Major Dominant Species Research Articles

Fluctuating salinity levels and an increasing pollution gradient on fish community structure and trophic levels in a small creek in the Niger delta, Nigeria

Assessing the ecological status of rivers, creeks, and streams is a fundamental and increasingly important water management issue worldwide. This study examines the variations in fish community structure along an increasing pollution gradient in a small Niger Delta creek in Nigeria in both time and space. Salinity of the area fluctuated between fresh and mesohaline brackish waters with values ranging from 0.4 to 5.2 PPT and electrical conductivity values ranging between 16.9 and 136.0 µS/cm. The site in the upper creek (Site 1) was relatively free from gross pollution, with significantly high dissolved oxygen levels and low nutrient and salinity levels. Site 3 recorded relatively higher values of 5-day biochemical oxygen demand (BOD5) and high nutrient levels, indicating substantial input of organic matter to the creek upstream. Six (6) species, Tilapia guineensis (Cichlidae), Bostrychus africanus (Eleotridae), Hemichromis fasciatus (Cichlidae), Ethmalosa fimbriata (Clupeidae), Gerres melanopterus (Gerreidae), and Clarias macromystax dominated the sample and accounted for about 70 % of the total catch. Tilapia guineensis constituted the major dominant species and accounted numerically for about 20 % of the total catches and 45 % of the total biomass. Multi-species fisheries dominate the coastal zone with Tilapia guineensis, Gerres melanopterus and Ethmalosa fimbriata, Liza falcipinus, Mugil spp., and Chrysichthys nigrodigitatus, the major species in the commercial catches. Canonical correspondence analysis indicated that dissolved oxygen, electrical conductivity, total nitrogen, BOD5, and temperature were important variables structuring the overall fish assemblages. Overall, salinity was the major environmental variable determining the diversity of fish communities at the various sites. The effect of anthropogenic activities and land use practices around the creek only marginally affected the abundance of the fish species but not the diversity. These findings indicate that the water body is still useful as a good fishing ground for the rural communities and every effort should be put in place to ensure its protection and conservation for the production of healthy fish.

Microbial and metabolic characterization of a denitrifying phosphorus-uptake/side stream phosphorus removal system for treating domestic sewage.

In this study, an advanced wastewater treatment process, the denitrifying phosphorus/side stream phosphorus removal system (DPR-Phostrip), was developed for the purpose of enhancing denitrifying phosphorus removal. The enrichment of denitrifying phosphorus-accumulating organisms (DPAOs) and the microbial community structure of DPR-Phostrip were evaluated by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), and the metabolic activity of seed sludge and activated sludge collected after 55 days of operation were evaluated by Biolog™ analysis. This experimental study of DPR-Phostrip operation showed that nutrients were removed effectively, and denitrifying phosphorus removal was observed during the pre-anoxic period. PCR-DGGE analysis indicated that DPR-Phostrip supported DPAO growth while inhibiting PAOs and GAOs. The major dominant species in DPR-Phostrip were Bacteroidetes bacterium, Saprospiraceae bacterium, and Chloroflexi bacterium. Moreover, the functional diversity indices calculated on the basis of Biolog analysis indicated that DPR-Phostrip had almost no effect on microbial community diversity but was associated with a shift in the dominant species, which confirms the results of the PCR-DGGE analysis. The results for average well color development, calculated via Biolog analysis, showed that DPR-Phostrip had a little impact on the metabolic activity of sludge. Further principal component analysis suggested that the ability to utilize low-molecular-weight organic compounds was reduced in DPR-Phostrip.

성주산 일대의 조류상과 포유류상

We investigated the avifauna at Mt. Seongju, Chungnam prov., Korea in August 22 and October 16 to 17, 2013. A total 803 birds of 49 species and 9 species mammals were recorded during consensus. Among birds Long-tailed Tit (Aegithalos caudatus) was the most abundant species. Following Eurasian Tree Sparrow (Passer montanus) and Vinous-throated parrotbill(Paradoxornis webbianus) were major dominant species. Among mammalia Eurasian red vulgaris (Sciurus vulgaris) and Siberian chipmunk (Tamias sibiricus) were the most abundant species. We researched the birds and mammalia in summer and autumn, at Mt. Seongju, Boryeong. We classified 3 types of bird

