Indian cucumber germplasm and challenges ahead

Cucumbers (Cucumis sativus) are considered to be native to India. The germplasm of cultivated and wild relatives is shown to grow in very diverse agroecological conditions of the country. The north-eastern region is shown to nold special significance for wild and cultivated germplasm. The disease and specific adaptation characters are bionted out. Future scope for commercial growing and research needs are emphasised.     

New Eyes for Looking Back to the Past and Thinking of the Future

While environmental pollution and destruction of nature are expanding on a global scale, it is becoming ever more important to comprehend the influence of human activities on the global environment and to consider the future. How does acid pollution caused by human activities influence the environment? When and how has it progressed, what is the situation now and how is it likely to shift in the future? Humans are creatures destined to consume energy and resources in the biosphere. Although we know that drastic and disproportionate increases in the consumption of natural and non-renewable resources have greatly altered the biosphere, reliable data on the actual levels of pollution existing in the past are scarce or lacking. Many methods involving natural or artificial materials have been used for historical monitoring, but there is still a need for new ones, which will allow us to look at the past and think of the future. The newly proposed scientific use of tree bark pockets as pollution time capsules gives us "new eyes" for historical monitoring of atmospheric pollution and changes in the global environment.

     

Bird collisions with power lines: Failing to see the way ahead?

Visual fields were determined in three bird species representative of families known to be subject to high levels of mortality associated with power lines; kori bustards Ardeotis kori, Otididae, blue cranes Anthropoides paradisea, Gruidae and white storks Ciconia ciconia, Ciconiidae. In all species the frontal visual fields showed narrow and vertically long binocular fields typical of birds that take food items directly in the bill under visual guidance. However, these species differed markedly in the vertical extent of their binocular fields and in the extent of the blind areas which project above and below the binocular fields in the forward facing hemisphere. The importance of these blind areas is that when in flight, head movements in the vertical plane (pitching the head to look downwards) will render the bird blind in the direction of travel. Such movements may frequently occur when birds are scanning below them (for foraging or roost sites, or for conspecifics). In bustards and cranes pitch movements of only 25° and 35° respectively are sufficient to render the birds blind in the direction of travel; in storks head movements of 55° are necessary. That flying birds can render themselves blind in the direction of travel has not been previously recognised and has important implications for the effective mitigation of collisions with human artefacts including wind turbines and power lines. These findings have applicability to species outside of these families especially raptors (Accipitridae) which are known to have small binocular fields and large blind areas similar to those of bustards and cranes, and are also known to be vulnerable to power line collisions.     

Patterns of energy use and the critical choices ahead

Patterns of energy use in the U.S. by industry, commerce, residential and agriculture with comparisons of Northern and Central California energy use in the same sectors are presented. End-use applications are also covered.     

内蒙古地区2009/2010年冬季低温雪灾影响评估

在全球气候变暖的背景下,内蒙古自治区2009/2010年出现了近年来少有的冷冬,大部地区发生了不同程度的低温、冰雪等气象灾害。为了做好低温冰雪灾害的防御工作,本文应用数理统计方法对内蒙古自治区当年冬季的极端最低气温、寒潮发生次数和降雪情况等进行了时段统计,进而对2009/2010年冬季全区的低温雪灾及其影响进行分析研究。结果表明,低温冰雪灾情较常年偏重,由于灾害影响,全区冬季牧业生产及设施农业遭受了很大的损失,同时造成大范围路面积雪结冰,给道路交通运输带来不利,影响人们正常的生产和生活。     

Seeding and mulching + seeding effects on post‐fire runoff,soil erosion and species diversity in Galicia (NW Spain)

The effects of two different soil rehabilitation treatments on runoff, infiltration, erosion and species diversity were evaluated in a shrubland area in Galicia (NW Spain) after an experimental fire by means of rainfall simulations. The treatments compared were: seeding, seeding + mulching and control (untreated). Rainfall simulations were conducted 9 months after fire and the application of soil rehabilitation treatments. A rainfall rate of 67 mm h⁻¹ was applied for 30 min to each runoff plot. Seeding significantly increased plant species richness in the treated plots relative to the control plots, although it had no effect on diversity or evenness. Rehabilitation treatments did not significantly increase soil cover or affect runoff and infiltration. Soil losses were low in all cases, varying from 75·6 kg ha⁻¹ in the seeded + mulched plots to 212·1 kg ha⁻¹ in the untreated plots. However, there were no significant differences in sediment yields between treatments. The percentage of bare soil appeared to be a critical variable in controlling runoff and erosion. Copyright © 2010 John Wiley & Sons, Ltd.     

