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1.
豆天蛾的滞育虫态是老熟幼虫,通过滞育可使其生长发育与适宜季节环境实现同步,进而抵御不利环境条件,保证个体存活和种群延续。通过总结其他昆虫的滞育研究进展,了解豆天蛾滞育过程,深入探讨豆天蛾滞育研究的必要性及滞育机制,以期能实现豆天蛾滞育诱导及滞育解除的人工干预,增加豆天蛾幼虫人工养殖代数,提高养殖效益,进而推动工厂化养殖及产业化发展。  相似文献   

2.
[目的]分析胡杨生长期内各环境因子对树干液流速率的影响程度,为干旱区自然植被耗水量的计算提供了新的方法和科学依据。[方法]对塔里木河下游2012单木胡杨整个生长季内树干液流以及空气温度、风速、有效光合辐射强度、空气湿度、土壤温湿度等环境因子进行连续观测。[结果]胡杨在整个生长季内的液流呈单峰波动曲线,有明显的昼夜变化规律;在生长期内,不同的观测尺度下,影响胡杨液流速率的环境因子不同。回归分析结果表明,对于瞬时液流流速,相关性较大的环境因子主要是大气温度、10cm深处的土壤温度;对于日液流量,主要影响因子为太阳净辐射;对于月液流量,主要影响因子为大气温度和太阳净辐射。[结论]研究区内胡杨生长受大气温度和太阳净辐射影响程度较其他因素大,并且回归方程具有很高的拟合精度。  相似文献   

3.
研究温度、光照周期以及盐度对刚毛藻生长的影响,以确定其最适应的生长环境。在实验室智能光照培养箱的培养环境下,用单因子实验研究不同温度、不同光照周期以及不同盐度对刚毛藻生长的影响。结果表明:刚毛藻最适温度条件为19.9~24.9℃,在温度为14.9℃和29.9℃时,刚毛藻生长速度较为缓慢,但依旧可以正常生长。当温度达到4.9℃时,刚毛藻出现负生长现象;刚毛藻在没有光照的条件下无法生存,但是当有光照的情况下,即使从来都没有接触到黑暗的环境,它都可以自然生长,当光照周期为12L∶12D时,其生长速度最快;而盐度对刚毛藻生长速度的影响虽然很显著,但刚毛藻对盐度的适应范围极其广泛,其在盐度为10‰~45‰的条件下均可以正常生长。  相似文献   

4.
环境因素对大棚温室无土草坪生产的影响研究   总被引:3,自引:0,他引:3  
以冷季型划种高羊茅(Festuca elata Keng)为材料,研究光、湿度、基质肥水条件以及植物生长素对大棚湿度草坪生产的影响结果表明,温度宜控制在15-25℃,且昼夜应保持一定温差;湿度宜在40%-60%间,为促进根系生长应控制在50%-60%间;光照应保持在1.5万lx以上;适当施肥补充养分和运用植物生长素可作为环境微调措施,有利于提高草坪质量和快速成卷。  相似文献   

5.
为对江淮地区现代化温室内梅雨季节的小气候进行模拟与分析,在建立相应的BP神经网络模拟模型的基础上,进一步研究了外部温度、湿度、风速、太阳总辐射和天窗开度5个因素对温室内温度、湿度、风速的影响。研究发现可以使用BP神经网络对梅雨季节的小气候进行模拟,模型具有较高的精度,是对物理模型的有益补充;梅雨季节室内湿度受室外湿度的强烈影响,在5个输入因素中所占比重为51.7%;室内风速主要受室外风速和天窗开度的共同影响,受室外温度的影响较小,所占比重仅为10%;室内温度主要受室外温度和太阳辐射的影响,二者所占比重分别为46.2%和27.9%。  相似文献   