마이크로네시아 축 환초내 잘피밭의 어류 종조성

The fish species composition of seagrass bed in Chuuk Lagoon, Micronesia, was investigated every month from August 2009 to July 2011, using a seine net for fish caught. A total of 32 fish species belonging to 18 families under 6 orders were identified during the study period. Of these fish, Atherinomrus lacunosus, and Strongylura incise were the major dominant species representing 85.0% in total number of individuals. The number of species and individuals were high from August to December 2009, 2010. The biomass was highest in September 2010 and the diversity index was higher in September 2009, April, August 2010 and July 2011. The 14 dominant species could be divided into 2 groups of 3 individuals based on appearance patterns; (1) resident species and temporal species (9 species, e.g. Atherinomrus lacunosus), juvenile and adults living in seagrass beds and juveniles living only in seagrass beds; (2) temporal species (2 species, e.g. Hemiramphus lutkei), juveniles living only in seagrass beds; (3) temporal species (3 individuals, e.g. Caranx sexfasiatus). For some species, the appearance patterns were affected by water temperature. However, the relationships between sea currents, salinity, tide, and structure of fish assemblage remain unclear. Further studies that regularly monitor sea grass habitats are necessary to clearly understand the correlation between environmental factors and sea grass habitat use patterns in fish assemblages.

남해도 주변 해역에서 새우조망으로 조사한 수산자원의 분포 및 계절 변화

It was turned out by the beam trawl survey in 2009 that flora of three phylum 16 species and fauna of eight taxa 68 families 97 species were inhabited in the Seomjin River estuary and western coastal waters of Namhae island. Winter season showed the most various appearance of species with 63 species and markedly several kinds of algae species, while summer season showed the lowest number of species with 44 species. However, the indices of species diversity and evenness were highest in summer, and vice versa in winter. Major dominant species were Crangon hakodatei, Leiognathus nuchalis, Asterias amurensis, Thryssa kammalensis, Luidia quinaria, Amblychaeturichthys hexanema, Oratosquilla oratoria, Charybdis bimaculata, Cynoglossus joyneri, Pennahia agentata. The 10 dominant species occupied at 81.4% of catch in number and 49.0% of catch in weight. There were seasonal fluctuations and differences by station in the Seomjin River estuary and western coastal waters of Namhae island, which brought to the difference of length structures, that is, bigger-sized individuals of major dominant species at station A (near to river estuary) than station C (near to ocean). Species compositions by season and by station were separated to two groups. Winter season showed a separated species composition from other seasons and station A exhibited a different species composition from other stations, which was located at near to the Seomjin River estuary.

Hebei Spirit 유류유출 사고 이후 암반 조간대 대형저서동물 군집 변화

In Korea, more than 300 oil spill accidents occur every year. Despite the frequency, only a small pool of data is available on the initial effect of oil spill on macrobenthic fauna inhabiting rocky shores. The aim of this study was to analyze the variation of macrobenthic fauna composition and community structure on rocky shores, and understand the impact of oil on rocky shore organisms after the Hebei Spirit oil spill. Field surveys were carried out in five regions dose to the wreck site in January, April and September 2008. Polluted sites after the Hebei Spirit oil spill showed that biological index consistently decreased for 9 months limited to breeding and recruitment of organisms by spilled oil. Macrobenthic community was subdivided into 3 groups by species elimination and differences between density of major dominant species: enriched biota community under a relatively stable environment, the second with relatively low ecological index and the last with poor community. In this study, species number did not clearly reflect the effect of oil on the rare and mobile species. However, mean density, biomass and community structure showed the effect of oil by considering breeding activity, decline in recruitment and variation pattern with time.

