Struktur Komunitas Odonata di Kawasan Wana Wisata Curug Semirang Kecamatan Ungaran Barat, Semarang

Dragonflies role as a predator in an ecosystem and become a healthy aquatic bio-indicators related to the life cycle. The diversity of habitat, food and predators affect community structure dragonfly. This study aims to determine the composition and community structure dragonfly morning and afternoon as well as the relationship with the physical environmental factors on four habitat in Semirang waterfall. Research using transect Point Count method. Statistically, the biodiversity of odonata in each habitat is significantly different. The results shows there are 15 species from 10 Family in morning observations and 12 species of 6 Family in afternoon observations, with a total of 17 species of 10 family of odonata. Biodiversity in each station is low to moderately with high evenness. The highest abundance found in river habitat without the canopy during the afternoon that Vestalis luctuosa (61.29%), while the lowest abundance found in the the canopied river habitat when afternoon that is Drepanosticta spatulifera (1.33%). Common species at area of Semirang waterfall are Euphaea variegata, Orthetrum sabina and Vestalis luctuosa. Endemic species at area of Semirang waterfall are Heliocypha fenestrata, Drepanosticta spatulifera and D. sundana. Key words : Community structure, Odonata, Semirang waterfall

Struktur Komunitas dan Anatomi Rumput Laut di Perairan Teluk Awur, Jepara dan Pantai Krakal, Yogyakarta

Seaweed has ecological benefits as well as economic value. Waters condition of Awur Bay and Krakal Beach supported this plant’s growth. There’s not yet the latest information about the vegetation. Utilization is still limited on some specieses. Tourist and inhabitant’s activities who take this plant would give impact to this plant’s vegetation. Therefore, it’s necessary to have data collecting, monitoring, and controlling at both of location. This research was aim to inventarisasi of seaweed for morphologic and anatomic characteristics at both of location. The research of method is explorative descriptive. The results showed that the amount of seaweed which was found at Awur Bay based on the morphology characteristics consist of two divisions was Chlorophyta (3 species) and Phaeophyta (5 species). Beside that, the amount of seaweed which was found at Krakal Beach based on the morphology characteristics consist of three divisons was Chlorophyta (4 species), Phaeophyta (2 species) and Rhodophyta (11 species). Three types of cell (anatomy) i.e. epidermis, kortex and medulla. The results of seaweed which found at Krakal Beach are density, frequency, cover percentage, important value index, and ecology index was taller than Awur Bay. Key words : Community Structure, Seaweed, Awur Bay, Krakal Beach Rumput laut bermanfaat secara ekologis maupun ekonomis. Kondisi perairan Teluk Awur, Jepara dan Pantai Krakal, Yogyakarta mendukung tumbuhan ini dapat tumbuh. Pemanfaatannya masih terbatas pada jenis tertentu. Aktivitas wisatawan dan penduduk sekitar yang mengambil tumbuhan ini akan berpengaruh sehingga perlu dilakukan penelitian tentang struktur komunitas di kedua lokasi tersebut. Penelitian ini bertujuan untuk mengetahui struktur komunitas, inventarisasi jenis baik secara morfologi dan anatomi. Metode yang digunakan yaitu metode deskriptif eksploratif. Hasil penelitian menunjukkan jumlah jenis rumput laut yang ditemukan di Teluk Awur terdiri dari dua divisi yaitu Chlorophyta (3 jenis) dan Phaeophyta (5 jenis). Jumlah jenis yang ditemukan di Pantai Krakal terdiri dari tiga divisi yaitu Chlorophyta (4 jenis), Phaeophyta (2 jenis) dan Rhodophyta (11 jenis). Tiga jenis sel penyusun thallus yaitu sel epidermis, korteks dan medulla. Struktur komunitas yang ditemukan di Pantai Krakal meliputi kepadatan, frekuensi, persentase penutupan, indeks nilai penting, dan indeks ekologi lebih tinggi daripada di Teluk Awur. Kata Kunci : Struktur Komunitas, Rumput Laut, Teluk Awur, Pantai Krakal

Struktur Komunitas Capung di Kawasan Wisata Curug Lawe Benowo Ungaran Barat

Dragonflies have an important role for the stability of the ecosystem that is as predator and prey at the same time. The availability of food resources and optimal environmental conditions affect the species richness of dragonflies in the habitats. Reasearch on dragonfly comunity structure aims to find out the differences of community structure in each habitat type in the region of Curug Lawe Benowo. The research was conductet in 4 different stations which focus on species of dragonfly, amount of an individual species, habitats, environmental conditions, and the corellation between the variables. The method used is point count. The results showed that there are 19 dragonfly species which came from 7 different Family. The total number of individuals encountered from 4 stations is 205. The common species that can be found in all of the stations is Euphaea variegata. The level of diversity are medium, the level of evenness is fairly even. Similarity of species in any habitat types indicate that the habitats has a three kind of similarity levels that is fairly equal, less equal and not equal. Data analysis shows that there is a corellations between environmental conditions, and dragonfly species, affecting abundance and distributions of a dragonfly in the habitats, and can be used to describe dragonflies community structure in the region. Key words: Community structure, dragonfly, Curug Lawe-Benowo

Exploitation of Marine Mammals: r-Selection of K-Strategists?

The importance of marine mammals as predators to the organization of marine communities is poorly known, although in several structurally analogous systems the ecological and evolutionary roles of predators are known to be of considerable importance. Occupation of the marine environment by mammals probably carried physiological constraints for single-young pregnancies thereby limiting all species to low intrinsic rates of population increase. As such, species subjected to high mortality rates from predation or other natural disturbances became extinct; those that survived probably were largely resource limited. In view of this scenario it is suggested that stable populations of marine mammals can be maintained at high levels without being manipulated in most communities. Exploitation probably constitutes a rather dramatic environmental change to marine mammals consequently subjecting them to selective forces fundamentally different from many of those under the influence of which they evolved. Key words: community structure, evolution, exploitation, fitness, life history, marine mammal, predation, resource limitation