Dune Slacks Research Articles

Environmental modifiers of the relationship between water table depth and Ellenberg’s indicator of soil moisture

Ellenberg indicator values for plant species are widely used metrics in ecology, providing a proxy measure of environmental conditions, without direct measurements. They integrate environmental conditions over time since species will only persist where conditions are favourable. Ellenberg moisture (F) values summarise the hydrological environment experienced by plants. However, the relationship between indicator values and hydrological metrics appears to be influenced by a range of other abiotic and biotic factors, limiting our ability to fully interpret Ellenberg F. Focussing on Ellenberg F, we evaluated how the unweighted mean plant community F value to hydrology, specifically water table depth, is influenced by other environmental factors, ground cover type and alpha diversity in UK seasonal coastal wetlands (dune slacks). As expected, water table depth had the strongest influence on unweighted mean Ellenberg F. We show that unweighted mean Ellenberg F was more sensitive to changes in water table levels for plant communities that were more nutrient limited, when the organic matter layer was thicker and there was less bare ground cover. Unweighted mean Ellenberg F was consistently lower for a given water table depth, when there was lower atmospheric nitrogen deposition, lower loss of ignition (a measure of organic matter content) and more diverse plant communities. These findings help us to better interpret what Ellenberg F indicator values tell us about hydrological conditions, by understanding the factors which alter that relationship.

First tracks of newborn straight-tusked elephants (Palaeoloxodon antiquus)

Tracks and trackways of newborns, calves and juveniles attributed to straight-tusked elephants were found in the MIS 5 site (Upper Pleistocene) known as the Matalascañas Trampled Surface (MTS) at Huelva, SW Spain. Evidence of a snapshot of social behaviour, especially parental care, can be determined from the concentration of elephant tracks and trackways, and especially from apparently contemporaneous converging trackways, of small juvenile and larger, presumably young adult female tracks. The size frequency of the tracks enabled us to infer body mass and age distribution of the animals that crossed the MTS. Comparisons of the MTS demographic frequency with the morphology of the fore- and hind limbs of extant and fossil proboscideans shed light into the reproductive ecology of the straight-tusked elephant, Palaeloxodon antiquus. The interdune pond habitat appeared to have been an important water and food resource for matriarchal herds of straight-tusked elephants and likely functioned as a reproductive habitat, with only the rare presence of adult and older males in the MTS. The preservation of this track record in across a paleosol surface, although heavily trampled by different animals, including Neanderthals, over a short time frame, permitted an exceptional view into short-term intraspecific trophic interactions occurring in the Last Interglacial coastal habitat. Therefore, it is hypothesized that Neanderthals visited MTS for hunting or scavenging on weakened or dead elephants, and more likely calves.

Fine‐scale hydrological niche segregation in coastal dune slacks

AbstractQuestionsHydrological niche segregation is widespread and has been found across a range of different habitats. Different plant species can occupy distinct hydrological niches, and as a result fine‐scale variability in hydrology can structure plant communities. However, these patterns may not be as clear in habitats where differences in hydrology are more short‐lived, such as coastal dune slacks. We explored the extent that the hydrological regime structures dune slack plant communities.LocationAinsdale Coastal Sand Dune National Nature Reserve, UK.MethodsSix hundred quadrats were surveyed, 100 in each of six coastal dune slacks. Water table levels are recorded monthly in each slack. Metrics summarising hydrological regime were calculated and adjusted for each quadrat based on elevation. We tested the relationship between water table depth, plant communities and topography across and within dune slacks.ResultsHalf (three) of the slacks showed a significant influence of hydrology on plant community composition. The three that did not were the ones that varied least topographically and contained less diverse plant communities. We also provide indirect evidence of niche segregation by modelling species‐specific responses between mean water table depth and probability of species presence.ConclusionsWe demonstrate that hydrology is a dominant driver of plant community composition across dune slacks. However, plant communities are not always structured by hydrology, demonstrating the complexity of vegetation patterns. Topographic variation appears to impact plant community patterns, as do successional processes, highlighting the need to create diverse habitats for slack restoration and management.

