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.

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

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.

Changing status of Blysmus compressus (Flat Sedge) in the Sefton Coast sand-dunes, north Merseyside, UK

A 2018 survey of the nationally ‘Vulnerable’ Blysmus compressus (Flat-sedge) in the Sefton Coast sand-dunes, north Merseyside (v.c.59, South Lancashire), aimed to update information collected on distribution and habitats a decade earlier. As in 2008, the plant was mainly found in calcareous dune-slacks of recent origin, with short, open, species-rich vegetation on gley soils with a relatively high pH. Sites with a lower sward height supported a higher percentage cover of B. compressus. The largest populations were associated with sites that had been disturbed by recreational trampling, occasional vehicle use and/or grazing, especially by rabbits. Twenty-two sites were recorded, seven being new. Overall, the area occupied by B. compressus declined by 17%, two 2008 sites being lost. Similarly, an estimate of 15-20,000 plants in the earlier survey fell to 12,600. Losses were attributed to vegetation overgrowth and scrub development, partly resulting from lower rabbit numbers and reduced management input. The plant occurred in a range of vegetation types but matches to known UK National Vegetation Classification communities were generally poor. Management methods to conserve B. compressus and other vulnerable taxa are discussed.

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.