Peak In August Research Articles

利用不同方法测定红松人工林叶面积指数的季节动态

PDF HTML阅读 XML下载 导出引用 引用提醒 利用不同方法测定红松人工林叶面积指数的季节动态 DOI: 10.5846/stxb201306181727 作者: 作者单位: 东北林业大学生态研究中心,东北林业大学生态研究中心,东北林业大学林学院,东北林业大学生态研究中心 作者简介: 通讯作者: 中图分类号: 基金项目: 林业公益性行业科研专项资助项目（201204320）；长江学者和创新团队发展计划资助（IRT1054） Seasonal dynamics of leaf area index using different methods in the Korean pine plantation Author: Affiliation: Center for Ecological Research,Northeast Forestry University,Center for Ecological Research,Northeast Forestry University,School of Forestry,Northeast Forestry University,Center for Ecological Research,Northeast Forestry University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:采用2种异速生长方程法、凋落物法、综合法（对光学仪器法进行木质部分及集聚效应校正后结合凋落物法）和光学仪器法测定了小兴安岭红松（Pinus koraiensis）人工林的叶面积指数（LAI）。首先利用光学仪器法测定有效叶面积指数（Le）的季节动态；其次为获得相对准确LAI，基于生长季节（5-8月）的展叶调查，结合凋落物法、综合法和2种异速生长方程法分别测定LAI的季节动态。结果表明：生长季节红松叶片8月初停止生长，迟于其他树种约两周；不同方法测定红松人工林LAI的季节变化均呈单峰型，且在8月初达到峰值，分别为异速生长方法-B（10.58） > 凋落物法（7.90） > 异速生长方法-A（6.70） > 综合法（4.41） > 光学仪器法（1.81）；在整个调查期内（5月至11月），相对于异速生长方法-B、凋落物法、异速生长方法-A和综合法，光学仪器法分别平均低估81.69%、75.50%、70.18%和48.90%。本研究探讨了非破坏条件下测定红松人工林LAI季节动态的直接方法，并比较了不同方法之间的差异，研究结果可为有效测定常绿针叶林LAI提供参考。 Abstract:Leaf area index (LAI), defined as half the total leaf area per unit ground surface area, and is one of the most important characteristics of the plant canopy structure. LAI controls the flux of carbon, solar energy, and water in forest ecosystems. Thus, accurately estimating LAI is essential for simulating the forest process. Furthermore, the seasonality of LAI estimation is of particular interest. Methods directly estimating LAI mainly include destructive sampling, allometry, and litterfall. The results of these methods are assumed to provide values close to the true LAI. However, the first two methods destroy the samples, as well as labor intensive. By contrast, the litterfall method is the best choice in obtaining accurate LAI. At present, the optical method has been widely used to estimate LAI because of its convenience and speed. However, the accuracy of optically measured LAI needs to be verified. This verification is performed because the indirect method often underestimates LAI. In the present study, allometry method (including two different allometry equations, namely, A and B), litterfall method, combinational method (the LAI derived from optical method were calibrated by taking into consideration the woody-to-total ratio (α), as well as the clumping index, and combining the litterfall method), and optical method were used to estimate LAI in the Korean pine (Pinus koraiensis) plantation in Xiaoxing'an Mountains. First, we estimated the effective leaf area index (Le) and its seasonality in the Korean pine plantation using optical method (hemispherical photography). To obtain accurate LAI, we estimated the LAI seasonal dynamics by combining litterfall method, combinational method, and allometry methods in accordance with the leaf seasonality observation from May to August. Subsequently, we compared the results obtained from the different methods. The results showed that P. koraiensis leaf stopped growing in early August, which was approximately two weeks later than the other tree species. The major species had different leaf fall pattern in the Korean pine plantation. P. koraiensis had two rapidly decreasing flush. The first flush was in June. The second was in late September. However, other species had single rapidly decreasing flush in late September. The LAI seasonal dynamic derived from different methods all show a uni-modal pattern with a peak in early August, with the following order: Allometry-B method (10.58) > Litterfall method (7.90) > Allometry-A method (6.70) > Combinational method (4.41) > Optical method (1.81). In the entire study period (from May to November), the LAI derived from optical method underestimated LAI by an average of 81.69%, 75.50%, 70.18%, and 48.90%, respectively, which were in contrast with contrast Allometry-B method, Litterfall method, Allometry-A method, and Combinational method. In the present study, we investigated a practical method for estimating LAI in the Korean pine plantation using a non-destructive method. Furthermore, we compared the difference between the different methods. In addition, this study lays a foundation for the valid LAI estimation of evergreen conifer forest in subsequent studies. 参考文献 相似文献 引证文献