Plant diversity and community composition in managed humid coastal dune slacks in NW England.

Humid coastal dune slacks are an endangered habitat in Northwestern Europe. In the UK, dune slacks are currently classified as being in ‘unfavourable’ condition, with projected decrease in England of up to 30% by 2036. Studies in mainland Europe suggest that regional factors (e.g. slack area, age, and isolation) are more important than local factors (e.g. soil, pH, soil nutrient and water status) in driving successional vegetation processes in coastal slacks. However, this has never been tested for the UK, where approximately 14% of European slacks occur. We used previously established survey protocols to test whether regional factors are more important than local factors in UK coastal slacks, along the Sefton Coast in NW England. We found that slack area and slack age were more important than local factors in driving plant community composition and species richness. We also showed that higher levels of management, such as active grazing and invasive shrub and tree removal, are effective in increasing soil moisture levels in slacks. Our results suggest that similar successional processes are likely to be important in slacks in the NW of England, compared to mainland Europe.

Current status of the rare British endemic Gentianella amarella subsp. occidentalis, Dune Gentian (Gentianaceae)

Gentianella amarella subsp. occidentalis, Dune Gentian, is a rare annual of dune slacks endemic to Western Britain. Its current status was compared to historic records. A maximum of 2250 plants were found in ten subpopulations in four sites in 2019-2020. It was not refound in three sites and 15 subpopulations. It is assessed as IUCN threat category ‘Endangered’. Its primary vegetation type is SD14d Salix repens - Campylium stellatum dune slack Festuca rubra subcommunity, within which it favours short, open structure on dry, low nutrient soils. Conservation requires managing and creating its niche in the dune slacks.

Exploring the Functional Strategies Adopted by Coastal Plants Along an Ecological Gradient Using Morpho-functional Traits

Coastal dunes are characterised by strong interactions between biotic and abiotic factors along a short gradient from the shoreline to the inland region. We carried out an ecological analysis of the vegetation in a protected area of the Italian coast to evaluate the relationships among species abundance, the occurrence of morphoanatomical traits related to leaves, stems, and roots, and soil variables. Three transects were established perpendicular to the shoreline, with 27 plots distributed in the frontal dunes, backdunes, and temporarily wet dune slacks. An analysis based on community-weighted mean values showed that the pioneer communities of the frontal dunes were dominated by ruderals that are well adapted to the harsh ecological conditions of these environments, showing succulent leaves, high limb thickness values, and low values for leaf dry matter content (LDMC). The backdune vegetation was a mosaic of annual herbaceous and perennial shrub communities showing both ruderal and stress-tolerant strategies (clonality, sclerified leaves, high LDMC values, root phenolics) consistent with less extreme ecological conditions. The dune slack areas were dominated by plants showing adaptations to both arid and flooded environments, such as C4 photosynthesis, amphistomatic leaves, and abundant aerenchyma in the roots. The invasive status, C4 photosynthesis, leaf trichomes, and aerenchyma in the roots were significantly correlated with soil humidity, organic matter content, and pH. These results demonstrate the usefulness of anatomical traits (including root system traits) in understanding the functional strategies adopted by plants. Invasive species tended to occupy plots with high levels of soil moisture, suggesting an avoidance strategy for the harsh environmental conditions of coastal sand dunes. Finally, we suggest including information regarding root systems into coastal monitoring programs because they are directly linked to soil parameters useful in coastal dune management and protection.

Comparison of Damselfly (Odanata: Zygoptera) diversity in wet dune slack habitat with canopied and non-canopied areas of Gumuk Pasir Parangkusumo, Yogyakarta, Indonesia

Gumuk Pasir Parangkusumo is one of the unique eolian ecosystem in Yogyakarta. This place which mostly formed by dune which in the rainy season is flooded by water, thus forming a pool called wet dune slack. Damselflies (Odonata: Zygoptera) are closely related to the occurrence of water. The aim of this research is to compare the diversity of damselflies in canopied and non-canopied areas on Gumuk Pasir Parangkusumo, Yogyakarta, Indonesia. The method which used in this research was the descriptive method with active exploration techniques around the wet dune slack to the vegetation formation. The result showed that there are 4 species of damselflies in canopied area and 5 species of damselflies in non-canopied area. The diversity index (H’) is 1.18 in canopied area and 1.01 in non-canopied area. The highest relative abundance of the species in canopied area is Ischnura senegalensis (45,65%) whereas in non-canopied area is Agriocnemis pygmaea (62,34%). The non-canopied areas has conditions more suitable for damselflies’s life.

