神农架植被及其生物多样性与垂直分布格局-兼论中国中、北亚热带植被带的划分

本文主要通过样线法和样方法相结合，进行了大量的群落学调查和分析，分别从植物区系、物种多样性的垂直分布格局和森林群落类型三个方面分析了神农架植被的基本特征及其物种多样性，结果表明： 1．神农架地区具有很高的物种丰富度，有高等植物3，479种，隶属于1，010属，202科。 其中，蕨类植物305种，80属，32科;种子植物3，174种，930属，170科，其中裸子植物32种，19属，6科，被子植物3，142种，911属，164科;单子叶植物501种，175属，21科，双子叶植物2，641种，736属，143科。植物区系属的分布区类型中北温带分布型最多，其次为东亚分布、泛热带分布、东亚北美间断分布、旧世界温带分布以及热带亚洲分布。中国特有成分占5.65%，较全国的8.12%低。温热比(温带分布型(8-11)属数与热带分布型(2-7)属数的比值）为1.200，比全国(0.385)高。 调查样方中共出现高等植物784种，隶属于454属，144科，其中蕨类植物41种，32属，16科;种子植物743种，422属，128科，其中裸子植物20种，14属，5科，被子植物723种，408属，123科;单子叶植物86种，58属，11科，双子叶植物637种，350属，112科。属的分布区类型中北温带分布型最多，其次为东亚分布、泛热带分布、东亚北美间断分布、旧世界温带分布以及热带亚洲分布。温热比为1.52，草本层>乔木层>灌木层分别为2.18、1.76和1.14。 2．神农架植被类型多样，具有常绿阔叶林、常绿落叶阔叶混交林、落叶阔叶林、针阔混交林、亚高山针叶林、硬叶常绿阔叶林和亚高山灌丛草甸等自然植被类型。本文，依据乔木物种的重要值将神农架地区的森林植被划分出了69个类型。用Twinspan将调查的森林群落划分为32组，能基本上反映群落间相似的关系。 3．神农架地区具有完整的植被垂直带谱：海拔900 (1300) m以下为常绿阔叶林带;海拔900 (1300) m～1500 (1800)ⅡI为常绿落叶阔叶混交林带;海拔1500 (1800) m-2000 (2200)m为落叶阔叶林带;海拔2000 (2200) m～2400 (2600)m为针阔混交林带：海拔2400 (2600)m以上为亚高山针叶林带。神农架地区植被的垂直带的分化从总体上比较显著，但由于小生境的异质性和人为干扰，垂直带谱又具有一定的模糊性和次生性。南北坡具有一定的差异，但不十分明显，也说明神农架植被的过渡性。 4．神农架物种多样性的垂直分布格局。神农架的物种多样性与海拔的关系，类似于“中间膨胀”规律(mid-altitude bulge)，在中低海拔处生物多样性最高。通过二次多项式回归拟合，得到如下拟合曲线： 1)海拔与总体物种数：y= _14.445x2+ 34.74lx+42.07，Xd=1.203km; 2)海拔与乔木层物种数：y=-6.9707x2+ 21.334x+0.2004，Xdrl.530km; 3)海拔与灌木层物种数：y=-6.1599x2+ 9.9747x+30.991，Xd=0.8 lOkm: 4)海拔与草本层物种数：y= _3.9907x2+ 10.455x+15.35，Xd-1.308km; 5）海拔与乔木层Shannon-Wiener指数：y=_0.3337x2+ 0.9877x+0.2537，Xd' 1.480km; 6)海拔与灌木层Shannon-Wiener指数：y=-0.1938xz+ 0.422lx+1.2103，Xd=1.089km： 7)海拔与草本层Shannon-Wiener指数：y=_0.1072x2+ 0.294lx+0.9954，Xd=1.372km; x为海拔( km)，y为各物种多样性指标，Xd为物种多样性的最大时的海拔。 