Diversitas Makrofauna Kaitannya Dengan Kualitas Air Sungai Metro Kecamatan Lowokwaru Kota Malang

Water is a natural resource that is needed for the life of human being, even for all the creatures. Therefore, these water resources must be protected so that humans and other living things can be utilized properly. The macrofauna community defines whether the water quality is good or not. The study of the effect of river water quality on the diversity of macrofauna in the Metro river flow of Lowokwaru Subdistrict, Malang City aims to determine the effect of river water quality and to compare the diversity of macrofauna in several Metro river locations in Lowokwaru District, Malang. The method used is quantitative descriptive by calculating the Shanon Winner diversity index. The results obtained for station I amounted to 1.95 classified as lightly polluted, at station II the results were 1,007 which were classified as moderately polluted, and at station III the results were 0.69 which were classified as heavily polluted. Key Words: water quality, macro fauna, Metro river ABSTRAK Air merupakan sumber daya alam yang diperlukan untuk kebutuhan hidup orang banyak, bahkan oleh semua makhluk hidup. Oleh karena itu, sumber daya air tersebut harus di lindungi agar tetap dapat di manfaatkan dengan baik oleh manusia dan makhluk hidup lainnya. Komunitas makrofauna menentukan kualitas air baik atau tidak. Penelitian tentang pengaruh kualitas air sungai terhadap keragaman makrofauna di aliran sungai Metro Kecamatan Lowokwaru kota Malang bertujuan untuk mengetahui pengaruh kualitas air sungai dan untuk membandingkan keanekaragaman makrofauna di beberapa lokasi aliran sungai Metro Kecamatan Lowokwaru kota Malang. Metode yang di gunakan yaitu deskriptif kuantitatif dengan melakukan perhitungan indeks keanekaragaman Shanon Winner. Indeks keanekaragaman yang di hasilkan pada stasiun I sebesar 1,95 yang tergolong tercemar ringan, pada stasiun II indeks keanekaragaman yang di hasilkan sebesar 1,007 yang tergolong tercemar sedang, dan pada stasiun III di dapat hasil indeks keanekaragaman 0,69 yang tergolong tercemar berat. Kata kunci: Kualitas air, makrofauna, sungai metro.

Applying plant disturbance indicators to reveal the hemeroby of soil macrofauna species

Hemeroby is an integrated indicator for measuring human impacts on environmental systems. Hemeroby has a complex nature and a variety of mechanisms to affect ecosystems. Hemeroby is often used to assess disturbances in different vegetation types but this concept has seldom been evaluated for animals. The role of the hemeroby gradient in structuring the soil macrofauna community was investigated. The experimental polygon was located in Botanical Garden of the Oles Honchar Dnipro National University (Dnipro City, Ukraine). There were 20 sites within the polygon. On each of them at 105 points samples of soil macrofauna were taken, soil penetration resistance, electrical conductivity of soil, depth of litter, height of grasses were measured. Within each site, a description of the vegetation cover was made. Based on the description of the vegetation, an indication of the level of ecosystem hemeroby within the polygons was conducted. In total, 48,457 invertebrate (Annelida, Arthropoda, and Mollusca) individuals of 6 classes, 13 orders, 50 families and 83 species or parataxonomic units were recorded. Phytoindication reveals that the level of hemeroby within the studied polygons varies from 34.9 to 67.2. The model V and VI from the HOFJO-list were the most optimal model of the species response to hemeroby gradient. The weighted average factor value was used to assess the optimal factor level for the species in a symmetrical bell-shaped response model. The optimal factor level of the hemeroby for the soil macrofauna species ranges from 34.9 to 66.0. Species also differ in degree of specialization to the factor of hemeroby. There was a regular change in the soil macrofauna community size and diversity in the hemeroby gradient. The limiting influence of anthropogenic transformation of the environment on the abundance of soil macrofauna community is clearly marked at the level of hemeroby above average. Species diversity of the community is greatest at moderate hemeroby level. Both relatively little transformed habitats and strongly transformed ones are characterized by lower species richness of the soil macrofauna community. The Shannon index shows a clear upward trend with increasing hemeroby. The Pielou index indicates that the main reason for this trend is an increase in community evenness with increasing hemeroby. The intermediate disturbance hypothesis was fully supported with respect to species richness. For the number of species, there is indeed a certain level of heterogeneity at which the number of species is highest. For another aspect of diversity, evenness, this pattern is not true. The evenness increases with increasing habitat disturbance. This result is due to a decrease in the abundance of dominant species.

Effect of Species Invasion on Transport of Solutes at Different Levels of Soft Sediment Macrofauna Diversity: Results from an Experimental Approach

Different irrigation or ventilation strategies by macrofauna may provide a competitive advantage to tolerant species invading impacted benthic systems and alter benthic-pelagic coupling. To comparatively analyze the effects of an exotic and a native polychaete burrower on sediment-water exchanges, two laboratory experiments were performed. In the first experiment, the invasive spionid polychaete Marenzelleria neglecta was added to defaunated sediments and fluxes of the inert tracer (bromide, Br−) were measured to quantify the effects of irrigation by the worm on the tracer transport. In the second experiment, M. neglecta or the native polychaete Hediste diversicolor were introduced to a relatively diverse Baltic soft-bottom macrofauna community. The effect of species on fluxes of reactive solutes (ammonium, NH4+, and phosphate, PO43−) and transport rates of Br− was estimated. The results indicate different invasion effects depending on the characteristics of the recipient habitat. In defaunated sediments, a single specimen of M. neglecta significantly enhanced originally low solute exchange rates. Total tracer flux was significantly enhanced over diffusive flux by a factor of 1.6 ± 0.14 (n = 3). In natural sediments, on the other hand, the addition of either M. neglecta or H. diversicolor had no statistically significant effects on benthic fluxes. Tracer flux estimates between control and treatment incubations differed by less than 10% on average, and both reactive solutes tended to increase by 10 to 40% after additions. One specimen of M. neglecta in cores with defaunated sediment generated approximately 20% of the tracer flux produced by the relatively diverse macrofauna community. Estimated net tracer fluxes in two experiments corresponded well with the number of adult polychaetes found in sediments (r2 = 0.73, p = 0.005, n = 12). The invasive M. neglecta produced a small effect on fluxes in biodiverse sediments, comparable to those of H. diversicolor, but it may deeply alter porewater chemistry in azoic sediment. As M. neglecta tolerates chemically reduced and sulphidic conditions, its bioirigation may favor sediment reoxidation and ultimately the recolonization by less tolerant, native species.