disturbances

干扰
  • 文章类型: Journal Article
    预计森林将受到气候变化和扰动制度的强烈影响,威胁到他们维持提供基本服务的能力。最近,促进耐旱物种或功能多样化的林分已成为应对全球变化的管理选择。我们的研究旨在使用基于单个过程的模型HETEROFOR评估对比林分水平的管理方案对北美东部和中欧的温带森林的复原力的影响。我们根据四种管理方案(一切照旧-BAU;气候变化适应-CC;功能多样性方法-FD;无管理-NM)模拟了未来极端气候下100年八个林分的演变,同时面临多种干扰,总共进行了160次模拟。我们发现FD在蒸腾作用和树木生物量方面表现出最大的恢复力,然后是CC,然后是BAU,而这三种情况在净初级生产方面是等同的。然而,这些结果取决于森林类型:增加功能多样性是增加针叶人工林恢复力的有力选择,而在阔叶和混交林中,BAU和适应性管理方案之间没有明显差异。FD促进了比其他任何情况下更高的树种多样性水平,所有管理方案在伐木量方面都是相似的。NM总是表现出最低的弹性,表明森林管理可以成为减轻全球变化不利影响的重要工具。我们的研究强调,树级基于过程的模型是一个相关工具,可以确定合适的管理方案,使森林适应全球变化,只要考虑到模型的局限性,以及替代管理选项,特别是那些基于功能多样性的,很有希望,应该从现在开始推广。
    Forests are expected to be strongly affected by modifications in climate and disturbance regimes, threatening their ability to sustain the provision of essential services. Promoting drought-tolerant species or functionally diverse stands have recently emerged as management options to cope with global change. Our study aimed at evaluating the impact of contrasting stand-level management scenarios on the resilience of temperate forests in eastern North America and central-western Europe using the individual process-based model HETEROFOR. We simulated the evolution of eight stands over 100 years under a future extreme climate according to four management scenarios (business as usual - BAU; climate change adaptation - CC; functional diversity approach - FD; no management - NM) while facing multiple disturbances, resulting in a total of 160 simulations. We found that FD demonstrated the greatest resilience regarding transpiration and tree biomass, followed by CC and then BAU, while these three scenarios were equivalent concerning the net primary production. These results were however dependent on forest type: increasing functional diversity was a powerful option to increase the resilience of coniferous plantations whereas no clear differences between BAU and adaptive management scenarios were detected in broadleaved and mixed stands. The FD promoted a higher level of tree species diversity than any other scenario, and all scenarios of management were similar regarding the amount of harvested wood. The NM always showed the lowest resilience, demonstrating that forest management could be an important tool to mitigate adverse effects of global change. Our study highlighted that tree-level process-based models are a relevant tool to identify suitable management options for adapting forests to global change provided that model limitations are considered, and that alternative management options, particularly those based on functional diversity, are promising and should be promoted from now on.
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  • 文章类型: Journal Article
    基于自然的气候解决方案(NCS)被视为缓解气候变化的主要工具。特别是在能够储存和封存大量碳的森林地区。新英格兰是美国森林最茂密的地区之一(按土地面积计算,森林面积>75%)。森林碳是气候缓解政策的重要组成部分。大量罕见的干扰,比如飓风,是依靠森林碳来缓解气候变化的政策的不确定性和风险的主要来源,特别是预计气候变化会改变飓风的强度和程度。迄今为止,大多数关于干扰对森林碳储量影响的研究都集中在火灾上。这里,我们表明,该地区的单个飓风可以下降121至250MMTCO2e或地上森林总碳的4.6%-9.4%,远高于新英格兰森林每年封存的碳(16MMTCO2e年-1)。然而,飓风的排放不是瞬时的;减少的碳变成净排放需要大约19年,减少的碳排放的90%需要100年。使用HURRECON和EXPOS模型在一系列历史和预计风速下重建飓风,我们发现,飓风风速增加8%和16%会导致严重受损区域(广泛的树木死亡率)的范围增加10.7和24.8倍。风速的增加也导致了前所未有的地理变化,内陆和北部,进入森林茂密的地区,传统上受飓风影响较小。鉴于单个飓风可以排放相当于新英格兰森林封存的10年以上的碳,这些森林作为持久碳汇的地位是不确定的。对于依赖森林作为NCS的决策者来说,了解干扰对森林碳储量的风险是必要的。
    Nature-based climate solutions (NCS) are championed as a primary tool to mitigate climate change, especially in forested regions capable of storing and sequestering vast amounts of carbon. New England is one of the most heavily forested regions in the United States (>75% forested by land area), and forest carbon is a significant component of climate mitigation policies. Large infrequent disturbances, such as hurricanes, are a major source of uncertainty and risk for policies relying on forest carbon for climate mitigation, especially as climate change is projected to alter the intensity and extent of hurricanes. To date, most research into disturbance impacts on forest carbon stocks has focused on fire. Here, we show that a single hurricane in the region can down between 121 and 250 MMTCO2e or 4.6%-9.4% of the total aboveground forest carbon, much greater than the carbon sequestered annually by New England\'s forests (16 MMTCO2e year-1). However, emissions from hurricanes are not