从这些拟合曲线中可以看出：总体物种多样性在海拔1200m左右的常绿落叶阔叶混交林带最高：乔木层物种多样性在海拔1500m左右的常绿落叶阔叶混交林带与落叶阔叶林的过渡带最高;灌木层物种多样性在海拔800-llOOm左右的常绿阔叶林与常绿落叶阔叶混交林带的过渡带最高;草本层物种多样性在海拔1300-1400m左右的常绿落叶阔叶混交林带最高。 但物种多样性随海拔变化有许多的起伏和波动。这些波动有些反映了群落的垂直带谱随海拔梯度变化的特点，在垂直带谱的过渡区物种多样性往往较高;有些波动反映了一些特殊的生境，有些反映了人为活动的影响，造成了神农架植被的次生性。因此，影响神农架物种多样性垂直分布的因素有：植被本身的性质和特点、过渡带的特点、生境的异质性和人为活动。 5．神农架植被水平地带性的过渡性。海拔1300m以下的植物属的分布区类型的温热比南坡总是比北坡小，而且相差十分显著，反映了神农架作为植被分界线的价值。神农架南坡的基带植被是常绿阔叶林，因此南坡属于中亚热带。北坡的基带植被，虽然也有常绿树种的零星分布，甚至有小块的常绿阔叶林，完全由于小生境所至，分布的主要类型是常绿落叶阔叶混交林，应属于北亚热带。因此，神农架是中、北亚热带重要的过渡地带。神农架地区中北亚热带的具体分界线宜按照分长江干流和汉水的水岭来划界，即猴子石、大窝坑、神农架、神农顶、老君山一线，南坡属于中亚热带，北坡属于北亚热带。 总之，神农架处于我国中、北亚热带的过渡带，具有过渡带的性质，具有很高的物种多样性，拥有完整的植被垂直带谱，具有多种多样的植物群落及其组成的生态系统。而且，具有我国许多特有植物和珍稀濒危保护植物和许多资源植物。因此，神农架植被在我国植被体系中具有重要的地位，是我国生物多样性最丰富的地区之一，是生物多样性保护的关键地区，也应是生物多样性研究的热点地区。 另外，调查分析了黄山和万朝山植被及其物种多样性与垂直分布格局，结果表明： 6．黄山样方中共出现高等植物259种，隶属于263属，110科，其中蕨类植物14种，II属，8科，种子植物345种，152属，105科，其中裸子植物9种，8属，6科，被子植物336种，144属，99科，其中单子叶植物37种，27属，6科，双子叶植物299种，117属，90科。属的分布区类型中北温带分布最多，其次为东亚分布和泛热带分布，再次为东亚北美间断分布、热带亚洲分布以及旧世界温带分布，与神农架和万朝山也较相似，但热带分布的属更多一些。温热比为1.1875，灌木层>草本层>乔木层，分别为1.3818、1.2609和1.2143。 黄山的森林植被类型有针叶林、常绿阔叶林、常绿落叶阔叶混交林、针阔混交林、落叶阔叶林和竹林。Twinspan将调查的森林群落划分为22组，反映群落间相似的关系，比较清楚和适用。依据乔木物种的重要值将森林植被划分出了34个类型。黄山物种多样性的与海拔的关系不十分明显。黄山植被的垂直带谱不是十分明显，将其垂直带谱划分为：海拔1300m(1500m)以下为常绿阔叶林带;海拔1300m(1500m)-1500m(1600m)常绿落叶阔叶混交林 带;1500m(1600m)以上为落叶阔叶林、黄山松林、山地灌木草丛带。垂直带谱在不同坡向上有差别，东、南、西坡的相似性较大，而北坡与其差别较大。 7．万朝山样方中共出现高等植物490种，隶属于339属，124科，其中蕨类植物21种，18属，11科，种子植物469种，321属，113科，其中裸子植物9种，7属，4科，被子植物460种，314属，109科，其中单子叶植物47种，37属，11科，双子叶植物413种，277属，98科。植物属的分布区类型中，北温带分布所占最多，其次为泛热带分布、东亚分布、东亚北美间断分布、旧世界温带分布以及热带亚洲分布，。温热比为1.3366，草本层>乔木层>灌木层，分别为1.5429、1.4063和1.0645。 万朝山的植被类型包括针叶林、落叶阔叶林、针阔混交林和常绿落时阔叶混交林，但没有典型的常绿阔叶林。依据乔木物种的重要值将森林植被划分出了20个类型。万朝山物种多样性与海拔的关系则不十分明显。万朝山的人为干扰比较强，植被的次生性很大，南、北坡物种多样性随海拔升高的起伏较大。

