Pond Communities Research Articles

Contribution of Hydrological Connectivity in Maintaining Aquatic Plant Communities in Remnant Floodplain Ponds in Agricultural Landscapes

Contribution of Hydrological Connectivity in Maintaining Aquatic Plant Communities in Remnant Floodplain Ponds in Agricultural Landscapes

Analysis of the structure and function of microbial community in late-stage of grass carp (Ctenopharyngodon idella) farming ponds

Microbial communities in aquaculture ponds play a critical role in pond productivity and the success of fish production. Nevertheless, our current understanding of the functional diversity of bacterial microbiomes in grass carp pond water and sediments is fragmentary. This study utilized high-throughput sequencing technology and community level physiological profiling (CLPP) methods to investigate microbial communities and metabolic activity of bacterial found in water samples and sediments from eight typical grass carp (Ctenopharyngodon idella) culturing pond in southern China. The correlations between putative function using PICRUSt2 and actual metabolic profiles via Biolog EcoPlates was assessed. Carbohydrates (32.51 %), amino acids (23.13 %), and polymers (16.61 %) were the most dominant carbon sources utilized by the microbial community in the sediment; while carbohydrates (34.72 %), amino acids (25.49 %), and polymers (16.15 %) were also utilized most often in the water samples. In the sediment samples, Proteobacteria (24.67 %), Chloroflexi (15.30 %), and Firmicutes (13.74 %) were the most dominant bacteria phyla. Actinobacteriota (32.62 %), Cyanobacteria (25.06 %), and Proteobacteria (17.51 %) were the most dominant bacteria phyla in the water samples. Moreover, our results suggested that the nitrogen transformations bacterial genera (Bacillus, Bradyrhizobium, Brocadia, Halomonas, and Vogesella) were positively correlated with carbon source utilization of the microbial community in the Biolog EcoPlates in the sediment. Dechloromonas and Pseudomonas were significantly negatively correlated in the water samples. In addition, there was a significant correlation between predicted function and the actual metabolic characteristics of microbial communities in sediment and water samples. The results facilitate detailed perspective of the relationship between the microbial community structure and the function in grass carp ponds and also provide a reference for the selection of suitable carbon sources in aquaculture wastewater treatment technology.

Dalit Histories, Pandemic Histories

Dalit Histories, Pandemic Histories

Convergence in floodplain pond communities indicates different pathways to community assembly

Disturbance can strongly influence ecosystems, yet much remains unknown about the relative importance of key processes (selection, drift, and dispersal) in the recovery of ecological communities following disturbance. We combined field surveys with a field experiment to elucidate mechanisms governing the recovery of aquatic macroinvertebrates in habitats of an alluvial floodplain following flood disturbance. We monitored macroinvertebrates in 24 natural parafluvial habitats over 60 days after a major flood, as well as the colonization of 24 newly-built ponds by macroinvertebrates over 45 days in the same floodplain. We examined the sources of environmental variation and their relative effects on aquatic assemblages using a combination of null models and Mantel tests. We also used a joint species distribution model to investigate the importance of primary metacommunity structuring processes during recovery: selection, dispersal, and drift. Contrary to expectations, we found that beta diversity actually decreased among natural habitats over time after the flood or the creation of the ponds, instead of increasing. This result was despite environmental predictors showing contrasting patterns for explaining community variation over time in the natural habitats compared with the experimental ponds. Flood heterogeneity across the floodplain and spatial scale differences between the experimental ponds and the natural habitats seemingly constrained the balance between deterministic and stochastic processes driving the ecological convergence of assemblages over time. While environmental selection was the dominant structuring process in both groups, biotic interactions also had a prominent influence on community assembly. These findings have profound implications towards understanding metacommunity structuring in riverscapes that includes common linkages between disturbance heterogeneity, spatial scale properties, and community composition.

Responses of bacterial and three sub-microeukaryote communities in the water of white shrimp Penaeus vannamei aquaculture ponds in two polyculture models.

