Succession Of Macrophytes Research Articles

Climate, hydrology, and human disturbance drive long-term (1988–2018) macrophyte patterns in water diversion lakes

Macrophytes are affected by many natural and human stressors globally but their long-term responses to these multiple stressors are not often quantified. We employed remote sensing and statistical tools to analyze datasets from both short-term (2017–2018) field investigations to explore seasonal patterns, and long-term (1988–2018) Landsat remote-sensing images to detect annual patterns of macrophyte distributions and study their responses to changes in climate, hydrology, and anthropogenic activities in a chain of water diversion lakes in eastern China. We found: 1) biomass and species richness of macrophytes peaked in summer with dominant species of submerged macrophytes Ceratophyllum demersum, Potamogeton pectinatus, and Potamogeton maackianus and floating macrophytes Trapa bispinosa, and non-native species Cabomba caroliniana spread in midstream Luoma Lake and Nansi Lake in summer, while Potamogeton crispus was dominant in all the lakes in spring; 2) water physicochemical parameters (chloride and water depth), lake characteristics (area and water storage), climate factors (air temperature and precipitation), and anthropogenic activities (commercial fishery and urban development) were significantly correlated to the seasonal distribution of macrophytes; 3) long-term data showed a significantly negative correlation between coverage of floating macrophytes and precipitation where the wettest year of 2003 had the lowest coverage of floating macrophytes; and 4) climate (air temperature) and hydrology (water level) were positively correlated with total macrophyte coverage, but human disturbance indexed by the gross domestic product was negatively driving long-term coverage of macrophytes. Our study has important implications for understanding the long-term succession of macrophytes under both natural and human stressors, and for future environmental management and ecological restoration of freshwater lakes.

Plant Macrofossils Reveal Aquatic Macrophyte Successions of a Typical Shallow Lake (Huanggai Lake, China) in the Past Century.

Aquatic macrophytes are one of the important biotic components of shallow lake ecosystems. Understanding the long-term evolution of the macrophyte community is crucial for lake management. Huanggai Lake, a typical shallow lake in the middle reach of the Yangtze River, was selected as the research site for this study. Based on 210Pb/137Cs dating, aquatic plant macrofossils were used to reconstruct the succession of aquatic macrophytes in the past century. Our results show that the lake maintained a consistent natural state before 1940, with a relatively low abundance of aquatic plants dominated by species such as Najas minor. From 1940 to 1974, human activities gradually intensified in the lake leading to the emergence of eutrophic species such as Potamogeton maackianus, along with the increasing abundance of other emergent and floating aquatic macrophytes. Since 1974, more pollution-resistant, emergent species such as Potamogeton maackianus and Potamogeton crispus have become dominant. The abundance of aquatic macrophytes reached its maximum in the early 1990s. Combined with macrofossil succession and other multiple sedimentary proxy analyses, driving mechanisms for aquatic macrophytes are discussed. Both the nearby Liangzi Lake and Huanggai Lake share many common features of aquatic plant evolution. This study is the first of its kind to use plant macrofossils (with identifiable images) as a proxy for aquatic macrophyte succession in a shallow Yangtze lake. In absence of long-term monitoring records, this study highlights the increased application of plant macrofossils for reconstructing the vegetation dynamics and restoration of degraded lakes exposed to severe anthropogenic impacts over the past century.

Plants as agents of hydromorphological recovery in lowland streams

This applied study investigated the recovery trajectory of a channelized, lowland stream following removal of channel dredging and livestock grazing. Fine-scale relationships between macrophyte establishment and key physical descriptors (flow velocity, water depth and substrate) were analysed to explain channel adjustments and associated pioneer landform development. Through a process of biogeomorphic succession, macrophytes regulated the cohesiveness, erosion and transport of sediments, thereby affecting morphological responses and improving physical habitat diversity. The observations and analysis in this study capture the role of flow-sediment-vegetation interactions in self-organisation of a lowland stream, and demonstrate how better understanding of this phenomenon may inform river management and restoration science. Coupled relationships between macrophyte succession, flow and sediment patterns promoted hydromorphological recovery and re-naturalisation of the stream form. This dynamic was reflected in greater depth and substrate diversity characterised by increasing substrate coarseness and higher mean velocities. By regulating variations in local flow velocities, macrophytes created both low velocity-fine bed substrate and high velocity-coarser substrate habitat patches, and a range of shallow and deeper depth habitat patches. The process encouraged landform development on the channel margins and extension of the riverbank into the channel, thereby enhancing planform sinuosity as a two-stage channel formed. Such natural progression towards more heterogeneous habitat may sustain greater species diversity than artificially simplified rivers and deserves greater attention in restoration science.

