Effects of anthropogenic disturbance on 13C and 15N of aquatic plants from a semiarid wetland

2019 ◽  
Author(s):  
Lilia Serrano-Grijalva ◽  
Raul Ochoa-Hueso ◽  
Raquel Sánchez-Andrés ◽  
Santos Cirujano ◽  
Salvador Sánchez-Carrillo
Keyword(s):  
Water Quality ◽  
Aquatic Plants ◽  
Vascular Plants ◽  
Environmental Changes ◽  
Anthropogenic Impacts ◽  
Vascular Plant ◽  
Regional Scale ◽  
Nitrogen And Phosphorus ◽  
Isotopic Signatures ◽  
La Mancha

Wetlands provide a great variety of environmental services to society, but they are currently globally threatened by human activities. We evaluated the effects of anthropogenic disturbances on the ecological quality of semiarid wetlands from central Spain (La Mancha Húmeda) through the natural abundance of isotopes (13C and 15N) of aquatic plants. We measured water quality and also compiled historical information about land-use and socioeconomic characteristics at local (100 m around the lagoon) and regional (sub-basin) scales. We then related this information to isotopic signatures of three types of aquatic plants: (i) charophytes, (ii) marginal aquatic macrophytes and (iii) vascular plants. Aquatic plants exposed to high levels of nitrogen showed very low δ13C values, consistent with negative physiological effects. Vascular aquatic plants were the group that best reflected the effects of nutrient enrichment in wetlands and lagoons through significant correlations between their δ15N values and total nitrogen and phosphorus concentrations in water. Demographic factors did not exert a clear influence on aquatic plant isotopic signatures, although we observed inverse correlations between the coverage of natural vegetation at regional scale and δ13C of marginal plants and δ15N of vascular plants. Furthermore, the isotopic signatures of Phragmites australis, present in 96% of the studied la-goons, were not significantly correlated with any of the environmental quality variables evaluated. Although δ13C signatures of Typha dominguensis and Cladium mariscus increased significantly due to changes in water quality, their narrow isotopic variability at the regional scale limits their use as a bioindicators of environmental changes in this wetland system. Finally, we propose the use of δ15N measured in the vascular plant Salicornia sp. as the most suitable bio-indicator of anthropogenic impacts in La Mancha Húmeda region, a highly emblematic system of semiarid Mediterranean wetlands that is unique in the Mediterranean region of Europe.

scholarly journals Where we Come from and where to Go: Six Decades of Botanical Studies in the Mediterranean Wetlands, with Sardinia (Italy) as a Case Study

Wetlands ◽  
2021 ◽  
Vol 41 (6) ◽  
Author(s):  
Alba Cuena-Lombraña ◽  
Mauro Fois ◽  
Annalena Cogoni ◽  
Gianluigi Bacchetta
Keyword(s):  
Vascular Plants ◽  
Vascular Plant ◽  
Regional Scale ◽  
Temporary Ponds ◽  
Evolutionary Strategies ◽  
Plant Groups ◽  
Research Themes ◽  
The Mediterranean ◽  
Taxonomic Groups ◽  
Water Saturated

AbstractPlants are key elements of wetlands due to their evolutionary strategies for coping with life in a water-saturated environment, providing the basis for supporting nearly all wetland biota and habitat structure for other taxonomic groups. Sardinia, the second largest island of the Mediterranean Basin, hosts a great variety of wetlands, of which 16 are included in eight Ramsar sites. The 119 hydro- and hygrophilous vascular plant taxa from Sardinia represent the 42.6% and 37.9% of the number estimated for Italy and Europe, respectively. Moreover, around 30% of Sardinia’s bryological flora, which is made up of 498 taxa, is present in temporary ponds. An overview at regional scale considering algae is not available, to our knowledge, even though several specific studies have contributed to their knowledge. In order to find the most investigated research themes and wetland types, identify knowledge gaps and suggest recommendations for further research, we present a first attempt to outline the work that has been hitherto done on plants in lentic habitats in Sardinia. Three plant groups (algae, bryophytes and vascular plants), and five research themes (conservation, ecology, inventory, palaeobotany and taxonomy) were considered. After a literature review, we retained 202 papers published from 1960 to 2019. We found that studies on vascular plants, as plant group, were disproportionately more numerous, and inventories and ecology were the most investigated research themes. Although efforts have recently been made to fill these long-lasting gaps, there is a need for updating the existing information through innovative methods and integrative approaches.

scholarly journals Impacts of changes in groundwater recharge on the isotopic composition and geochemistry of seasonally ice-covered lakes: insights for sustainable management