instantaneous; it takes approximately 19 years for downed carbon to become a net emission and 100 years for 90% of the downed carbon to be emitted. Reconstructing hurricanes with the HURRECON and EXPOS models across a range of historical and projected wind speeds, we find that an 8% and 16% increase in hurricane wind speeds leads to a 10.7- and 24.8-fold increase in the extent of high-severity damaged areas (widespread tree mortality). Increased wind speed also leads to unprecedented geographical shifts in damage, both inland and northward, into heavily forested regions traditionally less affected by hurricanes. Given that a single hurricane can emit the equivalent of 10+ years of carbon sequestered by forests in New England, the status of these forests as a durable carbon sink is uncertain. Understanding the risks to forest carbon stocks from disturbances is necessary for decision-makers relying on forests as a NCS.
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  • 文章类型: Journal Article
    基于网络的系统是我们日常生活的核心。无论是电子联网,电网或运输,用户希望网络正常运行,并提供安全和保障的感觉。然而,可能会有干扰。在本文中,我们考虑公共交通方面的干扰。这方面的重点是公共交通规划和运营。为了分类和应对干扰,一个人可以找到很多想法,包括鲁棒性,弹性,脆弱性,中断缓解或延迟管理。我们调查了相关的文献流,并对其进行了透视。作为一个主要见解,我们表明存在不同的文献链,这些文献可能会受益于变得更好的联系和交织。加上信息技术和解决方案的最新进展,包含鲁棒性和干扰的更综合的问题设置可以在未来的计划和操作中发挥重要作用。
    Network-based systems are at the core of our everyday life. Whether it is electronic networking, electricity grids or transportation, users expect the networks to function properly and provide a feeling of safety and security. However, there may be disturbances. In this paper, we consider disturbances in the context of public transportation. The focus in this respect is on public transport planning and operations. To classify and cope with disturbances, one can find many ideas, including robustness, resilience, vulnerability, disruption mitigation or delay management. We survey related streams of literature and put them into perspective. As a major insight we show that different strands of literature exist that may benefit from becoming better connected and intertwined. Together with recent advances in information technology and solution methods, more integrated problem settings incorporating robustness and disturbances can play a major role in future planning and operations.
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  • 文章类型: Journal Article
    好氧甲烷营养菌是一个专门的微生物群,催化甲烷的氧化。因此,扰动引起的甲烷菌多样性/丰度的损失导致该生物甲烷汇的损失。这里,我们综合并概念化了甲烷营养菌对零星的复原力,经常性的,和土壤中的复合干扰。甲烷营养菌对零星干扰表现出显著的复原力,活动和人口规模正在恢复。然而,当干扰持续存在或以增加的频率再次发生时,活动受到严重损害,并在土地利用变化后显著受损。接下来,我们巩固了土地转化后农业实践对土壤甲烷汇的影响。关键干预措施的影响(耕作,有机质输入,和覆盖种植)考虑了很多知识。这些干预措施与未经处理的农业土壤的成对比较表明,农业对甲烷汇的影响取决于种植系统,这可能与甲烷营养生物的生理学有关。农业的影响在旱地土壤中更为明显,其中甲烷营养菌在调节整体甲烷通量方面比产甲烷菌发挥更突出的作用。尽管能适应零星的干扰,甲烷营养生物容易受到人为活动引起的复杂干扰,显著影响甲烷汇功能。
    Aerobic methanotrophs are a specialized microbial group, catalyzing the oxidation of methane. Disturbance-induced loss of methanotroph diversity/abundance, thus results in the loss of this biological methane sink. Here, we synthesized and conceptualized the resilience of the methanotrophs to sporadic, recurring, and compounded disturbances in soils. The methanotrophs showed remarkable resilience to sporadic disturbances, recovering in activity and population size. However, activity was severely compromised when disturbance persisted or reoccurred at increasing frequency, and was significantly impaired following change in land use. Next, we consolidated the impact of agricultural practices after land conversion on the soil methane sink. The effects of key interventions (tillage, organic matter input, and cover cropping) where much knowledge has been gathered were considered. Pairwise comparisons of these interventions to nontreated agricultural soils indicate that the agriculture-induced impact on the methane sink depends on the cropping system, which can be associated to the physiology of the methanotrophs. The impact of agriculture is more evident in upland soils, where the methanotrophs play a more prominent role than the methanogens in modulating overall methane flux. Although resilient to sporadic disturbances, the methanotrophs are vulnerable to compounded disturbances induced by anthropogenic activities, significantly affecting the methane sink function.