6.
弱光条件下光质和光周期对水培生菜生长与品质的影响   总被引:1,自引:0,他引:1  
在弱光条件的人工光植物生长室中,设置两种不同红蓝光比例光质和两种不同光周期,水培盆栽红叶生菜(R)、绿叶生菜(G)和紫叶生菜(P),采收后测定3种生菜的生物量指标以及抗氧化物、可溶性糖等营养品质指标,以研究弱光条件下光质和光周期对3种叶色水培生菜产量和品质的影响。结果表明:(1)生菜产量主要受光周期影响,营养品质指标受光质和光周期的综合影响。光照时间延长显著增加了3种生菜叶面积。绿叶生菜和红叶生菜单位叶面积鲜重在不同光质及光周期下无显著差异。紫叶生菜单位叶面积鲜重对光周期变化的反应则因光质环境而异。延长光周期使3种叶色生菜地上部鲜重提高一倍多,但3种生菜地上部鲜重受光质影响不显著。(2)延长光照时长对3种生菜营养品质的影响因光质而异。在红蓝1:2光质下,延长光照时长降低了绿叶生菜总酚和类黄酮相对含量以及抗坏血酸和可溶性蛋白含量,提高了红叶生菜花青素和可溶性糖含量,但降低了抗坏血酸和可溶性蛋白含量,紫叶生菜总酚相对含量得到提高,但抗坏血酸含量显著降低。在红蓝2:1光质下,延长光照时长显著提高了绿叶生菜总酚和类黄酮相对含量,抗坏血酸含量有所降低,红叶生菜总酚和类黄酮相对含量、抗坏血酸、可溶性糖和可溶性蛋白含量均显著降低,紫叶生菜总酚含量显著提高。说明在弱光条件下延长光照时长可以显著提高3种不同叶色生菜产量。在红蓝1:2光质下,延长光照时长使红叶生菜的花青素含量和可溶性糖含量得到显著提高。在红蓝2:1光质下,延长光照时长可以提高绿叶生菜和紫叶生菜营养品质。  相似文献   

7.
小气候环境对于茶树的种植以及茶叶品质的影响不容忽视。基于此,以浙江省玉环市的火山茶种植园为例,分析当地温度、降水、大气湿度和日照天数等指标,探讨海岛火山小气候环境对茶叶种植生产的影响。  相似文献   

8.
温度、湿度和光照因素是蓝莓新梢温室扦插育苗的主要影响因素。蓝莓新梢温室扦插育苗环境因子调控对蓝莓育苗成活率和新苗质量的提升有着积极的促进作用。基于此,对蓝莓新梢温室扦插育苗环境因子调控问题进行了分析。  相似文献   

9.
设施蔬菜作物的生长发育与温室环境因子密不可分,生长发育进程明显受到温度的影响,而病害发生又与高湿度有着密切的联系。本文系统分析了日光温室内的光照、温度、湿度以及气体环境等特点,结合大棚的室内外环境特点,研究分析日光温室环境调控的关键技术。从加温、降湿、增加光照强度和补充二氧化碳等几个方面详细的阐述了进行温室环境调控,实现设施作物栽培的优质、高效生产,为日光温室的实际生产提供数据支持和技术依据。  相似文献   

10.
对永川区1950—2002年逐年森林虫害发生面积的周期分析表明,渝西地区森林虫害大发生存在5~7a周期,80年代呈准2a周期高位震荡;通过对森林虫害与气象要素的数理统计分析得出,春季、盛夏期间温度、湿度及初夏强降水是影响渝西地区森林虫害的主要气象要素。在相关分析的基础上,利用人工神经网络方法建立了当地森林虫害面积的气象预测模型,1985—2002年的模拟预报的平均误差为4.85%,回代检验效果较好。  相似文献   

11.
本文分析了化学药物对杀虫除草的作用及其对生物与人类造成的危害以及污染大气、水体、土壤和景观所带来的恶果,指出应当积极广泛地开展生物防治,利用害虫天敌、昆虫性引诱剂、雄性绝育等生态学方法有效地控制害虫与野草。同时修订现行的环境管理制度,严格管理食品和药物。  相似文献   

12.
Some phytophagous insects are rare because their host plants are rare. This study uses data on the distribution of plants and insects from Great Britain to establish whether a threshold exists for the geographical range of a host plant below which its specific insects can be consistently described as rare. Data on four well-studied insect taxa (macro-moths, gelechiid micro-moths, beetles, and tephritid flies) that have been afforded conservation status as Red Data Book (RDB) or scarce (nationally Notable-A and -B) are examined. The proportion of species that are rare in these taxa declines as host plant range increases. Extrapolating these patterns of host range/phytophagous insect rarity to less studied groups (aphids, agromyzid flies and tortricid micro-moths) identifies a large number of insects that are probable candidates for conservation. Empirical evidence supports the view that many of the species selected by this process are indeed rare and in need of conservation. Identifying a host plant range below which insect herbivores are therefore rare provides an economical and objective method for producing a shortlist of phytophagous insect species rare enough to warrant conservation measures.  相似文献   