2017 ◽  
Author(s):  
Marie Arnoux ◽  
Florent Barbecot ◽  
Elisabeth Gibert-Brunet ◽  
John Gibson ◽  
Aurélie Noret
Keyword(s):  
Water Quality ◽  
Water Balance ◽  
Isotopic Composition ◽  
Sustainable Management ◽  
Environmental Changes ◽  
Anthropogenic Impacts ◽  
Rapid Development ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Lake Water Quality

Abstract. Lakes are under increasing pressure due to widespread anthropogenic impacts related to rapid development and population growth. Accordingly, many lakes are currently undergoing a systematic decline in water quality. Recent studies have highlighted that global warming and the subsequent change in water use may further exasperate eutrophication in lakes. Lake evolution depends strongly on hydrologic balance, and therefore on groundwater connectivity. Groundwater also influences the sensitivity of lacustrine ecosystems to climate and environmental changes, and governs their resilience. Improved characterization of groundwater exchange with lakes is needed today for lake preservation, lake restoration, and for sustainable management of lake water quality into the future. Small groundwater-connected lakes were chosen to simulate changes in water balance and water quality expected under future climate change scenarios, namely Representative Concentration Pathways (RCP) 4.5 and 8.5. Contemporary baseline conditions, including isotope mass balance and geochemical characteristics, were determined through an intensive field-based research program prior to the simulations. Results highlight that future lake geochemistry and isotopic composition trends will depend on four main parameters: location (therefore climate conditions), lake catchment size (which impacts the intensity of the flux change), lake volume (which impacts the range of variation), and lake G-index (i.e., the percentage of groundwater that makes up total lake inflows), the latter being the dominant control on water balance conditions, as revealed by the sensitivity of lake isotopic composition. Based on these model simulations, stable isotopes appear to be especially useful for detecting changes in recharge to lakes with a G-index of between 50 % and 80 %, but response is non-linear. Simulated monthly trends reveal that evolution of annual lake isotopic composition can be dampened by opposing monthly recharge fluctuations. It is also shown that changes in water quality in groundwater-connected lakes depend significantly on lake location and on the intensity of recharge change.

scholarly journals FOREST MANAGEMENT AND WATER QUALITY IN LATVIA: IDENTIFYING CHALLENGES AND SEEKING SOLUTIONS

2018 ◽  
Author(s):  
Zane KALVITE ◽  
Zane LIBIETE ◽  
Arta BARDULE Arta BARDULE
Keyword(s):  
Water Quality ◽  
Forest Management ◽  
Forest Cover ◽  
Overland Flow ◽  
Anthropogenic Impacts ◽  
Regional Scale ◽  
Drainage System ◽  
Hazardous Substances ◽  
System Maintenance ◽  
The Impact

Rise in human population, industrialization, urbanization, intensified agriculture and forestry pose considerable risks to water supply and quality both on global and regional scale. While freshwater resources are abundant in Latvia, during recent years increased attention has been devoted to water quality in relation to anthropogenic impacts. Forest cover in Latvia equals 52% and forest management and forest infrastructure building and maintenance are among the activities that may, directly or indirectly, affect water quality in headwater catchments. Sedimentation, eutrophication and export of hazardous substances, especially mercury (Hg), are of highest concern. To address these topics, several initiatives have started recently. In 2011, cooperation programme between Latvian State Forest Research Institute (LSFRI) “Silava” and JSC “Latvia’s State Forests” was launched to evaluate the impact of forest management on the environment. This programme included research on the efficiency of water protection structures used at drainage system maintenance (sedimentation ponds, overland flow) and regeneration felling (bufferzones). In 2016, within the second stage of this cooperation programme, a study on the impact of forest management on water quality (forest road construction, drainage system maintenance, felling) was started on a catchment scale. Since 2016 LSFRI Silava is partner in the Interreg Baltic Sea Region Programme project “Water management in Baltic forests”. By focusing on drainage systems, riparian zones and beaver activity, this project aims at reducing nutrient and Hg export from forestry sites to streams and lakes. While this project mostly has a demonstration character, it will also offer novel results on Hg and methylmercury (MeHg) concentrations in beaver ponds in all participating states. This paper aims at summarizing most important challenges related to the impact of forest management on water quality and corresponding recent initiatives striving to offer solutions.