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  • 文章类型: Journal Article
    背景:睡眠障碍是精神疾病的核心症状。尽管已经开发了各种睡眠措施来评估睡眠模式和睡眠质量,这些措施在精神疾病患者中的一致性仍然相对难以捉摸。
    目的:本研究旨在检查3种睡眠记录方法之间的一致程度以及主观和客观睡眠测量之间的一致性,特别关注最近在患有精神疾病的人群中开发的设备。
    方法:我们分析了这项横断面研究的62名参与者,都有多导睡眠图(PSG)的数据,Zmachine,Fitbit,和睡眠日志。参与者完成了关于他们的症状的问卷调查,并在过夜睡眠评估后的早晨估计了睡眠时间。计算类间相关系数(ICC)以评估从每种仪器获得的睡眠参数之间的一致性。此外,Bland-Altman地块用于直观地显示PSG测量的睡眠参数的差异和一致性限制,Zmachine,Fitbit,和睡眠日志。
    结果:研究结果表明,PSG和Zmachine数据在总睡眠时间方面具有适度的一致性(ICC=0.46;P<.001),睡眠开始后醒来(ICC=0.39;P=0.002),和睡眠效率(ICC=0.40;P=.006)。相比之下,Fitbit与PSG表现出明显的分歧(总睡眠时间:ICC=0.08;睡眠开始后醒来:ICC=0.18;睡眠效率:ICC=0.10),并且与睡眠日志表现出特别大的差异(总睡眠时间:ICC=-0.01;睡眠开始后醒来:ICC=0.05;睡眠效率:ICC=-0.02)。此外,PSG之间的主观和客观一致性,Zmachine,睡眠日志似乎受到抑郁症状和阻塞性睡眠呼吸暂停的严重程度的影响,而Fitbit和其他睡眠仪器之间没有观察到这些关联。
    结论:我们的研究结果表明,在存在合并症临床症状的情况下,Fitbit的准确性会降低。虽然用户友好,Fitbit在评估精神疾病患者的睡眠时应考虑其局限性。
    Sleep disturbances are core symptoms of psychiatric disorders. Although various sleep measures have been developed to assess sleep patterns and quality of sleep, the concordance of these measures in patients with psychiatric disorders remains relatively elusive.
    This study aims to examine the degree of agreement among 3 sleep recording methods and the consistency between subjective and objective sleep measures, with a specific focus on recently developed devices in a population of individuals with psychiatric disorders.
    We analyzed 62 participants for this cross-sectional study, all having data for polysomnography (PSG), Zmachine, Fitbit, and sleep logs. Participants completed questionnaires on their symptoms and estimated sleep duration the morning after the overnight sleep assessment. The interclass correlation coefficients (ICCs) were calculated to evaluate the consistency between sleep parameters obtained from each instrument. Additionally, Bland-Altman plots were used to visually show differences and limits of agreement for sleep parameters measured by PSG, Zmachine, Fitbit, and sleep logs.
