青藏高原东缘短柄草-密生苔草草地植物群落组成及生产力的季节动态研究

通过对青藏高原东缘短柄草Brachypodium sylvaticum-密生苔草Carex crebra草地2年的定位监测研究,结果表明:该草地共有植物 70 种,分属 20 科 46 属.短柄草是优势种,占草群密度的45.5%;密生苔草为亚优势种.从地上植物量来看,短柄草产量在各月均居首位,所占比率为14%～29%,密生苔草占5.4%～16%.草地生产力月动态变化曲线呈单峰形,6-7月是地上植物量增长最快的时期,产量高峰出现在8月(217.9 g/m2).全年单位面积载畜量为2.388个羊单位/(hm2*年),青草期5-10月各月理论载畜量分别为:4.6,9.3,17.4,28.1,21.2,11.6个羊单位/hm2.     

山区、半山区县社会经济发展问题的研究

本文以蛟河市(县级市,以下同)为例,运用定性定量相结合的方法,研究了山区、半山区县社会经济发展的一些理论问题,简述了作者应用系统动力学的理论与方法建立起的县级社会经济发展系统动力学模型及应用这一模型所做的一些主要战略方案分析与政策试验,给出了一些主要模拟结果与推荐的政策。     

榛子果实发育中氮·磷元素动态变化

[目的]研究榛子果实发育过程矿物质的动态变化。[方法]研究3个榛子杂交品系果实发育中,氮、磷含量的动态变化规律。[结果]幼果迅速发育期和果仁发育期是榛子果实吸收、累积矿质元素的关键期。3个杂交品系中,氮素的变化规律为前期下降—中期平缓—后期快速增加,磷素的变化规律为前期下降—中期稳定—后期先快速增加,后快速下降。[结论]该研究为保证榛子果实发育中营养元素的合理补充提供理论依据。     

葡萄树体生长动态与根系分布研究

选取陕西省扶风县新集村7 a树龄的葡萄园为试验果园,在不同生育阶段对红地球葡萄树进行刨根、肢解,以测定其各器官生物量、养分含量及累积量的变化。结果显示,该葡萄园年生物量增加12 369 kg/hm。其中枝条（除新梢外其他枝条）与主干生物量增加2 481和1 939 kg/hm,占生物量总累积的19%和15%。新生器官即叶、果实、新梢生物量分别为2 357、4 866、6 118 kg/hm,新梢旺长期之后,新生器官生物量累积迅速。根系生物量在主要生长期内变化不大,于2 302～4 132 kg/hm范围内波动,但总体呈增加趋势,生物量净增加1 830 kg/hm,占整株的14.8%。葡萄根系不同时期在土壤中的分布情况变化不大,主要分布在0～40 cm的土层,占总根量的86.7%。随着土层深度的增加,葡萄树根量减少。40～60 cm的根量占7.4%,60～80 cm的根量只有3.6%,80～100 cm土层中仅为2.3%。5月10日至6月30日为0～20 cm根系的一次生长高峰。     

Dynamics of Nutrient Accumulation in Maize Plants Under Different Water and N Supply Conditions

The dynamics of accumulations of plant dry matter, nutrient uptake and N fertilizer recoverywere studied with different water and N supply, using summer maize (Zea mays L. var. Shandang) as an indi-cator crop. The total dry matter (including roots) and N, P, K uptake amounts were continuously increasedwith plant growth, and their accumulations with time during plant-growing period were shaped in S curves thatcould be described by exponential regression equations. Differentiating the regression equations fitting thecurves over time for first derivatives, the momentary rate was obtained of the dry matter and nutrient uptake.Results show that the dry matter and the nutrient uptake were not in the same rate at all time, but changedfrom one time to another. Usually, the rate increased rapidly at early stages, and gradually decreased afterreaching their peak. Of N, P and K, the uptake rate of N and K was higher, and their increase and decreasewere both fast while P was reversed. The time of the maximum absorptive rate appeared earlier for K, fol-lowed by N, and then by P. In any case, the maximum nutrient uptake rate appeared earlier than did the drymatter. The momentary N recovery rate was similar in trend to those of dry matter and N uptake, and its max-imum recovery rate occurred almost at the same time as its maximum uptake rate. Supplemental irrigationraised the cumulative and momentary rates of N. Although water and N supplies increased dry matter and nu-trient uptake rates, they did not alter their changing trends during the plant-growing period.     

Study of structure and dynamics of Korean pine forest in the Xiaoxing’an Mountains

The thesis for the Doctorate consist of two parts. The first is to study on structure, dynamics and tree growth of natural Korean pine forest. The second is to research for tree architecture, growth and stand structure of artificial Korean pine (Pinus koraiensis) forests.The thesis compares the stand structure, process of regeneration, and various tree growth patterns between natural forests and artificial forests. Its purpose is to give a basis for forest management and silviculture. The study was carried out in Liangshui Experimental Forest Farm, which is located in the southern Xiaoxing’an Mountains.     

北部湾底层渔业资源的数量变动和种类更替

根据渔业统计资料和底层渔业资源调查数据，分析了北部湾底层渔业资源的数量变动和种类更替。（１）北部湾底层渔业资源的密度指数有明显的季节变化，这一变化主要是本海域主要底层种类生长，死亡和补充共同作用的结果；（２）主要经济种类的组成随捕捞压力的增加而变化，其种类更替的趋向是质量差，寿命短，个体小和营养层次低的种类的比例上升，质量高，寿命长，个体大和营养层次高的种类的比例下降；（３）多鱼种渔业资源的潜在渔     

吉林省木材综合利用系统优化的理论分析

通过对吉林省林产工业现状的分析,运用耗散结构理论和系统动力学理论的方法,探求吉林省木材综合利用系统优化的理论与方法,经仿真实验,确定了决策方案的量化设计模型,为合理调整林产品结构提出了思路,具体是:决策前灵活运用战略实验室,决策时正确理解动态过程的时序,决策过程中始终坚持以扩大木材综合利用再生产的内涵来代替扩大木材综合利用再生产的外延的原则。     

闽东南沿海中部地区青花菜田间害虫发生动态及其可持续控制技术研究

青花菜是近年闽东南沿海地区发展迅速的一种出口蔬菜,但其病虫害发生过重,农残超标已严重制约了该地区青花菜的可持续发展,因此,建立并推广应用可持续病虫控制技术已势在必行。本研究以福建省惠安县青花菜生产田块为研究对象,在跟踪监测种植季节(9月份到翌年3月份)主要虫害发生动态并确立重点防治对象及其关键时期的基础上,研究了灯诱、性诱和高效低毒农药对其主要虫害的防治效果,从而建立起一套青花菜田间虫害的可持续控制技术。这一研究成果对闽东南沿海青花菜及类似十字花科蔬菜生产的可持续发展具有一定的指导意义。     

施用豆科绿肥后砖红壤酸度随时间的动态变化

利用尼龙网袋法分析马占相思、蝴蝶豆、蔓草虫豆、猪屎豆、葛、绒毛山蚂蝗和四棱豆7种热带绿肥施入砖红壤后,对其酸度的动态影响。结果表明:施用绿肥后,土壤pH值显著提高,交换性酸总量和交换性铝含量明显降低,并且均在施用后的前2个月内效果最好,此后,土壤pH值快速下降,交换性酸总量和交换性铝含量快速增加,马占相思8个月后pH值显著低于对照,交换性铝含量显著高于对照,蔓草虫豆1 a后的交换性铝含量也显著高于对照土壤,葛与猪屎豆降低酸度的效果最好。