Aquatic Plant Species Richness Research Articles

河西走廊水生植物多样性格局、群落特征及影响因素

PDF HTML阅读 XML下载 导出引用 引用提醒 河西走廊水生植物多样性格局、群落特征及影响因素 DOI: 10.5846/stxb201810242298 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 湖北省教育厅项目（T201701）；科学技术部资助项目（2013FY112300）；国家自然科学基金面上项目（31570366） Biogeographic pattern, main community types, and the influencing factors of aquatic macrophytes in the Hexi Corridor of Northwest China Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:水生植物是湿地生态系统重要组成部分，研究水生植物多样性分布格局及其影响因素对地区水生植物资源保护具有重要意义。通过野外调查并结合气候等环境因素，研究了河西走廊主要水生植物群落类型、数量特征、水生植物多样性分布格局及影响因素，并对中域效应假说进行了验证。研究结果表明：（1）河西走廊地区共有水生植物29科42属84种，群落的聚类分析可将河西走廊水生植物群落划分为15个主要群落类型；（2）河西走廊水生植物群落类型主要受到水温、海拔、经纬度等环境因子影响，群落物种多样性指数与盐度以及溶解性固体总量呈显著性相关；（3）河西走廊水生植物多样性空间格局呈现出"∩"型的单峰格局，中域效应模型能较好地解释该地区水生植物多样性水平的纬度格局及海拔垂直分布格局，对该区域水生植物物种丰富度在纬度和海拔梯度上的变异解释率分别为57.56%、63.5%。分析表明，河西走廊水生植物物种丰富度格局由几何（边界）限制和随机过程及其他未知因素共同控制，且几何（边界）限制和随机过程贡献率较大；同时本研究中未考虑的环境异质性、气候、人为干扰等因素也对河西走廊水生植物多样性空间分布产生重要影响。 Abstract:Aquatic plants are an important part of wetland ecosystems. Studies about the distribution pattern of aquatic plants and its influencing factors can provide important background for the regional protection of aquatic plant resources. In this study, the main aquatic plant community types, quantitative characteristics, species richness patterns, and influencing factors of aquatic plants in the Hexi Corridor were studied using field investigation data. The mid-domain effect hypothesis was used to explain geographical diversity patterns of aquatic macrophytes in the region. The main results are as follows:(1) there were 84 species belonging to 42 genera of 29 families of aquatic plants in the Hexi Corridor. Cluster analysis of the community showed that there were 15 main aquatic plant community types in this region; (2) the aquatic plant community types in the Hexi Corridor were mainly affected by environmental factors such as water temperature, elevation, latitude, and longitude. The community species diversity index was significantly correlated with salinity and total dissolved solids; (3) the spatial pattern of aquatic plant diversity in the Hexi Corridor exhibited a unimodal pattern. The mid-domain effect model better explained the latitudinal pattern and the vertical distribution pattern of aquatic plant diversity in the region, with explanation rates reaching 57.56% and 63.5%, respectively. These results indicate that the patterns of aquatic macrophyte species richness in the Hexi Corridor were determined by geometric (boundary) constraints, random processes, and other unknown processes. Geometric (boundary) constraints and random process showed a higher contribution rate on geographic richness gradients. Also, we highlight that unmeasured factors including environmental heterogeneity, climate, and human disturbance may greatly affect aquatic plant species richness in the Hexi Corridor of Northwest China. 参考文献 相似文献 引证文献

Different Stages of Aquatic Vegetation Succession Driven by Environmental Disturbance in the Last 38 Years

In recent years, investigating the trend of aquatic plant diversity in response to different disturbance events has received increasing interest. However, there is limited knowledge of the different stages of aquatic vegetation succession over a long period in eutrophic lakes. In this study, we analyzed aquatic plant species richness and its relation to the physical and chemical characteristics of water in Chenghai Lake for the period of 1980–2018. This study shows that the richness and distribution of aquatic vegetation in Chenghai Lake are related to chlorophyll-a concentration, dissolved nutrients, base cations, and micronutrients. The results show that the long-term succession of aquatic plants in this lake classified in different stages: (I) A peak in species richness occurred at an intermediate stage that lasted from 1980 to 1992, and this was caused by more aquatic species being able to coexist since the competition for resources was lower; (II) after 26 years of secondary succession (1992–2018), the diversity and distribution area of aquatic plants gradually declined because pioneer species or human activities may have altered habitat conditions to render habitats less beneficial to pioneer species and more suitable for new aquatic plant species. Thus, species diversity and growth performance of aquatic plants in their communities may be useful indicators of Chenghai Lake’s trophic status, especially during the transition period from a mesotrophic lake to a eutrophic one.