서울 당현천의 저서무척추동물상과 수생태 건강성 평가

The present study was performed to examine the aquatic ecosystem health assesment and community structure of Benthic Macroinvertebrates at Danghyun Stream in Seoul on April 29 to November 21, 2012. Total taxa of Benthic Macroinvertebrates were 63 species, 30 families, 13 orders and 6 classes in 4 phyla. All of them, non-insects were composed of 3 species in Annelida, 2 species in Mollusca, 1 species in Platyhelminthes and 1 species in Crustacea. Aquatic insects were composed of 17 species in Diptera, 16 species in Ephemeroptera, 14 species in Trichoptera, 3 species in Plecoptera, 3 species in Odonata, 1 species in Hemiptera, 1 species in Megaloptera and 1 species in Coleoptera respectively. Occurrence species was 43 species at upper site(site 1) and 15～21 species at restoreation water area(site 2～site 4). Major dominant species at site 1 was Semisulcospira liberta, simulium sp.1 and Glossoma KUa which are considered as clean water indicaters, dominant species at middle and lower area was Chironomidae sp. and Baetis fuscatus which are considered as somewhat pollution indicators. Species diversity index and species richness index were 3.54 and 3.29 at upper site, 2.26～2.53 and 1.60～1.81 at middle and lower area. Benthic Macroinvertebrates index was 90.2 at site 1, 44.1 at site 2, 53.1 at site 3 and 61.6 at site 4. Aquatic ecosystem health by Benthic Macroinverbrates index was very good level at site 1, good level at site 4, fair level at site 3 and poor level at site 2 respectively. Therefore, the results shows that site 1 is more stable Benthic Macroinvertebrate community structure than restoration water area at Danghyun Stream in Seoul.

우면산 일대의 조류상과 포유류상

We investigated the avifauna in Woo-myeon mountain from July 12 and October 23 to 24, 2012. A total 798 birds of 48 species and 8 species mammals were recorded during consensus. Eurasian Tree Sparrow (Passer montanus) was the most abundant species. Vinous-throated parrotbill( Paradoxornis webbianus) and Brown-eared Bulbul (Microcellis amaurotis) were major dominant species. Eurasian red vulgaris (Sciurus vulgaris) and Siberian chipmunk(Tamias sibiricus) were the most abundant species. We researched the censuses of birds and mammals in summer and autumn, at Woo-myeon mountain, Seoul. We classified 4 types; 25 residents, 16 summer visitors, 5 winter visitors and 2 passage migrants birds. We identified the mammals by tunnel, saw, song, and foot print, etc.

Macro-fungi of Karhiya Community Forest, western Terai, Nepal

This is the preliminary report on mycological investigation carried out at Karhiya Community Forest, in Terai region of western Nepal. Phytogeographycally, the area lies within a narrow limit of altitude between 160 and 195 msl in tropical deciduous riverine forest, where major dominant species of macro fungi are Amanita chepangiana, A. caesrea, A. pantherina, Macrolepiota procera, M. rhacodes, Marasamius perforans, M. oreades, Termitomyces clypeatus and T. eurhizeus. The samples collected in the present study represented 26 genera of Basidiomycetes belonging to 18 families and 30 species. The dried specimens are housed in the Nepalese herbaria (TUCH, Kath). The area embraces the mycophagus ethnic communities like Tharu, Magar, Kumal, Majhi, Thakali, Gugung, Girel and Chhantal. The mycoelements prevailing in this area need sustainable utilization and conservation. DOI: http://dx.doi.org/10.3126/njbs.v2i0.7495 Nepalese Journal of Biosciences 2 : 93-97 (2012)

Fish Assemblages in the Degraded Mangrove Ecosystems of the Coastal Zone, Benin, West Africa: Implications for Ecosystem Restoration and Resources Conservation

