Forage quality of leaf fodder from the main woody species in Iceland and its potential use for livestock in the past and present

Woody species played, and in many Nordic regions still play, a very important role in livestock feeding. However, forage quality (contents of macroelements and fibre fractions) of the leaves of common woody species is often inadequate. The aim of our study was to determine forage quality of leaves of Betula nana, Betula pubescens, Salix lanata, Salix phylicifolia and Sorbus aucuparia from Iceland and to compare it with the forage quality of the common native grass Deschampsia cespitosa and the introduced grass Alopecurus pratensis used by contemporary Icelandic farmers for forage production. Samples were collected at four localities in Iceland in late June 2013 and analysed for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), neutral and acid‐detergent fibre and lignin concentration. Analyses were compared with the optimum range for cattle and sheep nutrition. The nutritive value of leaves of the Icelandic woody species was relatively high, and analysis showed their nutritive content satisfied both cattle and sheep nutrient requirements for N, P, K, Ca and Mg, but the relatively high content of indigestible lignin in all woody species could cause problems for livestock metabolism. Grasses were characterized by lower P, Ca and Mg, but substantially higher K concentrations, and higher N:P and K:(Mg + Ca) ratios. The forage quality of leaves of woody species increased in the order B. nana < B. pubescens < S. phylicifolia < S. aucuparia < S. lanata. Results are discussed in relation to use of leaf fodder in the past, when woody species, particularly Salix spp., are likely to have played an important role in livestock feeding.     

我国热带海岛地区油菜有机栽培技术初探

[目的]探索适宜于热带海岛地区的油菜栽培技术。[方法]通过油菜有机栽培试验探索了适宜于热带海岛地区的蔬菜生产技术。[结果]椰糠基质栽培系统由环境调控系统、蔬菜栽植系统和肥水供给系统组成。智能系统自动感应温度和辐照度对遮阳网实现展开和收拢控制。智能系统自动感应降雨和风速对天窗实现开闭控制。苗期防苗徒长;3～4叶期定植;每隔5d滴灌1次天方黑宝200倍液,0.2L/株,或叶面喷施天方黑宝200～300倍液或亿安神力500倍液作为营养补充;苗期主要防治猝倒病,成熟采收期主要防治软腐病;防治虫害主要有小菜蛾、斜纹夜蛾、菜粉蝶、潜叶蝇、萝卜蚜等;35～50d后可收获无病、虫斑植株。[结论]该试验为热带海岛地区的蔬菜生产及解决驻岛官兵的＂吃菜难＂问题提供了技术支持。     

不同质地土壤中荒漠灌木梭梭“肥岛”的初步探讨

为检验荒漠灌木"肥岛"是否受土壤质地调节,本研究选取了中亚干旱区梭梭(Haloxylon ammodendron(C.A.Mey.))的两种原生生境:古尔班通古特沙漠的风沙土和绿洲区的灰漠土。两种土壤的质地有显著差异,风沙土中砂粒含量是灰漠土的2.1倍~2.4倍,而灰漠土中粉粒和黏粒含量分别是风沙土的3.0倍~3.6倍、2.9倍~5.1倍。通过对比分析两种土壤中梭梭冠下水分和养分的空间变异特征,获得了如下结果:两种土壤中均存在灌木"肥岛"效应,且随深度增加而减弱;在0~20 cm土层,与灰漠土相比,风沙土中冠下水分和养分的空间异质性更强,富集程度更高,风沙土中水分、有机质、有效氮和有效磷的富集率分别是灰漠土的4.6倍~12.3倍、3.4倍~8.6倍、3.0倍~4.9倍和2.1倍~2.6倍。本研究表明,两种土壤均存在灌木"肥岛"效应,而土壤质地可能决定了"肥岛"效应的强弱程度。     

Genetic diversity,population structure,and historical demography of a highly vagile and human-impacted seabird in the Pacific Ocean: The red-tailed tropicbird,Phaethon rubricauda

