日喀则的灯诱昆虫

<正> 日喀则处于北纬29°13′,东经88°55′,其海拔3,836米,高寒干燥,植被贫乏,年平均气温6.4℃,年降水量434毫米。农作物主要有青稞、小麦、豌豆、油菜等。为了探明本地发生的昆虫种类,特别是农业昆虫的发生情况,为预测预报和灯光治虫工作积累资料,我们从1976年开始,在日喀则地区农科所大田内设20瓦交     

南岭兽类考察报告(湖南部分)

1980年1月至1981年9月,我们在湖南省南岭山地进行了兽类调查,现将调查结果报道如下。 一、南岭山地自然概况 南岭位于湖南省最南部,东经110°—114°10′,北纬24°10′,介于湘、赣、粤、桂四     

资源介绍——西双版纳丰富的野生果树资源

西双版纳位于我国云南省南部,北纬21°10＇～22°0′,东经99°55′～101°50′,土地面积19,220平方公里,属于热带季风气候。年平均温度20～22℃,年降雨量1200～1800mm,年平均空气相对湿度70～80％左右。由于境内山脉众多,形成了各种类型的小气候,使许多不同类型的植物得以很好地生长,野生果树资源丰富多采。     

建立生态经济型橡胶园橡胶咖啡间作模式

一、云南植胶区的自然地理条件云南橡胶种植区位于云南高原南部,北纬20°09′—24°59′,东经93°31′—105°08′,海拔100—1000m之间的热带季风地区。包括文山、红河、思茅、西双版纳、临沧和德宏地区     

“蓝田人”年代的古地磁学研究

世界闻名的“蓝田人”的时代,过去根据地层、古生物、地貌以及化石本身形态特征,一般估计为前五十万年左右。 1976年我们用古地磁方法对含“蓝田人”化石地层的年代进行了研究。研究结果:陈家窝猿人下颌骨化石的年代为前65万年左右。公王岭猿人头盖骨化石的年代在前75—80万年之间。正极性期的极位置在北纬76°24′,东经39°42′。信任角a为7°36′。负极性相的极位置在北纬84°18′,西经49°30′。信任角a为14°。     

广西隆林隆或地区早石炭世皱纹珊瑚

广西隆林各族自治县隆或镇位于东经105°3′-105°50′,北纬25°20′-25°40′,地处云贵高原东缘,平均海拔在1000m以上,交通不便,解放前属地质工作的空白地区。1970-1972年广西区测队第五分队对本区进行了1/20万区域地质测量工作,为本区的区域地质工作奠定了基础(插图1)。本区大地构造单元属于右江褶皱带红水河     

绵阳地区肺吸虫第二中间宿主——淡水蟹类感染情况的调查

为了探索绵阳地区肺吸虫自然疫源地与人群感染的关系,自1981年起,我们先后对青川、平武、广元、江油、剑阁、梓潼、北川、安县等山丘地区10个县进行了调查,现将结果报告如下。 一、一般情况 绵阳地区位于四川盆地西北边缘,东经104°45′—107°45′,北纬30°20′—33°05′,由龙门山脉、大巴山脉构成北高南低垂直梯度较大     

江苏省沿海水鸟资源

江苏省沿海地区位于东径119°27′—120°56′,北纬31°33′—35°07′,地处北亚热带向暖温带过渡地区,面积为3.5万km~2,两端为丘陵山地,中部为广阔的滩涂沼泽,长年受海洋性气候的影响,年平均温度14.1℃,冬季月平均温度在0℃以上,年均相对湿度达80％以上,气候     

贵阳市蔬菜地生态特点的初步分析

一、基本概况贵阳位于黔中,地处东经106°27′—107°03′,北纬26°11′—26°55′,为长江水系和珠江水系之分水岭。面积2,436平方公里,平均海拔1071.2米。城区为山间坝子(盆地),四面环山,郊区厲丘陵地带。虽处亚热带,又具明显山地特点,气候温暖湿润。年均温15.3℃,年中最高极值和最低极值分别为33—34℃和-4——5℃,无霜期260—280天,年     

湖南省桃源县发现华南虎踪迹

近几年来,有关华南虎(Panthera tigris amoyensis)的报道非常少见,有人断言,华南虎已经灭绝。可是,最近我们在湖南省桃源县发现了一处新的华南虎活动地。 乌云界位于桃源县的南端,南邻安化,东接常德,北壤杨桥和桃花源,西靠茶安铺。地处东经111°06′～111°20′,北纬28°29′～28°40′,包括沙坪镇、牯牛山乡和茶庵铺镇的西溪村。     

