elevations but showed no linear trend. Further, Δ15N values of Collembola species occurring across all elevations increased with elevation. Changes in Δ15N values with elevation were most pronounced in hemiedaphic species, while Δ13C values increased strongest with elevation in euedaphic species. Δ15N values increased with decreasing body size in hemiedaphic and euedaphic species. Overall, the results suggest that Collembola species functioning as primary decomposers at lower elevations shift towards functioning as secondary decomposers or even predators or scavengers at higher elevation forests. The results further indicate that access to alternative food resources depends on Collembola life form as well as body size and varies between ecosystems.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

公众号