    The findings indicated a moderate agreement between PSG and Zmachine data for total sleep time (ICC=0.46; P<.001), wake after sleep onset (ICC=0.39; P=.002), and sleep efficiency (ICC=0.40; P=.006). In contrast, Fitbit demonstrated notable disagreement with PSG (total sleep time: ICC=0.08; wake after sleep onset: ICC=0.18; sleep efficiency: ICC=0.10) and exhibited particularly large discrepancies from the sleep logs (total sleep time: ICC=-0.01; wake after sleep onset: ICC=0.05; sleep efficiency: ICC=-0.02). Furthermore, subjective and objective concordance among PSG, Zmachine, and sleep logs appeared to be influenced by the severity of the depressive symptoms and obstructive sleep apnea, while these associations were not observed between the Fitbit and other sleep instruments.
    Our study results suggest that Fitbit accuracy is reduced in the presence of comorbid clinical symptoms. Although user-friendly, Fitbit has limitations that should be considered when assessing sleep in patients with psychiatric disorders.
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  • 文章类型: Journal Article
    Mangrove leaves have unique features that enable them to cope with shifting environmental conditions while preserving their general functionality and efficiency. We examined the morphological characteristics and chlorophyll content (spectroscopically) of 600 mature Avicennia germinans leaves selected from 30 trees located in one degraded, one restored, and one natural mangrove ecosystem along Guyana\'s coastline. Systematic sampling was carried out using the closest individual sampling method in the wet and dry seasons. We hypothesized that both habitat type and seasonality influence the leaf traits and chlorophyll content of A. germinans. Our findings showed that A. germinans leaves are mesophyllous, and traits such as leaf perimeter, area, length, width, dry mass, wet mass, turgid mass, leaf-specific area, and relative water content showed fluctuations in ecosystems (one-way ANOVA, p < .05) as well as seasonally (paired t-test, p < .05). Substantial, positive correlations (p < .05, R > .75) were also established for over 10 leaf parameters in both seasons while PCA and multiple regression analyses further confirmed the strong relationships between leaf morphological features and their respective locations. Changes in chlorophyll concentration were most noticeable in the degraded ecosystem while variations in leaf traits were more pronounced in the restored mangrove area. This may be due to the various disturbances found in each ecosystem coupled with fluctuations in the seasons. Our results demonstrate that mangroves, to some extent, alter their plant structures to cope with environmental stressors present in the various ecosystems they thrive in to maintain their survival.
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  • 文章类型: Journal Article
    积分控制器通常用于天文自适应光学。这项工作为自适应光学系统中的积分控制器提供了一种新颖的调谐程序,该程序依赖于有关测得的干扰的信息。该调谐过程包括两个主要步骤。首先,它使用Whittles的可能性和波前传感器输出信号将测量的干扰建模并识别为连续时间阻尼振荡器。第二,它通过最小化输出方差来确定自适应光学系统的积分控制器增益。通过使用面向对象的Matlab自适应光学工具箱进行的理论示例和数值模拟来评估该方法的有效性。仿真结果表明,该方法能够准确估计扰动模型,减小输出方差。即使在充满挑战的大气条件下,我们的建议也能提高性能和更好的天文图像。这些发现为天文观测站中的自适应光学系统操作做出了重要贡献,并将我们的程序确立为在天文自适应光学系统中微调积分控制器的有前途的工具。
    Integral controllers are commonly employed in astronomical adaptive optics. This work presents a novel tuning procedure for integral controllers in adaptive optics systems which relies on information about the measured disturbances. This tuning procedure consists of two main steps. First, it models and identifies measured disturbances as continuous-time-damped oscillators using Whittles´s likelihood and the wavefront sensor output signal. Second, it determines the integral controller gain of the adaptive optics system by minimizing the output variance. The effectiveness of this proposed method is evaluated through theoretical examples and numerical simulations conducted using the Object-Oriented Matlab Adaptive Optics toolbox. The simulation results demonstrate that this approach accurately estimates the disturbance model and can reduce the output variance. Our proposal results in improved performance and better astronomical images even in challenging atmospheric conditions. These findings significantly contribute to adaptive optics system operations in astronomical observatories and establish our procedure as a promising tool for fine-tuning integral controllers in astronomical adaptive optics systems.