Polyculture operations in freshwater aquaculture ponds can disrupt microbial communities. High-throughput sequencing was used to assess the impact of polyculture operations on bacterial and three sub-microeukaryote communities (fungi, zooplankton, and eukaryotic phytoplankton) in Penaeus vannamei aquaculture ponds containing oriental river prawns and giant freshwater prawns, respectively. The results showed that the bacterial community was less sensitive than the microeukaryote communities to both the polyculture activity and environmental variations. The polyculture of giant freshwater prawns rather than oriental river prawns was the primary factor affecting the beta diversity of the three sub-microeukaryote communities. This may be due to the larger biomass of the polyculture varieties of giant freshwater prawns compared with oriental river prawns. The polyculture activity of giant freshwater prawns with a higher density and that of oriental river prawns with a lower density increased the stochasticity of the community assembly of the three sub-microeukaryote communities. It also affected the topological properties of the microbial communities, including greater correlations between ecosystem elements, and reducing the correlations among zooplanktons. The eukaryotic phytoplankton was the only microbial community that could also be explained by nutrient variation (mainly the total nitrogen). This highlights the potential role of the eukaryotic phytoplankton as a suitable indicator of the effects of nutrient input into ecosystems.

Habitat complexity, connectivity, and introduced fish drive pond community structure along an urban to rural gradient.

Urbanization can influence local richness (alpha diversity) and community composition (beta diversity) in numerous ways. For instance, reduced connectivity and land cover change may lead to the loss of native specialist taxa, decreasing alpha diversity. Alternatively, if urbanization facilitates nonnative species introductions and generalist taxa, alpha diversity may remain unchanged or increase, while beta diversity could decline due to the homogenization of community structure. Wetlands and ponds provide critical ecosystem services and support diverse communities, making them important systems in which to understand the consequences of urbanization. To determine how urban development shapes pond community structure, we surveyed 68 ponds around Madison, Wisconsin, USA, which were classified as urban, greenspace, or rural based on surrounding land use. We evaluated how landscape and local pond factors were correlated with the alpha diversity of aquatic plants, macroinvertebrates, and aquatic vertebrates. We also analyzed whether surrounding land use was associated with changes in community composition and the presence of specific taxa. We found a 23% decrease in mean richness (alpha diversity) from rural to urban pond sites and a 15% decrease from rural to greenspace pond sites. Among landscape factors, adjacent developed land, mowed lawn cover, and greater distances to other waterbodies were negatively correlated with observed pond richness. Among pond level factors, habitat complexity was associated with increased richness, while nonnative fishes were associated with decreased richness. Beta diversity was relatively high for all ponds due to turnover in composition between sites. Urban ponds supported more nonnative species, lacked a subset of native species found in rural ponds, and had slightly higher beta diversity than greenspace and rural ponds. Our results suggest that integrating ponds into connected greenspaces, maintaining riparian vegetation, preventing nonnative fish introductions, and promoting habitat complexity may mitigate the negative effects of urbanization on aquatic richness. While ponds are small in size and rarely incorporated into urban conservation planning, the high beta diversity of distinct pond communities emphasizes their importance for supporting urban biodiversity.

The Responses of Sediment Bacterial Communities in Chinese Mitten Crab (Eriocheir sinensis) Culture Ponds to Changes in Physicochemical Properties Caused by Sediment Improvement

The interaction between nutrients, heavy metals, and sediment bacterial communities play a key role in the health of crabs and the biogeochemical cycles of aquaculture systems. However, the effects of sediment improvement activities in crab culture on nutrients and heavy metals and the response of bacterial communities to the relevant changes are unclear. In this study, 24 water and sediment samples were collected from two aquaculture sites (total of 12 ponds, 6 at each site). High-throughput sequencing was used to determine the structure of the bacterial community and the diversity in water and sediment samples. The relationship between nutrients, heavy metals, and bacterial communities and the changes of the three before and after the improvement of the sediment were analyzed. The results showed that Proteobacteria, Bacteroidetes, Acidobacteria, Chloroflexi, and Firmicutes were predominant at the phylum level of sediment. Sediment improvement has an effect on NH4+-N, sulfide, total organic carbon (TOC), and heavy metals in sediments to varying degrees. In addition, redundancy analysis found that NH4+-N, NO3−-N, TP, and heavy metals were key drivers in crab culture pond sediments. The results of functional prediction showed that carbon, nitrogen, and sulfur metabolism were the dominant processes in the two crab farming areas. Overall, changes in nutrients and heavy metals caused by sediment improvement further affected the structure and function of bacterial communities and may affect biogeochemical cycles. Our study has deepened the understanding of the effects of sediment improvement on nutrients, heavy metals, and bacterial communities in crab culture ponds.