Succession of submerged vegetation in a hydrologically reclaimed opencast mine during first 10 years

Succession of submerged vegetation was monitored from the early stages for a period of 10 years by Self‐Contained Underwater Breathing Apparatus (SCUBA) divers in Milada Lake. Milada Lake is the result of a flooded surface coal mine, the first large‐scale hydrological recultivation in the Czech Republic. The main focus was on apparent changes in the percentage cover of primary producers (macrophytes and macroalgae) during early successional stages. In total, data on 33 environmental factors (chemical, physical, and biological) were collected and the importance of their impact was statistically analyzed. Besides macrophytes, we also monitored macroalgae that mainly occupied deep areas (down to 12 m) and have been neglected in literature in contrast to macrophytes. Uniquely, the trophic state of the study site decreased in contrast to most water bodies worldwide. Changes in the plant species composition during succession, including replacement of the dominant group of Characeae with Vaucheria sp. (both macroalgae), correlated with a decrease in nitrate concentration, N–NO3. Furthermore, the herbivorous fish biomass and availability of uncovered lake bottom played important roles in the succession of macrophytes and macroalgae. Although some changes in submerged vegetation during succession of a newly created lake are to be expected, the main shifts observed apparently correlated with the studied factors. The conclusions may be useful for the prediction of succession in similarly created lakes in the future.

Satellite Imageries and Field Data of Macrophytes Reveal a Regime Shift of a Tropical Lake (Lake Ziway, Ethiopia)

Lake Ziway is one of the largest freshwater lakes located in the central Ethiopian rift valley. The lake shoreline is dominated by macrophytes which play an important role in immobilizing run-off pollution, stabilize sediments and support biodiversity. Monitoring the spatio-temporal changes of great lakes requires standardized methods. The aim of this study was to assess the current and long-term trends of macrophyte distribution, surface water area and the water level of Lake Ziway using remote sensing images from 1986 to 2016 with additional hydro-meteorological data. A supervised image classification with classification enhancement using Normalized Difference Aquatic Vegetation Index (NDAVI) and Normalized Difference Vegetation Index (NDVI) was applied. The classification based on NDAVI revealed eight target classes which were identified with an overall producer’s accuracy of 79.6%. Contemporary open water and macrophyte fringes occupied most of the study area with a total area of 407.4 km2 and 60.1 km2, respectively. The findings also revealed a regime shift in the mean water level of the lake and a decline in macrophyte distribution. The long-term water surface area of Lake Ziway also decreased between 1986 and 2016. The changes in water level could be explained by climate variability in the region and strong anthropogenic disturbance. A decline in water level was also associated with lowered surface water area, lakeward retreated macrophyte fringes and enhanced landward encroachment of mudflats, and resulted in a succession of macrophytes with semi-terrestrial vegetations.

Ecological succession of aquatic macrophytes on floating meadows in the Pantanal wetland

With the aim of documenting aquatic macrophyte succession on floating meadows and its relationship with histosol thickness, we sampled six-hundred 0.5 × 0.5 m2 plots of ten randomly chosen floating meadows in Baia Grande lake (Aquidauana, MS, Brazil). The floating meadows were marked in order to follow, since August 2014–August 2015, floristic and phytosociological changes and to assess their relationship with histosol thickness. We recorded 58 species belonging to 23 families and 47 genera. The richest families were Poaceae (8 species), Asteraceae (7) and Cyperaceae (6). Four species stood out for their high importance value: Oxycaryum cubense (Poepp. & Kunth) Lye, Ludwigia helminthorrhiza (Mart.) H. Hara, Eichhornia azurea (Sw.) Kunth and Vigna longifolia (Benth.) Verdc. Histosol thickness of the floating meadows varied from 1 to 51 cm, making it possible to classify them into three classes. We observed that most species (63.3%) were in the initial and intermediate stages of succession (1–34 cm histosol) and that species were replaced as a function of histosol thickness. We conclude that floating meadows have succession stages with various species of aquatic macrophytes related with histosol thickness, but species composition regarding succession stages differs from other water bodies in the Pantanal wetland.