Mapping and modeling Dirofilaria infections in Europe

Climate change and increasing temperatures are a global phenomenon that can influence the dynamics of a number of hematophagous arthropods, vectors of pathogens with importance in human and veterinary medicine. In fact, climatic changes, together with an increase in the movement of dogs across Europe, have caused an increase in the geographical range of Dirofilaria immitis and D. repens infections. A Geographic Information System based on thermal regimen was constructed to identify areas potentially suitable for Dirofilaria transmission in Europe. These models are based on evidence that: i) there is a threshold of 14 °C below which Dirofilaria development will not proceed in mosquitoes; ii) there is a requirement of 130 growing degree-days for larvae to reach infectivity, and; iii) there is a maximum life expectancy of 30 days for a mosquito vector. The output of these models predicted that the summer temperatures (with peaks in July and August) are sufficient to facilitate extrinsic incubation of Dirofilaria even at high latitudes. Recently, an additional model was constructed to verify the influence of temperature in the course of three decades (1980-1989, 1990-1999 and 2000-2012) on the risk of infection by Dirofilaria in Italy. The results showed an expected increasing trend of temperatures, an increase of the Dirofilaria generation numbers into the mosquitoes and a significant extension of the infection risk from 5-6 months (1980-1989) to 6.5 months (1990-1999), up to more than 7 months (2000-20012). These findings show that geospatial tools are very useful for mapping, monitoring, forecasting and surveillance of both heartworm and subcutaneous dirofilariasis.

Lesson Learned from the Emergence of Influenza Pandemic H1N1 in 2009 in Indonesia: The Importance of Influenza-Like Illness (ILI) Surveillance

Background. In 2009 there were outbreaks of influenza pandemic H1N1 in Indonesia that were caused by different virus from the previous circulated H1N1. Further, the influenza-like illness (ILI) surveillance plays an important role in the early detection of influenza outbreaks in outpatients. To understand the disease burden of ILI in the community at the time of H1N1 pandemic 2009, a sentinel-based survey was performed. Methods. The nasal and throat swabs were obtained from 20 primary health centers of ILI sentinel in Indonesia in 2009. Identification of virus influenza pandemic H1N1 was carried out by real-time RT-PCR using primers that are specific for influenza A. Results. Out of 3254 ILI cases from community-based ILI surveillance in 2009, 11.03% cases were Influenza A positive and 42.59% cases were influenza pandemic H1N1. The first influenza pandemic HINI case was detected at week 15 in April, a case from the province of Banda Aceh, reaching a peak in August and ending at week 44 in November of 2009. Conclusion. The influenza pandemic H1N1 outbreak was detected in ILI surveillance network in Indonesia. This outbreak lasted for eight months which was the final wave of the influenza pandemic H1N1 in the world.

Dewfall Monitoring in Wetland Ecosystem

Dew is a crucial factor of water cycle in wetland ecosystem. This study aims to investigate the dewfall in Carex lasiocarpa marsh in the Sanjiang Plain. The experiment was carried out during the growing season from mid-May to mid-October in 2008 and 2009. Dew was monitored by woodsticks. Results indicated that dew intensity in 2008 was lower than it in 2009 obviously because of the much higher relative humidity in 2009. But annual dewfall was almost the same, which reached 8.76 mm and 8.38 mm in 2008 and 2009, respectively. The dew intensity reached the peak in August in both years. The Carex lasiocarpa marsh was the important site for the dew deposit.