Influence of climate,geology and humans on spatial and temporal nutrient geochemistry in the subtropical Richmond River catchment, Australia

2001 ◽  
Vol 52 (2) ◽  
pp. 235 ◽  
Author(s):  
Lester J. McKee ◽  
Bradley D. Eyre ◽  
Shahadat Hossain ◽  
Peter R. Pepperell
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Agricultural Land ◽  
Anthropogenic Impacts ◽  
Inorganic Nitrogen ◽  
Point Sources ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Nitrogen And Phosphorus ◽  
River Catchment

Water quality was monitored on a spatial and temporal basis in the subtropical Richmond River catchment over two years. Nutrient concentrations varied seasonally in a complex manner with highest concentrations (maximum =3110 µg N L – 1 and 572 µg P L –1 ) associated with floods. However, median (444 µg N L – 1 and 55 µg P L – 1 ) concentrations were relatively low compared with other parts of the world. The forms of nitrogen and phosphorus in streams varied seasonally, with greater proportions of inorganic nitrogen and phosphorus during the wet season. Minimum nutrient concentrations were found 2—3 months after flood discharge. With the onset of the dry season, concentration increases were attributed to point sources and low river discharge. There were statistically significant relationships between geology and water quality and nutrient concentrations increased downstream and were significantly related to population density and dairy farming. In spite of varying geology and naturally higher phosphorus in soils and rocks in parts of the catchment, anthropogenic impacts had the greatest effects on water quality in the Richmond River catchment. Rainfall quality also appeared to be related both spatially and seasonally to human activity. Although the responses of the subtropical Richmond River catchment to changes in land use are similar to those of temperate systems of North America and Europe, the seasonal patterns appear to be more complex and perhaps typical of subtropical catchments dominated by agricultural land use.

scholarly journals Different temporal trends in vascular plant and bryophytes communities along elevational gradients over four decades of warming

2020 ◽  
Author(s):  
Antoine Becker-Scarpitta ◽  
Diane Auberson-Lavoie ◽  
Mark Vellend
Keyword(s):  
Plant Communities ◽  
Vascular Plants ◽  
Environmental Changes ◽  
Vascular Plant ◽  
Elevation Gradient ◽  
Temporal Trends ◽  
Community Change ◽  
Ecosystem Functions ◽  
Ecological Communities

Abstract1: Despite many studies showing biodiversity responses to warming, the generality of such responses across taxa remains unclear. Very few studies have tested for evidence of bryophyte community responses to warming, despite the fact that bryophytes are major contributors to diversity in many ecosystems, playing a central role in ecosystem functions. Understanding variation among taxa in their responses to warming is crucial for identifying priorities in conservation.2: We report an empirical study comparing long-term change of bryophyte and vascular plant communities in two sites with contrasting long-term warming trends. To assess long-term responses of ecological communities to warming, we used “legacy” botanical records as a baseline for comparison with contemporary resurveys.We hypothesized that ecological changes would be greater in sites with a stronger warming trends, and that vascular plant communities would be more sensitive than bryophyte communities to climate warming. For each taxon in each site, we quantified the magnitude of changes in species’ distributions along the elevation gradient, species richness, and community composition.3: Temporal changes in vascular plant communities were consistent with the warming hypothesis, but this was not the case for bryophytes. We also did not find clear support for the hypothesis that vascular plants would show greater sensitivity than bryophytes to warming, with results depending on the metric of community change. As predicted for sites with a strong warming trend, we found a significant upward shift in the distributions of vascular plants but not bryophytes.Synthesis: Our results are in accordance with recent literature showing that local diversity can remain unchanged despite strong changes in composition. Regardless of whether one taxon is systematically more or less sensitive to environmental change than another, our results suggest that vascular plants cannot be used as a surrogate for bryophytes in terms of predicting the nature and magnitude of responses to warming. In sites that experienced the same environmental changes, we found that communities of bryophytes and vascular plants did not predictably change in the same ways. Thus, to assess overall biodiversity responses to global change, data from different taxonomical groups and community properties need to be synthesized.

scholarly journals Impacts of changes in groundwater recharge on the isotopic composition and geochemistry of seasonally ice-covered lakes: insights for sustainable management

2017 ◽  
Vol 21 (11) ◽  
pp. 5875-5889 ◽  
Author(s):  
Marie Arnoux ◽  
Florent Barbecot ◽  
Elisabeth Gibert-Brunet ◽  
John Gibson ◽  
Aurélie Noret
Keyword(s):  
Water Quality ◽  
Water Balance ◽  
Isotopic Composition ◽  
Sustainable Management ◽  
Environmental Changes ◽  
Anthropogenic Impacts ◽  
Rapid Development ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
The Future