Effect of Hydrologic Alteration on the Community Succession of Macrophytes at Xiangyang Site, Hanjiang River, China.

With the intensification of human activities over the past three decades in China, adverse effects on river ecosystem become more serious especially in the Hanjiang River. Xiangyang site is an important spawn ground for four domestic fishes in the downstream region of Hanjiang River. Based on the field survey results of macrophytes during 1997–2000 and 2013-2014, community succession of aquatic macrophytes at Xiangyang site was evaluated and discussed. Two-key ecologic-related hydrologic characteristics, flow regime and water level, were identified as the main influence factors. The EFC (environmental flow components) parameters were adopted to evaluate the alteration of flow regimes at Xiangyang site during 1941–2013. Evaluation results demonstrate a highly altered flow process after being regulated by reservoir. The flow patterns tend to be an attenuation process with no large floods occurring but a higher monthly low flow. Furthermore, the water level decreased and fluctuation reduced after the dam was built, which caused the decrease of biomass but favored the submerged macrophytes during 1995–2009. However, with the water level increasing after 2010 and gently fluctuating, due to uplift by the hydraulic projects downstream as well as the flow attenuation, the dominant position of submerged macrophytes will be weakened.

Disentangling natural and anthropogenic drivers of changes in a shallow lake using palaeolimnology and historical archives

Shallow lakes are susceptible to catastrophic regime shifts characterised by the presence or absence or macrophytes. However, the long-term controls on macrophyte succession in shallow lakes are incompletely understood. To investigate this, we analysed multiple sediment proxies in Lake Rotcze (Eastern Poland), a small, shallow and densely macrophyte-covered lake to (1) reconstruct the ‘reference conditions’ (sensu WFD) and development of the lake in recent centuries, (2) compare historical evidence with the sedimentary record, and (3) identify the natural and anthropogenic drivers of macrophyte succession. Before the twentieth century, conditions in the lake may be referred to as ‘reference conditions’. Subsequently forest clearance in the catchment resulted in lower water transparency, but concurrent catchment drainage lowered water levels and increased macrophyte development. Since 1950 elevated nutrient supply and climatically driven increases in water levels led to the deterioration of water transparency and partial macrophyte withdrawal. At the end of the twentieth century lake-level drawdown led to low phytoplankton biomass and clear water creating a novel ecosystem where macrophytes invade the whole lake. These patterns suggest that both natural and anthropogenically induced water level fluctuations have been critical drivers of macrophyte development.

Diversity and community succession of macrophytes in Lake Changhu, Hubei Province

在2011年的调查基础上,结合已有资料,研究长湖水生植物多样性、群落特征、水生植被分布现状及水生植物多样性的动态变化和群落演替规律,探讨驱动水生植物群落演替的主导因素.结果显示长湖现有水生植物95种,水生植物优势群落12个.与1985年相比,长湖水生植物无论是在优势种还是优势群落上均发生了巨大变化,从原来以沉水植物为主的优势群落逐步演替为以挺水植物+漂浮浮叶植物为优势的水生植物群落.同时水生植被分布面积急剧缩小,生物量显著下降,2011年全湖水生植被覆盖率仅为4.2%,单位面积平均生物量只有2001年的10%,全湖生物总量相比于2006年下降了88.5%.分析表明,大规模围网养殖等人为干扰活动及水体富营养化是致使长湖水生植物多样性显著下降和群落发生逆向演替的主要原因.;Based on previous results and data obtained from field investigation in 2011, the distribution of aquatic vegetation, species diversity and its dynamic changes, community characteristics and succession features of Lake Changhu were studied and the primary driving factors of community succession were analysed. Results showed that there were 95 species of aquatic plants and 12 dominant plant associations in Lake Changhu in the year of 2011. Compared with the results of 1985, both dominant species and preponderant associations changed dramatically. Dominant aquatic plant associations gradually varied from submerged macrophytes associations to the emergent and floating macrophytes. Furthermore, vegetation coverage of the whole lake declined dramatically to 4.2% and the mean biomass per m² decreased by 88.5%. Our analyses indicated that human disturbances such as large-scale seine farming activities and water eutrophication were main reasons for diversity reduction and adverse succession of Lake Changhu.