Human Threat On Phenological Cycle Of Selected Dry Deciduous Tree Species In North Gujarat Region (Ngr), Gujarat, India

Phenological observations were taken for 13 woody species for two years (Jan 2006 - Dec 2007) in dry deciduous forest of North Gujarat. The phenological behavior of most of the woody species was almost similar in two different years. Leaf initiation started in the month of March with peak April – May before pre-monsoon showers and leaf - fall began in October with a peak in November and December. Flowering in most of the woody species was observed in the month of February continued till May, fruit appearance for these species from March, with a peak of August. In July and August 69% of woody species appeared in fruit ripening stage. While monsoon begins same duration, that allow to the optimal germination of tree species. An observing human impact on selected species facing seasonal threats, more number of species faced cutting during leaf fall period or before on setting of flowers. International Journal of Environment, Volume-2, Issue-1, Sep-Nov 2013, Pages 60-69 DOI: http://dx.doi.org/10.3126/ije.v2i1.9208

우리나라 서해에서의 해양환경변화와 동물부유생물의 장기간의 출현량 변화

Abstract Spatial and temporal variations of sea surface temperature (SST), abundances of copepods, euphausiids, amphipods, and chaetognaths were investigated in the western waters of the Korean Peninsula. Zooplankton and SST were monitored at 63 stations arrayed in six transects (124°00´-126°30´E, 34°00´-37°00´N) in February, April, June, August, October, and December during 1978-2010. In general, SST increased 0.7-3.8°C during the last three decades with spatio-temporal variations. SST was lowest in February and highest in August. SST was highest in the northernmost transect and declined gradually along transects to the south. The general pattern of interannual variations of SST was similar to the global pattern, which has been increasing. Trends of abundances of all zooplankton groups slightly increased interannually and peaked seasonally in June and August, except chaetognaths, which fluctuated around the long-term mean value with a seasonal peak in August and October. Abundances of zooplankton groups were highest in the northernmost transect while those of euphausiids were highest in the southern transect. We discuss the distribution patterns of SST and zooplankton groups in relation to oceanographic characteristics in the study area.Key words : Sea surface temperature, Copepods, Euphausiids, Amphipods, Chaetognaths, Zooplankton

시화호 인공습지에서 수생식물의 유기물 생산과 낙엽 분해

To provide the information for the wetland management considering the water treatment ability of macrophytes, the growth characteristics and primary production by reed (Phragmites australis) and cattail (Typha angustifolia), and the decomposition rate of organic matter produced were investigated in two sub-wetlands (Banweol and Donhwa wetlands) of the Sihwa Constructed Wetland (CW) with different chemistry of inflows. The shoot height of P. australis and Typha angustifolia began to increase in March, and reached its peaks in July and August (340cm and 320cm, respectively). The shoot density of P. australis ranging was higher than that of T. angustifolia (max. ). Standing biomass of P. australis ranged from , with maximal biomass in Banwol Upper Wetland. And it was larger in upper wetlands than lower wetlands. On the other hand standing biomass of T. angustifolia () was similar to that of P. australis in Banwol Upper Wetland. Primary productivity of P. australis was in the order of Banwol Upper Wetland () > Donghwa Lower Wetland () > Banwol Lowerr Wetland () Donghwa Lower Wetland (), and that of T. angustifolia () was higher than P. australis. Annual production of organic matter produced by P. australis and T. angustifolia was 845 ton DM/yr (423 ton C/yr), and about 90% was comprised of that by P. australis. From the litter decomposition rate (k) (P. australis: leaf 0.0062/day, stem 0.0018/day; T. angustifolia: leaf 0.0031/day, stem 0.0018/day), leaf was rapid degraded compare to stem in both P. australis and T. angustifolia. The litter decomposition rate of leaf was two times rapid P. australis than T. angustifolia, whereas that of stem was same in both. Annual litter decomposition amount of P. australis than T. angustifolia was 285 ton C/yr(67.3% of organic matter produced by macrophytes), indicating that 32.7% of organic matter produced by macrophytes is accumulated in the Sihwa CW.

