Comparing the Survival Rate of Mangrove Clam, Polymesoda (Geloina) spp. (Solander 1876) Through Field Experiments in Mangrove Forests of Iriomote Island

2017 ◽  
Vol 34 (3) ◽  
pp. 223-228
Author(s):  
Yasuko Washitani ◽  
Reiko Hayakawa ◽  
Meihua Li ◽  
Shozo Shibata
Biotropica ◽  
1985 ◽  
Vol 17 (4) ◽  
pp. 277 ◽  
Author(s):  
Susumu Kuraishi ◽  
Kiyohide Kojima ◽  
Hiroshi Miyauchi ◽  
Naoki Sakurai ◽  
Hiroyuki Tsubota ◽  
...  

Author(s):  
Gebru Eyasu Siyum ◽  
Tuemay Tassew ◽  
Abadi Gidey

Tree planting on degraded lands play a key role in forest rehabilitation processes through afforestation and/or reforestation. Moisture harvesting structures (MHSs) has significant impact on seedling survivals at degraded lands. The objectives of this study were to investigate the impact of water harvesting techniques on seedling survival and growth performance of trees. Field experiments were conducted for two rainy seasons in southern Tigray, Atsela watershed. The experimental design followed was the split plot design. The MHSs as main plot used were eye-brow basins (EBs), micro trench (MTs), improved pit (IPs) and as control normal pit (NPs). The tree species grown as subplots were Eucalyptus camaldulensis, Grevillea robusta, Olea europaea and Cupressus lusitanica. The four tree species were planted by using seedlings. The tree survival rate, height, crown width (CW) and root collar diameter (RCD) of the four tree species were measured every six months after transplanting. The result shows that MHSs were significant in tree seedling height, CW and RCD but not in tree survival rate. Tree seedling height and CW grown in EBs were significantly higher than those grown in MTs, IPs and NP (P≤0.05). RCD of tree seedling was higher when grown in EBs than NP (control) (P≤0.05). The interaction of tree species seedlings and MHSs shows that those seedlings grown on MHSs were significantly thicker, taller and more survived than those grown on the NPs (control) (P≤0.05). So based on the experiments, it is concluded that MHSs particularly the eyebrow basin was considered as the most appropriate planting pit. Therefore, further demonstration of eyebrow basin tree planting should be carried out.


Weed Science ◽  
1987 ◽  
Vol 35 (5) ◽  
pp. 637-639 ◽  
Author(s):  
Mark U. Magnusson ◽  
Donald L. Wyse ◽  
Joseph M. Spitzmueller

Field experiments were conducted to determine whether aerial and subterranean stem sections taken from Canada thistle [Cirsium arvense (L.) Scop. # CIRAR] plants in four stages of development (spring-vegetative, bud, postbloom, and fall-vegetative) could survive and produce infestations the following year. Partially buried aerial stem sections from all stages of development had greater survival 28 days after planting than completely buried aerial stem sections. Few completely buried aerial stem sections survived. Partially or completely buried subterranean stem sections from Canada thistle at the postbloom stage had the highest survival rate. Few partially or completely buried subterranean stem sections from the other three growth stages survived. Surviving stem sections from spring-vegetative, bud, and postbloom stages of Canada thistle produced adventitious roots that overwintered and produced new infestations the following spring. Surviving stem sections from Canada thistle at the fall-vegetative stage did not develop an adequate root system for winter survival.


1985 ◽  
Vol 1985 (1) ◽  
pp. 577-582 ◽  
Author(s):  
Charles D. Getter ◽  
Thomas G. Ballou

ABSTRACT Field experiments were conducted to determine the effects of oil and dispersant on red mangroves (Rhizophora mangle). Two experimental sites were chosen on the basis of their biological and physical similarity and treated with either undispersed Prudhoe Bay crude oil or with Prudhoe Bay crude and dispersant Corexit 9527. Short- and long-term effects on biota were monitored to determine the effects of using dispersants on spilled oil in mangrove forests. Significant differences were noted in effects on seedling and adult mangroves, most notably in survival and growth of adults. Undispersed oil caused significantly lower survival and growth of seedlings, and significantly lower growth and foliage cover in adults. Addition of dispersant to crude oil greatly increased its mobility in the water column, and decreased its residence time in the intertidal zone. Retention of oil within the mangrove forest was the primary factor in controlling impacts to mangroves, and dispersants appeared to greatly reduce the amount of oil retained in the intertidal zone of the mangrove forest. Additional research is underway to investigate the impact of dispersed oil on the subtidal communities associated with mangrove forests.


