白蜡吉丁啮小蜂蛹期发育起点温度和有效积温的研究

白蜡吉丁啮小蜂是蛀干害虫白蜡窄吉丁的重要寄生性天敌,寄生于寄主幼虫的体内,为人工聚殖和应用于生物防治,在7个温度梯度下观测了白蜡吉丁啮小蜂蛹的发育速率,并应用“最小二乘法”测得该小蜂蛹期的发育起点温度为（16．823±1．381）℃,有效积温为（78．851±0．442）日度。     

Environmental key factors and their thresholds for the avifauna of temperate montane forests

Mixed montane forests cover large tracts of the low mountain ranges that dominate Central Europe and also contain much of the area that is important to forest related nature conservation. However, beyond general patterns little is known about ecologically effective driving factors in this habitat. This results in a lack of precise values that can be used to formulate guidelines for nature conservation oriented management strategies. To improve this situation, we used birds as indicators for forest habitat qualities.     

Density effect and intraspecific competition in a leaf-mining moth on bamboo leaves

When confined to a single leaf, the larvae of most leafminers should suffer intense intraspecific competition. The survival and performance of individuals are expected to decline with increasing larval density within a leaf, showing a negative density-dependent effect. The maximum density of an Elachista Treitschke(Lepidoptera:Elachistidae) miner on Indocalamus tessellatus(Munro)Keng f.(Poaceae: Bambusoideae) under natural conditions can be greater than 40 per leaf, making this a good system for studying intraspecific competition and density effects.We counted the number of leaves with different mine densities in the field and found a clumped distribution of leafminer larvae among host leaves. The emergence rates of pupae(and last-instar larvae), adults and parasitoids were inversely correlated with larval density. Pupal weight and adult weight also showed negative relationships with larval density. However, pairwise tests showed that there might be no differences in pupal or adult weight at larval densities of 1–10 mines per leaf, indicating that densitydependent effects are more obvious at densities greater than 10 mines per leaf. Intraspecific competition could lead to stable density and consistent body size in surviving individual insects, which would help maintain a sustainable population size. The density threshold could be an indicator of the balance between intraspecific competitive detriments and conspecific aggregation benefits; however, the validity of the threshold density hypothesis requires further testing and confirmation.     

The impact of a fungicide and an insecticide on soybean growth, yield, and profitability

A growing number of soybean producers have begun to incorporate below threshold fungicide and insecticide treatments into their management programs in attempts to increase yield. The objective of this study was to determine the influence of a fungicide and insecticide on soybean yield and growth when disease and insect pressure is minimal. Soybean was planted at three locations across Indiana, USA, in 2009 and 2010 and treated with various combinations of glyphosate, pyraclostrobin, and lambda-cyhalothrin. Yield was increased by 100 kg ha⁻¹ and 150 kg ha⁻¹ by a R4 application of pyraclostrobin alone and by lambda-cyhalothrin alone, respectively. Seed mass was increased 3% by pyraclostrobin, while seed number m⁻² was increased 5% by lambda-cyhalothrin. No other yield component was influenced by the fungicide or insecticide. Economic analysis using Simulation and Econometrics to Analyze Risk (SIMETAR) demonstrated a single, post application of glyphosate to be the most efficient treatment option across a range of risk attitudes. This study indicates that yield increases are possible using below threshold applications of fungicides and insecticides. However, growers may not benefit from such applications if input costs are higher than the economic returns of the increased yield.     

徐州市水资源承载力研究

结合徐州市经济发展的基本现状和多年统计资料,以工业、农业、生活和生态四个方面需水作为指标体系,采用灰色预测模型GM（1,1）模型,以1986年为规划基准年,以2010和2020年为目标年对上述社会经济发展的指标进行了预测。以最大可支撑人口单目标模型为基准,根据灰色预测模型计算出的徐州市目标年人口和对因水资源可承载下的最大人口比较。结果表明,2010年徐州市水资源量是可承载的;2020年,徐卅市水资源极其缺乏,无法负担预测人口的正常生活。最后,对徐州市水资源合理利用提出了建议。     

海南省甜菜夜蛾发育起点温度和有效积温的研究

在恒温条件下,测定海南甜菜夜蛾发育起点温度和有效积温。研究结果表明,海南甜菜夜蛾卵的发育起点温度为15.49℃,有效积温为39.72日度;幼虫的发育起点温度为9.80℃,有效积温为239.64日度;蛹的发育起点温度为15.02℃,有效积温为61.87日度;产卵前期的发育起点温度为6.00℃,有效积温为39.63日度。推算出甜菜夜蛾在海南北部的海口市和南部的三亚市的年发生世代数分别为12代和13代,为其在海南的预测预报及防治提供了理论依据。     