Impacts on particles and ozone by transport processes recorded at urban and high-altitude monitoring stations

In order to evaluate the influence of particle transport episodes on particle number concentration temporal trends at both urban and high-altitude (Aitana peak-1558m a.s.l.) stations, a simultaneous sampling campaign from October 2011 to September 2012 was performed. The monitoring stations are located in southeastern Spain, close to the Mediterranean coast.The annual average value of particle concentration obtained in the larger accumulation mode (size range 0.25–1μm) at the mountain site, 55.0±3.0cm−3, was practically half that of the value obtained at the urban station (112.0±4.0cm−3). The largest difference between both stations was recorded during December 2011 and January 2012, when particles at the mountain station registered the lowest values. It was observed that during urban stagnant episodes, particle transport from urban sites to the mountain station could take place under specific atmospheric conditions. During these transports, the major particle transfer is produced in the 0.5–2μm size range. The minimum difference between stations was recorded in summer, particularly in July 2012, which is most likely due to several particle transport events that affected only the mountain station. The particle concentration in the coarse mode was very similar at both monitoring sites, with the biggest difference being recorded during the summer months, 0.4±0.1cm−3 at the urban site and 0.9±0.1cm−3 at the Aitana peak in August 2012. Saharan dust outbreaks were the main factor responsible for these values during summer time. The regional station was affected more by these outbreaks, recording values of >4.0cm−3, than the urban site. This long-range particle transport from the Sahara desert also had an effect upon O3 levels measured at the mountain station. During periods affected by Saharan dust outbreaks, ozone levels underwent a significant decrease (3–17%) with respect to its mean value.

Fecundity in Captivity of the Green Anoles,Anolis carolinensis, Established on the Ogasawara Islands

The iguanid lizard, green anole Anolis carolinensis, has currently established breeding colonies on several tropical and subtropical Pacific islands. In the Ogasawara Islands, predation by the green anole has collapsed the endemic insect community. Now that the Ogasawara Islands have been inscribed on the World Heritage List as a natural heritage by UNESCO, it is necessary to study the current status and ecological aspects of the green anole there to improve the effectiveness of control efforts. When planning population management for an alien species, information regarding its fecundity (number of eggs laid per female per year) is essential. This species lays only one egg at a time, but lays multiple times during an extensive reproductive season each year. It is therefore difficult to estimate fecundity by ordinary methods, such as gonadal examination by necropsy. In the present study, we maintained 10 female anoles from Chichijima Island in indoor captivity under conditions similar to those of the Ogasawara Islands to record their egg-laying conditions. Egg-laying occurred from April to October with a peak in August, during which each female laid 0.95 eggs/week on an average. The average number of eggs laid by a female in a year was 13.7. Sites selected for laying were spaces between the leaves of ferns and in hollows on the ground. We consider that for efficient control of this species, we should intensively hunt females in April, before their egg-laying frequency begins to increase.

Variability of aerosol properties over Eastern Europe observed from ground and satellites in the period from 2003 to 2011