5. Community of higher aquatic plants

The most recent data (obtained in July, 2011) regarding species composition and community structure of macrophytes from Lake Drūksiai after the shutdown of the INPP are presented. The characteristics of overgrowth and productivity of aquatic plants are given. The current flora composition is compared with the data of previous investigations. According to the data obtained on the development of macrophyte communities, the lake can be referred to as a mesotrophic water body, and after the shutdown of the NPP the macrophyte succession is at the initial stage.

Succession of aquatic macrophytes in the Modern Yellow River Delta after 150 years of alluviation

This study evaluated the succession process of aquatic macrophytes after 150 years of alluviation in the Modern Yellow River Delta, China, and identified the roles of various environmental parameters that regulate vegetation succession. From 2007 to 2008, 214 quadrats were surveyed and 19 environmental parameters were measured, including elevation, plot distance from the seashore, 10 water parameters, and 7 soil parameters. Forty-six aquatic macrophytes belonging to 20 families and 34 genera were identified across the entire delta. Emergent and submerged plants were the most frequent species, accounting for 58.7 and 34.8 % of all species, respectively. Detrended canonical correspondence analysis showed that the presence of aquatic macrophytes in this delta was primarily regulated by water salinity, soil salinity, and distance from the seashore, followed by nutrient concentrations (e.g., NH4 +, total soil N and PO4 − of water). Salinity-tolerant species (e.g., Ruppia maritima, Phragmites australis, and Typha angustifolia) tended to be widely distributed across the entire delta. In contrast, salinity-sensitive species (e.g., Ceratophyllum demersum, Hydrilla verticillata, and Potamogeton malaianus) tended to be distributed in areas at the early stages of succession, which were relatively distant from the shore. Moreover, this study also confirmed that species richness and diversity were negatively correlated with water and soil salinity, which in turn were negatively correlated with plot distance from the shore. These data indicate that the primary drivers of aquatic macrophyte succession in this delta are water and soil salinity. The information assimilated here is used to propose management practices for the protection of aquatic macrophytes in the Yellow River Delta.

Water HyacinthEichhornia crassipes(Mart.) Solms-Laubach Dynamics and Succession in the Nyanza Gulf of Lake Victoria (East Africa): Implications for Water Quality and Biodiversity Conservation

This study, conducted in Nyanza Gulf of Lake Victoria, assessed ecological succession and dynamic status of water hyacinth. Results show that water hyacinth is the genesis of macrophyte succession. On establishment, water hyacinth mats are first invaded by native emergent macrophytes, Ipomoea aquatica Forsk., and Enydra fluctuans Lour., during early stages of succession. This is followed by hippo grass Vossia cuspidata (Roxb.) Griff. in mid- and late stages whose population peaks during climax stages of succession with concomitant decrease in water hyacinth biomass. Hippo grass depends on water hyacinth for buoyancy, anchorage, and nutrients. The study concludes that macrophyte succession alters aquatic biodiversity and that, since water hyacinth infestation and attendant succession are a symptom of broader watershed management and pollution problems, aquatic macrophyte control should include reduction of nutrient loads and implementing multifaceted approach that incorporates biological agents, mechanical/manual control with utilization of harvested weed for cottage industry by local communities.

The macrophytes of lake Velenjsko Jezero, Slovenia – the succession of macrophytes after restoration of the lake

The macrophyte vegetation in the artificial lake Velenjsko jezero has been monitored since 1996.The pH of the lake was around 12 up to 1994, when it was remediated. After that macrophytes started to colonize a large proportion of the littoral very quickly. The pioneer species, which appeared in the first survey year (1996), were Chara sp., Nuphar lutea, Potamogeton crispus and Myriophyllum spicatum. Potamogeton crispuswas the dominant species till 1997. In the following years Najas marina and Potamogeton filiformis prevailed over other species in the lake. Since the beginning of the colonization, the species composition had become more heterogeneous and the quantitative relationships between the species varied enormously. In the year 2004, 9 species were detected in the lake. While species Najas marina, Potamogeton filiformis, Potamogeton lucens, Potamogeton nodosus show positive development progress, in the last years minor appearance of Charasp., Potamogeton crispusand Najas minor was observed.