Mangrove forests are unique habitats in their function as potential food source and nurseries, and support an important fisheries resource. In the Benin coastal zone, the mangrove fishes have been surveyed to investigate fish species diversity, community structures and ecosystem degradation impacts in order to protect and to improve the mangrove fish resources. Results from wet, high-water and dry season samplings revealed that the two dominant mangrove species, Rizophora racemosa and Avicennia africana, are being intensively degraded for domestic use such as firewood and house building. Fifty one (51) fish species belonging to 25 families were recorded with Eleotridae (7 species), Cichlidae (5 species), and Mugilidae (5 species), the most speciose families. Dominant trophic guilds were detritivores (54.57%) and planktinovores/microcarnivores (30.41%). Six (6) species, Sarotherodon melanotheron, Dormitator lebretonis, Gerres melanopterus, Hemichromis fasciatus, Ethmalosa fimbriata, and Aplocheilichthys spilauchen, dominated the samples and accounted for about 80.27%. Sarotherodon melanotheron constituted the major dominant species and accounted numerically for about 29% of the total catches and 46.7% of the total biomass. The Margalef index of species richness ranged between 2.42 and 4.43, the Shannon-Weaver index of species diversity between 1.39 and 2.27, and the evenness between 0.50 and 0.62. Lower indices were observed for the highly degraded and the moderately degraded sites whereas higher indices were recorded for the less degraded and the restored sites. Species richness, species diversity and dominant species abundance were positively correlated with depth and transparency and negatively correlated with temperature. Multi-species fisheries dominate the coastal zone with Sarotherodon melanotheron, Dormitator lebretonis, Gerres melanopterus, Ethmalosa fimbriata, Liza falcipinus, Mugil sp. and Chrysichthys nigrodigitatus, the major species in the commercial catches. In addition to the mangrove destruction, the hydro electrical dam have greatly modified the Mono River flooding regime, water quality and the fish composition of the Benin coastal lagoon system. An integrated approach of the mangrove resource management/conservation, including intensive mangrove restoration, management of key fish species, freshwater prawns (Macrobrachiun sp.), peneids shrimps, mangrove oysters (Crassostrea sp.), and crabs (Callinectes sp., Cardiosoma sp.), and habitat protection is required for ecosystem recovery and sustainable exploitation.

경운과 무경운에 따른 토양 내 잡초종자의 수직적 분포양상

번거로운 토양 종자은행 조사를 위해 간편한 모니터링 방법을 고안하였으며 이를 이용하여 경운과 무경운에 따른 토양내 잡초종자의 수직적 분포 양상을 관찰하였다. 본 시험은 강원도 화천의 유기농 옥수수 포장에서 수행되었다. 포장의 조성은 2010년부터 경운과 무경운 조건으로 2년간 조성된 무경운 포장에서 30 cm 깊이의 비파괴 토양 시료를 채취한 후 그 안에서 발생하는 잡초를 헤아려 종자의 토양 분포정도를 조사하였다. 토양속 잡초 종자의 분포는 경운구의 경우 15 cm 이내에 75%의 종자가 분포되어 있는 등 30 cm 깊이까지 대체로 고르게 분포되고 있었던 반면 무경운 조건에서는 15 cm 이내에 85% 이상의 종자가, 20 cm 이내에 93%의 종자가 분포되어 대체로 토양 표면에 집중되었다. 한편 잡초의 발생초종수와 개체수는 경운구가 무경운구에 비해 3배나 많은 양이 발생되었으며 주요 우점초종은 돌피, 석류풀, 바랭이 등의 일년생 초종이었다. A simple monitoring method was designed to evaluate seed bank in a upper soil (0 to 30 cm depth), which was observed for the pattern of vertical distribution of weed in the soil under tillage or no-tillage condition. The field experiment was established at an organic corn field located in Hwacheon in Kangwon-do from 2010 to 2011. Undistributed linear soil samples were taken using non-destructive soil sampler from 0 to 30 cm depth at the tillage or no-tillage soils. Weed seed distribution in the linear soil samples was estimated by counting the number of weed germinated according to the soil depth. Under tillage condition, the weed seeds were more evenly distributed from 0 to 30 cm depth, with being 75% of weed seeds located in 0 to 15 cm depth compared to the no-tillage condition. Soil samples taken by no-tillage condition had 85% of weed seeds within 15 cm of soil depth, with being 93% of weed seeds from 0 to 20 cm depth. The number of weeds or the number of weed species were three times higher for tillage soil compared to no-tillage soil, and the major dominant weed species were observed for annual plants, such as Echinochloa crus-gall, Mollugo pentaphylla, and Digitaria ciliaris.