北方农牧交错区农业生态系统生产力对气候波动的响应——以准格尔旗为例

气候变化对区域生态系统结构和功能有重大影响。以中国北方农牧交错区的准格尔旗为例,利用气象和《统计年鉴》数据,采用数理统计方法分析准格尔旗1961—2009年降水量、平均气温的波动特征,计算出该地区1961—2009年农业生态系统NPP值和主要农作物的气候产量,论述了准格尔旗农业生态系统生产力对气候波动的响应。结果表明:(1)降水量和平均气温的年际、年内波动均显著。(2)准格尔旗农业生态系统生产力呈现阶段性地波动上升趋势。排除社会、科技等影响,气候生产力对气候波动表现出较强的敏感性,是作物气候生态适应的结果。(3)中国北方雨养旱作区,粮食气候产量受降水量年际波动(特别是7、8月)显著影响;谷子、糜黍、玉米、薯类、大豆和油料等农作物的气候产量与降水量年际波动呈显著正相关;谷子、糜黍的气候产量与生长季降水量年内波动呈显著负相关。集水型生态农业是北方农牧交错区生态环境友好的农业发展模式。(4)谷子、糜黍、薯类、大豆和油料等农作物的气候产量与6、7、8月平均气温年际波动呈显著负相关;生长季平均气温年内波动对谷子、糜黍、大豆和油料等农作物的气候产量有显著负面影响。因此,需要综合采取工程、生物和农业措施,将气候变化对主要农作物气候产量的不利影响降到最低。     

Mind the gap: how do climate and agricultural management explain the ‘yield gap’ of croplands around the world?

Aim As the demands for food, feed and fuel increase in coming decades, society will be pressed to increase agricultural production – whether by increasing yields on already cultivated lands or by cultivating currently natural areas – or to change current crop consumption patterns. In this analysis, we consider where yields might be increased on existing croplands, and how crop yields are constrained by biophysical (e.g. climate) versus management factors. Location This study was conducted at the global scale. Methods Using spatial datasets, we compare yield patterns for the 18 most dominant crops within regions of similar climate. We use this comparison to evaluate the potential yield obtainable for each crop in different climates around the world. We then compare the actual yields currently being achieved for each crop with their ‘climatic potential yield’ to estimate the ‘yield gap’. Results We present spatial datasets of both the climatic potential yields and yield gap patterns for 18 crops around the year 2000. These datasets depict the regions of the world that meet their climatic potential, and highlight places where yields might potentially be raised. Most often, low yield gaps are concentrated in developed countries or in regions with relatively high‐input agriculture. Main conclusions While biophysical factors like climate are key drivers of global crop yield patterns, controlling for them demonstrates that there are still considerable ranges in yields attributable to other factors, like land management practices. With conventional practices, bringing crop yields up to their climatic potential would probably require more chemical, nutrient and water inputs. These intensive land management practices can adversely affect ecosystem goods and services, and in turn human welfare. Until society develops more sustainable high‐yielding cropping practices, the trade‐offs between increased crop productivity and social and ecological factors need to be made explicit when future food scenarios are formulated.     

Simulating evolutionary responses of an introgressed insect resistance trait for ecological effect assessment of transgene flow: a model for supporting informed decision‐making in environmental risk assessment

Predicting outcomes of transgene flow from arable crops requires a system perspective that considers ecological and evolutionary processes within a landscape context. In Europe, the arable weed Raphanus raphanistrum is a potential hybridization partner of oilseed rape, and the two species are ecologically linked through the common herbivores Meligethes spp. Observations in Switzerland show that high densities of Meligethes beetles maintained by oilseed rape crops can lead to considerable damage on R. raphanistrum. We asked how increased insect resistance in R. raphanistrum – as might be acquired through introgression from transgenic oilseed rape – would affect seed production under natural herbivore pressure. In simulation experiments, plants protected against Meligethes beetles produced about twice as many seeds as unprotected plants. All stages in the development of reproductive structures from buds to pods were negatively affected by the herbivore, with the transition from buds to flowers being the most vulnerable. We conclude that resistance to Meligethes beetles could confer a considerable selective advantage upon R. raphanistrum in regions where oilseed rape is widely grown.     

Crop management affects pollinator attractiveness and visitation in oilseed rape

Ecological intensification of agriculture implies managing ecological processes to improve performance of agricultural systems. However, impacts on relevant ecological functions such as insect pollination from other crop management factors are poorly explored. Pest insects and crop resources such as water availability can directly affect crop yields, but it is unknown if there are indirect effects through effects on insect pollination. With a factorial experiment, we examined how irrigation and control of pollen beetles affected crop attractiveness and pollinator visitation in an open-pollinated spring oilseed rape cultivar. We studied how irrigation and pest control modified the production of flowers and nectar in oilseed rape, and if this in turn affected the flower-visitation of honey bees and bumble bees. Pest control increased the number of oilseed rape flowers by 69%, and the amount of nectar per flower with 36%, but for the latter only in non-irrigated plots. Furthermore, we found higher pollinator densities in plots with reduced pollen beetle densities. Pest control also reduced the number of non-legitimate flower visits, suggesting higher pollination efficiency in plots with reduced pollen beetle densities. We show that crop management affects the value of mass-flowering crops as a resource for pollinating insects. Development of pest control tools that are harmless to pollinators could increase the value of flowering crops as food resources for pollinating insects.     