Distribution of macrophytes in different water-bodies (habitats) influenced by the Gabčíkovo hydropower station (Slovakia) - present status

The distribution of macrophytes in the Slovak reach of the Danube is presented in three types of water bodies with different environments and management regimes: i) The Old Danube River (1839-1811 km), ii) the anabranch system, iii) the seepage canal. The succession and content of aquatic plants changed depending on the hydrological regime. The succession of macrophytes started in the Old Danube. Zannichellia palustris is the first hydrophyte that overgrows the river bed, which is covered by a thin layer of fine sediment. Temporary denuded pools on flat littoral zone provided favourable conditions for succession. The semi-natural anabranch system supported high biodiversity, where 24 species in three backwaters were recorded. Also the new artificial habitat of the seepage canal is species-rich. Some of the rare and endangered species, such as Groenlandia densa, Hippuris vulgaris, Apium repens and Characeae found suitable habitats here. The distribution of the neophyte Elodea nuttallii increased rapidly in the Slovak part of the Danube flood plain.

Macrophyte succession in Minnesota beaver ponds

Beavers (Castor canadensis Kuhl.) are keystone species that dramatically alter nutrient cycles and food webs in aquatic and terrestrial ecosystems by modifying their hydrology and selectively removing riparian trees. We documented macrophyte succession in 36 beaver ponds ranging from 4 to over 40 years old. We used impounded bogs, because they were isolated from other waterbodies and less prone to washout. Richness and diversity increased linearly in ponds during the first four decades. Pond age and the product of pond size and the number of neighboring ponds in a 0.25-km radius explained 64% (p = 0.001) of the variation in richness. Compositional trends were best explained by propagule dispersal traits. Initial colonists included vagile species, like free-floating macrophytes and desirable foods for waterfowl, like the narrow-leaved pondweeds. Ponds of intermediate age (11–40 years) had the highest diversity, with both floating-leaved and submersed life forms represented. Two community types were identified in older ponds: one characterized by dense lily pad cover and the other characterized by a rich assemblage of Potamogeton. By developing a predictive model for macrophyte succession in beaver ponds, we provide a basis for studying a variety of ecological processes and organisms that depend on macrophytes in these regionally abundant habitats.Key words: macrophyte, succession, beaver, bogs, Minnesota, pond.

Chironomid stratigraphy in the shallow and eutrophic Lake Søbygaard, Denmark: chironomid–macrophyte co‐occurrence

1. A sediment core from the shallow, hypertrophic Lake Søbygaard (mean depth ∼1 m; [TP] 310 μg P L−1) was analysed for subfossil remains to reconstruct chironomid community changes in relation to the succession and disappearance of aquatic macrophytes. 2. Species composition in the 1.10 m core indicates a succession from a ‘naturally’ eutrophic state to a hypertrophic state during recent centuries. Radiometric dating (210Pb) of the uppermost 20 cm of the sediment core (∼1932–93) indicates that sediment accumulation rate had doubled in recent decades. 3. Changes in chironomid assemblages were in close agreement with changes in both diatoms and macrophyte remains in the same core. Distinct changes in chironomid communities reflect the eutrophication process and macrophyte succession through Chara, Ceratophyllum and Potamogeton dominance to the present state, with complete loss of submerged vegetation and dominance by phytoplankton. 4. The co‐occurrence and relationship between aquatic macrophyte diversity and recent subfossil chironomid assemblages were assessed from an additional 25 Danish lakes. There was good agreement between the macrophyte and chironomid‐based lake groupings. Overall, a significant difference (P<0.001) was found in chironomid assemblages among lakes in different macrophyte classes. In a pair‐wise comparison, the poorly buffered mesotrophic lakes and the alkaline eutrophic lakes had significantly different chironomid assemblages. 5. Chironomid taxa commonly reported to be associated with macrophytes (Cricotopus, Endochironomus and Glyptotendipes) were shown also to be indicators of highly productive lakes lacking abundant submerged vegetation.