Is catchment geodiversity a useful surrogate of aquatic plant species richness?

AbstractAimConserving freshwater biodiversity in a rapidly changing world requires updated planning schemes and research efforts. Geodiversity – the diversity of Earth surface forms, materials and processes – and biodiversity are interlinked at a fundamental level. This relationship is being considered in a growing number of studies, yet research from freshwater environments is scarce. We used geodiversity (rock‐type, soil‐type and geomorphological richness), local and climatic variables to explore whether geodiversity can be used as a surrogate for aquatic plant species richness in lakes and rivers.LocationFinland.TaxonAquatic plants.MethodsWe compared geodiversity variables (measured within 1‐km2 grid cells) to well‐studied local (e.g. area, alkalinity) and climate (e.g. growing degree‐days) variables, and examined the patterns between habitat types (lakes and rivers) and among all taxa and major functional groups (helophytes and hydrophytes). We modelled lake (n = 145) and river (n = 146) plant species richness with generalized linear models, and further partitioned variation to measure the independent and shared contributions of the geodiversity, climate and local environmental variable groups. As a complementary analysis, and to identify single important variables explaining variation in aquatic plant species richness, we utilized boosted regression trees.ResultsWe found a positive relationship between aquatic plant species richness and catchment geodiversity variation with recurring patterns across two different freshwater habitat types and two aquatic plant functional groups. Higher variation in geodiversity (measured at landscape scale) supported higher freshwater biodiversity (measured at the local scale) of lakes and rivers.Main conclusionsGeodiversity can be a useful addition to biodiversity modelling, and it should be considered in conservation schemes and monitoring efforts, further supporting the principle of conserving nature's stage. Yet, differences between habitats and functional groups suggest that more habitat‐specific approaches and multiple biodiversity measures should be considered. Our study is an important signpost guiding further studies on the biodiversity–geodiversity relationship in freshwater ecosystems.

Biological invasion by a benthivorous fish reduced the cover and species richness of aquatic plants in most lakes of a large North American ecoregion.

Biological invasions are projected to be the main driver of biodiversity and ecosystem function loss in lakes in the 21st century. However, the extent of these future losses is difficult to quantify because most invasions are recent and confounded by other stressors. In this study, we quantified the outcome of a century-old invasion, the introduction of common carp to North America, to illustrate potential consequences of introducing non-native ecosystem engineers to lakes worldwide. We used the decline in aquatic plant richness and cover as an index of ecological impact across three ecoregions: Great Plains, Eastern Temperate Forests and Northern Forests. Using whole-lake manipulations, we demonstrated that both submersed plant cover and richness declined exponentially as carp biomass increased such that plant cover was reduced to <10% and species richness was halved in lakes in which carp biomass exceeded 190kg ha-1 . Using catch rates amassed from 2000+ lakes, we showed that carp exceeded this biomass level in 70.6% of Great Plains lakes and 23.3% of Eastern Temperate Forests lakes, but 0% of Northern Forests lakes. Using model selection analysis, we showed that carp was a key driver of plant species richness along with Secchi depth, lake area and human development of lake watersheds. Model parameters showed that carp reduced species richness to a similar degree across lakes of various Secchi depths and surface areas. In regions dominated by carp (e.g., Great Plains), carp had a stronger impact on plant richness than human watershed development. Overall, our analysis shows that the introduction of common carp played a key role in driving a severe reduction in plant cover and richness in a majority of Great Plains lakes and a large portion of Eastern Temperate Forests lakes in North America.