Abstract. The paper presents some results of the study on aerosol variability in the period from 2003 to 2011 over the Eastern Europe region, with latitude ranging from 40° N to 60° N and longitude from 20° E to 50° E. The analysis was based on the POLDER/PARASOL and POLDER-2/ADEOS satellites and AERONET (AErosol RObotic NETwork) ground-based sun photometer observations. The aerosol optical thickness (AOT) of the studied area is characterized by values (referenced to 870 nm wavelength) ranging from 0.05 to 0.2, except for in the period of July–August 2010 with strong forest and peat wildfires when the AOT typical values range from 0.3 to 0.5 according to both retrievals. The analysis of seasonal dynamics of aerosol loading has revealed two AOT high value peaks. The spring peak observed in April–May is the result of solitary transportation of Saharan dust in the atmosphere over Eastern Europe, infrequent agricultural fires, transportation of sea salt aerosols by southern winds to Ukraine and Moldova from the Black and Azov seas. The autumn peak in August–September is associated with forest and peat wildfires, considerable transportation of Saharan dust and the presence of soil dust aerosols due to harvesting activity. The maximum values of AOT are observed in May 2006 (0.1–0.15), April 2009 (0.07–0.15) and August 2010 (0.2–0.5). Furthermore, the study has identified a distinct pattern of anthropogenic aerosols over the industrial areas, especially in central Ukraine and eastern Belarus as well as Moscow region in Russia. The comparison of the AOT derived by standard algorithm POLDER/PARASOL with those recomputed from AERONET inversions for fine mode particles with radius < 0.3 μm was performed over several AERONET sites. The correlation coefficients for the POLDER/AERONET AOT retrieval comparisons are equal: 0.78 for Moscow site, 0.76 – Minsk, 0.86 – Belsk, 0.81 – Moldova (period 2005–2009), 0.93 – Kyiv and 0.63 for Sevastopol sites (2008–2009). The deviations are explained by the spatial inhomogeneity of the surface polarization that has a stronger effect on aerosol retrieval for clear atmospheric conditions with low aerosol loading when surface impact on satellite observations is more pronounced. In addition, the preliminary analysis of the detailed aerosol properties derived by a new generation PARASOL algorithm was evaluated. The comparison of AOT and single scattering albedo retrieved from the POLDER/PARASOL observations over Kyiv with the closest AERONET retrievals within 30 min of satellite overpass time and with a cloudless day shows acceptable agreement of the aerosol dynamics. The correspondence of those data is observed even for extreme AOT440 value 1.14, which was caused by the forest and peat fires in August 2010.

Sexual reproduction in Sarcotragus spinosulus from two different shallow environments

AbstractThe reproductive cycle of the demosponge Sarcotragus spinosulus from two different shallow environments (La Pierta and La Strea) of the Ionian coasts of Apulia (SE Italy) was studied from February 2006 to February 2007 in 20 tagged specimens. The sponge is viviparous. All the monitored specimens showed sexual reproduction, even if the process usually involved small portions of the sponge tissue. Most of the specimens showed hermaphroditism, with contemporaneous production of oocytes and spermatic cysts in the same reproductive season. Young oocytes occurred from June to September in specimens from La Pierta and from June to October in those from La Strea. Large mature eggs, measuring up to 200 μm, showed a peak in August to September, concomitant with the appearance of spermatic cysts, whose density values were about 100 times higher than those estimated for female elements. At La Pierta, embryos were present for 11 months, whereas at La Strea they were very scarce during the first 4 months of observation, with the results that there was a significant difference in the production of embryos between the two groups of sponges. Embryo development occurred in patches inside the choanosomal region. Cleavage started in September and led in June to a solid stereoblastula, which, only at La Pierta, produced parenchymella larva (371.3 + 31.3 μm on average) from June to July. In the specimens from La Strea, larvae were never observed. The slight differences in the reproductive cycle between the two groups of sponges may be explained in the light of the major variability of the environmental parameters which could have affected the specimens from La Strea negatively.