Environmental Factors Controlling Zooplankton Communities in Thermokarst Lakes of the Bolshezemelskaya Tundra Permafrost Peatlands (NE Europe)

Environmental physical and chemical factors controlling the abundance and biodiversity of zooplankton in permafrost-affected lakes are poorly known yet they determine the response of aquatic ecosystems to on-going climate change and water warming. Here, we assess the current status of zooplankton communities in lakes of the Bolshezemelskaya Tundra (permafrost peatlands of NE Europe), and provide new information about the composition and structure of zooplankton. The results demonstrate that the structure of zooplankton communities is influenced by the morphometric features of lakes and the degree of lake overgrowth by macrophytes. According to the level of quantitative development of zooplankton, most tundra lakes were of the oligotrophic type with an average wet biomass of up to 1 g/m3. The largest number of species was observed in zooplankton communities of small thaw ponds with an area of up to 0.02 km2 and overgrown with macrophytes. The analysis of factors that influence the formation of the lake zoocenosis demonstrated that the species composition and quantitative characteristics of zooplankton are chiefly controlled by pH and water mineralization. A comparison of the results obtained with the literature data on the lakes of this region collected 60 years ago suggests that the ecosystems of these lakes are in a stable state. Overall, these new insights will improve our knowledge of factors controlling the zooplankton spatial dynamics in unique but quite abundant thermokarst lakes of NE European Tundra, subjected to on-going climate warming.

Non‐native fish facilitate non‐native snails and alter food web structure in experimental pond communities

Abstract Contemporary ecosystems commonly support multiple non‐native species, which can alter community structure and directly or indirectly interact with one another. Novel interactions between invasive species can result in the facilitation or suppression of one or both invaders, making it important to understand the underlying mechanisms that affect invasion outcomes. Goldfish Carassius auratus and Chinese mystery snails Cipangopaludina chinensis have been introduced widely through the aquarium trade and co‐occur in their non‐native ranges. We used an outdoor mesocosm experiment to assess separate and combined effects of goldfish and mystery snails on urban pond community structure and to investigate whether goldfish and mystery snails affected one another positively, neutrally or negatively. We predicted that the distinct trophic levels of each species and the anti‐predator traits of mystery snails would lead to positive interactions between invaders and synergistic effects on the aquatic community. Goldfish directly increased turbidity and decreased filamentous algae, zooplankton, juvenile native snails and survival of amphibians via consumptive effects. Goldfish indirectly increased periphyton, phytoplankton and body size of surviving native green frogs Lithobates clamitans through trophic cascades and/or release from competition. Mystery snails had more subtle effects including reducing growth rates of native grey tree frogs Hyla versicolor, likely through competitive interactions. With goldfish present, mystery snails showed increased reproductive success (higher biomass of juveniles), likely due to indirect competitive release from other herbivores. In contrast to their effects on native snails, goldfish did not consume juvenile mystery snails, likely due to their unique traits (e.g. large size and shell thickness). Mystery snails slightly reduced goldfish growth but did not affect their survival. These results suggest unidirectional facilitation between invaders via indirect changes in the food web. Overall, our study found strong direct and indirect effects of invasive aquarium species, particularly goldfish, and provides experimental support for the invasional meltdown hypothesis within urban waterbodies, which are especially prone to invasions. Read the free Plain Language Summary for this article on the Journal blog.

Effects of submerged macrophytes (Elodea nuttallii) on water quality and microbial communities of largemouth bass (Micropterus salmoides) ponds.