Facilitating the restoration of aquatic plant communities in a Ramsar wetland

Human activities such as land clearing and intensive land use around water bodies, particularly wetlands, have a detrimental impact on water quality and quantity, aquatic plant communities, and associated wetland fauna. Lake Alexandrina and Lake Albert are internationally significant Ramsar wetlands located at the terminus of the Murray River, Australia's longest river system. Agriculture, water regulation, and extraction and droughts have had a detrimental impact on native plant communities in the lakes. We studied the influence of young (<1–3 years) and old (8–11 years) plantings of a native sedge (bulrush), Schoenoplectus tabernaemontani, to facilitate the establishment of aquatic plant communities in comparison with remnant and control sites. We also measured how planting structure (height, stand width, and stem density) changed with age in comparison with remnant sites. Results suggest that as plantings age they get substantially wider and have a greater maximum height, although do not reach similar stand widths by 11 years when compared to remnant areas. However, old plantings do not differ from remnant habitats in relation to aquatic plant species richness, counts of aquatic plants, and community composition. Young plantings have substantially less abundant and diverse plant communities, but are developing on a similar trajectory to old plantings. It is likely that planting sedges along lake shorelines causes a breakwater effect that facilitates the recolonization of wetland plants between the planted area and the water's edge. Management agencies should consider restoring native sedges to increase aquatic biodiversity, and potentially reduce erosion.

Determination of tipping points for aquatic plants and water quality parameters in fish pond systems: A multi-year approach

High levels of nutrients in fish ponds by fish farming may cause significant eutrophication leading to a loss in species richness and a decrease of cover of aquatic plants to phytoplankton dominance. This shift can be represented by a tipping point where a significant change in the state of the ecosystem is observed such as a change from high to low aquatic plants species richness and cover. A total of 100 fish ponds were studied during five years in the Dombes region, France, to determine tipping points in aquatic plant richness and cover using chlorophyll α (CHL), water transparency, Total N (TN) and Total P (TP) gradients with two statistical methods. The relationships between tipping points, nutrient loads and yearly variations in weather conditions were also evaluated. Looking at the five years data, tipping points were observed in aquatic plant richness at 6 and 60μg/L for CHL, and at 3.90mg/L for TN concentration; as well as at 70cm for water transparency, but no tipping point was found with TP. For aquatic plant cover, tipping points were observed at 11μg/L for CHL, 2.42mg/L for TN, 0.05mg/L for TP, and at 62cm for water transparency. These tipping points showed a significant decrease of aquatic plant species richness and cover, linked to the nutrient concentrations which drive the competition between the primary producers phytoplankton and aquatic plants. However, tipping points could vary significantly between years. The inter-annual variability may be due to an early occurrence of phytoplankton blooms in some ponds in a year preventing the establishment of aquatic plants, and thus influencing the value of tipping points. Weather conditions influence the competition between primary producers by impacting chlorophyll α and nutrients concentrations. When weather conditions supported increased nutrient concentrations, the development of phytoplankton and aquatic plants was facilitated and tipping points in aquatic plant richness and cover occurred with relatively high values. Thus, a significant decrease of plant cover and richness occurred at higher level of nutrients compared to the other years. In these cases, aquatic plants dominated over phytoplankton for the spring period, and also often during summer. In conclusion, tipping points observed are mainly linked to the competition between aquatic plants and phytoplankton. In shallow and eutrophic systems like fish ponds where nutrients are not a limiting resource, weather conditions act temporarily during spring as the main regulator of this competition.

Environment and biogeography drive aquatic plant and cladoceran species richness across Europe

Summary The relative role of environmental and regional processes in determining patterns of biodiversity may vary across spatial scales. In inland aquatic communities, macrophytes and zooplankton have the potential to disperse over large spatial scales (hundreds of kilometres), but the role of environmental and regional processes in determining species richness (SR) at different spatial scales is poorly understood. To assess the relative importance of environmental and regional processes acting on both regional (within‐region) and continental (among‐region) scales, we surveyed 139 waterbodies in five geographic regions (Spain, Italy, the Netherlands, Scotland and Norway) and in each region measured environmental variables, descriptors of connectivity and SR of two aquatic taxa, namely aquatic plants and cladocerans. Analyses using boosted regression trees and generalised linear models, integrated with multiple imputation of missing data, indicated that both environmental and regional processes were related to local SR. Total phosphorus was the main environmental correlate of SR, showing a unimodal relationship with both taxonomic groups. Conductivity and lake depth were also related to cladoceran SR, and Secchi depth was related to aquatic plant richness. The SR of aquatic plants and cladocerans were significantly correlated, but this relationship was mainly indirect (i.e. determined by the effect of common environmental variables). The limited role of connectivity and space (lack of spatial autocorrelation in model residuals) relative to environment suggests that dispersal limitation is not as important as the environment in explaining richness patterns for both groups within regions. However, region identity strongly influenced SR, which suggests an important effect of biogeographic factors (e.g. the level of endemicity; the number of unique species in each region) and/or dispersal limitation at the continental scale. We conclude that environmental factors and biogeographic processes largely determine the patterns of local and regional SR in aquatic plants and zooplankton.