畜牧工程技术的跃进与反思

近十年来,集约化畜牧生产在中国的一些城市郊区有了很大发展,同时推动了畜牧工程技术的进展。这些工作表明,中国的畜牧工程技术人员已经具备了设计、建造畜牧工程与设备的能力。中国人多地少,资金与能源紧缺,发展以高投入、高能耗、精饲料型为特点的全封闭、高密度饲养方式显然不符合中国国情,而只能走适合自己的道路。在企业中任何工程措施的采用,所花代价必须由其在生产中的经济效益所补偿。在任何情况下衡量畜牧生产效益只能根据动物的生产性能,不能根据生产单位的机械化水平。在城市郊区不顾环境的承受能力,过分追求城市肉、蛋、奶自给,由于大量家畜粪尿得不到妥善处理,将构成严重的威胁。总之,中国畜牧工程的发展必须从中国国情出发,走农牧结合的道路。     

植物营养中理论问题的追本溯源

本文分析了近200年来,国际上植物营养研究特别是有关植物营养理论研究的发展过程,从早期对植物营养的研究开始,论述了腐殖质营养理论的形成与发展以及腐殖质营养理论的具体内容;论述了植物营养矿物质理论的发现过程及李比希否定腐殖质营养理论的理由与事实;介绍了李比希对矿质营养理论的论述与完善过程,分析了矿质营养理论早期的争议及争议的原因;评价了矿质营养理论对农业的贡献。本文还针对目前出现的有机营养理论及碳营养进行质疑,指出了小分子有机物质对植物生长发育的作用。     

1959-2009年秦岭山地气候变化趋势研究

以秦岭山地39个气象站点1959—2009年近50a来的气温、降水资料为基础,分析研究了秦岭南北坡半个世纪气温与降水的变化趋势及特征。结果表明:(1)近50a来研究区气温总体上呈增加趋势,北坡气温倾向率为0.24℃/10a,南坡为0.15℃/10a;20世纪80年代中期以后,年均温呈极显著的增加趋势,特别是北坡地区气温倾向率高达0.74℃/10a,1993年后秦岭地区气候暖化趋势显著。(2)近50a来除夏季季均气温呈微弱的减少趋势外,研究区春、秋、冬3季均温均呈极显著的上升趋势(p<0.01),尤以冬、春两季平均气温上升更为显著;但1983—2009年27a间秦岭夏季气温呈上升趋势。(3)在50a尺度内秦岭北坡年均降水量在增加,而南坡年均降水量在减少,导致南北降水量差值减少;但近15a来秦岭南北坡年均降水量均有所增加,且北坡降水量增加速度更快(230.4mm/10a),说明秦岭北坡地区气候有暖湿化趋势。     

植物根际促生菌(PGPR)的研究与应用前景

植物根际微生物主要以细菌为主,多样性高且活跃,分为有益菌（2 % ~ 5 %）、有害菌（8 % ~ 15 %）以及中性菌（80 % ~ 90 %）。从有益菌中筛选出的植物根际促生菌（Plant Growth Promoting Rhizobacteria,简称PGPR）具有促进植物生长、防治病害等功能,成为土壤科学领域的研究热点。本文目的是了解PGPR在国内外的研究现状,寻求高效、长效且安全的开发与利用方式对PGPR促生及生物防控功能具有重要意义。基于Web of Science核心合集数据库,采用CiteSpace、VOSviewer、HistCite等工具对PGPR研究领域的发文数量与学科分布、发文国家及机构间的合作关系、发文期刊、主要研究热点以及发展趋势等进行了计量分析。结果表明：① 印度、中国、美国、巴基斯坦、德国等国在该领域发文的引用频次较高,研究较为深入。②全球对PGPR研究的重视程度越来越高,主要集中于植物科学学科与微生物学学科。③ 发文主要期刊有Frontiers in Microbiology、Frontiers in Plant Science及Plant and Soil,关键文献中PGPR的促生、抗胁迫、污染修复等内容占据较高比例。④ 关键词聚类主要分为生物修复功能与措施、PGPR的促生及胁迫耐受性等、根际功能菌群的种类及系统抗性、根际菌群促生及生物防控功能等4类。生物防控是PGPR领域的一个研究热点,该领域未来研究趋势主要集中于PGPR及其它土著菌群与植物之间的互作关系以及PGPR高效应用的方式等。     