Young soils of a temperate barrier island under the impact of formation and resetting by tides and wind

The island Spiekeroog (Germany) at the southern North Sea coast exhibits an island tail (Ostplate) of which large parts formed after 1860 by gradual eastward deposition of marine sediments. This study aimed to (i) provide a first overview of soils on the Ostplate, (ii) verify whether soil formation stages in different landscape elements (dune chain, dune slacks, saltmarsh, pioneer zone) are linked to the island’s gradual development and (iii) to assess the impact of tides and winds on soil formation. Standard physicochemical properties of dune -and dune slack topsoils and 19 pedons (i.a. pH, total organic carbon (TOC), total inorganic carbon (TIC), total nitrogen (TN), and mean weight diameter (MWD) of water stable aggregates) were analyzed. Soils of the dune slacks, the saltmarsh and the pioneer zone classified as Gleysols which showed no trend towards differences along the Ostplate. The dune chain exhibited Protic Arenosols that were initially acidified in lee positions (min. pH = 5.1). Carbon (C) and nitrogen (N) isotopes (δ13C, δ15N) signatures of saltmarsh sediments were used as a proxy for the tidal influence on soil formation. In addition, sulfur (S) isotope (δ34S) signatures revealed insights on sulfur sources in the saltmarsh. The δ13C signatures of organic matter (OM) decreased and TOC/TN -and TOC/total sulfur (TS) ratios increased with increasing elevation and decreasing flooding frequency. At higher flooding frequency, δ15N resembled the dominant input of OM from the southern North Sea, at a lower interaction level, mixing of a wider range of sources was indicated. S isotopes indicated dissolved sulfate and reduced species as sulfur sources. It was concluded that an ongoing impact of wind-induced sand movement at the dunes, and flooding-induced sediment movement in the saltmarsh and the pioneer zone, repealed any potential disparities in soil formation stages, which might have existed along the Ostplate.

In situ morphometric survey elucidates the evolutionary systematics of the orchid genus Gymnadenia in the British Isles

Circumscriptions of both the genus Gymnadenia and the 11–27 species that it contains are highly controversial. These Eurasian terrestrial orchids are nectar-rewarding and pollinated primarily by Lepidoptera. Opinions expressed on the number of species occurring in the British Isles range from one to four, though there exists broad agreement that at least three recognizable, ecologically differentiated taxa are widespread. Here, we use a large-scale morphometric survey of these supposedly ‘cryptic’ taxa to determine whether phenotypic differentiation exists alongside their documented genotypic and ecological differentiation, seeking the most diagnostic morphological characters. Ten Gymnadenia plants were measured in each of 29 populations that encompassed the entire taxonomic range and geographic distribution of the genus within the British Isles. Results were subjected to detailed multivariate and univariate analyses, and interpreted in the context of molecular phylogenies, including a bespoke Europe-wide nrITS phylogeny that includes 17 plants sampled across Britain and Ireland. Floral micromorphology was investigated through scanning electron microscopy. Ecotypes occurring respectively in calcareous grasslands (G. conopsea s.s.), acid heaths (G. borealis) and calcareous to neutral marshes (G. densiflora) are subtly but reliably distinct, both morphologically and molecularly, though locally their morphological distinctiveness is somewhat weakened by the occurrence of infrequent populations in dune slacks and chalk downs that are intermediate in phenotype between the grassland and marsh ecotypes ('subsp. cf. friesica'). A polythetic taxonomic key emphasizes the characters and character-state ranges that are demonstrably the most diagnostic. Given that they are reliably genetically differentiable, and individuals can be distinguished with ∼85% confidence using morphological characters such as flower dimensions, depth of flower colour, and leaf number and size, we uphold our previous arguments that the three ecotypes merit species-level recognition. In the continued absence of field sequencing devices, identification is best attempted through quantitative examination of morphology focused at the population level, rejecting records of isolated plants. Despite their strong morphological similarity, genus-wide molecular data show that the British species are not each other's closest relatives. Gymnadenia borealis remains one of only three orchid species putatively endemic to the British Isles.