1. Many seabird breeding colonies have recovered from heavy anthropogenic disturbance after conservation actions. The widely distributed red-tailed tropicbird, Phaethon rubricauda, was used as a model species to assess potential anthropogenic impacts on the genetic diversity of breeding colonies in the Pacific Ocean.
2. Cytochrome c oxidase subunit I and control region sequences analyses were conducted across the range of the species in the Pacific Ocean. The study sites were at islands without human-related disturbance (non-impacted islands) and with human-related disturbance (impacted islands). We hypothesized that (i) breeding colonies of the red-tailed tropicbird on impacted islands have lower genetic diversity compared with colonies on non-impacted islands, and (ii) breeding colonies of the red-tailed tropicbird show significant fine and broad-scale genetic structure across the Pacific Ocean. Bayesian skyline analyses were conducted to infer past changes in population sizes.
3. Genetic diversity was similar between impacted and non-impacted islands. There was significant broad-scale genetic structure among colonies separated by over 6,000 km, but a lack of significant fine-scale genetic structure within Australasia and Hawai'i, although a significant level of differentiation was found within Chile with Φ_ST analyses. Skyline analyses showed that effective population sizes remained relatively constant through time, but experienced either a slight decrease or the end of an expansion event through the last 1,000 years. These changes may be related to the arrival of humans on Pacific islands.
4. Impacted islands may have received immigrants from other relatively close islands, buffering the loss of genetic diversity. However, it is also possible that colonies have retained ancestral variation or that a large effective population size coupled with a long generation time (13 years) has prevented the loss of genetic diversity in human-impacted islands. Future research using higher-resolution markers is needed to resolve the population genetic structure of the red-tailed tropicbird in an ecological time-scale.

     

我国热带海岛地区不同基质栽培模式对番茄生产效率的影响

[目的]为了探索我国热带海岛地区更有效的番茄（Lycopersicon esculentum Mill.）栽培模式.[方法]在我国热带海岛地区先期建立的蔬菜椰糠基质栽培系统（常规栽培模式）基础上,研究改善型栽培模式对番茄生产的影响.其中常规栽培模式为：栽培槽槽底衬聚乙烯黑色塑料膜,发酵后的椰糠按体积比4∶1掺入细沙作为栽培基质,将基质平铺满栽培槽后进行栽培;改善型栽培模式为：栽培槽槽底衬较宽的银黑地膜,宽余的地膜覆盖在番茄株行间,发酵后的椰糠按体积比10∶1∶1.5掺入细沙和0.5 mm粒径陶粒,基质槽内基质中间开沟,呈“V”型栽培.[结果]与常规栽培模式相比,改善型栽培模式降低了地温,提高了番茄坐果率和产量,水生产效率得到显著提高.[结论]改善型栽培模式是一种更有效的番茄栽培模式.     

Assessing the risks of introduced chickens and their pathogens to native birds in the Galápagos Archipelago

Poultry production is an important economic activity on inhabited islands of the Galápagos archipelago. There has been a recent surge in both small-scale backyard chickens and larger scale broiler production associated with growth in the human population and the tourist industry. With increased poultry production, concerns have been expressed about the increasing risk of transfer of disease from chickens to native Galápagos bird species that may have little resistance to introduced pathogens [Wikelski, M., Foufopoulos, J., Vargas, H., Snell, H., 2004. Galápagos birds and diseases: invasive pathogens as threats for island species. Ecology and Society 9(5). Available from: URL:http://www.ecologyandsociety.org/vol9/iss1/art5]. This study evaluates risks posed by chicken disease to endemic and native Galápagos bird species, based on empirical evidence of pathogens present in chickens on the islands and a literature review of effects of these pathogens in wild species. Pathogens identified in domestic chicken populations of immediate avian conservation concern are Newcastle disease, Mycoplasma gallisepticum, and the proventricular parasite Dispharynx sp. Newcastle disease (avian paramyxovirus-1) poses an imminent threat to Galápagos penguins (Spheniscus mendiculus), flightless cormorants (Phalacrocorax harrisi), and lava gulls (Larus fuliginosus), species with very small population sizes (less than 1500 animals each). Additionally, litter from broiler farms could affect ecological processes in local ecosystems. Improved poultry biosecurity measures are urgently needed on the Galápagos Islands for avian disease management, yet developing these strategies presents political, social, and economic challenges.     