Utilisation of trash fish. Pt. 2. Studies on preparation of fish soup mix

The paper deals with the investigations carried out on the preparation of fish soup mix using partially deodorized trash fish meat. The product contained about 25% protein and had a storage life of 4 months at ambient temperature (28-31°C).

Energetics of resting metabolism in an Indian major carp (Catla catla Ham.)

Resting metabolism in Indian major carp, Catla catla Ham. fingerlings were investigated. For this purpose a water recirculatory system in the laboratory was used. The metabolic energy losses were determined by the indirect method of oxygen consumption by the fish and were then multiplied by an oxycalorific coefficient (Q-ox). Five metabolism chambers in the experimental system were used where there were two same treatment runs in quadruplicate of mean total weight of fish fingerlings of 109.5, 110.4, 112.8 and 111.6g/chamber. The water temperature in the system was 28±0.5°C. The mean metabolic rate in the replicates showed no significant variation (p>0.05) and was found to be 151.66, 153.91, 150.25, 152.74 mgO-2/kg/h respectively. This showed an equivalent energy loss 5.40, 5.52, 5.51 and 5.56 KJ/chamber/day (35.60, 35.92, 36.67 and 36.40 KJ/kg/day) respectively. Energetics of resting metabolism in an Indian major carp (Catla catla Ham.)

Análise dos efeitos económicos das opções de gestāo da pescaria de camarāo de águas pouco profundas

The paper deals with the proper management of fishing resources of shrimps in shallow waters, those currently constitute the main source of foreign currency trade of the country. The analysis of the level of the productive sector is presented by the local Institute of Fisheries Research.

Effect of water on mechanical properties of mineralized tissue composites

In the current study, the effects of polar solvents on tissue volume and mechanical properties are considered. Area shrinkage measurements are conducted for mineralized bone tissue samples soaked in polar solvents. Area shrinkage is used to calculate approximate linear and volume shrinkage. Results are compared with viscoelastic mechanical parameters for bone in the same solvents (as measured previously) and with both shrinkage measurements and mechanical data for nonmineralized tissues, as taken from the existing literature. As expected, the shrinkage of mineralized tissues is minimal when compared with shrinkage of nonmineralized tissues immersed in the same polar solvents. The mechanical changes in bone are also substantially less than in nonmineralized tissues. The largest stiffness values are found in shrunken bone samples (immersed in acetone and ethanol). The mineral phase in bone thus resists tissue shrinkage that would otherwise occur in the pure soft tissue phase. © 2007 Materials Research Society.

Sperm cryopreservation of Indian major carp, Labeo rohita: cryodiluents, sperm: cryodiluent dilution ratio and cryoprotectan t concentration