猪乳头数的参数估计及翻乳头遗传方式的判定

太原花猪总乳头数和先天有效乳头数分别为１４．７２和１３．３４个。山西黑猪分别为１４．３３和１３．６３个。乳头数具有显著的母体效应及性别和品种差异，且品种和性别间存在显著互作。按阈性状估计遗传力可以消除某些系统误差。山西黑猪翻乳头的出现范围大致是０￣６个，多出现在２￣５对乳头。翻乳头呈常染色体隐性遗传，其隐性基因频率为０．４５，外显率为８．４１％。由于其不完全外显，可能呈主基因遗传。     

近红外在线检测装置参数对苹果糖度模型适用性的影响

目的 近红外(Near-infrared)光谱在线检测装置的检测速度和积分时间等因素会影响所建立苹果糖度模型的性能,本文旨在分析检测速度和积分时间对模型适用性的影响,以提高在线检测的精度。方法 近红外光谱在线检测装置检测速度和积分时间分别设置为0.3 m/s+100 ms、0.5 m/s+70 ms、0.5 m/s+100 ms、0.5 m/s+120 ms、0.5 m/s+150 ms,共5个实验组,试验所用苹果样本共180个,在350~1 150 nm波长下采集5个试验组苹果的近红外光谱,应用偏最小二乘法(Partial least squares,PLS)建立苹果可溶性固形物含量(Soluble solid content,SSC)的预测模型。结果 近红外在线检测装置积分时间对苹果糖度的检测存在阈值,当积分时间低于70 ms时,模型预测性能较差。预测模型中建模集与预测集的检测速度与积分时间相同时的预测效果优于二者不同时的。检测速度和积分时间会影响在线检测的精度,不同检测速度和积分时间下,光线在苹果内部的传输路线不同,会导致光纤探头获得的内部信息有所差异,使预测性能变差。在0.3 m/s+100 ms、0.5 m/s+100 ms、0.5 m/s+120 ms和0.5 m/s+150 ms 4个试验组中使用Kennard-Stone算法挑选出135个具有代表性的样本光谱,建立了混合检测速度和积分时间的预测模型,其预测集相关系数(R_P)均在0.85以上,预测集均方根误差(RMSE_P)均低于0.65。结论 本研究建立的混合检测速度和积分时间的预测模型可对苹果的糖度达到更好的预测,满足不同检测装置参数下苹果糖度在线检测的要求。     

我国华北地区落叶松林碳储量动态研究

通过对解析木及一类林业调查样地材料碳储量及碳密度的研究,求出树木碳增量的年降水、材积及时间阀值,得出落叶松碳密度增长的材积限制条件年生长量现实林为2.84m3/hm2,近自然林6.837m3/hm2,理想林8.052m3/hm2,均不能高于这一阀值;时间限制条件为近自然林为区间(3.58a,19.95a),理想林为(6.4a,20.33a);降水量限制条件为年降水量区间现实林为(586.18mm,756.86mm),近自然林(435.55mm,1508.1mm),年降水量高于690.3mm,出现负相关,理想林(0,958.87mm),年降水量高于690.5mm,出现负相关,因此年降雨量超过690.3mm,不宜进行浇水作业,即使进行浇水,也不要高于这一当量。平均递增速度最快的年份近自然林为16.14a;即时递增速度最快的年份为8.07a。过多的人为干扰使树木适应的生态位宽度(包括时间生态位、降雨量生态位、材积生长量等)明显变得狭窄,引起蓄积量及碳密度拓展空间明显变小,因此发展近自然林业势在必行。     

水力负荷对垂直流人工湿地堵塞的影响

[目的]为了缓解人工湿地的堵塞问题,探讨水力负荷对垂直流人工湿地堵塞的的影响。[方法]该试验通过人工土柱模拟垂直流人工湿地,设置4个水力负荷水平即50、100、150、200 cm/d,找出水力负荷对人工湿地堵塞的影响,并探索该因素运行过程的阈值。[结果]不同水力负荷水平在人工湿地堵塞过程中影响较大,在高水力负荷条件200 cm/d下,系统有效使用寿命只有半年时间,而且可以推测单因素水力负荷的阈值应该处于100~150 cm/d之间;低水力负荷系统的运行时间还可以持续6个月,中水力负荷系统的运行时间还可以持续3个月。[结论]对以后湿地堵塞试验提供分析依据。