The traits of “trait ecologists”: An analysis of the use of trait and functional trait terminology

Trait and functional trait approaches have revolutionized ecology improving our understanding of community assembly, species coexistence, and biodiversity loss. Focusing on traits promotes comparability across spatial and organizational scales, but terms must be used consistently. While several papers have offered definitions, it remains unclear how ecologists operationalize “trait” and “functional trait” terms. Here, we evaluate how researchers and the published literatures use these terms and explore differences among subdisciplines and study systems (taxa and biome). By conducting both a survey and a literature review, we test the hypothesis that ecologists’ working definition of “trait” is adapted or altered when confronting the realities of collecting, analyzing and presenting data. From 486 survey responses and 712 reviewed papers, we identified inconsistencies in the understanding and use of terminology among researchers, but also limited inclusion of definitions within the published literature. Discrepancies were not explained by subdiscipline, system of study, or respondent characteristics, suggesting there could be an inconsistent understanding even among those working in related topics. Consistencies among survey responses included the use of morphological, phonological, and physiological traits. Previous studies have called for unification of terminology; yet, our study shows that proposed definitions are not consistently used or accepted. Sources of disagreement include trait heritability, defining and interpreting function, and dealing with organisms in which individuals are not clearly recognizable. We discuss and offer guidelines for overcoming these disagreements. The diversity of life on Earth means traits can represent different features that can be measured and reported in different ways, and thus, narrow definitions that work for one system will fail in others. We recommend ecologists embrace the breadth of biodiversity using a simplified definition of “trait” more consistent with its common use. Trait‐based approaches will be most powerful if we accept that traits are at least as diverse as trait ecologists.     

银川不同湿地陆生昆虫群落多样性与稳定性

【目的】调查和分析银川不同湿地陆生昆虫群落结构组成、功能多样性及其稳定性变化。【方法】2016年5-10月选取银川黄河湿地(HH)、鸣翠湖湿地(MCH)、芦花台湿地(LHT)、水洞沟湿地(SDG)4种湿地生境,采用棋盘式扫网和陷阱捕捉的方法进行昆虫采集。根据调查数据进行昆虫群落结构多样性分析、主成分分析和聚类分析。【结果】4种湿地生境共采集昆虫38 668头,隶属13目97科370种。双翅目、同翅目、膜翅目在4种生境中均为优势类群。植食性(Ph)昆虫功能团的科数和种数在4种生境昆虫群落中占比均最大。植食性-中性昆虫(Ph-Ne)间个体数在4种生境下均存在显著负相关(P<0.01);植食性-捕食性昆虫(Ph-Pr)间个体数在MCH生境下存在显著正相关(P<0.05);中性-捕食性昆虫(Ne-Pr)间个体数在MCH生境下存在显著负相关(P<0.01),在LHT生境下存在显著负相关(P<0.05);4种功能团结构的其他组合的个体数在4种生境下均不存在显著相关性。主成分分析结果表明,捕食性类群是4个类群中影响构成昆虫群落组成的主要成分。同种功能团在4种生境下的多样性分析结果表明,捕食性功能团(Pr)与寄生性功能团(Pa)在4种生境群落中的群落丰富度、均匀程度［辛普森指数(Simpson index)］差异性显著(P<0.05),而植食性功能团(Ph)与中性功能团(Ne)的群落丰富度、均匀程度的差异性不显著(P>0.05);中性功能团(Ne)在4种生境群落中个体出现的不确定程度［香农-维纳指数(Shannon-Wiener index)］差异性不显著(P>0.05),在4种生境的均匀度指数(Pielou evenness index)差异性显著(P<0.05),其余3个功能团在4种生境下的香农-维纳指数均差异性显著(P<0.05),在4种生境下的均匀度指数均差异性不显著(P>0.05)。4种生境昆虫群落特征指数的聚类分析分为2类,永久性湿地HH和MCH为第1类,季节性湿地LHT和SDG为第2类。Ss/Si和Sa/Sp两个稳定性指标均显示MCH昆虫群落稳定性最高,4种生境昆虫群落最稳定的时期是5和9月。【结论】双翅目和膜翅目昆虫在银川不同湿地生境中均为优势类群,可作为环境指示参考;昆虫群落稳定性最好的湿地类型为永久性湖泊湿地;不同生境昆虫群落多样性随季节时序变化,在银川最稳定的时期是5和9月。气候因子、环境因素如何驱动各湿地昆虫群落多样性及稳定性的变化因素还有待开展研究。     