Morphodynamics of short-lived wetlands of coastal dune slacks, Manawatū, New Zealand

While coastal sand dunes are common in New Zealand, dune slack wetlands are one of the country's most rare and threatened ecosystems, containing a number of rare turf species of seasonally aquatic habitats. To understand changes in such wetlands, historical aerial images were analysed for three study sites along the prograding Manawatū coast and mapped using GIS. Morphometrics, times of origin, turnover and longevity of wetlands were derived. Dune slack wetlands are located amongst depressions in parabolic dune fields, about every 250 m along the coast, have a grand mean of 6130 m2 for area of open water, with a maximum of 8 ha, and are 2.3 times longer than wide, with the long axis mostly oriented 113 degrees from the strandline. They maintain seasonally wet areas for an average of 20–30 years, before being gradually infilled by aeolian sand. New wetlands can recur at the same place as previous wetlands, but adjacent plantations of exotic pines appear to alter their morphodynamics. These results indicate that Manawatū's dune slack wetlands form very dynamic, short-lived ecosystems, which may be internationally unique. They need to be better understood to formulate adequate management initiatives, essential for the perpetuation of the rare plant communities that inhabit them.

Habitat selection of Coot (Fulica atra) and Moorhen (Gallinula chloropus) in a remnant Mediterranean wetland (Italy): Implications for conservation

AbstractThe habitat selection of two abundant and widespread Palearctic rallids (Coot Fulica atra; Moorhen Gallinula chloropus) across a range of wetland types was investigated. The distribution of these two species varied according to water depth, as implied by the dominant vegetation present in the study area. Coots most frequently used wet dune slacks dominated by Phragmites australis, whereas Moorhens were mostly present in anthropized ecotones. It is hypothesized that because these two rallid species respond differently to various environmental pressures, they could be used as useful indicators for biomonitoring remnant wetlands. Indeed, they are relatively generalist, common, widespread and medium‐sized species, relatively easy to detect and exhibit a high sensitivity to specific water‐related habitat types, also at a small‐scaled spatial resolution.

Disparities between plant community responses to nitrogen deposition and critical loads in UK semi-natural habitats

Abstract Empirical critical loads are widely used to quantify and manage the ecological impacts of reactive nitrogen (N) deposition. Critical load values aim to identify a level of N deposition below which significant harmful effects do not occur according to present knowledge. Critical loads have been primarily based on experiments, but these are few in number and have well-known limitations, so there is a strong imperative to test and validate values with other forms of evidence. We assembled data on the spatial variability in vegetation communities in the United Kingdom and used Threshold Indicator Taxa Analyses (TITAN) to investigate linkages between species changes and modelled current and cumulative N deposition. Our analyses focused on five datasets: acid grasslands, alpine habitats, coastal fixed dunes, dune slacks and wet grasslands. In four of these habitats there was evidence for a significant decline in the cover of at least one species (a ‘species-loss change-point’) occurring below the critical load, and often at very low levels of N deposition. In all of the habitats there was evidence for clustering of many individual species-loss change-points, implying a community change-point analogous to an ecological threshold. Three of these community change-points occurred below the critical load and the remaining two overlapped with the critical load range. Studies using similar approaches are now increasingly common, with similar results. Across 19 similar analyses there has been evidence for plant species loss change-points below the critical load in 18 analyses, and community-level species loss change-points below the critical load in 13 analyses. None of these analyses has shown community change-points above the critical load. Field data increasingly suggest that many European critical loads are too high to confidently prevent loss of sensitive species.

