基于地统计学的新疆棉田烟粉虱(Bemisia tabaci (Gennadius))危害动态与时空分布

应用地统计学(GS)的原理与方法研究了外来入侵有害生物烟粉虱(Bemisia tabaci (Gennadius))为害新疆棉田的时空动态,并与经典统计学进行对比分析.两种方法一致表明,烟粉虱成虫在空间上呈聚集分布的格局,而各时期成虫的聚集程度依据空间变异随机程度所占的比例不同而不同.经频次分布检验,以零频率法参数拟合的负二项分布来表达其空间分布型最为合适.运用GS的分析方法,进一步得到种群分布面积变化与扩散的趋势,并依此对昆虫种群的扩散模型进行模拟.棉田烟粉虱成虫在田间7～8月份均存在一定的空间相关性,随机程度为19.22%～49.99%;空间相关距离(相关程)在一个月内从32m急速增至6372m,随后在2000～3000m的范围波动.从整个发生过程看出,烟粉虱从越冬场所顺风侵入大田后,迁飞扩散在很大程度上受风向的影响,属于典型的借助风力扩散的昆虫,其在棉田的垂直分布则与吐鲁番地区独特的暖温带大陆性干旱荒漠气候特征有关.顺风扩散时多从棉株上部叶片开始危害, 而逆风扩散时从棉株中、下部叶片危害.烟粉虱在棉株上建立稳定种群后,中、下部虫口密度要略高于上部, 这是烟粉虱对吐鲁番地区特殊气候的适应.     

东灵山辽东栎虫损种子调查

2000年8月底至9月底,在北京东灵山地区小龙门林场对2块辽东栎样地中虫损种子下落动态进行了调查.结果表明:2块样地辽东栎种子产量分别高达19.15和91.23颗·m-2,而2块样地虫损种子较多,分别为49.23和33.38个·m-2,所占种子库比例分别为36.93%和25.96%;1999年研究发现(阎文杰,2000),2样地辽东栎种子产量为13.09和7.24颗·m-2,其中虫损种子产量为10.87和5.90颗·m-2,虫损率高达82.22%和75.43%.2年的观察结果均证实虫损种子在种子雨早期迅速下落,且低产年份的虫损种子在种子库中的比例显著高于高产年份.高比例的虫损种子可能是导致辽东栎实生苗更新率低的重要因素.     

不同灌溉条件下棉叶螨的种群动态

研究了不同灌溉方式（滴灌和沟灌），以及在滴灌条件下，不同灌水量和不同灌水时期处理下，新疆棉花主要害螨——土耳其斯坦叶螨（Tetranychus turkestani）的发生动态。结果表明：不同的灌溉方式和不同灌水量都对棉叶螨的发生有一定的影响；沟灌棉田有利于棉叶螨的发生，滴灌棉田不利于棉叶螨的发生；滴灌条件下，水量过高或过低的棉田均有利于棉叶螨的发生，叶螨发生盛期早于常规水量棉田，数量也高于常规棉田叶螨数。不同灌水时期对棉叶螨的发生影响不大。     

南昌市不同植物类群叶片氮磷浓度及其化学计量比

对南昌大学前湖校区89种主要植物叶片的N、P浓度及其化学计量比进行了研究,结果表明:乔灌、常绿、针叶、种子、裸子和单子叶植物类群的N浓度分别低于相对应的草本、落叶、阔叶、蕨类、被子和双子叶植物类群,而C3和C4植物差异不显著;乔灌、常绿和裸子植物类群的P浓度含量分别低于相对应的草本、落叶和被子植物类群,而针叶和阔叶、蕨类和种子、单子叶和双子叶、C3和C4植物类群间差异不显著;乔木、阔叶、被子和双子叶植物类群叶片N/P分别高于相对应的灌草、针叶、裸子和单子叶植物类群,而常绿和落叶、蕨类和种子、C3和C4植物类群之间差异不显著.可见,不同类型植物对N和P的吸收利用存在差异,且对不同养分供应采取不同的适应对策.结合研究区土壤养分现状,建议优先选择常绿、针叶、裸子和单子叶植物类群作为城市园林植物.     

Responses of growth and litterfall production to nitrogen addition treatments from common shrublands in Mt. Dongling,Beijing, China

