排序方式: 共有53条查询结果,搜索用时 15 毫秒
1.
蔡竞 《四川农业大学学报》2001,19(3):286-288
四川是一个地处内陆的西部省份 ,也是一个传统农业占有重要地位、农业产业化经营发展势头良好、农业和农村经济结构战略性调整任务繁重的农业大省。面对新的形势和任务 ,四川省委、省政府提出了“把工作的着力点转到调整结构 ,增加农民收入上来”和“要实现农业现代化 ,必须推进农业产业化”的正确决策和工作思路。我认为 ,就四川广大丘陵地区、盆周山区和平坝地区而言 ,在着力推进农业产业化经营的过程中 ,除要加大乡镇企业“二次创新”力度 ,高标准建设一批示范性小城镇 ,着力改善农村经济发展的市场环境、确保农产品供应充足、总量基本平… 相似文献
2.
通过定位试验,分析了四川盆地马尾松低效防护林系统改造恢复6年后群落学及土壤理化性质的效应变化,探讨了改造措施对马尾松低效防护林效应的影响。 相似文献
3.
《African Journal of Range and Forage Science》2013,30(2):131-145
This study assessed the importance of spatial and temporal variation in plant quality and quantity for determining sustainable stocking rates in game, commercial and communal ranches in semi-arid savanna of the Northern Cape Province, South Africa, in wet and dry seasons over a two-year period. We focussed on variation in plant biomass, phosphorus (P), crude protein (CP) concentrations and dry matter digestibility as parameters most likely to affect sustainable stocking rates. Habitat type had greater effects on plant quality, plant biomass and species composition than management type. The commercially-managed area had the highest tree density in the rocky habitat and lower plant quality than other management types. All of these features indicate that land degradation is occurring on commercial ranches in spite of rotational grazing and lower stocking density than on communal ranches. We recommend that commercial ranchers should introduce a greater variety of stock and/or game to reduce selective grazing of certain plant species. Quality measures (CP and P) gave more conservative predictions of stocking density than biomass. In this region of the Northern Cape, seasonally-inundated pan habitats are particularly valuable in spite of low-standing crop because they have the highest year-round quality. Contrastingly, ranchers should only lightly stock open savanna habitats, in spite of high standing biomass, because they have low vegetation quality and may be particularly susceptible to degradation and invasion by poisonous and unpalatable plants. 相似文献
4.
马尾松低效防护林多层经营技术研究 总被引:5,自引:0,他引:5
用系统整体的观点。结合乔木层郁闭度(Xl)、灌木层盖度(X2)、草本层盖度 (X3)、枯落物层盖度(X4)与林地土壤侵蚀模数建立的回归模型分析,提出了多 层经营的概念,即“同步经营林分的乔木层。灌木层、草本届和枯落物层,根 据各层目标功能确定经营措施,获取生态经济的整体效益。使林分在高效高产 水平上持续协调发展”。并通过分析马尾松低效防护林系统群落各层次的目标 功能,确立了多层经营的指导思想,据此分层阐述经营技术。 相似文献
5.
云南松研究现状及动态 总被引:19,自引:1,他引:19
李贤伟 《四川农业大学学报》1995,13(3):309-314,363
对1980—1993年有关云南松研究的文献进行统计归类和分析研究,揭示出云南松生物学特性、生态特性、森林保护和森林经营以及开发利用方面的研究现状和发展趋势。 相似文献
6.
农业生态经济系统分区方法研究——以四川盆周山区为例 总被引:1,自引:0,他引:1
郭守前 《四川农业大学学报》1997,(3)
农业生态经济系统分区,涉及到自然、生态、经济、社会等多方面因素,边界具有很强的模糊性。运用模糊聚类方法与判别分析相结合,既能适应上述特点,又有效解决了独立样本的合理归类问题。利用主分量分析选取聚类指标,并以各指标对主分量的负荷和作用为依据确定其聚类时的权重。 相似文献
7.
《Southern Forests》2013,75(3):269-274
South Africa is a world leader in the forest products industry and this industry contributes significantly to the country's economy. Challenges to the industry's future include land reform, water use, global competition, regulations, outsourcing and privatisation (the decreased role of government in forest management). These issues impact forestry skills, jobs and education. As part of the Department of Forest and Wood Science's curriculum revision at Stellenbosch University, a survey was sent to forest industry representatives to better understand the transition in forestry and what is expected from upcoming forestry graduates, specifically in business and economic-related studies. Major issues that surfaced included skill shortages, timber supply constraints and land/legal issues. The most important skills lacking in future foresters were people and business management skills. The survey results confirm that, although forest managers still need a core technical toolbox, they are also required to address multiple issues and require a broader 'package' of skills. 相似文献
8.
分别就农村金融组织体系中的商业性金融、政策性金融、农村信用合作社和农业保险等同改革与完善提出相应的对策,以发挥农村金融体系的整体作用支持农业和农村经济的发展。 相似文献
9.
本文通过对我校历年获奖成果及其课题组的统计分析,探讨科研课题组的结构与获奖的关系。统计分析认为,课题组的人才群体结构、研究人员数量、研究周期等因素都对获得成果及其大小有较大的影响。 相似文献
10.
核桃产量预测模型及其应用 总被引:1,自引:0,他引:1
本文运用多元逐步回归分析,建立核桃产量预测模型,分析影响核桃产量的主导林分因子与立地环境因子,并探讨发展核桃的丰产经营措施。 相似文献