Cryogenic preservation trials of spermatozoa of Labeo rohita were carried out. Twenty four cryodiluents (extender + cryoprotectant), with the combination of six extenders such as egg-yolk citrate, urea-egg-yolk, 0.9% NaCl, Kurokura-2, Ma and Mb and four cryoprotectants viz. DMSO, glycerol, methanol and ethanol, were used to screen out the suitable cryodiluents. Sperm was preserved in 0.25ml plastic straw in programmable freezer. Two step freezing method was followed. Sperm preserved with egg-yolk citrate and urea-egg-yolk containing 10% DMSO showed best post-thaw motility (80%) followed by 0.9% NaCl (60%) and Kurokura-2(30%) solutions. Sperm with the extenders M" and Mb clotted at the time of equilibration and also after few days of preservation. Egg-yolk citrate mixed with ethanol and methanol also showed good percentage of motility (80%) but egg-yolk citrate with glycerol showed less sperm motility (>60%). To determine suitable dilution ratio of milt and cryodiluent two best extender eggyolk citrate and urea-egg-yolk with four cryoprotectants such as DMSO, glycerol, methanol and ethanol at different ratio viz 1:2,1:4,1:7,1:10,1:15 and 1:20 were used. Highest post-thaw motility (>80%) was observed when milt was preserved with egg-yolk citrate containing 10% DMSO at 1:2, 1:4, 1:7 and 1:10 dilutions. Meanwhile using glycerol as cryoprotectants provided less post thaw motility at lower dilution ratio but with the increase of its dilution showed good sperm motility compared with other cryoprotectants. Finally, evaluation on the effect of cryoprotectant concentration on post-thaw sperm motility was conducted. Egg-yolk citrate and four cryoprotectant i.e. DMSO, glycerol, methanol and ethanol with six different concentrations namely 5%,7%, 10%, 15%, 20% and 30%.were evaluated. Among the cryoprotectants DMSO, methanol and ethanol showed highest post-thaw motility (about 80%) at 7% and 10% concentrations. Although glycerol was not suitable at low concentration but its 20% and 30% concentration levels provided best post-thaw motility. No post-thaw motility was obtained with DMSO at 30% concentration. The overall analysis on cryoprotectant concentration indicated that below 5% and above 20% cryoprotectant concentrations could not be suitable for effective cryopreservation of spermatozoa.

Effects of Pallas' viper (Agkistrodon halys pallas) venom on blood coagulation and characterization of a prothrombin activator

The action of Pallas' viper (Agkistrodon halys pallas) venom on blood coagulation was examined in vitro and a strong anticoagulant effect was observed. This action was abolished after treatment with a specific inhibitor of phospholipase A(2) activity (p-bromophenacyl bromide), revealing a procoagulant action in low concentrations of treated venom (around 1 mu g/ml). The effect of the venom an haemostasis was further characterized by measuring its ability to activate purified blood coagulation factors. It is concluded that A. halys pallas venom contains prothrombin activation activity. A prothrombin activator (aharin) was purified from the venom by Sephadex G-75 gel filtration and ion-exchange chromatography on a Mono-Q column. It consisted of a single polypeptide chain, with a mol. wt of 63,000. Purified aharin possessed no amidolytic activity on chromogenic substrates. It did not act on other blood coagulation factors, such as factor X and plasminogen, nor did it cleave or clot purified fibrinogen. The prothrombin activation activity of aharin was readily inhibited by ethylenediamine tetracetic acid (a metal chelator), but specific serine protease inhibitors such as diisopropyl fluorophosphate and phenylmethanesulfonyl fluoride had no effect on it. These observations suggest that, like those prothrombin activators from Echis carinatus and Bothrops atrox venoms, the prothrombin activator from A. halys pallas venom is a metalloproteinase. (C) 1998 Elsevier Science Ltd. All rights reserved.

Effect of sublethal concentration of artificial seawater on oxygen uptake and opercular frequency in an Indian major carp, Labeo rohita (Ham.)

The present study reports the effect of artificial seawater on oxygen uptake and opercular frequency in an Indian major carp, Labeo rohita. Whereas a control fish of 7.34 g average body weight consumed 1.538 ml O sub(2.) hˉ¹, the 24h and 96h exposed fish of the same body weight consumed 1.07 4 and 0.897 ml O sub(2.) hˉ¹, respectively. The oxygen uptake per unit body weight under controlled condition was 0.219 ml. gˉ¹. hˉ¹, whereas in 24h and 96h exposed fish, it was 0.152 and 0.124 ml. gˉ¹, hˉ¹, respectively. The change in opercular movement in 24h exposed fish was 7.67% higher, whereas in 96h exposed fish, it was 22.43% higher as compared to the control one. All changes are highly significant (p<0.001).