近55年来民勤绿洲胡杨林物候对气候变化的响应

利用民勤绿洲气象站1955—2009年日平均气温资料,采用气候倾向率、Mann-Kendall等方法,分析了胡杨年生长期开始日、终止日、生长期天数、展叶始日和叶黄始日的变化特征及其对气候的响应。结果表明:近55a来,民勤绿洲胡杨年生长期开始日有明显提早趋势,终止日有明显推后趋势,生长期天数有显著延长趋势,展叶始日有明显提早趋势,叶黄始日有显著推迟趋势。胡杨年生长期终止日、天数、叶黄始日与其对应月平均气温呈显著正相关关系,相关系数分别为0.580 5,0.610 7和0.489 9。而开始日、展叶始日与其对应月平均气温呈负相关关系,相关系数分别高达0.728 7和0.660 3。突变分析表明:年生长期开始日在1957年、2005年和2007年发生突变;年生长期终止日在1961年,1997年和1998年;生长期天数在1960年和2002年;展叶始日在1958年、1997年和2003年;叶黄始日在1962年、1987年和1988年。可见,胡杨对气候变化的响应敏感。     

水保生态环境建设使敖汉旗面貌焕然一新

敖汉旗水土流失面积6415km2,年均土壤侵蚀模数5000~8000t/km2,个别地方高达1.50万t/km2。至2004年底,全旗水土保持综合治理措施保存面积达3300km2,治理程度达51.4%,林草保存面积4249.5km2,森林覆盖率由治理前的10.5%提高到44%,生态环境和农牧业生产条件得到了极大改善;年粮食总产量稳定在5亿kg左右,比20世纪70年代年均总产量翻了两番,90%的农牧民实现了稳定脱贫;重点治理小流域年土壤侵蚀量减少80%,蓄水量提高85%,保水率提高到85.4%。介绍了水土保持生态环境建设的发展历程、取得的成效和具体的做法与经验。     

2000-2009年青海省植被覆盖时空变化特征

基于2000-2009年MODIS-NDVI植被覆盖指数,采用线性趋势分析、标准差等数理分析方法,对青海省"退耕还林还草"实施10 a来植被覆盖时空变化特征进行分析。结果表明:(1) 2000-2009年青海省植被覆盖呈明显增加趋势为0.018/10 a,远快于三北防护林工程区1982-2006年植被覆盖平均增速0.007/10 a; (2) 2000-2009年青海省植被恢复具有阶段性,"退耕还林还草"实施前6 a,植被覆盖呈现快速上升,2005年后呈波动下降趋势; (3)青海省植被恢复以轻微改善为主(32.66%),中度改善次之(13.32%),明显改善区主要分布在柴达木盆地东南边缘、青海湖盆地、茶卡-共和盆地、河湟谷地及黄南低地; (4)青海省植被呈退化趋势区域比重为18.40%,主要分布于青南高原三江源地区和祁连山中东段;(5)青海省2000-2009年植被稳定性存在明显地域差异。空间格局主要表现为"东南波动,西北稳定,高原温带波动,高原寒带、亚寒带稳定"。青海东部中低山地、丘陵、盆地地区变化幅度最为明显。     

Rethinking the ‘back to wilderness’ concept for Sundaland’s forests

Traditional biodiversity conservation approaches emphasize the protection of pristine forests. However, it has become increasingly difficult to secure large tracts of undisturbed forests, particularly in the developing tropics. This has led some conservation scientists and organizations to explore the conservation potential of human-modified habitats, such as selectively logged forests. On the other hand, other scientists have highlighted the perils of overselling the conservation value of degraded habitats and advocate for re-focusing of efforts and resources on protecting primary forests. While there are merits to both contentions, we argue that the “back to wilderness” paradigm has limited relevance in the Sundaland region. This is because: (1) primary forest only makes up a small minority of the remaining forest in the region and most of it is already protected by law; (2) vast areas of selectively logged forest are still susceptible to plantation conversion; and (3) selectively logged forest are important habitats for some of the world’s most endangered species. To meet both conservation and development goals, we suggest that tracts of selectively logged forest be assessed for their ecological value and forests of high conservation value be prioritized for better protection through their inclusion into existing protected area networks and/or improved sustainable forestry management.     