13.
基于改进深度置信网络的大棚冬枣病虫害预测模型   总被引:3,自引:2,他引:1  
导致冬枣病虫害发生的原因很多而且很复杂,利用传统的数学方法和神经网络(neural network,NN)很难建立正确的病虫害预测模型.由于典型的深度置信网络(deep belief network,DBN)的各层之间缺乏有监督训练,使得网络误差逐层向上传递,降低了预测模型的预测率.针对这些问题,引入冬枣病虫害的先验信息,提出一种基于环境信息和改进DBN的冬枣病虫害预测模型.在该模型中,通过无监督训练和有监督微调从冬枣生长的环境信息序列中获取可表征冬枣病虫害发生的深层特征的隐层参数,并形成新的特征集,然后在预测模型的顶层通过一个后向传播神经网络(back propagation neural network,BPNN)进行病虫害预测.从2014—2017年的4 a时间内,利用农业物联网传感器采集30个大棚冬枣常见的2种虫害和3种病害发生的环境信息序列6000多条,由此验证所提出的预测模型,平均预测正确率高达84.05%.与基于强模糊支持向量机、改进型NN和BPNN的3种病虫害预测模型进行了试验比较,预测正确率提高了20多个百分点.试验结果表明,该模型极大提高了大棚冬枣病虫害的预测正确率.该研究可为大棚冬枣病虫害预测提供技术参考.  相似文献   

14.
Insect populations have a substantial impact on Canada's forest. They are a dominating disturbance factor and during outbreaks they can cause tree mortality over vast areas of forest. If the predicted climate changes take effect, the damage patterns caused by insects may be drastically altered, especially for the many insects whose occurrence in time and space is severely limited by climatic factors. This possibility substantially increases the uncertainties associated with the long-term planning of pest control requirements, with hazard rating models, with depletion forecasts, and with projections for the sustainability of future timber supplies. Moreover, because insect damage affects the rates of various processes in nutrient and biogeochemical cycling, potential changes in damage patterns can affect ecosystem resilience. This paper presents a number of plausible scenarios that describe how some key processes in the boreal forest's insect defoliator outbreak systems may respond to climate change. The spruce budworm,Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), is used as an illustrative case study throughout. The potential importance of phonological synchrony in the dynamical interactions between species is emphasised. It is argued that natural selection may be a particularly important process in the response of insects to climate change and that climate change may already be influencing some insect lifecycles. The importance of threshold effects, rare but extreme events, and transient dynamics is emphasised, and the inadequacy of ‘equilibrium’ models for forest:pest systems noted. We conclude by discussing approaches to developing forecasts of how one of the boreal forest's insect defoliator-based disturbance regimes, as a whole, might respond to climate change.  相似文献   

15.
电子流注入水稻幼穗组织培养效应的研究   总被引:2,自引:0,他引:2  
以两用核不育系新光S幼穗为材料,以γ射线辐照作对照,研究了电子流注入对水稻离体培养的反应。结果表明,电子流注入对离体培养的效应与γ射线辐照具有相似性。对愈伤组织的诱导、分化主要表现为抑制效应,但对植株再生具有促进作用。10~15秒电子流注入可使幼穗的出愈率和分化率保持对照水平或略低,而再生能力大幅度提高。  相似文献   

16.
Forest management in temperate and boreal regions is often based on a strong foundation of applied ecological research. Increasingly, this has allowed the needs of saproxylic (dead wood associated) insects to be addressed. However, there has been very little equivalent research in tropical forests, where saproxylic insect faunas are likely to be much richer and where forestry is usually subject to weaker environmental controls. This study compares the saproxylic beetle fauna of old-growth, selectively logged and regrowth rainforest in the Daintree lowlands of northeastern Queensland, Australia. Old-growth levels of abundance, species richness, assemblage composition and guild structure were not maintained in logged and regrowth forest, suggesting that intact assemblages may not survive in the long-term in managed tropical rainforest. However, retaining a continuous supply of commercially overmature trees in the managed stand may prevent a repeat of the widespread extinctions of saproxylic insects witnessed in temperate and boreal forest regions.  相似文献   