土地利用驱动的土壤性状变化影响微生物群落结构和功能

微生物在调节陆地生态系统地球化学循环过程中具有重要作用。土地利用方式改变显著影响土壤微生物群落结构和功能,但对土地利用驱动的土壤性状变化与微生物群落结构和功能关系的研究相对匮乏。依托长期定位监测试验（始于1984年）,通过16S rRNA基因片段和ITS高通量测序,研究了土地利用方式（裸地、农田、草地）驱动的土壤碳氮变化对微生物群落结构和功能的影响。结果表明：对于细菌群落而言,裸地中α-多样性最高、其次是草地、农田中最低,农田和草地中细菌优势菌群变形菌（Proteobacteria）和放线菌门（Actinobacteria）相对丰度较裸地低4.5%、3.9%和5.5%、3.8%;对于真菌群落而言,裸地子囊菌门（Ascomycota）相对丰度最高、农田次之、草地最低;化能异养型、好氧化能异养型细菌相对丰度裸地显著高于农田和草地（P<0.05）,而硝化型和好氧氨氧化型细菌裸地显著低于农田和草地（P<0.05）;腐生型真菌相对丰度大小排序为：裸地>农田>草地。细菌群落变化主要与土壤容重、全氮、矿质氮、C ： N比和微生物量碳有关,而真菌群落与土壤矿质氮有关。细菌和真菌功能菌群主要受土壤容重、土壤有机碳、土壤全氮、C ： N比和微生物量碳影响。因此,土壤容重、土壤全氮、土壤有机碳、C ： N比、微生物量碳、矿质氮差异可能是影响不同土地利用方式中微生物群落和功能变化的主要因素。     

功能多样性和功能冗余对高寒草甸群落稳定性的影响

功能多样性和功能冗余是影响群落稳定性的重要因素,但它们对稳定性影响的相对强弱尚有争论。通过在青藏高原高寒矮嵩草(Kobresia humilis)草甸为期6a的刈割(不刈割、留茬3cm、留茬1cm)和施肥(施肥、不施肥)控制实验对此进行了探讨。研究结果显示,群落稳定性随着功能多样性和功能冗余的增大而单调增加,但由于功能多样性的变异性大于功能冗余的变异性,功能多样性与物种多样性间的相关性强于功能冗余与物种多样性间的相关性,功能多样性与群落稳定性间的相关性也强于功能冗余与群落稳定性间的相关性,因此,尽管功能冗余产生的保险效应对维持群落稳定性具有促进作用,但功能多样性的互补效应对维持群落稳定性的作用更大。结果表明,功能多样性和功能冗余对群落稳定性的相对影响与其变化程度正相关,功能多样性与群落稳定性的变化具有更紧密的联系,能更好地预测生态系统稳定性的变化。研究为草原生态系统的可持续管理提供了重要启示。     

植物群落功能多样性计算方法

以性状为基础的功能多样性指数在预测生态系统功能中起到越来越重要的作用.本文对近年来陆续出现的植物群落功能多样性指数进行综述.依据物种多样性指数的组成,功能多样性指数分为功能丰富度、功能均匀度和功能离散度指数.介绍了这3类指数的计算方法,有助于更好、更准确地理解“生物多样性-环境-生态系统功能”的关系.     

Disentangling phylogenetic from non‐phylogenetic functional structure of bird assemblages in a tropical dry forest

Understanding the factors driving assembling structure of ecological communities remains a fundamental problem in ecology, especially when focusing on ecological and evolutionary relatedness among species rather than on their taxonomic identity. It remains critical though to separate the patterns and drivers of phylogenetic and functional structures, because traits are phylogenetically constrained, but phylogeny alone does not fully reflect trait variability among species. Using birds from the Brazilian dry forest as a study case, we employed two different approaches to decompose functional structure into its components that are shared and non‐shared with the phylogenetic structure. We investigated the spatial pattern and environmental hypotheses for these phylogenetically constrained and unconstrained aspects of functional structure, including climate‐induced physiological constraints, historical climatic stability, resource availability and habitat partitioning. We found only partial congruence between the two methods of structure decomposition. Still, we found a differential effect of factors on specific components of functional structure of bird assemblages. While climate affects phylogenetically constrained traits through endurance, habitat partitioning (especially forest cover) affects the functional structure that is independent of phylogeny. With this strategy, we were able to decompose the patterns and drivers of the functional structure of birds along a semiarid gradient and showed that the decomposition of the functional structure into its phylogenetic and non‐phylogenetic counterparts can offer a more complete portrait of the assembling rules in ecological communities. We claim for a further development and use of this sort of strategy to investigate assembling rules in ecological communities.     