주목(Taxus cuspidata) 개체군의 구조와 동태

This study analyzed on the characteristics of community structure, species composition, population conditions and annual mean radial growth of Taxus cuspidata in the subalpine zone of the Seoraksan, Deokyusan, and Hallasan National Parks. Deokyusan and Hallasan sites had three layers of stratification structure without tree layer in it and four layer in Seoraksan site. The major dominant species in the order of importance value were as follows: T. cuspidata, Acer tschonoskii var. rubripes, Quercus mongolica, Abies koreana and Sorbus commixta. The trees (> 5 cm DBH) of T. cuspidata were extremely high with 986.0 individuals/ha at the Hallasan site. Average DBH class were 42.0 cm at the Hallasan site and mainly showed large class. The populations of seedlings and saplings with 357.3 individuals/ha, and juvenile with 128.6 individuals/ha, as a succession tree, were found to be the highest at the Hallasan site. In the size frequency distribution, the populations of T. cuspidata in Mt. Halla site showed a reverse J-shaped curve and it was estimated that T. cuspidata community of this site might be maintained continuously as a stable state like present state. Annual mean radial growth of T. cuspidata populations at Seoraksan, Deokyusan, and Hallasan sites showed up as 1.27 mm/year, 0.93 mm/year and 0.89 mm/year respectively.

가막만 모자반군락지내 부착생물의 종조성 및 월별변동

We studied the organisms attached to Sargassum beds in Gamak Bay from November 2007 to June 2008. The water temperature ranged from 3.3 to <TEX>$28.7^{\circ}C$</TEX> and salinity from 30.6 to 33.8 psu. Eighteen species <TEX>$143,432\;ind./m^2$</TEX> were sampled during study periods. The biomass of the Sargassum beds ranged from a highest of <TEX>$196.08\;g\;dw/m^2$</TEX> in March to a lowest of <TEX>$0\;g\;dw/m^2$</TEX> in July. The major dominant species were Barleeia angustata (<TEX>$134,430\;ind./m^2$</TEX>), Caprellidae sp.(<TEX>$2,443\;ind./m^2$</TEX>) and Gammaridae sp.(<TEX>$4,201\;ind./m^2$</TEX>). The ecological indices of diversity, evenness, and richness were 0.11-0.86, 0.04-0.39, and 0.74-1.06, respectively.

울릉도 나리분지 주변 산림의 임분구조 및 동태

울릉도의 성인봉을 중심으로 나리분지와 주변 산림에 대한 지속가능한 보전을 위한 생태적 기초 자료를 제공하고자 나리분지 내 산림과 외륜의 동, 서, 북사면의 산림에 대하여 군락생태학적 방법으로 임분 구조 및 종 조성 특성을 조사 분석 하였다. 조사 대상 산림 내 임분의 층위 별 중요치를 산출하여 비교 분석한 결과, 나리분지 외륜산림 방위 및 고저 별 대부분의 임분에서는 너도밤나무와 고로쇠나무가 대체로 우점하는 경향이었으며, 임분간 식물 종의 조성에서도 큰 차이를 보이지 않았다. 그러나 나리분지내의 산림에서는 너도밤나무림, 두메오리나무림, 소나무림, 낙엽활엽수림의 다양한 임분이 형성되어 있었고, 임분에 따라 종 조성도 큰 차이를 보였다. 그리고 임분의 성숙도와 안정도 등 간접적인 군락의 속성을 파악하기 위하여 종 다양도를 비교 분석한 결과 임분의 각 층위에서 모두 나리분지 내 산림이 외륜의 산림에 비해 높은 종 다양도를 보였으며, 나리분지 내 산림에서는 소나무림과 낙엽활엽수림이 너도밤나무와 두메오리나무림에 비해 각 층위에서 대체로 높은 종 다양도를 보였다. 