Short‐term succession of aquatic plant species richness along ecosystem productivity and dispersal gradients in shallow lakes

AbstractQuestionsThe highest species richness is usually expected at an intermediate stage of development since the last major disturbance event, but some studies have shown that ecosystem productivity and dispersal may modify this pattern, suggesting the need for further studies on the effects of productivity and dispersal on the dynamics of species richness through succession. In this study, we analysed aquatic plant species richness in relation to (1) succession stage, measured as numbers of years since the last disturbance that affected the ecosystems; (2) lake productivity, measured as the chlorophyll a concentration; and (3) connectivity to similar nearby ecosystems, a proxy for the potential input of diaspores.LocationShallow lakes of the Dombes region, France.MethodsEvery 5–7 yr these shallow lakes are emptied and left to dry out for 1 yr. These drought disturbances lead to complete destruction of the submerged aquatic plant communities. Sixty lakes arranged along a gradient of productivity were selected. The probability of diaspore input was considered to increase from upstream to downstream, as lakes are organized in hydrologically connected networks via ditches, through which the downstream lakes receive water from the upstream lakes. For each lake, the aquatic plant species richness (from systematic summer vegetation sampling), time since the last disturbance (last summer drying), productivity (estimated as chlorophyll a concentration) and probability of diaspore input (assessed from position in the network) were recorded.ResultsThe aquatic plant species richness decreased with the time since the last disturbance for all of the lakes, but there was a significant interaction with the chlorophyll a concentration and position of the lake in the network. At the lowest ecosystem productivities, the relationship between successional stage and species richness was hump‐shaped, whereas the species richness decreased with increasing time since the last disturbance when productivity increased. The lake's position in the network did not influence species richness during the first 2 yr after disturbance, but from year 3 and thereafter, lakes connected to high numbers of upstream lakes consistently exhibited decreased richness, contradicting the expected trend of increasing species richness with increasing diaspore inputs.ConclusionsThis study indicates that both ecosystem productivity and connectivity strongly affected the relationship between aquatic plant species richness and succession, and that these factors should be taken into account in further developments of the intermediate disturbance hypothesis.

長野県上伊那地域における水路網ネットワーク単位での水生植物の分布と立地環境条件との関係

Recently, the loss of diversity of aquatic plants has become an important issue. The purpose of this study was to determine the relationship between aquatic plant distributions and environmental conditions in canal networks in order to develop appropriate conservation species. Six types of water areas (river, reservoir, paddy field, irrigation canal, drainage, and fish-breeding pond) in canal network in Ina district, Nagano prefecture, central Japan were selected as the study sites. The dominance of the aquatic plants in these sites was surveyed using provisional quadrates. The flora of aquatic plants in these study sites were surveyed in the summer and the fall seasons of 2009. The environmental conditions were measured and recorded as follows; water quality, agricultural and dredging managements and so on. The number of appearance species was 51 in the summer. On the other hand in the fall, the one was 26. It was recognized that the species richness of the paddy field plots were highest with the exception of mid-summer drainage ones. There were a large number of appearance species in the irrigation canal plots with periodic artificial disturbance. As a result, it seems that the maintenance such as paddy field farming with periodic artificial disturbance can be increased the species richness of aquatic plants.

淡路島北部における放棄ため池の現状と水生植物保全上の課題

To clarify the current status of irrigation pond abandonment and the problem for aquatic plant conservation, we investigated the percentage of abandoned pond in local area, the relationship between the depth of pond and aquatic and meadow plants diversity at farm village on hilly terrain in northern part of Awaji Island. The investigation was carried out by interviewing 133 pond manager and by field survey. We found half of ponds had been abandoned already, and, we verify the strong correlation between depth of pond and species richness of aquatic plants.