Temporal intraspecific trait variability drives responses of functional diversity to interannual aridity variation in grasslands

Interannual climate variation alters functional diversity through intraspecific trait variability and species turnover. We examined these diversity elements in three types of grasslands in northern China, including two temperate steppes and an alpine meadow. We evaluated the differences in community‐weighted means (CWM) of plant traits and functional dispersion (FDis) between 2 years with contrasting aridity in the growing season. Four traits were measured: specific leaf area (SLA), leaf dry matter content (LDMC), leaf nitrogen concentration (LNC), and the maximum plant height (H). CWM for SLA of the alpine meadow increased in the dry year while that of the temperate steppe in Qinghai showed opposing trends. CWM of LDMC in two temperate steppes became higher and CWM of LNC in all grasslands became lower in the dry year. Compared with the wet year, FDis of LDMC in the alpine meadow and FDis of LNC in the temperate steppe in Qinghai decreased in the dry year. FDis of H was higher in the dry year for two temperate steppes. Only in the temperate steppe in Qinghai did the multi‐FDis of all traits experience a significant increase in the dry year. Most of the changes in CWM and FDis between 2 years were explained by intraspecific trait variation rather than shifts in species composition. This study highlights that temporal intraspecific trait variation contributes to functional responses to environmental changes. Our results also suggest it would be necessary to consider habitat types when modeling ecosystem responses to climate changes, as different grasslands showed different response patterns.     

吉林蛟河针阔混交林功能性状分布格局及其对地形因素的响应

森林群落的构建过程及其内在机制是生态学研究的热点问题。植物功能性状是指能够代表植物的生活史策略,反映植物对环境变化响应的一系列植物属性。通过植物功能性状的分布格局及其对环境因素的响应有助于推测群落的构建过程及其内在作用机制。以吉林蛟河21.12hm²温带针阔混交林样地为研究对象,采集并测量了样地内34种木本植物的6种不同的功能性状。以20m×20m的样方为研究单元,通过计算平均成对性状距离指数（mean pairwise trait distance;PW）和平均最近邻体性状距离指数（mean nearest neighbor trait distance;NN）来探讨群落中单个性状和综合性状的分布格局。同时结合地形因子采用回归分析探讨功能性状的分布格局对局域生境变化的响应。基于PW的结果显示：单个性状中除叶面积外,其余性状的分布格局均为聚集分布多于离散分布;基于NN的结果显示：除叶面积和最大树高外,其余性状的分布格局为聚集分布多于离散分布。此外,由6种单个性状组成的综合性状的分布格局同样为聚集分布多于离散分布。基于回归分析的结果显示：森林群落中功能性状的分布格局受到海拔、坡度和坡向等因素的显著影响,而凹凸度的影响则不显著。研究结果表明包括环境过滤和生物相互作用的非随机过程能够影响温带针阔混交林的群落构建过程,中性过程对该区域群落构建过程的影响不显著。     