Traditional aquaculture ponds are one of the most vulnerable ecosystems; thus, ecological aquaculture is increasingly valued for its beneficial ecological properties and ecosystem services. However, little is known about ecological aquaculture of largemouth bass with submerged vegetation. Here, we designed three ecological ponds of cultured largemouth bass with submerged macrophytes (the EM group) and three ponds with traditional aquaculture (the M group) to reveal the response of water quality, and phytoplankton and bacterial communities, to submerged macrophyte bioremediation during a 90-day culture period. We observed that Cyanobacterial outbreak occurred in the M group ponds from day 7 to the end of the experiment; however, there were no Cyanobacterial blooms in the EM group ponds throughout the culture period. Compared with the M group ponds, the EM group ponds, which had submerged hydrophytes, had significantly decreased concentrations of TP, TN, and CODMn, but significantly increased DO concentrations throughout the experimental period. Moreover, ecological aquaculture with submerged macrophytes showed strong effects on the phytoplankton and bacterial community compositions. In particular, the M group ponds had higher phytoplankton density and mainly included Cyanobacteria, whereas the EM group had lower phytoplankton density and mainly included Chlorophyta. Moreover, higher alpha diversity, as determined by Ace and Simpson index values, was detected for bacterial communities in the EM group ponds. Furthermore, PCoA clearly grouped the bacterial communities according to the two culture modes throughout the culture period. These results indicate that ecological aquaculture with submerged macrophytes can improve water quality, control Cyanobacterial blooms, and affect the diversity and composition of bacterial communities. These valuable effects seem to be beneficial and consistent to maintaining aquaculture ecosystem stability.

Assessing the effect of nutrient management on the plankton community: a substantial aquaculture approach

Because of their impact on environmental variables, understanding plankton communities is crucial for aquaculture. This assay was performed with a view to examining the ecological effect of nutrient managements on plankton community in pond with four treatments having three replications; T0 was control without feed and fertilizer, T1 with only fertilizer, T2 with fertilizer and feed and T3 with only feed. Tilapia (Oreochromis niloticus) fry was stocked and fed initially at 50% of body weight in T3 and gradually reduced to 5%. Feed in T2 was half of treatment T3; fertilization was done weekly. In the study, four phytoplankton groups were identified: Chlorophyceae, Cyanophyceae, Bacillariophyceae, and Euglenophyceae, along with four zooplankton groups: Rotifera, Copepoda, Cladocera, and Crustacea. The most dominant phytoplankton and zooplankton groups were found as Chlorophyceae and Rotifera, respectively. The treatments showed significant difference (P <0.05) in plankton, notably between T2 and T0. The mean plankton abundance was highest in treatment T2. Findings indicated that application of both fertilizers and feed was better for plankton population growth than other treatments. So, the study could recommend that combined application of fertilizers and supplemental feed as the best option for semi-intensive fish farming.

An evaluation of crustacean and rotifer diversity and composition in a temporary pond metacommunity: Comparing results from field samples and a hatching experiment

Abstract Many aquatic invertebrates that inhabit temporary ponds produce resting forms to overcome the dry period, building up the egg bank. When the wet phase returns, the resting forms hatch and the community is restored, and then pioneer species may have a major influence on how the pond community will assemble. We aimed to evaluate the diversity of an initial pond metacommunity by comparing the early active metacommunity collected in the field and the egg bank metacommunity (by carrying out a hatching experiment) of 32 Mediterranean temporary ponds. We hypothesised that both metacommunities would be similar but also that species turnover may play an important role, and that γ diversity would be similar with both approaches. After the identification and counting of rotifers and crustaceans in both metacommunities (i.e. the field vs. the experiment) we performed a Partial Triadic Analysis comparing the field metacommunity with those corresponding to each of the eight times the hatching experiment was checked for hatchlings. Furthermore, we compared the field and experimental metacommunities with a PROTEST analysis and identified the taxa responsible for differences between metacommunities with a SIMPER analysis. We assessed γ diversity using a size‐based rarefaction curve and an evenness profile and explored β diversity and its components (turnover and nestedness) for the two metacommunities. Our experimental results showed differences in the temporal pattern of emergence between groups of organisms, with copepods, rotifers, and anostracans appearing first, but ostracods and rotifers reaching the highest diversity at the end of the experiment. The active and experimental pioneer metacommunities were similar according to a Procrustes analysis. Nevertheless, β diversity was high in both metacommunities and the differences among ponds and between both assemblages were mostly explained by species turnover. Both the active and experimental pond metacommunities showed some exclusive species that may be more difficult to uncover with only one type of approach. Furthermore, the high β diversity observed indicates that each temporary pond is an important contributor to γ diversity in the metacommunity. These results show that hatching experiments provide information that is complementary to standard sampling of the active community, and consequently is a useful tool to uncover pond biodiversity.