Neglected and at risk: bryophyte diaspore banks of coastal dune systems

ABSTRACT Introduction. Bryophyte diaspore banks are virtually ubiquitous in soil environments but remain poorly known and rarely given attention during conservation planning. This study investigates the frequency and composition of bryophyte diaspore banks of coastal dune slacks and considers conservation implications. Methods. A total of 327 soil samples was collected from 28 slacks at eight coastal dune systems in Wales (UK), subjected to germination trials in a growth chamber. Identification of emergent species was based on morphology supplemented by DNA barcoding. Species composition of above ground bryophytes was recorded at a subset of locations and compared to the diaspore bank composition. Results and conclusions. Viable bryophyte diaspores can be abundant in dune slacks, ranging from long-lived perennials to short-lived ephemerals, representing significant phylogenetic diversity. Bryophytes grew in 211 (63%) samples, including 34 taxa identified to species level (7 liverworts and 27 mosses) and a further four to aggregate. Five species of conservation concern were detected. DNA barcoding was sometimes useful but often equivocal in helping to inform species determinations. Occurrence of germination across soil samples at 0–5 cm depth was very high (97%), declining sharply to 17% at 15–20 cm. Compared to species in surface vegetation of mature slacks, those in diaspore banks tend to have significantly smaller adult gametophytes and produce asexual propagules more often. Bryophyte diaspore banks need to be considered carefully when making conservation assessments and land-use decisions, and there is an urgent need for further research to help understand and manage this important resource.

Short Communication: Community of phytoplankton in peatland canal, Riau, and wet dune slacks of Parangtritis, Yogyakarta, Indonesia

Abstract. Mawarni A, Azizah FNN, Sartika HW, Hadisusanto S, Putri DM, Reza A. 2020. Short Communication: Community of Phytoplankton in peatland canal, Riau, and wet dune slacks of Parangtritis, Yogyakarta, Indonesia. Biodiversitas 21: 1874-1879. The ecosystems of peatland canal and wet dune slacks have specific characteristics for phytoplankton community. This study aimed to elaborate on the distribution and abundance of phytoplankton community in peatland canal of Sungai Tohor Village, Meranti Islands, Riau and wet dune slacks of Parangtritis, Special Region of Yogyakarta. Phytoplankton was collected using a 2-L modified Van Dorn water sampler. In peatland, canal phytoplankton was sampled at 3 different locations, each with 5 repetitions. Meanwhile, in wet dune slacks, phytoplankton was sampled at 5 locations, each with 3 repetitions. Phytoplankton samples were filtered with Wisconsin plankton-net 120 mesh and fixed with 3 drops of formaldehyde 4%. The measured physical and chemical factors were air temperature, water temperature, dissolved oxygen, alkalinity, carbon dioxide, pH, depth, transparency, nitrate, sulfate, and phosphate concentration. The results showed that the distribution and abundance of phytoplankton community in wet dune slacks were greater than those of the peatland community. This research found 18 species of phytoplankton in peatland canal, dominated by Synedra acus and 116 species of phytoplankton in wet dune slacks, dominated by Cyclotella meneghiniana.

Establishment, development, and decline of Salix psammophila communities: Changes in soil conditions and floristic composition in dune slacks

The Mu Us Sandy Land is a unique and sensitive dune system in northern China. Salix psammophila communities, as a natural large landscape in inland dune slacks, have seldom been investigated, especially the characteristics of their different developmental stages. Thus, in this study, we explored the differences in soil conditions, floristic composition, and vegetation types between developmental stages of Salix psammophila communities to protect natural shrubland in a semiarid ecosystem. We used transects and quadrats methods to investigate the communities. One-way analysis of variance was performed to detect differences in seed germination rates, species diversity, and edaphic variables among different developmental stages. Relationships between communities regarding species composition and edaphic variables were analyzed using the redundancy analysis. The results showed that the soil conditions required for seedling establishment included good soil surface moisture (water table 28–40 cm), lower saline alkalinity (soil saturation pH 8.7–9.0; soil electrical conductivity 29–40 μs/cm), sandy soil (coarse sand 57%–69%; fine sand 30%–42%), low C/N (6.19–8.58), and open spaces. Vegetation cover, soil moisture, saline-alkalinity, soil total carbon, soil total nitrogen, fine sand, and silt content increased, whereas coarse sand content decreased from the seedling to mature stages. Soil texture was a major driving factor in all developmental stages. We concluded that Salix psammophila seedling recruitment was related to dune mobility (where bare damp blowouts are newly created by wind) and aquatic–terrestrial areas. Optimal conditions for colonization by Salix psammophila communities included fresh, open, bare, and moist sandy soil.