또한 산림의 방위 및 고저 별 임분에 대한 유사성을 추정하기 위해서 S<TEX>$\O$</TEX>rensen의 유사도계수(Cs)를 비교 분석한 결과 동, 서 북사면과 나리분지 내 산림간 유사도 지수는 0.68~0.69의 범위로서 차이가 거의 없었고, 능선부와 산복부, 산록부, 평탄지간 유사도 지수는 0.85~0.95의 범위로서 거의 동일한 임분형을 보였으며, 나리분지 내 네 임분 간 유사도 지수도 0.66~0.88의 범위로 높은 유사도를 보였다. 나리분지 외륜의 능선부와 산복부, 산록부, 평탄지에 대한 산림의 천이의 진행에 따라 임분구조 및 개체군의 동태를 예측하기 위하여 주요 구성종의 직경급 분포도를 작성한 결과 다소의 형태적 차이는 있었지만 대체로 정규분포형에 가까운 종형(Bell-shape)을 이루고 있었으며, 이들 산림 내 임분은 대체로 안정적으로 유지될 것으로 판단되었다. 따라서 성인봉을 포함한 나리분지와 외륜 산림의 임분들은 지형적 특성에도 불구하고 대체로 구조와 종조성에 있어서 높은 유사도를 보였으며, 기후변화에 의한 임분의 단순화가 지속될 것으로 판단되어, 산림 내 생물 종 및 생태계 다양성에 대한 보전과 관리 대책이 필요하다. For the sustainable conservation of forests within and around the somma of Nari basin in Ulleung Island, the stand structure and dynamics with the aspect, altitude and stand types were estimated by using analyses of importance value, plant species diversity, S<TEX>$\o$</TEX>rensen's similarity index and distributions of diameter classes. Results of the importance value analysis with vegetation stories on each stand showed that Fagus engleriana and Acer okamotoanum were dominant in most stands regardless of the aspect and altitude of the forest around the somma of Nari basin and the plant species composition among stands was not significantly different. The forest within Nari basin was composed of pine, beech, alder and deciduous-mixed stand. Moreover, the species composition was greatly different among the four stands. The diversity of plant species within stand was in general higher within Nari basin than around the somma, and among stands within Nari basin, the plant species diversity of pine and deciduous-mixed stand showed higher values than that of beech and alder stands. The similarity index among stands with aspect and altitude showed that the index among stands of eastern, western and northern slope in forest around the somma and forest within the basin ranged from 0.68 to 0.69, and the similarity among four stands with altitude was very high having index range from 0.85 to 0.95. The patterns of diameter class distribution of the major dominant species from four altitude classes followed an almost normal bell-shaped distribution. The results were interpreted as an indication that these forests will in general maintain a stable stand structure. Therefore, despite diverse topographic features around Nari basin, the stand structure and plant species composition among stands were not diversified as expected. For the conservation of diversity of forest plant species and of forest ecosystems, a promising and intensive program should be considered.