The role of habitat features in patterns of population connectivity of two Mediterranean amphibians in arid landscapes of central Iberia

ContextMediterranean wetland ecosystems are in continuous decline due to human pressure. Amphibians are key elements of biotic communities of Mediterranean temporary ponds and streams, and their persistence depends on the availability and inter-connectivity of breeding sites.ObjectivesWe investigated the role of different factors potentially driving functional connectivity patterns in two amphibian species at the landscape and local scales. We focused on two Mediterranean endemic pond-breeding amphibians inhabiting semi-arid landscapes of central Spain, the common parsley frog (Pelodytes punctatus) and the common midwife toad (Alytes obstetricans).MethodsWe genotyped 336 individuals of P. punctatus and 318 of A. obstetricans from 17 and 16 breeding populations at 10 and 17 microsatellite loci, respectively. We used remotely sensed vegetation/moisture indices and land use/cover data to derive optimized resistance surfaces and test their association with estimates of gene flow and migration rates across populations.ResultsWe found evidence for higher population connectivity in common midwife toads than in common parsley frogs, with a strong effect of water availability in patterns of population connectivity of both species. However, the two species differ in the role of landscape features on population connectivity, with the distance and spatial distribution of artificial land-use types positively influencing connectivity in A. obstetricans and meadows/pastureland favouring P. punctatus. This is in line with reported breeding site preferences for the two species, with A. obstetricans successfully breeding in artificial water bodies that P. punctatus generally avoid.ConclusionsThis study highlights the importance of assessing species–habitat relationships shaping connectivity when developing and implementing conservation and management actions to benefit fragmented amphibian populations in the Mediterranean region. Our results show that amphibian species respond differently, even contrastingly to landscape features and thus require alternative, complementary strategies to improve population connectivity and ensure long-term viability.

Pelatihan Aplikasi Perkantoran Bagi Perangkat Desa Dalam Upaya Peningkatan Kinerja Dan Pelayanan Prima

Rawa Panjang Village is one of the villages in the Citayam area, Bogor district. In this village there is abeautiful swamp that is produced into a tourist spot and fishing and community ponds. Problems found in thearea, namely the limited ability of village officials to use and operate IT-based applications used in providingservices to community needs, so that the services provided are still below the standard of excellent service.The solution that can be given as a step to anticipate and develop services is to provide training on the use ofIT-based office applications that are expected to improve the skills and knowledge of village officials, so asto improve service performance towards excellent service and provide satisfaction for the community. Thetarget output expected after the implementation of this IT-based office application training activity is anincrease in the ability and skills of village officials so as to improve performance and excellent service

Hydrology regime and hydrology recruitment niche predict changes in plant community composition across a pond habitat

AbstractQuestionsNiche differentiation is widely accepted as a key mechanism important for species coexistence. Seed germination and seedling survival were recognized as important contributors to niche segregation and could be a crucial filter for determining species' distributions and community composition. Only a little is known about the direct relationship between hydrology recruitment niche, hydrology regimes, and community composition. Therefore, the main aim of this study is to identify the changes in the composition of a pond community with respect to the hydrological regime and predict them by the recruitment niche of species.LocationThe Gloggere pond in the Altdorfer forest (47.848 N, 9.698 E, Ravensburg vicinity, Upper Swabia, Baden‐Wuerttemberg, Germany).MethodsA transect with 46 permanent plots was established throughout the Gloggere pond, and species percentage cover was recorded in September 1992–1995, 2006, and 2017. Pond drawdown was implemented in 1993. Sediment samples were collected in March 1995 across the transect, and a pot germination experiment with six hydrological treatments was performed. The hydrology recruitment niche from the seed bank germination experiment was compared with the field hydrology niche to show the importance of the hydrology regime for community composition.ResultsThe hydrological regime determined the community composition in both the germination experiment and the field. Species‐specific hydrology niche from the field correlated with species‐specific recruitment niche measured in the germination experiment.ConclusionsOur results support the importance of recruitment niche as a driver of community composition for pond areas. For understanding and predicting changes in plant community composition, it is necessary to combine knowledge about the recruitment niche and the ability of seeds’ survival in the sediment along a hydrological gradient with knowledge about abiotic filters, biotic interactions, and species‐specific traits. Recognizing the recruitment niche is useful for better predicting the effect of future environmental changes, especially in the context of climate change and conservation management.