The biocenotic values of Slitere National Park, Latvia: With special reference to inter-dune mires

Inter-dune wetlands in Europe harbour many Red List species because they are very nutrient-poor ecosystems. Most of these wetlands are geologically very young and no or little peat formation has occurred. In Slitere National Park the numerous inter-dune wetlands are relatively old, up to 4500 years old, and most mire communities are peat forming and they are well preserved. However, the hydrological systems that have conserved the mires are largely unknown. In the present study we analysed 128 vegetation relevees of dune mires in order to assess the variation in ecological mire types. We also carried out several short-time studies to get an insight into the peat development and hydrological conditions that sustain the mires. We describe peat profiles and measured temperature profiles and electrical conductivity in 26 dune valleys. We distinguished three main vegetation units and ten sub-units, representing various stages in peat formation. Based on electrical conductivity and temperature profiles we hypothesised that the mires were sustained by both local and more regional groundwater flows, of which the latter were possibly disturbed by anthropogenic influences, mainly outside the National Park. The importance of the Park was evaluated by comparing it to species lists of wetlands from all countries bordering the Baltic Sea. On the European scale the inter-dune wetlands of Slitere National Park are very important because they represent well-developed examples of mire formation on a landscape scale, which elsewhere in most of Europe are rare or have become extinct due to intensive land use.

Mechanisms of soil moisture availability in vadose zone of a sand dune system: Linking soil physical properties and rainfall patterns

AbstractSand dune systems in the arid region of north‐western China are maintained by sand‐stabilizing vegetation, which provides critical ecosystem services. Limited knowledge of soil moisture recharge in these systems hinders sand stabilization efforts. To increase the understanding of soil moisture response to rainfall, we analysed soil water transport in the desert vadose zone of sand dunes and dune slacks following four natural rainfall events during the growing season of 2017. Rainfall was dominated by small rain events (<5.0 mm), accounting for 58% of total rainfall events. Soil moisture at 5–25 cm depth in dune slacks was significantly higher and more variable to 60 cm depth than in sand dunes. Soil moisture at 5 cm depth was replenished with rainfall amounts of <5 mm in dune slacks, but not in sand dunes. When rainfall amount reached 20 mm, soil moisture in dune slack and in sand dune increased, but was much higher in dune slack than in sand dune at depth of 5 cm; after the rain, soil moisture remained at a relatively high level in dune slack but not in sand dune. This was possible because dune slacks had higher silt contents and root biomass, which played a key role in improving soil water holding capacity or accelerating rainfall infiltration at 0–25 cm depth. Overall, the rainfall‐driven hydrological regime coupled with soil physical factors regulated spatial and temporal variability of soil moisture in a sand dune system.

Tracking environmental changes in restored Mediterranean dune slacks.

Restoration is an ecological tool that aims to recover the prior conditions and functioning of a degraded habitat. Three restoration projects targeted a dune slack system in the Eastern Iberian Peninsula and created a mosaic of ponds restored over three different periods: 1998, 2003 and 2007, the latter coinciding with the start of our study. Restoration works consisted of digging out the pond basin to its original morphometry. We monitored 12 restored ponds (six recent, three intermediate and three older ones) monthly, over four consecutive hydrological years (from 2007 until 2011) characterizing the most important limnological factors in order to disentangle the effects of man-made restoration over time. A multivariate statistical approach was used to detect the environmental trends of these ponds related to their restoration ages. Recently restored ponds tended to converge with older ones by decreasing values of conductivity, pH, oxygen and depth and increasing vegetation cover over time. Detected differences seem to address age-specific processes which increase over time after restoration: silting, salt leaching or an increase in organic matter decomposition. These processes could strongly influence the community build-up and biodiversity therein.