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  • 文章类型: Journal Article
    食物网是复杂的生态网络,揭示了生态系统中物种的相互作用和能量流动。关于森林溪流的普遍生态知识表明,它们的食物网基于异源碳,由来自邻近植被的有机物质的恒定供应和由于弱光条件而导致的初级生产有限的驱动。极端的气候干扰可以通过改变资源的可用性来破坏这些自然生态系统的动态,这导致食物网结构和功能的变化。这里,我们量化了流食物网对两个主要飓风(Irma和María,分别为5类和4类),于2017年9月袭击波多黎各。在两条热带森林溪流中(一阶和二阶),我们在飓风发生前6个月和之后2、9和18个月收集了生态系统和食物网数据。我们评估了结构(例如,树冠)和水文(例如,排放)生态系统的特征和监测的基础资源变化(即,藻类,生物膜,和落叶),消费者(例如,水生无脊椎动物,河岸消费者),并使用13C和15N的同位素组成应用了Layman的全社区指标。连续流排放测量表明,飓风没有引起极端水文事件。然而,冠层开放的六倍增加和相关的垃圾输入变化似乎引发了初级生产的增加。这些食物网主要基于飓风之前的陆地碳,但是大多数类群(包括阿提亚和西菲卡利斯虾,生物量最高的消费者)在飓风发生后的2个月内将食物来源转移到了自生碳。我们还发现了飓风极大地改变了食物网结构的证据,导致更短(即,较小的食物链长度),较窄(即,碳源多样性较低)食物网,以及增加营养物种包装。这项研究证明了飓风干扰如何改变溪流食物网,通过物理环境的变化将营养基础从异源资源改变为本地资源(即,冠层落叶)。由于气候变化,飓风变得更加频繁和严重,我们的发现极大地有助于我们理解在全球变化中维持森林河流营养相互作用的机制。
    Food webs are complex ecological networks that reveal species interactions and energy flow in ecosystems. Prevailing ecological knowledge on forested streams suggests that their food webs are based on allochthonous carbon, driven by a constant supply of organic matter from adjacent vegetation and limited primary production due to low light conditions. Extreme climatic disturbances can disrupt these natural ecosystem dynamics by altering resource availability, which leads to changes in food web structure and functioning. Here, we quantify the response of stream food webs to two major hurricanes (Irma and María, Category 5 and 4, respectively) that struck Puerto Rico in September 2017. Within two tropical forested streams (first and second order), we collected ecosystem and food web data 6 months prior to the hurricanes and 2, 9, and 18 months afterward. We assessed the structural (e.g., canopy) and hydrological (e.g., discharge) characteristics of the ecosystem and monitored changes in basal resources (i.e., algae, biofilm, and leaf litter), consumers (e.g., aquatic invertebrates, riparian consumers), and applied Layman\'s community-wide metrics using the isotopic composition of 13 C and 15 N. Continuous stream discharge measurements indicated that the hurricanes did not cause an extreme hydrological event. However, the sixfold increase in canopy openness and associated changes in litter input appeared to trigger an increase in primary production. These food webs were primarily based on terrestrially derived carbon before the hurricanes, but most taxa (including Atya and Xiphocaris shrimp, the consumers with highest biomass) shifted their food source to autochthonous carbon within 2 months of the hurricanes. We also found evidence that the hurricanes dramatically altered the structure of the food web, resulting in shorter (i.e., smaller food-chain length), narrower (i.e., lower diversity of carbon sources) food webs, as well as increased trophic species packing. This study demonstrates how hurricane disturbance can alter stream food webs, changing the trophic base from allochthonous to autochthonous resources via changes in the physical environment (i.e., canopy defoliation). As hurricanes become more frequent and severe due to climate change, our findings greatly contribute to our understanding of the mechanisms that maintain forested stream trophic interactions amidst global change.