黑龙江省表层冻土细菌群落结构组成和功能特征

冻土是气候变化的敏感区,冻土中细菌对于预测冻土和气候之间的潜在反馈机制至关重要,研究冻土区土壤中细菌的多样性和种群结构将有助于及时检测环境变化并采取有效的应对措施。以黑龙江省表层冻土为研究对象,运用Illumina MiSeq高通量测序分析技术,系统分析黑龙江表层冻土细菌群落结构组成和功能特征,探究影响因素。结果表明,得到的785640条原始序列可划分为30个门,109个纲,209个目,326个科,512个属,598个种。优势菌门主要包括Proteobacteria、Actinobacteria、Acidobacteria、Chloroflexi、Bacteroidetes、Verrucomicrobia,在P0.01水平上,Proteobacteria与Actinobacteria、Chloroflexi极显著负相关,与Acidobacteria极显著正相关,Actinobacteria与Acidobacteria极显著负相关,与Chloroflexi极显著正相关,Acidobacteria和Chloroflexi之间则无显著相关性。属水平上,Aetherobacter属在各样本之间显著性差异最大,Flavobacteriu属和Burkholderia属,Microlunatus属和Massilia属之间呈现显著负相关。RDA多元回归分析发现,土壤pH是影响细菌群落结构组成的最主要因子,门水平上与Crenarchaeota、Verrucomicrobia、Thermi呈极显著正相关,与Elusimicrobia呈极显著负相关;属水平上,与Arthrobacter属、Blastococcus属、Chelatococcus属在P0.001水平上呈现显著正相关。基于细菌基因组的16S rRNA序列对菌群代谢功能进行预测发现,细菌群落主要代谢功能表现在膜转运功能、氨基酸代谢功能以及碳水化合物代谢功能三方面。黑龙江省区域尺度范围内,表层冻土中细菌群落结构分异主要受土壤理化性质影响,而土壤利用方式对微生物群落结构影响不显著。     

Fish community structure in the Missouri and lower Yellowstone rivers in relation to flow characteristics

Human alteration is commonplace among large rivers and often results in changes in the flow regime which can lead to changes in fish community structure. We explored the features of fish community structure, morphological characteristics, functional composition, and life-history attributes in relation to six unique flow regimes in the Missouri and lower Yellowstone rivers where we found significant differences in community composition and abundance. The clearest pattern was the distinction between the channelized portion of the river below the mainstem reservoirs and all other parts of the Missouri and lower Yellowstone rivers due to a marked reduction of species richness above the reservoirs. We also found morphological, functional, and life-history differences among the flow units, with the inter-reservoir communities consisting of slightly more generalist characteristics. Our results suggest some relation between flow and fish community structure, but that human alteration may have the strongest influence in distinguishing community differences in the Missouri and lower Yellowstone rivers.     

元江锥群落垂直结构的构建机制初探

基于功能性状探讨物种共存机制,已成为近年来群落生态学研究的热点内容。为探讨群落垂直结构构建的成因,该研究以昆明筇竹寺地区的半湿润常绿阔叶林为对象,调查乔木层、灌木层及草本层不同层次间植物叶片的功能性状。结果表明:(1)植物各功能性状均存在不同程度的随层次变化的趋势。(2)按照植物的生活型将元江锥群落分为乔木、灌木以及草本3层,与功能性状的聚类结果基本一致。(3)乔木、灌木和草本3个层次的S.E.S PW值均小于0,可知群落内物种的功能性状结构均呈现显著的发散。综上结果认为,植物群落不同物种的叶片功能特征对群落垂直方向上不同光照和水分条件组合的适应是群落垂直结构构成的主要影响因素,支持生境过滤是群落垂直结构构建的主要生态过程; 在不同层次内的物种具有不同的功能性状,同一层次内通过竞争排斥加大物种多样性; 群落垂直结构的形成是群落内垂直方向上环境因子发生变化的结果,对资源有不同需求的物种分布在不同空间高度上,群落垂直结构则是对资源的有效利用,增加了群落内物种多样性。     

蚂蚁群落与栖境关系研究进展及新趋势

生物群落与栖境的关系是生态学研究的核心之一,蚂蚁群落由于在陆地生态系统中的生物量、分布以及具备的生态功能的重要性,是研究这种关系的理想对象。在查阅大量文献的基础上,简述了蚂蚁物种多样性与栖境关系研究现状。介绍了蚂蚁功能群划分以及在不同尺度上与栖境关系的应用研究,评述了功能群应用的限制。阐明了功能特征的定义以及基于形态特征和营养级方面的蚂蚁群落功能特征与栖境的研究,并对功能特征的研究趋势进行了展望。     

Functional traits explain ecosystem function through opposing mechanisms

The ability to explain why multispecies assemblages produce greater biomass compared to monocultures, has been a central goal in the quest to understand biodiversity effects on ecosystem function. Species contributions to ecosystem function can be driven by two processes: niche complementarity and a selection effect that is influenced by fitness (competitive) differences, and both can be approximated with measures of species’ traits. It has been hypothesised that fitness differences are associated with few, singular traits while complementarity requires multidimensional trait measures. Here, using experimental data from plant assemblages, I show that the selection effect was strongest when trait dissimilarity was low, while complementarity was greatest with high trait dissimilarity. Selection effects were best explained by a single trait, plant height. Complementarity was correlated with dissimilarity across multiple traits, representing above and below ground processes. By identifying the relevant traits linked to ecosystem function, we obtain the ability to predict combinations of species that will maximise ecosystem function.     