Crustacean plankton abundance in the Danube River and in its side arms in Hungary

The spatial distribution and seasonal dynamics of the crustacean zooplankton were studied in the Danube River and in its side arms near Budapest, Hungary. Microcrustaceans were sampled biweekly from October 2006 to November 2007 at eleven sites. Thermocyclops crassus, Moina micrura and Bosmina longirostris added up to 57.6% of the total density. Comparisons of the different water bodies stressed the separation of the eupotamal and parapotamal side arms. Densities in the side arms were one respectively two orders of magnitude higher as compared to the main channel, which was relatively poor in plankton. There were remarkable longitudinal and transversal variations in the abundance of the major zooplankton groups (cladocerans, adult copepods, copepodites, nauplii) and dominant species (t-test, P < 0.05). However, no general pattern was observed, the spatial distribution depended on the examined objects. There were statistically significant seasonal differences in zooplankton abundance (Tukey-test, P < 0.05). Water residence time and water discharge were not found to be related to zooplankton abundance, but water temperature was positively correlated with microcrustacean density.

COMMUNITY CHARACTERISTICS OF SHRIMPS IN THE OFFSHORE WATERS OF THE MID-SOUTHERN EAST CHINA SEA

Based on the data of the shrimp resources sampled by single trawler as investigation boat in 18 stations in the offshore waters of the Mid-Southern East China Sea (26°00'N—28°30'N,121°00'E—126°00'E) in May,August,November,2006 and February,2007,total catch from each trawler was counted and identified to species in taxonomy,and the spatial variation of the shrimp species composition,index of relative importance (IRI),the diversity and similar characteristics of the community structure were analyzed. 32 species of shrimp were caught in this survey,which belonged to 22 families under 11 genera. Comparison of the amounts of various species in different seasons:there are 22 species in the autumn which are the most; 20 species in winter,17 and 18 species in the spring and the summer respectively. According to the standard of index of relative importance (IRI) (the species with IRI above 1000 were regarded as the dominant species in this paper),there were 10 dominant species:Metapenaeopsis longirostris,Metapenaeopsis dalei,Solenocera alticarinata,Plesionika izumiae,Ibacus novemdentatu,Parapenaeus fissuroides,Solenocera koelbeli,Solenocera crassicornis,Parapenaeopsis hardwickii and Solenocera crassicornis,and 5 of them were major dominant species which were Metapenaeopsis longirostris,Metapenaeopsis dalei,Plesionika izumiae,Parapenaeus fissuroides and Parapenaeopsis hardwickii. Defined the ones with IRI values ranging from 100 to 1000 as common species,we got 7:Metapenaeopsis barbata,Penaeus japonicus,Plesionika dentirostris,Palaemon gravieri,Alpheus japonicus,Parapandalus spinipes and Sicyonia cristata. The abundance of the dominant species was varied with seasons. For example,5 were in May:Metapenaeopsis longirostris,Metapenaeopsis dalei,Parapenaeopsis hardwickii,Solenocera alticarinata and Plesionika izumiae,89.15% of the total catch and 92.14% of the total individuals. In August,there were 7 dominant species:Metapenaeopsis dalei,Plesionika izumiae,Metapenaeopsis longirostris,Parapenaeus fissuroide,Solenocera crassicornis,Ibacus novemdentatus and Solenocera alticarinata,91.82% of the total catch and 95.05% of the total individuals. In November,the number of dominant species increased to 8:Metapenaeopsis longirostris,Plesionika izumiae,Parapenaeus fissuroides,Metapenaeopsis dalei,Solenocera crassicornis,Ibacus novemdentatus,Solenocera koelbeli and Solenocera alticarinata,occupying 95.31% and 97.56% of the total catch individuals,respectively. In February,the number reduced to 5:Metapenaeopsis longirostris,Parapenaeus fissuroides,Metapenaeopsis dalei,Solenocera koelbeli and Plesionika izumiae,88.76% and 94.93% respectively. Based on their adaptability to habitats,all recorded species of shrimps were categorized into the hyperthermal and hysaline community in the Mid-Southern East China Sea. The stations with high abundance were mainly located in the west of the 120m isobaths,and gradually lower toward the autumn to winter,while it reached the lowest in winter. Margalef index (D) and Shannon-Wienner index (H') were higher in summer and autumn than those in winter and spring,Pielou's evenness index (J') in the offshore waters of the Mid-Southern East China Sea was stable through every season. The result indicated that the diversity index west of the 120m isobaths was higher than in the east. By hierarchical cluster analysis and non-metric multidimensional scaling (NMDS) assisted analyzing,the types of shrimp assemblage determined by influential factor such as aquatic system,water mass and salinity etc. in the East China Sea in spring were also discussed in the article,two main assemblages were identified in the offshore waters of the Mid-Southern East China Sea,which were deeper costal shrimp assemblage and out shelf sea shrimp assemblage.

Estimation of forest biophysical variables from Indian Earth Observation Satellite Cartosat‐1 stereo data

Indian Earth Observation Satellite Cartosat‐1 data were evaluated for the estimation of biophysical variables, including as tree height, crown diameter, canopy density and canopy gap, that are crucial for the estimation of stand volume, biomass and generation of site index (an indicator of site quality of growing stock). Investigations were carried out at a site covering the major dominant forest species grown in India. Cartosat‐1 stereo data were analysed in conjunction with differential global positioning system (DGPS) measurements to generate a digital elevation model (DEM) and an orthoimage, which were used to estimate the biophysical variables. Analysis using grey‐level co‐occurrence texture measures was performed for separation of forest species, homogeneity of the classes of forest stands, stratification and measurement of crown area, canopy gap and stand density. Field measurements of tree height, diameter at breast height (DBH), stand density, age and crown diameter were conducted for each stand. Empirical models for the estimation of DBH were developed and validated with Cartosat‐1‐derived height and crown diameter. Measured and estimated values were found to be in close proximity to each other. A local contrast co‐occurrence measure (contrast, mean and variance) was suitable for the estimation of average crown diameter, stand density and canopy gap area for each forest stand class. The texture image provided information on structural attributes (i.e. stand density, crown diameter and canopy gap of the forest tree stands). The results presented in this study show that the Cartosat‐1‐derived DEM and orthoimage have potential for the estimation of stem volume, growing stock conditions, and biomass and site index for important timber species.