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  • 文章类型: Journal Article
    根据政府间气候变化专门委员会(IPCC)的第六次评估报告,全球气候变化现在是明确的。突尼斯,像许多其他国家一样,受到气候变化的影响,包括气温上升,强烈的热浪,和改变的降水制度。突尼斯的年平均气温在20世纪上升了大约+1.4°C,自1970年代以来最迅速的变暖发生。干旱是导致树木退化和枯萎的主要因素。长期干旱会导致树木生长和健康下降,从而增加了它们对害虫和病原体的敏感性。据报道,树木死亡率的增加表明,在高温和更长时间下,全球森林的脆弱性正在加速,更严重的干旱。为了评估这些气候变化对突尼斯森林生态系统现状及其演变的影响,需要进行调查研究。这里,我们回顾了有关气候变化对突尼斯硬叶和半落叶林生态系统影响的现有知识。近年来的自然干扰,以及一些森林物种对气候变化的适应性和复原力,被调查过。标准化降水蒸散指数(SPEI)是基于气候数据的多标量干旱指数,已用于分析干旱变异性。SPEI时间尺度分析显示,在1955-2021年期间,突尼斯森林地区呈负趋势。2021年,突尼斯因火灾损失了280平方公里的树木,相当于2008年至2021年总损失面积的26%。不断变化的气候条件也影响了物候参数,绿色季节(SOS)开始9.4天,在绿色季节(EOS)结束时延迟5天,因此,绿色季节(LOS)的持续时间平均延长了14.2天。所有这些令人震惊的发现都邀请我们寻求森林生态系统的适应战略。因此,使森林适应气候变化是科学家以及政策制定者和管理者面临的挑战。
    According to the sixth assessment report of the Intergovernmental Panel on Climate Change (IPCC), global climate change is now unequivocal. Tunisia, like many other countries, has been affected by climate changes, including rising temperatures, intense heatwaves, and altered precipitation regimes. Tunisia\'s mean annual temperatures has risen about +1.4 °C in the twentieth century, with the most rapid warming taking place since the 1970s. Drought represents a primary contributing factor to tree decline and dieback. Long-term drought can result in reduced growth and health of trees, thereby increasing their susceptibility to insect pests and pathogens. Reported increases in tree mortality point toward accelerating global forest vulnerability under hotter temperatures and longer, more intense droughts. In order to assess the effect of these climate changes on the current state of forest ecosystems in Tunisia and their evolution, an investigative study was required. Here, we review the current state of knowledge on the effects of climate change on sclerophyllous and semi-deciduous forest ecosystems in Tunisia. Natural disturbance during recent years, as well as the adaptability and resilience of some forest species to climate change, were surveyed. The Standardized Precipitation Evapotranspiration Index (SPEI) is a multi-scalar drought index based on climate data that has been used to analyse drought variability. The SPEI time scale analysis showed a negative trend over the 1955-2021 period in Tunisian forest regions. In 2021, Tunisia lost 280 km2 of tree cover to fires, which is equivalent to 26% of the total lost area between 2008 and 2021. Changing climate conditions have also affected phenological parameters, with an advance in the start of the green season (SOS) of 9.4 days, a delay at the end of the green season (EOS) of 5 days, with a consequent extended duration of the green season (LOS) by an average of 14.2 days. All of these alarming findings invite us to seek adaptation strategies for forest ecosystems. Adapting forests to climate change is therefore a challenge for scientists as well as policymakers and managers.
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  • 文章类型: Journal Article
    目的:保护区外保护是中国生物多样性保护工作的主要贡献者,在支离破碎的景观中,在植树造林和低强度农业中实现了生物多样性保护。与分类多样性相比,功能性状与生态过程的关系更为紧密,并且反映了生态系统功能和物种对环境变化的反应。在这项研究中,我们选择了5个不同干扰程度的栖息地来探索土地利用对蚂蚁群落组成的影响,性状分布和功能多样性变化。我们评估了栖息地干扰如何影响蚂蚁群落组成和性状分布,并询问蚂蚁功能多样性是否对当地尺度的干扰作出反应?地点:吕春县,云南省,中国西南。方法:使用陷阱对蚂蚁群落进行调查。此外,我们测量了蚂蚁的四个形态特征(眼睛直径,眼睛之间的距离,后腿的股骨长度和韦伯的长度)以评估功能性状的分布和功能多样性。蚂蚁相对丰度的阴影图用于探索不同栖息地之间的物种分布。核密度图用于探索不同栖息地之间的蚂蚁性状分布模式。非度量多维缩放排序,根据蚂蚁韦伯的长度,用于探索不同栖息地之间的蚂蚁性状组成。第四角模型用于评估蚂蚁性状与环境变量之间的关联。Fric,选择RaoQ和FEve指数作为不同生境的多元功能性状空间和功能冗余的三个互补指标。结果:我们收集了14258只蚂蚁,代表89个物种,40属和七个亚科。Aphaenogasterschurri和Tetramoriumciumciatus是次生林的常见物种;P.sagei,P.Pieli,心脏condylawroughtonii,经常性的risnuwa,Tapinnomamelanocephalum,Monomoriumpharaonis和M.orientale是人工林中的常见物种;Iridomyrmexanceps和Cardiodylanuda是管理农场中的常见物种。蚂蚁的眼睛直径中等,眼睛之间的距离很窄,中等腿的长度和较小的身体尺寸在严重干扰的栖息地;和蚂蚁有一个增加的眼睛直径和眼睛之间的空间缩小,而在中度扰动的栖息地,腿长和韦伯的长度变得更短。蚂蚁性状组成,根据韦伯的长度,在五个栖息地之间显示出显着差异。第四角分析表明,蚂蚁物种性状与环境变量显着相关。次生林的功能多样性,紫胶种植和紫胶种植-玉米农林高于旱地农场和稻田。功能多样性与裸露地面覆盖呈显著负相关,与凋落叶覆盖呈显著正相关,落叶厚度和植物覆盖率。主要结论:我们的结果表明,蚂蚁性状的分布格局受到土地利用变化的影响,其次是局部尺度的人为干扰压力。受干扰较大的栖息地中的蚂蚁性状组成也与受干扰较小的栖息地不同。在更开放的栖息地中,人为干扰更大,这不利于大型蚂蚁的生存。与次生林相比,旱地农场和稻田的抵抗力较低,更脆弱,紫胶种植园具有蚂蚁群落的功能多样性,这表明紫胶人工林作为次生林可能对物种丧失具有抵抗力。