Author(s):  
M.G. Chapman ◽  
K. Michie ◽  
T. Lasiak

Leaf litter, pneumatophores, saplings and patches of macro-algae are common characteristics of habitats in mangrove forests. The amounts of these vary among different parts of mangrove forests. In Port Jackson, some parts of forests under the canopy of trees appeared to have more saplings, longer pneumatophores and greater amounts of leaf litter and macro-algae than did other similarly shaded parts of the forest. The former also appeared to have greater densities of snails, Ophicardelus spp. and Salinator solida, which was confirmed by quantitative sampling. Two field experiments were carried out, in which the amount of litter or algae and the length of the pneumatophores, were manipulated to test six alternative models about influences of these features of habitat that might explain these patterns. In each experiment, both species decreased rapidly in plots with reduced litter and showed no response to the length of the pneumatophores. In the first experiment, there was no response to reductions of algae, but in the second experiment, each species showed a decrease in density when algae were reduced. The implications of these rapid responses to changes in small-scale features of habitat are discussed with respect to managing disturbed habitats.


2020 ◽  
Vol 12 (2) ◽  
pp. 101
Author(s):  
Budijono Parni ◽  
Eko Prianto ◽  
Muhammad Hasbi ◽  
Andri Hendrizal

Hutan mangrove merupakan salah satu ekosistem pesisir yang berperan penting dalam mendukung kehidupan biota laut. Keberadaan hutan mangrove di Kabupaten Kepulauan Meranti saat ini terus mengalami degradasi yang berimplikasi terhadap menurunnya fungsi ekologis, sosial dan ekonomi masyarakat lokal. Upaya meminimalisir kerusakan hutan mangrove terus dilakukan oleh pemerintah daerah dan masyarakat lokal hingga saat ini. Salah satu upaya yang dapat dilakukan melalui budidaya kepiting bakau dengan sistem sylvofishery. Metode penelitian yang digunakan adalah eksperimen dan wawancara yang dilakukan di Kelurahan Teluk Belitung dan Desa Bandul Kabupaten Meranti. Data dan informasi dihimpun dari penelusuran, dan penelahaan data dan informasi hasil penelitian serta laporan kegiatan yang terkait dengan budidaya kepiting bakau dengan sistem silvofishery. Hasil kajian menunjukkan potensi pengembangan budidaya laut di Kabupaten Kepulauan Meranti tersebar di beberapa pulau seperti Pulau Padang, Tebing Tinggi dan Pulau Rangsang dengan luas lahan sebesar 438 ha. Luasnya lokasi budidaya didukung pula dengan kualitas perairan yang cukup bagus dan cocok untuk dikembangkan budidaya kepiting dengan sistem sylvofishery. Ujicoba penerapan sylvofishery kepiting bakau model kurungan tancap diperoleh tingkat survival rate mencapai 70 % dan pertumbuhan rata-rata berkisar 100 – 140 g per bulan. Pemeliharaan kepiting bakau dengan sistem sylvofishery selama 3 bulan dapat memberikan keuntungan dan tambahan penghasilan per bulan sebesar Rp. 1.070.150. Dalam satu siklus pembesaran jika kondisi normal dapat mengembalikan investasinya sehingga sylvofishery kepiting bakau layak dijadi usaha alternatif bagi masyarakat pesisir.Mangrove forest is one of the coastal ecosystems were plays a role in supporting marine life. Existence of mangrove forests in the Meranti Kepulauan district is experiencing degradation which has implications for the decline to ecological, social and economic functions of the local community. The efforts for minimize damage of mangrove forests have been carried out by local governments and local communities. One of the effort could be done through the cultivation of mud crabs with sylvofishery system. Experiment method was applied and interview was done in Teluk Belitung and Bandul villages, Meranti Regency. Data and information were collected and had been analyzed and activities reported that related to mud crab culture using the silvofishery system. The resut of the study showed that potential development of marine culture in the Kepulauan Meranti district is spread across several islands such as Padang Island, Tebing Tinggi and Pulau Rangsang with an area of 438 ha. The extent of the aquaculture site is also supported by good waters quality and suitable for developing mud crab culture with the sylvofishery system. The trial application of the mud crab silvofishery model of fixed confinement obtained a survival rate of up to 70% and an average growth of around 100-140 g per month. Maintenance of mangrove crabs with the sylvofishery system for 3 months can provide benefits and additional income per month of IDR. 1,070,150. In one cycle of enlargement if normal conditions, it’s can return the investment so the mangrove crab sylvofishery deserves to be an alternative effort for coastal communities.


Author(s):  
M. Jose Yacaman

In the Study of small metal particles the shape is a very Important parameter. Using electron microscopy Ino and Owaga(l) have studied the shape of twinned particles of gold. In that work electron diffraction and contrast (dark field) experiments were used to produce models of a crystal particle. In this work we report a method which can give direct information about the shape of an small metal particle in the amstrong- size range with high resolution. The diffraction pattern of a sample containing small metal particles contains in general several systematic and non- systematic reflections and a two-beam condition can not be used in practice. However a N-beam condition produces a reduced extinction distance. On the other hand if a beam is out of the bragg condition the effective extinction distance is even more reduced.


2004 ◽  
Vol 171 (4S) ◽  
pp. 209-209
Author(s):  
James B. Benton ◽  
Frank A. Critz ◽  
W. Hamilton Williams ◽  
Clinton T. Holladay ◽  
Philip D. Shrake

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