Seasonal changes in the trade-off among fig-supported wasps and viable seeds in figs and their evolutionary implications

What the real trade-off is among fig-supported wasps and the viable seeds of figs is heatedly debated in the studies of fig/fig wasp mutualism. In the present study, we collected wasp offspring (galls) and the viable seeds of premature fruits, and determined the foundress number in receptive fruits and all the types of wasps supported by Ficus racemosa L. during both the rainy and dry seasons in Xishuangbanna, China. The data show that the galls were positively correlated with viable seeds (n=32;r=0.74; P < 0.001) when the proportion of vacant female flowers (PVFF) was high, in April (68.0%), and were negatively correlated with viable seeds (n=48;r=-0.59; P < 0.05) when PVFF were limited (PVFF 42.6%) during a colder month (January). The mean foundress number per fruit during the colder months is significantly lower than during the warmer months (F-5,F-603 = 27.9; P < 0.001) and pollinator wasps can live longer during the colder months, During the colder months, the proportions of non-pollinators and wasp offspring are higher than those found during other months, whereas the proportion of viable seeds is not different compared with that of other months. Non-pollinator wasps tend to oviposit the female flowers that have been oviposited by pollinator wasps. The non-pollinators only negatively affect pollinator wasps and there is no obvious negative effect of non-pollinator wasps on viable seeds, so ovipositing by non-pollinator wasps will not result in the extinction of the figs during the process of evolution. The results of the present study indicate that figs can allow less foundresses to be in fruit cavities when PVFF are limited, which provides supporting evidence for the previous assumption that the plants have developed a mechanism to maintain a stable system because of the conflicts between the parties involved.

Investigations on wooden floating materials: the loss of buoyancy under continuous immersion in water and the rate of its redemption by drying

A wooden fishing float under immersion in water for long periods is liable to absorb water, the quantity of water absorbed possibly being dependent upon the physical factors like the specific gravity and the inherent property of the material, the time of soaking and the pressure acting on it. Consequently a wooden float is likely to become heavy and loss its original buoyancy. However, when the float is removed from water and dried, the lost buoyancy is regained on complete drying. The present paper is an attempt to elucidate these two important characteristics of some of the chief wooden floating materials used on the West Coast of India.

Preparation of smoke cured fillets from oil sardine

A method of preparation of smoke cured fillets of oil sardine is described. Various procedural steps like brining, smoking, packaging etc. have been described and the shelf life assessed. Sodium propionate treatment is recommended to enhance storage life; BHA to control rancidity; and thermal treatment to overcome the insect infestation. The product has good consumer appeal.

Double-rig shrimp trawling, its rigging, comparative efficiency and economics

A radical and revolutionary change from the hitherto employed shrimp trawling is reported for better productivity and economy in deep sea trawling with medium and large vessels. Studies carried out off Veraval with a 13.7 m. four seam shrimp trawl as conventional single-rig and two 6.8 m four seam shrimp trawls as double-rig from a 15.2 m fishing vessel showed an increase of 98% shrimp catch by double-rig over single-rig at 86.3 % of the power utilised by the latter. It has also been worked out, theoretically, how better this available power can be utilised for further improvement of catch. An increase of 15% head rope length in case of double-rig over the optimum single-rig gear of any vessel is recommended.

Molecular genetic basis for the rhino mouse from Chinese KM subcolony

Both the rhino mouse and hairless mouse resulted from hairless gene mutation, but they show different phenotypes of skin physiology. The rhino mouse has more similar histological characters to human papular alopecia. Therefore rhino mouse is a good experimental animal model for human papular alopecia. This study reports a hairless mouse named rhino KIZ, arose from KM colony in Kunming Institue of Zoology, by systematic studies on morphology, skin histopathology, gene sequence, pedigree and protein domain analysis. The results demonstrate that a C-to-T transition in exon 11 of hr gene (The mutant gene has been applied for a Chinese patent (patent No. 03135280)) results in the rhino KIZ. The rhino KIZ with clear genetic mechanism will be a useful animal model.