Effect of Bag Limits on Angler Harvest, Catch Rates, and Satisfaction at Put‐and‐Take Community Pond Fisheries

AbstractCommunity pond fisheries are valuable recreational resources for anglers because of their ease of access and often‐regular stocking frequency. Effective management of these fisheries requires an understanding of how bag limits, stocking frequency, stocking density, and angler effort affect angler satisfaction and catch rates. We released tagged, catchable‐sized Rainbow Trout Oncorhynchus mykiss and conducted creel surveys at Idaho ponds with either two‐ or six‐trout daily bag limits (hereafter, “two‐trout ponds” and “six‐trout ponds”) to evaluate whether the bag limit affected catch rates between stocking events. Angler catch rates averaged 0.53 fish/h at two‐trout ponds and 0.76 fish/h at six‐trout ponds. Catch rates declined in the days after trout stocking but did so at similar rates in ponds with different bag limits. Catch rates were negatively affected by air temperatures throughout the study. Fifty‐four percent of anglers reported being somewhat satisfied or very satisfied with their fishing experience at two‐trout ponds compared to 64% of anglers at six‐trout ponds. This measure of satisfaction was positively related to an individual's catch rates. Despite the threefold difference in daily bag limits, 57% of anglers harvested two or fewer fish at six‐trout ponds. Angler‐reported tags indicated that stocked trout remained at large longer (mean = 29 d) in two‐trout ponds compared to six‐trout ponds (mean = 17 d). Tag returns suggested that on average, total use (harvested trout plus caught‐and‐released trout) was much higher at six‐trout ponds (57%) compared to two‐trout ponds (34%). Although the recruitment potential and accessibility of community ponds are well known, our results suggest that catch‐related outcomes of community pond management are a complex result of environmental factors, fisheries regulations, and fish stocking variables.

Sediment sulfate content determines assembly processes and network stability of bacteria communities of coastal land-based shrimp aquaculture ponds

Sediment bacteria communities in shrimp pond are intricately linked to ecosystem function and the provision of services, such as nutrient cycling and excess nutrient metabolism in sediment. However, little is known about the main factor (assembly processes) governing abundant and rare bacterial diversity in land-based shrimp ponds. This study quantified the composition, spatial distribution, and assembly mechanisms of bacterial communities sampled from the sediment of 78 land-based shrimp ponds distributed along approximately 1700 km of the southeastern coastal zone of China. This was done using 16S rRNA gene amplicon sequencing. The bacterial community similarities decreased with spatial distance. Variation of bacterial community was mostly attributed to deterministic (environmental filtering) processes. Sediment sulfate concentrations regulated the balance between stochastic and deterministic bacterial community assembly processes, as indicated by the negative relationship between the stochasticity ratio, and network analysis highlighted increasingly sparse interconnections and less frequent co-occurrences among bacterial communities under greater sulfate concentrations. Our results demonstrate the negative impacts of sulfates associated with coastal aquaculture on sediment bacterial community dynamics, community assembly, and ecosystem function.