Spatial and Temporal Variations of Microphytobenthos on the Common Reed Phragmites australis bed in a Marine Protected Area of Yeoja Bay, Korea

To characterize seasonal variation of microphytobenthos (MPB) biomass and composition in a Phragmites australis bed, the algal pigments in the top 20 mm of the sediments in a macrophyte marsh in a marine protected area in Yeoja Bay (Korea) were investigated monthly using high-performance liquid chromatography from November 2009 to December 2010, and compared with the upper and middle parts of a bare intertidal flat. Chlorophyll a (chla) concentration showed similar seasonal trends at all the sites, with bimodal peaks in April and August. The seasonal chla peaks were more pronounced on the bare flat than on the P. australis bed. While high amounts of pheophorbides a suggest an increased grazing activity during April–September on the bare flat, high ratios of pheophytins a/pheophorbides a on the P. australis bed indicate high levels of microbial degradation. While the dominance of diatoms characterized by high fuco/chla ratios appeared at all sites, the peaks of some accessory pigments (chlb, lutein, and zeaxanthin) at the P. australis bed led to the compositional difference in algal pigments from the bare sites. Altogether, our results suggest that the MPB biomass and composition in the P. australis bed are mediated by the vascular plant canopy.

Ungfågelspridning och höstflyttning hos svart rödstjärt Phoenicurus ochruros i södra Sverige

The number of ringed Black Redstarts at Ottenby, Falsterbo and Nidingen bird observatories showed two distinct peaks after the breeding season. During the first peak in July–August, with 63, 67 and 89 percent of the total catch, the proportions of yearlings were 92, 100 and 96 percent, respectively, and most of them had not yet begun their postjuvenile moult and showed relatively low weights. During the second peak in October–November, all yearlings had completed this moult and carried more fat. Black Redstarts have a delayed postjuvenile moult, a unique strategy among European thrushes. This allows for wide dispersal during late summer. Several ringed Belgian and German yearlings have moved up to 290 km northward during this time. This paper confirms, using ringing data and observations from a population study in western Sweden, that summer dispersal is well separated from autumn migration. I speculate that some of the birds of the July–August peak could have their origin in southern breeding populations, for example Denmark, where a major population increase has occurred in recent decades.

Independent Estimates of Catch by Private and Public Access Fishers Avoid Between‐Group Sources of Error in a Recreational Fishing Survey

AbstractMany recreational fishing surveys assume that fishers who use private or public property to gain access to the fishery behave similarly, but divergent behavior may result in bias and excessive error due to between‐group variation. In a 2002 survey of the recreational catch of blue crab Callinectes sapidus in Maryland, we interviewed waterfront property households by telephone and sampled public access boat ramps to obtain independent estimates of private and public access catch and effort. Waterfront property households caught more crabs than fishers from public boat ramps but achieved this only by using effort over an order of magnitude larger. They maintained a consistent catch from July to September, whereas catch from public access sites showed a well‐defined peak in August. Estimating catch independently for private and public access avoided bias and between‐group error generated by such differences. As a result, independent estimation of catch by private and public access users is a useful option for marine recreational surveys, under the conditions of significant and exclusive private access, large public access bias, and low correlation between effort and catch.

Reproduction of the invasive bluespotted cornetfish Fistularia commersonii (Teleostei, Fistulariidae) in the Mediterranean Sea

We investigated the reproduction of the bluespotted cornetfish Fistularia commersonii, one of the most successful invaders of the Mediterranean Sea and Europe. The results highlighted a multiple spawning pattern with asynchronous oocyte development and an unrestricted testicular organization with cystic spermatogenesis. Eight maturity stages in females and four in males were described. The reproductive season lasted at least six months, from May to October, with a peak in August, but gravid specimens were observed up to December. The gonadosomatic index and condition factors were significantly correlated with water temperature. Spawning started at an average water temperature of 22°C. The species is reproductively adapted to the conditions occurring in the Mediterranean Sea and it is suggested that warming conditions could facilitate its success along the Northern and Western sectors of the basin.