DISTRIBUSI DAN KEMELIMPAHAN PLANKTON DI WET DUNE SLACKS GUMUK PASIR PARANGTRITIS, BANTUL, DIY.

Komunitas plankton memiliki peran penting pada proses rantai makanan, siklus nutrien dan proses suksesi awal wet dune slacks. Kawasan wet dune slacks merupakan cekungan yang berada di antara punggung gumuk dan kondisi permukaan air tanah sangat bervariasi tergantung musim. Habitat unik yang telah dilindungi di benua Eropa ini justru belum banyak dipelajari di Indonesia. Tujuan penelitian ini adalah untuk mempelajari distribusi dan kemelimpahan plankton di wet dune slacks serta faktor fisiko-kimia yang paling mempengaruhi distribusi dan kemelimpahannya. Pencuplikan sampel dilakukan pada bulan Februari 2018 di Gumuk Pasir Parangtritis, Bantul, Daerah Istimewa Yogyakarta. Sampel air dicuplik menggunakan ember sebanyak 10 liter dengan 3 ulangan pada 5 wet dune slacks yang berbeda. Sampel air kemudian disaring menggunakan plankton-net ukuran 120 mesh serta diukur parameter fisiko-kimianya. Hasil dari pengamatan sampel plankton menunjukkan terdapat 37 spesies diatom pennate, 1 spesies diatom sentrik, 23 spesies alga unisel, 28 spesies alga koloni, 18 spesies alga filamen, 3 spesies dinoflagellata, 6 spesies protozoa berklorofil, 22 spesies rotifera, 6 spesies cladocera, 11 spesies ostracoda, 5 spesies copepoda, dan 5 spesies protozoa. Spesies plankton yang berhasil mengsuksesi kawasan wet dune slacks merupakan spesies yang memiliki strategi bertahan di habitat kekeringan dengan berubah ke fase istirahat, cyst, spora, dan resting eggs. Spesies fitoplankton yang mendominasi adalah Cyclotella meneghiniana sedangkan untuk zooplankton adalah Chlamydotheca flexilis dan Alona rectangula. Parameter fisiko-kimia kecepatan angin, C-organik, alkalinitas, sulfat, temperatur air, temperatur udara, intensitas cahaya,fosfat, pH dan oksigen terlarut menjadi faktor yang paling mempengaruhi distribusi dan kemelimpahan fitoplankton. Sedangkan untuk faktor fisiko-kimia yang paling mempengaruhi distribusi dan kemelimpahan zooplankton adalah kadar oksigen terlarut, CO2 terlarut, pH, temperatur air, temperatur udara, jeluk, jeluk Secchi, kecepatan angin, intensitas cahaya, C-organik, sulfat, fosfat.
 

Climate variability impacts on coastal dune slack ecohydrology

The hydrological regime of freshwater systems plays a crucial role in shaping the dynamics of the different biological communities that inhabit them. Climate change is expected to cause major alterations in the hydrological regime of dune slacks by producing shifts in temperature, precipitation and evapotranspiration. Across seasons, we explore the controls on common water fleas (Cladocera) and aquatic plant communities relative to water level regime, water chemistry, weather and geomorphological setting, in a slack of the Sheskinmore dune system, Co. Donegal, northwest Ireland. Cladoceran abundance and diversity peak in summer, but also vary inter-annually, and drivers for this and hydrological variability are discussed. Vegetation is likewise affected by hydrology in a spatial sense, where distribution follows wet/dry patches of water. Water chemistry is more variable within the same season than across different years, particularly related to the drying out of the slack. Rainfall through 2016-2017 was lower than average and evapotranspiration showed higher values than average for the same time period. The influence on the slack of this decreased precipitation extended across successive seasons. The water table is the most important driver of slack ecology, with incidence on biological communities expressed by the increased variability inter-annually, as opposed to seasonal variation.