Abstract. Lakes are under increasing pressure due to widespread anthropogenic impacts related to rapid development and population growth. Accordingly, many lakes are currently undergoing a systematic decline in water quality. Recent studies have highlighted that global warming and the subsequent changes in water use may further exacerbate eutrophication in lakes. Lake evolution depends strongly on hydrologic balance, and therefore on groundwater connectivity. Groundwater also influences the sensitivity of lacustrine ecosystems to climate and environmental changes, and governs their resilience. Improved characterization of groundwater exchange with lakes is needed today for lake preservation, lake restoration, and sustainable management of lake water quality into the future. In this context, the aim of the present paper is to determine if the future evolution of the climate, the population, and the recharge could modify the geochemistry of lakes (mainly isotopic signature and quality via phosphorous load) and if the isotopic monitoring of lakes could be an efficient tool to highlight the variability of the water budget and quality. Small groundwater-connected lakes were chosen to simulate changes in water balance and water quality expected under future climate change scenarios, namely representative concentration pathways (RCPs) 4.5 and 8.5. Contemporary baseline conditions, including isotope mass balance and geochemical characteristics, were determined through an intensive field-based research program prior to the simulations. Results highlight that future lake geochemistry and isotopic composition trends will depend on four main parameters: location (and therefore climate conditions), lake catchment size (which impacts the intensity of the flux change), lake volume (which impacts the range of variation), and lake G index (i.e., the percentage of groundwater that makes up total lake inflows), the latter being the dominant control on water balance conditions, as revealed by the sensitivity of lake isotopic composition. Based on these model simulations, stable isotopes appear to be especially useful for detecting changes in recharge to lakes with a G index of between 50 and 80 %, but response is non-linear. Simulated monthly trends reveal that evolution of annual lake isotopic composition can be dampened by opposing monthly recharge fluctuations. It is also shown that changes in water quality in groundwater-connected lakes depend significantly on lake location and on the intensity of recharge change.

scholarly journals Vascular plant and bryophyte species richness in response to water quality in lowland spring niches with different anthropogenic impacts

2018 ◽  
Vol 190 (6) ◽  
Author(s):  
Katarzyna Puczko ◽  
Piotr Zieliński ◽  
Szymon Jusik ◽  
Anita Kołakowska ◽  
Elżbieta Jekatierynczuk-Rudczyk
Keyword(s):  
Water Quality ◽  
Species Richness ◽  
Anthropogenic Impacts ◽  
Vascular Plant ◽  
Response To Water

scholarly journals Paleontological methods in environmental science

1992 ◽  
Vol 6 ◽  
pp. 40-40
Author(s):  
Grace S. Brush ◽  
Humaira Khan
Keyword(s):  
Water Quality ◽  
Environmental Conditions ◽  
Human Disturbance ◽  
Large Scale ◽  
Environmental Changes ◽  
Nitrogen And Phosphorus ◽  
Ecological Requirements ◽  
Inorganic Substances ◽  
Stratigraphic Record

Long term environmental changes, induced both by natural and anthropogenic causes, cannot be assessed by looking solely at historical records of temperature, rainfall, water quality, etc. Frequently, such records are nonexistent. Where they do exist, they are often too short to be of much use. However, sediments contain a stratigraphic record of environmental change that allows comparison of the historic period influenced largely by humans, with prehistoric time when climate was the major determinant of environmental conditions.The stratigraphic record contains various fossilized organic materials which reflect environmental conditions at the time of the their deposition. Most abundant are pollen and spores of aquatic and terrestrial plants. Correspondence between pollen assemblages and vegetation has been found in all parts of the world. Therefore stratigraphic changes in pollen taxa reveal much information regarding the vegetational history of a region. Knowledge of the ecological requirements of various taxa can then be used to infer past climatic conditions. For example, dominance of Juglans (walnut) pollen indicates wet conditions while abundance of Pteridium (bracken fern) spores is an indicator of fire, suggesting drier conditions. Pollen can also be used to trace human disturbance to the environment. Sharp increases in the pollen of Ambrosia (ragweed) in sediment cores indicate large scale land clearance by man.Seeds preserved in sediments provide another measure of temporal vegetational change. Generally, seeds are not dispersed far from the parent plant; hence they provide a more local record of vegetation than pollen. A decrease in seeds of aquatic plants and increase in seeds of higher ground taxa when accompanied by increased sedimentation rates is an indicator of infilling of an aquatic environment. If unaccompanied by increased sedimentation, the change more likely represents lowering of sea level. Disappearance of seeds of taxa sensitive to turbidity and eutrophication provide another long term record of human disturbance.Distributions of diatoms are affected by temperature, salinity, oxygen, light availability and nutrient levels in the water. Therefore changes in diatom species preserved in the sediments can be used as indicators of climate, turbidity, anoxia and eutrophication in aquatic ecosystems.Many inorganic substances preserved in sediments also provide a long term record of changes in the environment. Nitrogen and phosphorus can be measured in cores and used as a surrogate record of water quality in lakes and estuaries. Sharp increases in sedimentary accumulation of metals record wastewater discharge and fuel emissions, related to human activity.