Life history of the amphidromous shrimp Caridina leucosticta (Decapoda: Caridea: Atyidae) in the Isazu River, Japan

The life cycle of a freshwater amphidromous shrimp Caridina leucosticta Stimpson, 1860 was studied in a temperate river from October 2005 to November 2006, including all aspects of its growth and reproduction, larval drift, distribution of developing larvae, and recruitment of developed juveniles. The growth rate of C. leucosticta was generally low when the water temperature decreased between October 2005 and April 2006. The growth rate then increased from April 2006 as the water temperature rose. Females grew faster and reached a larger body size at a given age than males. Brooding females occurred from June to September 2006. Larvae hatched in freshwater habitats were observed to flow downstream from July to October 2006, with a peak in July and August. Developing larvae were collected in September 2006, at two stations 0.6 and 2.0 km offshore from the river mouth, but were not found in the brackish estuary of the river. Developed juveniles were observed in the uppermost part of the brackish river estuary from August to November 2006. Juveniles were found in the freshwater habitat from October 2005 to April 2006 and from August to November 2006. Longevity was estimated to be 15-25 months. The life history of C. leucosticta as illustrated in the present study indicates that this species uses a broad range of habitats from fresh water to marine. Conservation measures should be considered for each habitat corresponding to each developmental stage and should also allow for connectivity between these habitats.

Suprabenthic amphipods from the littoral zone of Barlovento, Venezuela: spatial distribution and seasonal variation

Peracarid crustaceans are a very diverse benthic group and one of the dominant taxa within the suprabenthic community. The Barlovento beaches in Venezuela are characterised by large inputs of organic matter and an important assemblage of amphipods has been observed to thrive in this area. In this paper we describe the species composition of this amphipod assemblage along with their spatial and temporal variation and relationship with some environmental variables on four beaches (Agua Sal, Los Timones, Las Cabañas, Valle Seco). Results showed no significant differences in the amphipod community structure and total density of organisms regardless of the season (rainy and dry). From the 7569 amphipods collected, a total of 20 species were identified within 14 families and 17 genera. The species Apohyale media (Dana, 1953), Metatiron tropakis (J. L. Barnard, 1972) and Nototropis minikoi (A. O. Walker, 1905) were the most abundant species in terms of density, and the last two also in terms of frequency of occurrence. Differences in biomass were not significant at any level (season, beach and their interactions); however, the highest amphipod biomass throughout the year was observed at Valle Seco Beach with peaks in January, August and December coinciding with large accumulations of bryozoans and wood debris. Amphipod density and biomass had low correlation values with the environmental variables; the material caught in the suprabenthos net being the most common variable influencing the community.

Somatic Condition, Growth and Reproduction of Hake, <i>Merluccius merluccius</i> L., in the Portuguese Coast

Weight/length relationships, condition factor, gonadosomatic and hepatosomatic indices, conversion factor for gutted to total weight and spawning season of hake in the Portuguese Coast (36.92 to 42.22 degrees latitude N; 9.61 to 6.07 degrees longitude W) were investigated for the first time, aiming to fill the lack of information on the biology of hake of the Portuguese waters. Data were obtained from commercial samples collected between 2005 and 2010 and pooled by month. Sex ratio observed in fish below 40 cmwas close to 1:1; females were always dominant above50 cmlength. All the parameters were analysed by month and by sex and by combined sexes. The relationships obtained for combined sexes for the entire period concerning the growth in length and weight were: total length-total weight =0.0038L3.172, total length-gutted weight =0.0052L3.059. The relationship total weight-gutted weight was Wt = 15.8112 + 0.8480Wg and the conversion factor was of 1.1524. The growth rate is similar for both sexes but different when based on total weight or gutted weight. The analysis of the condition factor, gonadosomatic index, hepatosomatic index and the monthly distribution of the maturity stages seem to indicate that hake from thePortugueseCoasthas a long spawning season, with three spawning peaks in March, May and August but the start of the spawning season seems independent of the fish length.