坡向因子对黄土高原草地群落功能多样性的影响

研究群落水平上的植物功能性状特征及功能多样性随坡向的变化规律,对认识不同坡向上的植物群落形成过程具有重要意义。以黄土高原不同坡向上的自然草地群落为研究对象,比较研究了植物功能性状(株高和比叶面积)和功能多样性测度指标(功能丰富度、功能均匀度和功能离散度)随坡向的变化规律。研究结果显示:(1)阴坡的株高和比叶面积显著高于其他坡向;(2)一元性状的功能丰富度在不同坡向间均无显著差异;阴坡和半阴坡的多元性状功能丰富度显著高于阳坡;(3)阴坡的株高功能均匀度显著高于半阳坡,而比叶面积功能均匀度在各坡向的差异并不显著;多元性状功能均匀度在不同坡向差异显著,阴坡最高,半阳坡最低;(4)阴坡和半阴坡的株高功能离散度显著高于阳坡和半阳坡,而半阴坡的比叶面积功能离散度显著高于阳坡;半阴坡的多元性状功能离散度Rao指数显著高于阳坡。研究结果暗示了,在阴坡和半阴坡上,植物对群落内的生态位空间和资源利用更充分,种间竞争强度较低,不同物种之间生态位高度分化;而在阳坡和半阳坡上,由于水分等条件的限制植物可占据的生态位空间有限,导致其对占据的生态位空间使用不足,物种间资源竞争较强烈。在群落水平上,研究地区的植物功能性状及功能多样性随坡向的规律性变化,反映了黄土高原植被群落构建过程中坡向因子对功能性状的筛选效应。该研究结果对该区的植被恢复重建的物种选择及植被布局规划具有重要实践意义。     

Distinguishing the signatures of local environmental filtering and regional trait range limits in the study of trait–environment relationships

Understanding the imprint of environmental filtering on community assembly along environmental gradients is a key objective of trait‐gradient analyses. Depending on local constraints, this filtering generally entails that species departing from an optimum trait value have lower abundances in the community. The community‐weighted mean (CWM) and variance (CWV) of trait values are then expected to depict the optimum and intensity of filtering, respectively. However, the trait distribution within the regional species pool and its limits can also affect local CWM and CWV values apart from the effect of environmental filtering. The regional trait range limits are more likely to be reached in communities at the extremes of environmental gradients. Analogous to the mid‐domain effect in biogeography, decreasing CWV values in extreme environments can then represent the influence of regional trait range limits rather than stronger filtering in the local environment. We name this effect the ‘trait‐gradient boundary effect’ (TGBE). First, we use a community assembly framework to build simulated communities along a gradient from a species pool and environmental filtering with either constant or varying intensity while accounting for immigration processes. We demonstrate the significant influence of TGBE, in parallel to environmental filtering, on CWM and CWV at the extremes of the environmental gradient. We provide a statistical tool based on Approximate Bayesian Computation to decipher the respective influence of local environmental filtering and regional trait range limits. Second, as a case study, we reanalyze the functional composition of alpine plant communities distributed along a gradient of snow cover duration. We show that leaf trait convergence found in communities at the extremes of the gradient reflect an influence of trait range limits rather than stronger environmental filtering. These findings challenge correlative trait–environment relationships and call for more explicitly identifying the mechanisms responsible of trait convergence/divergence along environmental gradients.     