The Canary in the Coal Mine: Testate Amoebae Record Anthropogenic Impacts in Sediments of Oligotrophic Lake George, NY, USA

2020 ◽  
Vol 50 (2) ◽  
pp. 128-140
Author(s):  
Krystyna M. Kornecki ◽  
Matthew S. Schuler ◽  
Miraim E. Katz ◽  
Rick A. Relyea ◽  
Francine M. G. McCarthy ◽  
...  
Keyword(s):  
Water Quality ◽  
Environmental Changes ◽  
Anthropogenic Impacts ◽  
Testate Amoebae ◽  
Oligotrophic Lake ◽  
Quality Data ◽  
Testate Amoeba ◽  
Water Quality Data ◽  
Salt Loading ◽  
Lake George

ABSTRACT Lake George (NY) is surrounded by Forever Wild Forest in the Adirondack Park and has a Class AA Special water quality rating, yet lake monitoring has revealed increasing anthropogenic impacts from salt and nutrient loading over the past 30 years. To reconstruct anthropogenic influence on the lake (e.g., salt loading, eutrophication, climate warming), we characterized modern stable isotopes and testate amoeba and diatom assemblages in surface sediments from 33 lake-wide sites and compared their variability to 36 years of water-quality data. Linear regression analyses support testate amoebae as rapid responders and recorders of environmental change because taxa are strongly correlated with percent change of important water quality parameters. Our assessment indicates that: 1) Netzelia gramen is associated with aquatic plants and filamentous algae, making them a valuable aquatic plant/alga indicator, which is supported by the co-occurrence of the diatom Cocconeis spp.; 2) difflugids are generally good indicators of eutrophication, except for Difflugia protaeiformis; and 3) seasonal differences in water quality trends are reflected in the fossil record on decadal time scales. We show that testate amoebae are highly sensitive to small environmental changes in an oligotrophic lake and exhibit established relationships from eutrophic and mesotrophic lakes as well as new, likely oligotrophic-specific correlations. Correlation coefficients of water quality variables and strains within a species also illustrate gradational relationships, suggesting testate amoebae exhibit ecophenotypic plasticity. Diatom and testate amoeba assemblages categorize modern lakebed sites into four subgroups: 1) benthic macrophyte; 2) high nutrient; 3) high alkalinity; and 4) salt loading assemblages.

scholarly journals Community-level functional traits of alpine vascular plants, bryophytes and lichens after long-term experimental warming

2021 ◽  
Author(s):  
Kristel van Zuijlen ◽  
Kari Klanderud ◽  
Oda Sofie Dahle ◽  
Åshild Hasvik ◽  
Maria Skar Knutsen ◽  
...  
Keyword(s):  
Vascular Plants ◽  
Environmental Changes ◽  
Plant Traits ◽  
Species Turnover ◽  
Nitrogen Concentration ◽  
Vascular Plant ◽  
Community Level ◽  
Experimental Warming ◽  
Plant Nitrogen ◽  
Vegetation Height

We measured community-level traits of vascular plants, lichens and bryophytes in an alpine Dryas octopetala heath in Finse, Norway, after nearly two decades of experimental warming by open top chambers. We hypothesized that under warming 1) vascular plant traits would shift from resource conservative towards more resource acquisitive, and 2) lichen and bryophyte traits would shift to those associated with drier conditions, due to increased evapotranspiration. Both hypotheses were not supported, as vascular plant nitrogen concentration decreased while carbon to nitrogen ratio increased with warming, indicative of a less resource acquisitive strategy, and lichen specific thallus area and water holding capacity (WHC) were unresponsive. Bryophyte specific shoot length increased, and carbon concentration and WHC tended to decrease under warming, concurrent with increased vegetation height and litter cover indicating stronger competition from vascular plants. Intraspecific variation was most important for vascular plant and lichen traits, while species turnover was the main driver of bryophyte trait variation. This indicates that bryophytes may be affected more strongly by future warming than vascular plants and lichens in our study system. We highlight the importance of studying traits of different primary producer groups simultaneously, as they may respond differently to the same environmental changes.

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