中亚热带人工针叶林生态系统碳通量拆分差异分析

涡度通量观测可直接获取陆地生态系统与大气之间CO₂净交换量(NEE),但深入认识碳循环过程和校验生态系统模型需要不同时间尺度总初级生产力(GPP)和生态系统呼吸(Re)等碳通量数据。利用中国陆地生态系统通量观测与研究网络(ChinaFLUX)中亚热带人工针叶林生态系统2003-2009年的涡度通量和气象观测数据,分析了两种NEE拆分方法对不同时间尺度GPP和Re评估的影响,结果表明:(1)两种拆分方法得到的生态系统碳通量组分(GPP和Re)的季节动态变化一致,都在生长季7、8月份达到峰值;(2)非线性回归模型拆分得到的全年Re和GPP相较于光响应曲线模型分别高出2%-28.6%和1.6%-23%,最大高出317.6 gC·m^-2·a^-1(2006年),逐月最大差值主要发生在8、9月份;(3)不同时间尺度上,两种方法拆分得到的GPP 和Re之间差值的环境响应因子不同。在广泛采用非线性回归模型进行拆分时,如果当月光合有效辐射接近到905 mol·m^-2·月^-1,月平均空气饱和水汽压差接近1.18 kPa时,需要考虑使用光响应曲线模型拆分该月通量,结合两种拆分方法以减小全年的误差。;Net ecosystem exchange (NEE) between terrestrial ecosystem and atmosphere can be directly observed by eddy covariance flux observation system, but we need to get accurately ecosystem gross primary productivity (GPP) and respiration (Re) under different time scales in order to get insights into carbon cycle process. This paper analyzed the eddy carbon flux and meteorology measurement data of a mid-subtropical planted coniferous forest at Qianyanzhou station from 2003 to 2009, and explored the impacts of two different NEE partition methods on estimation of ecosystem GPP and Re under different time scales. Results indicated that ecosystem Re and GPP estimated by different eddy flux partition methods showed similar seasonal dynamics, both of which reached the peaks in July or August of growing season. However, the annual Re and GPP estimated by nonlinear regression model were 2%-28.6% and 1.6%-23% higher than those estimated by light response curve model, respectively. The maximum annual ecosystem respiration difference between two methods existed in 2006 (317.6 gC·m^-2·a^-1), and the maximum monthly ecosystem respiration difference mostly appeared in August or September. Also, we found that environmental factors significantly affect differences between two derived Re (or GPP) with various time scales. For example, the vapor pressure deficit and photosynthetic active radiation were found to explain 63% and 60% of the ecosystem respiration difference between two methods at daily time scale, respectively. Moreover, precipitation, vapor pressure deficit and photosynthetic active radiation could explain 48%, 85% and 89% of the ecosystem respiration difference between two methods at monthly time scale. Third, 78% of the ecosystem respiration difference between two methods could be explained by the photosynthetic active radiation at yearly time scale. It means that the photosynthetic active radiation could explain the most of Re difference between two methods under three time scales. In spite of the wide application of the nonlinear regression model, it was necessary to allow for the light response curve model to partition the carbon flux of that month whose monthly PAR is about 905mol·m^-2·mon^-1 and the vapor pressure deficit is around 1.18 KPa as a reference, compared with those partitioned by the nonlinear regression model. Furthermore, the research got access to improvements on the partition results of ecosystem carbon flux and reduced the partition uncertainty.

Reproductive Biology of an Endangered Coldwater Fish Golden Mahseer, Tor Putitora (Ham.) From Anji Mahseer Hatchery Reasi (J&K)

The Golden Mahseer (Tor Putitora) forms an important fishery resource in coldwater areas of Himalaya, India. The study covers reproductive factors of T. putitora from Anji Mahseer Hatchery Reasi, Jammu & Kashmir. Fecundity and Gonadosomatic Index (GSI) of T. putitora was calculated monthly for a period of six months from March’ 2011 to August’ 2011. The observations related to fecundity and GSI are based on six female specimens of T. putitora ranging from 260mm to 550mm in total fish length and weight ranging between 280 grams to 800 grams. The mean value of fecundity was estimated as 5566 eggs for a fish with a mean total body length of 395mm and mean body weight of 455gms. The value of GSI was found to increase from March onwards reaching a peak in June, July and August. The peak was maintained in June, July and august, the highest value for GSI was calculated as 10.812 in the month of August.