Impact of marine aquaculture wastewater discharge on microbial diversity in coastal waters

Numerous pollutants exist in marine aquaculture wastewater, such as organic matter and antibiotics, with uncontrolled discharge affecting both marine and coastal ecological environments. Microbial communities respond sensitively to changes in aquatic environment, exhibiting altered species numbers and population composition. In this study, NGS technology was applied to analyze the composition and diversity of microbial communities in marine aquaculture ponds and the surrounding seawater. The analysis aimed to explore the relationship between microbial diversity in the marine aquaculture industry and the surrounding marine environment, with Dongzhai bay selected as the research object. Water samples were collected from five sampling points, according to marine aquaculture water discharge and diffusion patterns. The dominant bacteria included Proteobacteria, Cyanobacteria, Bacteroidetes, and Actinobacteria, while the dominant fungi included Ascomycota, Basidiomycota, Mortierellomycota, and Rozellomycota. Diversity within microbial communities was found to be related to environmental factors such as pH, NH4+-N, COD (Chemical Oxygen Demand), and TN (Total Nitrogen). Unique microbial species were found to exist in different environments. According to the analysis of OTUs and Alpha diversity, the population and species diversity of microbial populations in P. vannamei culture ponds were lower than in other areas, while mangrove areas showed increased microbial diversity in comparison to other areas. Results showed that the discharge of aquaculture water results in eutrophic substance diffusion in different areas of the bay, which in turn affects the surrounding oceanic microbial community.

Commons, communities and commodification: a review of reforms in land, water and local democracy in Kerala, India

ABSTRACT As India is releasing its third National Water Policy in the last 20 years, this paper seeks to review the earlier policies relevant to a critical yet under-studied surface water ecosystem of rural community ponds. The paper examines how the notion of commodification informed the policies on water, land and local democracy, impacting the governance of rural community ponds in the state of Kerala, India. The review shows that while earlier country-level policies largely showed a tendency to treat water as a commodity, decommodification tendencies are perceptible in the water policy of Kerala. Nonetheless, the land reforms in Kerala resulted in Dalit Bahujans being systematically excluded from accessing land, even though it ended the operation of commoditised human bodies, and enforced land ceilings. Huge tracts of plantations were kept out of the purview of land reforms, signifying the operation of commodification. A positive aspect of the land ceilings was that many private enclosures like rural ponds were transferred to the state. The reforms in local democracy, to a great extent, led to accessible policy-making. The framework of ‘double movement’ is useful in analysing the trends in environmental sociology and evaluating policies related to socio-ecological systems.

Small Islands, Small Ponds, Small Communities-Water Beetles and Water Boatmen in the Faroe Islands.

Simple SummaryThe Faroe Islands in the North Atlantic consist of several small islands, and numerous small freshwater ponds can be found on most of them. These ponds are inhabited by species-poor aquatic communities. Faroese ponds are thus simple systems which lend themselves well to studying diversity of water insects and their interactions with the environment, which ultimately contributes to our understanding of patterns of biodiversity. In this study, we systematically collected water beetles and water boatmen from 57 ponds on the islands Streymoy and Eysturoy to obtain information on species distributions, diversity, and community composition, as well as their relationship with habitat characteristics. We found six small species of Dytiscidae and Haliplidae (Coleoptera) and two species of Corixidae (Heteroptera). There was a higher species diversity in shallower ponds, and community composition differed according to pond size. Geographical location and isolation between ponds did not influence diversity and community composition. We thus conclude that the distribution of water beetles and water boatmen in the Faroes is explained by habitat characteristics, specifically size and depth of the pond.Water beetles of the families Dytiscidae and Haliplidae (Coleoptera) as well as water boatmen (Heteroptera: Corixidae) are well-studied groups in Northern Europe. In the Faroe Islands, their diversity is much lower than in the British Isles and Fennoscandia. Here, we first describe the communities of water beetles and water boatmen in Faroese ponds and, secondly, assess whether community compositions are driven by habitat characteristics or dispersal abilities of species. To this end, we sampled 57 ponds, ranging between <50 m2 and >50,000 m2. Environmental variables such as pond size, temperature, pH, and depth were measured, and distance to nearest neighboring pond was calculated as a measure of isolation. The sampling yielded 1522 individuals of eight species, with species richness of the ponds ranging between zero and six. Pond size (shoreline length) did explain differences in community composition, whereas water depth explained differences in diversity indices with lower diversity in deeper ponds. We found species-specific relations between abundance and shoreline length, e.g., H. fulvus and H. palustris being restricted to larger ponds. Lastly, water beetle and water boatmen communities in Faroese ponds are discussed in the light of island biogeography and species distributions in the North Atlantic islands.