基于RS&GIS的内湖岛屿湖域视景资源开发分析

[目的]通过量化研究探索内湖岛屿湖域视景资源开发过程中的可持续发展途径,为此类区域风景规划、低影响开发和湖域景观保护等提供依据。[方法]以太湖西山岛及周围湖域为典型研究范围,基于RSGIS的空间分析技术及方法,从路域视景、湖岸视景、视域开阔度、视景丰富度、地形因子等方面进行量化研究,并提取适宜的观景平台选址作为成果展现。[结果]首先通过最佳坡度坡向、平台地基尺寸、洪水淹没、低影响开发、路域可达度等指标初步筛选出30处拟选址。其次通过视域、水景开阔度和视景资源丰富度进行分析,确定最终选址。[结论]建立在量化数据基础上的视景资源开发属于源头控制,观景平台的选址科学有效,有利于视景资源的永续利用和区域生态。     

浙江大鹿山森林植物资源及发展利用

在森林植物资源调查的基础上,对浙江省玉环县大鹿山森林公园的植物种质资源、植物群落类型、森林面积与蓄积与外来树种资源进行了分析评价。针对资源现状和海岛生态环境特点及森林旅游发展的现实需要,提出了大鹿山森林公园森林植物资源保护、改造与开发的初步意见。参７     

江苏省海岛潮间带底栖生物分布特征

2007年春、秋2季对江苏北部的东西连岛、车牛山岛、达山岛及平山岛4个海岛设置9条断面进行潮间带底栖生物调查。共发现潮间带生物127种,种类组成以藻类居首位（占35.43%）,其次为软体类（占28.35%）,甲壳类居第三（占16.54%）。内湾海岛共发现56种,主要种类为软体类;外海海岛92种,主要种类为藻类。优势种主要有白条地藤壶（Chthamalus withersi）、厚壳贻贝（Mytilus coruscus）和褶牡蛎（Alectryonella plicatula）。该区域潮间带生物平均生物量4150.42g·m^-2,以软体类最高（占81.93%）。平均生物密度17642ind·m^-2,以甲壳类最高（占76.91%）。不同生境的生物量分布为外海〉内湾;不同潮区的生物量分布为低潮区〉中潮区〉高潮区;季节分布为秋季〉春季。     

吉尔伯特群岛海域延绳钓渔场大眼金枪鱼的环境偏好

为了掌握基里巴斯吉尔伯特群岛附近海域大眼金枪鱼的环境偏好,2009年9月至12月,金枪鱼延绳钓船"深联成719"在该海域进行了调查。利用仪器获取海洋环境数据,结合每天渔获数据,应用逐步回归方法,建立钓钩深度预测模型,计算大眼金枪鱼在各水层、温度、盐度、叶绿素、含氧量、水平海流和垂直海流范围内的渔获率,渔获率最大的各环境因子范围为大眼金枪鱼偏好的环境。结果表明:(1)大眼金枪鱼偏好的水层、水温、盐度、叶绿素、含氧量、水平海流和垂直海流范围分别为200.0~240.0 m、14.0~15.0℃、35.00~35.10、0.24~0.26μg/L、3.0~4.0 mg/L、0.00~0.20 m/s和0.03~0.04 m/s;(2)一般情况下,接近成熟的大眼金枪鱼偏好的水温为14.0~17.0℃;(3)大眼金枪鱼的适盐性较广;(4)溶解氧高于门限值(0.8 mg/L)时,大眼金枪鱼的分布由其它环境因子决定。