17.
基于2011-2013年超级稻岳优6135分期播种田间试验数据,利用抽穗普期-成熟期每5d一次的千粒重动态观测资料并计算相应的灌浆速率,与同时段逐日气温和日照时数进行数理统计分析,建立基于不同温度要素、日照时数及温光组合的灌浆速率和千粒重的模拟模型,探究该水稻品种灌浆特性与各气象因子间的关联以及达到最优灌浆效果的气象条件。结果表明:灌浆速率、千粒重与各温度要素及日照时数间均呈一元二次函数关系,与各温光组合间呈二元二次函数关系。灌浆特性与各温度要素间的相关性优于其与日照时数间的相关性,不同温度要素及温光组合与千粒重的相关性优于与灌浆速率的相关性;日最低气温累积值与日照时数的组合是影响超级稻岳优6135灌浆特性的最重要温光因子。灌浆期积温达900℃·d,日照时数接近300h时,千粒重达到最大,灌浆过程趋于完成,籽粒趋于饱满,籽粒充实度最理想。  相似文献   

18.
To conserve the foraging habitat of Daubenton’s bat (Myotis daubentonii) in a large lowland river, we investigated the influence on this bat of prey variables (number or biomass) and insect origin (aquatic or terrestrial). We tested the hypothesis that river restoration (re-meandering) conducted in the Shibetsu River, northern Japan, enhances foraging habitat quality by increasing the abundance of aquatic insects. From June to September 2004, flying insects were collected using Malaise traps in restored and channelised reaches in the Shibetsu River. Bat activity was recorded by bat detectors placed near the Malaise traps in each of the two reaches. Foraging activity of Daubenton’s bat was more strongly related to the number of insects than to biomass, and to adult aquatic insects than to terrestrial insects. The high dependence of Daubenton’s bat on aquatic prey was attributed to the fact that aquatic insect numbers were always higher than those of terrestrial insects. Contrary to the hypothesis, Daubenton’s bat was more active in the channelised reach than the restored reach in all months except June, and it synchronized its foraging activity with the seasonal distribution of adult aquatic insects. However, the study was undertaken just two years after restoration and the riparian vegetation had not yet established itself. Our results demonstrate the importance of aquatic insect abundance for Daubenton’s bat throughout the seasons in large lowland rivers. A further decrease in aquatic insects, associated with progressive anthropogenic alteration of river environments, undoubtedly exerts a harmful influence on the conservation of this species.  相似文献   

19.
The decline of flower-visiting insects is a threat to ecological processes and to the services these insects provide. Roadside verges in the Netherlands span approximately 80,000 km and are often covered with semi-natural grasslands. As such, they also provide a suitable habitat for many insects, but this has received little attention so far. We investigated the effects of different management treatments on flower-visiting insects. We studied flower visitation in a 3 years old experimental set-up with five mowing treatments each replicated five times. Management types were: no management and mowing once or twice per year with and without the removal of hay, representing common forms of management and neglect. During an entire growing season, both flowers (number of species and inflorescences) as well as insects (total abundance and actual flower visits) were investigated. Mowing twice per year with removal of hay showed highest values for all measured variables and this effect persisted throughout the growing season. The early summer cut proved to be very important for insect feeding opportunities, due to the re-flowering of plants later in the growing season. Flower abundance showed high correlations with both plant species richness and the number of insect visits. Although overall, mowing twice a year with hay removal was the most beneficial treatment for flower-visiting insects, these plots were entirely devoid of flowers for some period right after mowing, indicating that a rotational scheme might further promote insect diversity and abundance.  相似文献   

20.
储粮害虫检测新技术及应用现状   总被引:4,自引:2,他引:4  
储粮害虫的检测是粮食储藏部门的研究热点。害虫种类的正确识别是粮食管理人员进行害虫综合防治的必要依据。文章扼要评述了几种储粮害虫检测的新方法:声测法、近红外光谱法、X射线法、电导法、微波雷达检测法、图像识别法和电子鼻法,并展望了未来的发展趋势,为更好地进行储粮害虫检测提供了新思路。  相似文献   

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