The relative importance of dispersal and the local environment for species richness in two aquatic plant growth forms

Local species richness can be affected by both the dispersal process and by environmental conditions (species sorting process). The evaluation of the relative roles of these two processes contributes not only to further understanding of the mechanisms determining species richness but also to biodiversity conservation. We studied the relative importance of hydrological dispersal and water chemistry for species richness of submerged and floating‐leaved macrophytes using 31 sets of interconnected ponds with different numbers of component ponds (defined as connection class). Connection class was slightly more important than, or equally important to, water chemistry in determining species richness of floating‐leaved macrophytes. In contrast, submerged macrophyte richness was much more influenced by water chemistry than by connection class, although increasing connection class had some positive effect. Similarly, the occurrence of a particular species of submerged macrophyte was better explained by pond water chemistry than by the occurrence of the same species in the pond immediately upstream. The reverse was true for floating‐leaved macrophytes; the presence of a given species was better explained by its presence in the pond immediately upstream than by water chemistry. These results indicated that the relative importance of the two processes that shape the species richness of aquatic plants is a consequence of the growth form of the plants. However, both the dispersal process via hydrologic connection and species sorting by water chemistry play some role in determining the species richness of both floating‐leaved and submerged macrophytes.

Shifts in aquatic macrophyte abundance and community composition in cottage developed lakes of the Canadian Shield

In this study, we examined how the biomass and species composition of aquatic plant communities relates to cottage development of Canadian Shield lakes. Within the North Kawartha Region of Ontario, we sampled the macrophyte communities at two water depths (0.5 m and 1.5 m) in lakes ( n = 12) having a range of cottage densities (0–23 cottages km −1 of shoreline). Across all lakes, 39 species were found, with individual lake richness ranging from six to ten. Macrophyte biomass decreased with increasing cottage density, irrespective of depth (ANCOVA dev’t*depth p = 0.925). In contrast, only the shallower depth showed a relationship between cottage development and richness and diversity; highly developed lakes had three or fewer species and diversities less than 1.5. There was also a shift in structural plant type from floating leaf and emergent on undeveloped lakes to submersed and submersed low-lying on developed lakes. Ordination analysis demonstrated that cottage development (and to a lesser extent, lake area) was strongly correlated ( p = 0.05) with community species composition in southern Ontario lakes. Our results thus demonstrate that the management of cottage development should minimize the loss of biomass and species richness of aquatic plants given the likely negative effects of these alterations on other taxa in littoral zones and foodwebs in lake ecosystems.

The Effect of Typhoons on the Diversity and Distribution Pattern of Aquatic Plants on Hainan Island, South China

ABSTRACTTyphoons are an important meteorological feature of the tropical southwest Pacific. However, little is known about their effects on aquatic plants. Here, we describe the potential influence of typhoons on the diversity and distribution of aquatic plants on Hainan Island, South China. Using a combination of field survey and published data, 266 species or sub‐species belonging to 115 genera in 57 families were found across typhoon impacted regions of the island. Multiple regression analysis indicated that species richness of aquatic plants was correlated with typhoon incidence rather than the area of aquatic habitat within each region. Heavy rainfall, flooding, and strong winds are likely to create suitable habitats and increase the diversity of aquatic habitats in regions frequently affected by typhoons, which may explain the higher species richness found in those regions. Beta diversity and cluster analyses showed that distinct aquatic floras occurred in regions that were impacted by different typhoon pathways. By comparing the aquatic floras of the Philippines and the typhoon‐affected regions of Hainan, we suggest that typhoons have the potential to transport aquatic plants long distances, although there are a number of other potential explanations for the patterns observed in the aquatic flora of Hainan Island.

The Effect of Aquatic Plant Species Richness on Wetland Ecosystem Processes

The Effect of Aquatic Plant Species Richness on Wetland Ecosystem Processes

Unifying the relationships of species richness to productivity and disturbance.

Although species richness has been hypothesized to be highest at 'intermediate' levels of disturbance, empirical studies have demonstrated that the disturbance-diversity relationship can be either negative or positive depending on productivity On the other hand, hypothesized productivity diversity relationships can be positive, negative or unimodal, as confirmed by empirical studies. However, it has remained unclear under what conditions each pattern is realized, and there is little agreement about the mechanisms that generate these diverse patterns. In this study, I present a model that synthesizes these separately developed hypotheses and shows that the interactive effects of disturbance and productivity on the competitive outcome of multispecies dynamics can result in these diverse relationships of species richness to disturbance and productivity The predicted productivity diversity relationship is unimodal but the productivity level that maximizes species richness increases with increasing disturbance. Similarly, the predicted disturbance diversity relationship is unimodal but the peak moves to higher disturbance levels with increasing productivity Further, these patterns are well explained by the opposite effects of productivity and disturbance on competitive outcome that are suggested by the change in community composition along these two environmental gradients: higher productivity favours superior competitors while higher disturbance levels favour inferior competitors.