    Aim: Off-reserve conservation is a major contributor to China biodiversity conservation efforts, biodiversity conservation being achieved within afforestation and low-intensity agriculture in fragmented landscapes. Functional trait is more strongly related to ecological processes than taxonomic diversity and reflects ecosystem functioning and species responses to environmental changes. In this study, we selected five habitats that differ in degree of disturbance to explore the effects of land use on ant community compositions, traits distributions and functional diversity change. We assessed how habitat disturbance affects the ant community compositions and traits distributions and asked if ant functional diversity respond to disturbance at the local scale? Location: Lüchun County, Yunnan Province, southwest China. Methods: Pitfall traps were used to survey ant communities. Additionally, we measured four ant morphological traits (eyes diameter, distance between eyes, femur length of the hind-leg and Weber\'s length) to assess the functional traits distributions and functional diversity. Shade plot of ant relative abundance was used to explore species distribution amongst different habitats. Kernel density plot was used to explore ant traits distribution patterns amongst different habitats. Non-metric multi-dimensional scaling ordination, based on ant Weber\'s length, was used to explore the ant traits compositions amongst different habitats. The fourth corner model was used to evaluate the association between ant traits and environmental variables. The FRic, RaoQ and FEve indices were selected as three complementary measures of the multivariate functional traits space and functional redundancy of different habitats. Results: We collected 14258 ants, representing 89 species, 40 genera and seven subfamilies. Aphaenogasterschurri and Tetramoriumciliatum were the common species of secondary forest; P.sagei, P.pieli, Cardiocondylawroughtonii, Recurvidrisnuwa, Tapinnomamelanocephalum, Monomoriumpharaonis and M.orientale were the common species in plantations; and Iridomyrmexanceps and Cardiocondylanuda were the common species in managed farms. Ants had medium eye diameters, narrow distances between eyes, medium leg lengths and smaller body sizes in greatly-disturbed habitats; and ants had an increasing eye diameter and narrowing of the space between eyes, while the leg length and Weber\'s length became shorter in moderately-disturbed habitats. Ant trait composition, based on Weber\'s length, showed significantly differences amongst five habitats. The fourth corner analysis indicated that ant species traits were significantly correlated with environmental variables. The functional diversity of secondary forest, lac plantation and lac plantation-corn agroforest were higher than those in dryland farm and rice paddy. Functional diversities were significantly negatively correlated with bare ground cover and significantly positively correlated with leaf-litter cover, leaf-litter thickness and plant cover. Main conclusion: Our results indicated that ant traits distribution patterns were affected by land-use changes, followed by anthropogenic disturbance pressures at the local scale. Ant traits compositions in greatly-disturbed habitats also differed from the habitats with less disturbance. It is unfavourable for the survival of the large body-size ants in more open habitats with more anthropogenic disturbance. Compared with secondary forest, dryland farm and rice paddies were less resistant and more vulnerable and lac plantations had approximately functional diversity of ant communities, suggesting that lac plantations might be resistant as secondary forest to species loss.
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