氮素添加对呼伦贝尔草甸草原植物氮钾元素含量和计量比的影响

钾(K)是植物叶片中仅次于氮(N)的第二大营养元素,在调节植物生长发育、稳态维持和胁迫响应等方面具有重要作用。以往关于氮素输入对植物养分状况影响的研究中多关注了氮磷养分,较少关注钾及其与其他元素的计量关系。本研究以内蒙古呼伦贝尔草甸草原为对象,研究氮素添加和刈割对植物功能群水平和群落水平钾含量及计量特征(N∶K)的影响,分析功能群自身养分状况和群落组成改变对群落水平养分状况变化的相对贡献。结果表明: 为期6年的氮素添加提高了所有植物功能群的N含量以及根茎禾草和豆科植物的K含量,刈割降低了根茎禾草和丛生禾草的N含量,而对所有功能群的K含量和N∶K均无显著影响。氮素添加显著提高了群落水平植物N和K含量,刈割仅增加了群落植物的N含量。氮素添加和刈割对功能群和群落水平上的植物N∶K均无显著影响。功能群本身的养分变化情况对群落水平植物养分状况的贡献大于群落组成的贡献。在对群落水平养分特征的影响方面,功能群本身养分变化的贡献与群落组成的贡献具有负的协变关系。呼伦贝尔草甸草原植物具有较高的N∶K内稳性,能够较好地调节自身的氮钾平衡,这对氮沉降背景下维持氮钾元素计量关系具有重要意义。     

Functional traits composition predict macrophytes community productivity along a water depth gradient in a freshwater lake

Functional trait composition of plant communities has been proposed as a helpful key for understanding the mechanisms of biodiversity effects on ecosystem functioning. In this study, we applied a step‐wise modeling procedure to test the relative effects of taxonomic diversity, functional identity, and functional diversity on macrophytes community productivity along water depth gradient. We sampled 42 plots and 1513 individual plants and measured 16 functional traits and abundance of 17 macrophyte species. Results showed that there was a significant decrease in taxonomic diversity, functional identity (i.e., stem dry mass content, leaf [C] and leaf [N]), and functional diversity (i.e., floating leaf, mean Julian flowering date and rooting depth) with increasing water depth. For the multiple‐trait functional diversity (FD) indices, functional richness decreased, while functional divergence increased with water depth gradient. Macrophyte community productivity was strongly determined by functional trait composition within community, but not significantly affected by taxonomic diversity. Community‐weighted means (CWM) showed a two times higher explanatory power relative to FD indices in determining variations in community productivity. For nine of sixteen traits, CWM and FD showed significant correlations with community productivity, although the strength and direction of those relations depended on selected trait. Furthermore, functional composition in a community affected productivity through either additive or opposite effects of CWM and FD, depending on the particular traits being considered. Our results suggested both mechanisms of mass ratio and niche complementarity can operate simultaneously on variations in community productivity, and considering both CWM and FD would lead to a more profound understanding of traits–productivity relationships.     

Changes in functional composition and diversity of waterbirds: The roles of water level and submerged macrophytes

1. Water level and submerged macrophytes are critical players for the functioning of shallow lake ecosystems; understanding how waterbird communities respond to changes in both can have important implications for conservation and management. Here, we evaluated the effects of changes in water level and submerged macrophyte status on wintering waterbird community size, functional group abundances, functional diversity (FD), and community assembly by using a dataset compiled over 50 years.
2. We built generalised linear models to evaluate the effects of water level and submerged macrophyte status on the above-listed attributes of the waterbird communities by using mid-winter waterbird censuses, water level measurements, and submerged macrophyte surveys, along with submerged macrophyte macrofossil records from two shallow lakes in Turkey. Using a relevant set of functional traits, we defined functional groups, calculated four FD measures, and simulated null distributions of the FD measures for assessing assembly rules.
3. We found that macrophyte-dominated years had significantly higher abundances of waterbirds in one of the study lakes, and had more diving herbivores and omnivores in both lakes, while diving/scooping fish-eating waterbird abundance was lower in macrophyte-dominated years. Community size in Lake Beyşehir exhibited a negative association with water level; surprisingly, however, none of the functional group abundances and FD indices were significantly related to water level.
4. In our study communities, standardised effect sizes of functional richness and functional dispersion—two indices that are particularly sensitive to community assembly processes—were mostly lower than those of randomly assembled communities, which implies functional clustering. Shifts to a scarce-macrophyte state were associated with increases in these two indices, possibly due to either changes in the relative strength of environmental filtering and limiting similarity in community assembly or sampling of transitional communities. Further studies covering a wider range of the trophic/macrophyte status spectrum are needed to be certain.
5. The results of this study indicate that shifts between abundant and scarce-macrophyte states can have significant effects on wintering waterbird abundances, FD and community assembly. The results also suggest that shallow lakes in macrophyte-dominated states can support more wintering waterbirds, especially diving omnivores, some of which are globally threatened.