Macrophyte Succession in Dianchi Lake and Relations with the Environment

通过滇池水生植被和水体污染状况的全面调查(1995-1997年),揭示了水生植被的演替动态与环境质量变化的关系结果表明,滇池现有水生植物22种,以凤眼莲(Eichhornia crassipes)、喜旱莲子草(Alternanthear Philoxeroides)、龙须眼子菜(Potamogeton petinatus)和聚草(Myriophyllum spicatum)等为优势种,其水生植被可划分为 9个群丛.与历史资料比较表明, 40年来,滇池的水生植被面积从 20世纪 50-60年代的 90%下降到 1996年的 1.8%,生物量由过去的1363.1gm^-2(鲜重)下降到1367 gm^-2.群落结构迅速简化和退化,原来的优势物种如海菜花、轮藻等已绝迹,菹草、马来眼子菜、苦草等已到濒临消失的边缘,耐污种如凤眼莲、喜旱莲子草和龙须眼子菜等大发展.;The investigation of the aquatic vegetation in Dianchi Lake has been carried out from 1995-1997.This paper described the sepcies composition, community structure, distribution, biomass and succession dynamics of aquatic vegetation in the Lake, and analyzed the interaction between the change of the aquatic vegetation and the environmental quality.Comparing with over 100 species found in the 1950s in Dianchi Lake, there are only 22 sepcies of auqatic vascular plants collected from this lake, among which Eichhornia crassipes, Alternanther phiLoxeroides, Pota-mogeton malainus and Myriophyllum spicatum are the dominant species off aquatic vegetation.The aquatic vegetation of Dianchi Lake from 1995 to 1997 could be divided into 9 associations.Due to the eutrohpication and the water pollution, the area of the aquatic vegetation decreased from 90% to 1.8% and the biomass decreased from 1363.1 g m^-2 to 136.73 g m 2during tl.last 50 years.The community structure has simplicated and deteriorated drastically, the biodiversity changed periodcally along with the succession of the major species.The Dianchi Lake has completed the transition from submerged-plant-dominant-type, and Caohai has being in the third alternative stable state which the floating plant is dominant.

Vegetation structure and primary production in acidified lakes in southwestern Sweden

Research during the last two decades has clearly pointed out that dramatic ecosystem changes have occured in lakes due to deposition of acid substances and decreased pH. Today a large number of lakes and running waters in Scandinavia are suffering biological damage with disappearing fish populations, overgrowth of the bottom by mosses and filamentous algae, reduced invertebrate fauna, increased transparency etc.—Of all documented biological changes the effect on macrophyte succession, in particular that ofSphagnum, is the most striking effect. Along with the growth of filamentous algae, these changes have brought about major shifts in the composition of the primary producers. The biomass in one lake was estimated to be 6.5 t (dry wt) corresponding to about 24 g m−2, the relevant proportions being 52% forSphagnum, 34% forLobelia and 15% forIsoetes. Percentage production in the whole lake is 54% forSphagnum, 29% forLobelia and 17% forIsoetes, which gives an estimated production of 2.9 t yr−1 or 9 g m−2 yr−1.Sphagnum is a recent flora element and its occurrence is related to the acidification of the lakes. The investigations also show that the growth ofLobelia is reduced in acid lakes compared to other oligotrophic lakes due to shading by the benthic mat of filamentous algae, detritus andSphagnum debris.—One can conclude that there are several quantitative and qualitative changes in the macrophyte community which are related to acidification. One can also conclude that liming of lakes cause elimination ofSphagnum and some increase in the production ofIsoetids.

Macrophyte succession in Swedish lakes caused by deposition of airborne acid substances

Recurrent biological investigations have been made in six lakes in two areas in western Sweden. It has been found that the supply of acid substances induces long-term biological perturbations at all trophic levels in the lake ecosystem. Among these changes, the Sphagnum expansion is believed to strongly affect the dynamics in the lake. A quantification of the Sphagnum expansion in different depth zones of a lake was made. The rate of this invasion was found to be highest in shaded and sheltered areas of the littoral. The abundance of Sphagnum mats is furthermore negatively correlated to the pH of the lake water. The further consequences for the lake ecosystem of this occupation of ever-larger bottom areas by dense Sphagnum mats are discussed.