Rostislav Sergeevich Il’in: A soil scientist and geologist ahead of his time

The most important aspects of the research of Il’in that turned out to be ahead of his time are analyzed. These aspects are as follows: the relationships and simultaneous development of surface rocks, relief elements, and soils; the integrity of the development and hierarchical spatial-temporal variability of landscapes; the continuous displacement of natural zones (evolutionary and revolutionary, when moving to the equator and poles, respectively); the succession of climatic phases of the geological cycle—from the interglacial xerothermic phase to the glacial cold and humid one separated by transitional phases with a temperate climate; and the complex subaerial-stream theory of the origin of loess.     

1981-2009年江苏省气候变化趋势及其对水稻产量的影响

利用江苏省1981-2009年7个农业气象站点的气象和水稻物候、产量资料,从平均气温和降水量对水稻产量影响的基本方程入手,定义了平均气温和降水量变化趋势对水稻产量趋势的贡献率,揭示江苏省近30a气候变化趋势对水稻产量的影响.结果表明,近30a来,江苏省水稻全生育期平均气温和最低气温呈上升趋势,最高气温的变化在苏南和苏北地区差异较大,尤其在开花-成熟阶段,苏南地区呈上升趋势,而苏北地区则呈相反变化趋势.气温(包括平均气温、最低气温和最高气温)与水稻产量呈正相关,1981-2009年平均气温升高对江苏省水稻产量影响的平均值约为1.2％,对产量趋势的贡献率约为30.0％.降水量的变化趋势不明显,降水量与水稻产量的相关性亦不显著,说明在研究区内降水量的变化对水稻产量的影响较小.总体上,江苏省近30a气候变化有利于水稻生产.     

西藏曲水-桑日地区1988-2009年土地利用景观格局演变研究

土地利用景观格局反映环境特征及社会经济发展模式,可为资源开发和环境保护提供参考。应用1988年、2000年和2009年遥感数据,通过遥感信息提取、景观格局指标和转移矩阵计算,研究西藏曲水—桑日地区土地利用时空演变特征。结果表明:1988—2009年,研究区土地利用时空演变显著,各地类均发生转移,转移面积约占总面积的6%,灌木林、滩地、沙地和草地变化较大;耕地和沙地面积先增后降,建筑用地和工矿用地持续增长,高山湖泊面积总体减少;平均斑块面积增加,斑块密度减小,蔓延度先增后减,边缘密度、总边界长度和散布与并列指数先减后增;地类破碎度增加,有林地、建筑用地和工矿用地边缘密度增加;耕地、滩地、沙地和有林地平均斑块面积先增后减;滩地和湖泊散布与并列指数减小,工矿用地增大。该结果对土地资源保护具有重要意义。     

黑河流域1960-2009年平均风速时空变化特征

利用黑河流域气象站点1960-2009年的逐月、逐年的风速观测资料,运用Mann-Kendall检验法和反距离加权插值法(IDW)及相关分析法对黑河流域平均风速时空变化特征进行了分析。结果表明,近50a来黑河流域年平均风速呈减小趋势,其变化趋势指标β值为-0.01;春、夏、秋、冬季平均风速均表现为下降趋势,β值分别为-0.012,-0.011,-0.007和-0.008。年代际变化在60-70年代为正距平,80年代以后为负距平。年内变化表现为偏双峰型,第1峰值远大于第2峰值,分别出现在4月和11月。空间变化上,上游山区年平均风速呈上升趋势,平均每年增加0.01m/s;中游和下游均表现为下降趋势,降幅在0.005~0.029m/s,同时在不同季节空间差异明显。年平均风速突变发生在1985年左右,春、夏、秋、冬季突变分别出现在1986,1984,1983和1985年。年、春季风速下降与平均气温、平均最低/最高气温以及潜在蒸散有关,夏、秋季平均最高气温的影响变小,而冬季仅有潜在蒸散通过了0.01的显著性检验,说明风速下降是造成黑河流域冬季潜在蒸散量减小的主要因素。