Smith fir population structure and dynamics in the timberline ecotone of the Sejila Mountain, Tibet, China

Smith fir ( Abies georgei var. smithii), which grows on cool aspects with elevations ranging between 3600 m and 4400 m, is a major native dominant alpine tree species in Southeast Tibet, China. The smith fir population structure, dynamics and characteristics were investigated in the timberline ecotone of the Sejila Mountain. Results indicate that the minimum crown closure (≤20%) was reached at 4320 m above sea level, where two types of alpine species exist, smith fir and blackseed savin ( Sabina saltuaria). On the warm aspects, blackseed savin is a dominant species. Forest line was formed gradually with a wider timberline ecotone. While on the cool aspects, smith fir is a dominant species. Forest line was formed clearly with a narrow timberline ecotone. Furthermore, the upper limits of the distribution of the alpine species were 4570 m and 4390 m on warm and cool aspects, respectively. The timberline ecotone widths of the two species on the warm and cool aspects were 250 m and 70 m, respectively. The optimal distribution of smith fir on the cool aspects was from 3700 m to 3800 m. The smith fir's diameter class distribution was of reversed “J” shape and its density was about 380 stem·hm −2, while the age structure appeared to be of pyramid-shape, suggesting an expanding population. Finally, the static life table and the survivorship curve showed that the populations had experienced severe environmental selection during their first 20 years, self-thinning between 60 to 100 years, and environmental changes related mortality at later stages. The smith fir's physiological life span was around 200 years, and its maximum age was about 400 years old.

Using δ15N- and δ18O-Values To Identify Nitrate Sources in Karst Ground Water, Guiyang, Southwest China

Nitrate pollution of the karstic groundwater is an increasingly serious problem with the development of Guiyang, the capital city of Guizhou Province, southwest China. The higher content of NO3- in groundwater compared to surface water during both summer and winter seasons indicates that the karstic groundwater system cannot easily recover once contaminated with nitrate. In order to assess the sources and conversion of nitrate in the groundwater of Guiyang, we analyzed the major ions, delta(15)N-NH4+, delta(15)N-NO3-, and delta(18)O-NO3- in surface and groundwater samples collected during both summer and winter seasons. The results show that nitrate is the major dominant species of nitrogen in most water samples and there is a big variation of nitrate sources in groundwater between winter and summer season, due to fast response of groundwater to rain or surface water in the karst area. Combined with information on NO3- /Cl-, the variations of the isotope values of nitrate in the groundwater show a mixing process of multiple sources of nitrate, especially in the summer season. Chemical fertilizer and nitrification of nitrogen-containing organic materials contribute nitrate to suburban groundwater, while the sewage effluents and denitrification mainly control the nitrate distribution in urban groundwater.

Structure and regeneration dynamics of dominant tree species along altitudinal gradient in a dry valley slopes of the Bhutan Himalaya

The aim of our study was to characterize the structure and regeneration dynamics of dominant tree species along altitudinal gradient in dry valley slopes of the Bhutan Himalaya. In the typical dry valley slopes of west-central Bhutan, we analyzed forest stratification, tree crown projection, and population structure from lower dry valley bottom (1520 m a.s.l.) to upper humid ridge top (3370 m a.s.l.) across five major forest types: i.e. (1) dry pine forest with Pinus roxburghii as a dominant species; (2) mixed broad-leaved forest with Quercus lanata (evergreen), Quercus griffithii, (deciduous), and Rhododendron arboreum (evergreen) as major canopy species; (3) evergreen broad-leaved forest dominated by Quercus semecarpifolia, Quercus glauca and Quercus oxyodon; (4) cool conifer forest dominated by Abies densa and Tsuga dumosa; (5) cold conifer forest with A. densa and Juniperus recurva as dominants. In general, regeneration pattern of major dominant species shifted from inverse-J (lower altitudes), to sporadic (mid-altitudes), and to uni-modal type (upper altitudes) corresponding to three regeneration trends: (1) invasive at the lower, warm, dry forest under relatively strong human disturbances; (2) stable/balanced at the mid-altitude, in a relatively stable, mature moist evergreen broad-leaved forest with gap regeneration; and (3) poor/low regeneration at the upper, cool, humid conifer forest with a continuously cattle-grazed understory. Overall, regeneration patterns were balanced in all forest types, however care should be taken to prevent excessive exploitation of dry pine forest of lower valley bottom, and to control cattle grazing at higher altitudes. Our findings can be incorporated into management plans for sustainable management and conservation of mountain forests.