Aims The shrublands of northern China have poor soil and nitrogen (N) deposition has greatly increased the local soil available N for decades. Shrub growth is one of important components of C sequestration in shrublands and litterfall acts as a vital link between plants and soil. Both are key factors in nutrient and energy cycling of terrestrial ecosystems, which greatly affected by nitrogen (N) addition (adding N fertilizer to the surface soil directly). However, the effects and significance of N addition on C sequestration and litterfall in shrublands remain unclear. Thus, a study was designed to investigate how N deposition and related treatments affected shrublands growth related to C sequestration and litterfall production of Vitex negundo var. heterophylla and Spiraea salicifolia in Mt. Dongling region of China.
Methods A N enrichment experiment has been conducted for V. negundo var. heterophylla and S. salicifolia shrublands in Mt. Dongling, Beijing, including four N addition treatment levels (control (N₀, 0 kg N·hm^-2·a^-1), low N (N₁, 20 kg N·hm^-2·a^-1), medium N (N₂, 50 kg N·hm^-2·a^-1) and high N (N₃, 100 kg N·hm^-2·a^-1)). Basal diameter and plant height of shrub were measured from 2012-2013 within all treatments, and allometric models for different species of shrub’s live branch, leaf and root biomass were developed based on independent variables of basal diameter and plant height, which will be used to calculate biomass increment of shrub layer. Litterfall (litterfall sometimes is named litter, referring to the collective name for all organic matter produced by the aboveground part of plants and returned to the surface, and mainly includes leaves, bark, dead twigs, flowers and fruits.) also was investigated from 2012-2013 within all treatments.
Important findings The results showed 1) mean basal diameter of shrubs in the V. negundo var. heterophylla and S. salicifolia shrublands were increased by 1.69%, 2.78%, 2.51%, 1.80% and 1.38%, 1.37%, 1.59%, 2.05% every year; 2) The height growth rate (the shrub height relative growth rate is defined with the percentage increase of plant height) of shrubs in the V. negundo var. heterophylla and S. salicifolia shrublands were 8.36%, 8.48%, 9.49%, 9.83% and 2.12%, 2.86%, 2.36%, 2.52% every year, respectively. Thee results indicated that N deposition stimulated growth of shrub layer both in V. negundo var. heterophylla and S. salicifolia shrublands, but did not reach statistical significance among all nitrogen treatments. The above-ground biomass increment of shrub layer in the V. negundo var. heterophylla and S. salicifolia shrublands were 0.19, 0.23, 0.14, 0.15 and 0.027, 0.025, 0.032, 0.041 t C·hm^-2·a^-1 respectively, which demonstrated that short-term N addition had no significant effects on the accumulation of C storage of the two shrublands. The litter production of the V. negundo var. heterophylla and S. salicifolia communities in 2013 were 135.7 and 129.6 g·m^-2 under natural conditions, respectively. Nitrogen addition promoted annual production of total litterfall and different components of litterfall to a certain extent, but did not reach statistical significance among all nitrogen treatments. Above results indicated that short-term fertilization, together with extremely low soil moisture content and other related factors, lead to inefficient use of soil available nitrogen and slow response of shrublands to N addition treatments.     

动态适应性生态经济区划模型及其应用

提高城市生态经济区划的精确性和动态性,对科学指导城市化发展具有重要的理论意义和应用价值。利用夜间灯光数据与人口密度建立线性模型,探索了以往用行政区域为最小统计单元数据的模拟细化问题;然后通过引入可变参数构建了动态适应性生态经济区划模型,在增强模型动态适应性的同时,将一级区划结果统一划分为生态管控区域、生态优先区域、优化开发区域和重点开发区域4个区域。以广州市增城区为典型案例,通过改进的动态适应性生态经济区划模型,运用GIS将增城区在两种情景下进行了模拟和对比,并提出了政策建议。区划结果符合当地发展特征,也为其他城市与区域的生态经济区划研究提供了科学方法。     

猪胰脏冻干粉对肉鸡生长性能的影响

目的:研究日粮中添加猪胰脏冻干粉时肉鸡生长性能和血液生化指标的影响.方法:择8日龄内鸡390只,随机分为5组,每组3个重复,每重复26只,5个组分别在基础日粮中添加不同剂量猪胰脏冻干粉.结果:在饲料中添加0.4%猪胰脏冻干粉可提高28日龄肉鸡采食量5.35%、日增重3.96%(P＜0.05);猪姨脏冻干粉组血清总蛋白含量偏高,但对提高肉鸡血糖、血清总胆固醇、甘油三酯含量和尿素氮含量没有显著性影响(P＞0.05);同时显示,猪胰脏冻干粉可提高肉鸡十二指肠食糜和空肠食糜蛋白酶活性4.41%和14.17%(P＜0.05);也显著影响了肉鸡养分表现利用率(P＜0.05).结论:猪胰脏冻干粉具有提高肉鸡生长性能、采食量、食糜蛋白酶活性和日粮能量利用率的作用.     

啮齿类取食的物种偏好与时空格局

通过强烈消耗土壤种子库，动物取食种子对植物种群更新和群落动态产生深远的影响。一般认为种子被食概率的空间格局取决于种子密度和离母树的距离，而环境（如地形）异质性的影响则一直没有得到足够的关注，与此相关的机制及其影响程度亦不清楚。研究设计在野外埋放种子以模拟种子扩散后的情形，监测啮齿类对种子的取食，以检验种子取食受埋藏生境、时间及动物对种子种类的偏好等因素的影响。结果表明，经过1a实验，8种落叶阔叶树种子的累计取食概率为0～48．25％，平均值为20％；山顶部位的取食概率大致是其它部位概率的3倍；埋放在凋落物层中的种子被食概率大约为埋放在土壤层中概率的2倍。利用logistic回归模型进行统计分析表明，种子被食概率变化的45％可以被上述因素解释。其中，物种偏好是影响种子被取食概率的首要因素，其后依次是地形、埋藏时间和深度。啮齿类明显喜好较大的种子；其取食行为在山脊部位明显较其它部位更频繁和剧烈；对埋藏种子的取食从3月份开始加剧，到7月份以后平息下来。种子埋放深度对啮齿类的取食概率有显著影响。     

佛坪自然保护区6种有蹄动物的活动痕迹监测

野生动物监测在保护管理自然资源以确保可持续利用上占有关键地位.然而,我国对大型哺乳动物的长期监测基本尚未纳入常规.佛坪自然保护区自20世纪90年代中期就大熊猫等珍稀动物及其栖息环境展开了长期监测.以该保护区2000～2006年监测数据为基础,探讨了该地有蹄类动物(除扭角羚外)的资源动态及在生境因子利用上的差异.结果表明该保护区内有蹄类动物资源在不同区域的分布并不均衡,以三官庙区域的痕迹密度最高而以龙潭区域为最低.监测期间有蹄类动物资源呈现出逐步下降的趋势.物种两两之间在海拔、坡度等生境因子的利用上大多存在显著差异,表现出不同的微生境利用模式.最后就监测对象的确定以及监测方法的选择进行了探讨,该保护区所采用的监测方法较为科学有效.