Correlation Analysis between Productivity of Chinese Pine Pinus tabulaeformis (Carr.) Plantations and Ecological Factors in Shaanxi Province

This paper centers on the relationships between productivity of Chinese pine stands and ecological factors. The effects of geographictopographic factors, climatic factors, stand factors, soil factors, and combination of these factors are analysed. The whole 84 step-by-step and multiple regression equations are obtained. There are 6 best equations selected for future use. The standard regression coefficients of environmental factors in each equation are calculated. According to their effects on the production of tree components the important sequence is put in order. At last, the practical utilization of study on the relationships between productivity and ecological factors is explored.     

黑河中游主要农作物灌溉制度优化

科学的灌溉制度是干旱半干旱地区农业生产的重要保障。黑河位于西北干旱区,是我国第二大内陆河,且当地中游农业灌溉和下游生态需水矛盾十分突出。利用DSSAT （Decision Support for Agro-technology Transfer）模型模拟了黑河中游地区玉米、小麦、油菜、马铃薯的生长情况,对比分析了四种作物生育期内需水量变化与当地降水条件、现行灌溉制度之间的差异。通过设置灌溉组合探究了四种作物最适宜的灌溉制度,并计算了优化灌溉制度下的节水潜力。结果表明：DSSAT模型通过参数校正与验证后,对四种作物生长过程模拟性能较好,产量标准化均方根误差（nRMSE）均低于15.0%,决定系数（R²）均达到0.65以上。缺水量模拟结果表明,四种作物生长季平均水分亏缺介于122.5-367.0 mm。通过调整灌溉制度,可使玉米、小麦、油菜、马铃薯的水分利用效率分别提高54.8%、25.0%、18.3%和51.3%,且产量变幅均低于5.0%,实现了高产节水的目的。在研究区实施最优灌溉制度,中游农业灌区每年可以节省8.1×10⁸ m³的水资源量,用于支持下游生态保护。     

陕西省油松人工林的生产力与生态因素的相关分析

本文研究了油松林分生产力和生态因素的关系,分析了地理、地形,气候、林分和土壤因素单独及综合对林分生产的影响,得到84个逐步回归方程和全回归方程,选出了6个最优方程。计算了各林分外部因素的标准回归系数,找出了影响林分不同部分生产量的因素重要性序列,还探讨了生产力与生态因素相关关系的研究在实践中的应用。     

Comparison of climate change impacts on the growth of C3 and C4 crops in China

Global agricultural production has been significantly affected by climate change. As a large but also weak agricultural country, China must take corresponding adaptation measures in regard to climate change. As C3 and C4 crops have different carbon sequestration pathways, the responses of their growth to climate change are different. This study comprehensively compared the impacts of climate change on the growth of C3 and C4 crops in China by considering several key variables, such as solar radiation, temperature, precipitation, CO₂ concentration, and agro–climatic constraints. The WOFOST (WOrld FOod STudies) model was used to quantitatively simulate and analyze the impacts of these variables on crop yield under four different scenarios. The results show that 1) during the growth period, solar radiation had the most significant change, followed by temperature difference between day and night, daily minimum temperature, daily maximum temperature, and precipitation; 2) the growth indicators of both C3 and C4 crops were more strongly correlated with solar radiation and temperature; and 3) under the four scenarios, changes in temperature and solar radiation had negative effects on both C3 and C4 crops in most regions, and changes in CO₂ concentration had greater impacts on crop yields than other factors. This study revealed the temporal and spatial patterns of crop growth indicators under different climate change scenarios in the past 30 years, which provides a scientific basis for exploring how to adapt to climate change and provide higher levels of crop productivity in China.     

Next generation of elevated [CO2] experiments with crops: a critical investment for feeding the future world

A rising global population and demand for protein-rich diets are increasing pressure to maximize agricultural productivity. Rising atmospheric [CO₂] is altering global temperature and precipitation patterns, which challenges agricultural productivity. While rising [CO₂] provides a unique opportunity to increase the productivity of C₃ crops, average yield stimulation observed to date is well below potential gains. Thus, there is room for improving productivity. However, only a fraction of available germplasm of crops has been tested for CO₂ responsiveness. Yield is a complex phenotypic trait determined by the interactions of a genotype with the environment. Selection of promising genotypes and characterization of response mechanisms will only be effective if crop improvement and systems biology approaches are closely linked to production environments, that is, on the farm within major growing regions. Free air CO₂ enrichment (FACE) experiments can provide the platform upon which to conduct genetic screening and elucidate the inheritance and mechanisms that underlie genotypic differences in productivity under elevated [CO₂]. We propose a new generation of large-scale, low-cost per unit area FACE experiments to identify the most CO₂-responsive genotypes and provide starting lines for future breeding programmes. This is necessary if we are to realize the potential for yield gains in the future.     

生态分区的原则、方法与应用—内蒙古自治区生态分区图说明

 区域分异原则是生态学中的重要原理之一。任何陆地生态系统都具严格的区域特点,因此对土地资源的利用必须因地制宜。而生态分区就是正确认识草地资源区域特征的重要手段。本文以内蒙古自治区生态分区图说明为例,提出3个分区等级(生态区、生态亚区和生态小区)及其概念,并结合分区对内蒙古土地资源的管理和利用提出建议,以建立稳定的粮油糖生产基地。