广西珠江防护林体系建设现状与发展

广西珠江防护林体系于1996～2000年、2001～2010年分二期建设,共完成营造林49.10万hm2,森林资源总量的增加和质量的提高,使森林涵养水源和保育土壤的生态功能得到增强.文中总结了防护林体系建设中建立示范点,带动工程建设等成功经验,分析了工程用地限制条件太严,工程造林树种、林种结构不合理,防护林效益低等问题.藉此,提出了提高补偿标准,加大营林投入,放宽工程用地限制条件,增加造林地类等对策与建议.     

中亚五国内陆渔业产业衰退析因及其重振策略探讨

中亚包括哈萨克斯坦、吉尔吉斯斯坦、塔吉克斯坦、土库曼斯坦、乌兹别克斯坦五国,是"丝绸之路经济带"的核心区域,内陆渔业资源禀赋雄厚,世界第一大湖里海以及第四大湖咸海均分布在域内。在前苏联时期中亚各国捕捞渔业和水产养殖发展态势良好,随着东欧巨变及前苏联政局陷入动荡直至解体,渔业生产急剧萎缩,至今虽有复苏但尚未能恢复到苏联时期的发展水平。本文主要基于我们前期研究基础以及FAO和世界银行等统计数据,提出对苏联解体后中亚各国渔业崩溃的原因解读,并探讨在"一带一路"框架下,中国和中亚各国可行的渔业合作方式以及重振中亚渔业的策略方法。     

保定市环城林带生态效益分析

通过调查将保定环城林带分成不同郁闭度、林带宽度、群落结构。并定点定时测定绿地中心和对照点的湿度、温度、噪音、粉尘、空气中细菌数。结果表明,林带绿地郁闭度、宽度增加,其降温增湿、滞尘、降噪功能越明显,而抑菌能力却下降;群落结构类型对林带生态效益的影响依次是乔灌草〉乔灌〉乔草〉灌草。     

辽宁滨海公路降噪林带模式研究

在对滨海公路噪声污染进行实时监测的基础上,利用相关文献研究成果,设计出不同声环境功能区降噪林带的基本模式:1类、2类、3类和4a类功能区的林带宽度分别为90、53、24和5 m,平均木胸径15 cm,等边三角形交错式栽植,株距分别为:3.04、3.02、2.93和2.32 m。该模式不仅为滨海公路的全线绿化建设提供了科学依据,而且为同类型的道路绿化设计提供了参考。     

The role of shelter in Australia for protecting soils,plants and livestock

The purpose of this review is to examine the current knowledge of the role of trees in providing shelter for pastures, crops, and livestock, for controlling erosion of soils and improving productivity and sustainability of agricultural production in Australia — and the extent to which this knowledge has been applied.Land degradation — tree loss and associated soil salinity, water and wind erosion, soil acidification, soil structural decline and nutrient degradation — is evidence that our primary production systems are not sustainable. We have sought increased production without proper consideration of the ecological context of that system. About half of Victoria's crop and pasture lands are affected or at risk, and in Western Australia about 25% of the cleared agricultural land is wind-eroded and 60% is potentially susceptible, salinity affects 0.43 m ha and half of the divertible surface water is affected by salinity. Similar problems occur in other States. At least 43 m ha or 13% of our rangelands are seriously degraded by wind erosion caused by overgrazing, often coinciding with drought or a run of drier years.Minimum tillage and stubble management for erosion control in cropping has been a major extension and research activity in Australian agriculture. Severe weather, combined with imperfect adoption of appropriate grazing and crop management systems, shows the weakness of complete reliance on these methods of erosion control. An effective system must accommodate the impact of extreme events, which are the most damaging. However, the complementary use of windbreaks to reduce soil erosion is rare, and their establishment has not been promoted, despite the wide-spread adoption of this technology by other countries.In the cropping and higher rainfall grazing areas, the systematic planting of 10% of the land in a net of shelterbelts/timberbelts/clusters could achieve a 50% windspeed reduction; this would substantially improve livestock and pasture production in the short and long-term. Wind erosion could be dramatically reduced and crop production probably increased by the use of windbreaks. Wheat and oat yield at Rutherglen (Victoria), and lupin yield at Esperance (Western Australia), were increased in the sheltered zone by 22% and 47%, and 30%, respectively.In semi-arid and dry temperate areas, planting of 5% of the land to shelter could reduce windspeed by 30–50% and soil loss by up to 80%. This planting would also contribute substantially to achieving other objectives of sustainable agriculture. Agroforestry — particularly timberbelts applications — will be important in the long-term strategy for achieving revegetation. If some of the trees yield a marketable product then the adoption of the system will be more readily achieved.In the arid (pastoral) areas there is an urgent need to promote the ethic that preservation and improvement of the perennial grass and shrub vegetation is critical for the protection of the soil and maintenance of land capability. Control of animal grazing remains the sole means of preventing erosion in much of this zone. While satellite imagery allows us to assess the condition of leasehold lands, we have failed to achieve stocking policies that will halt the degradation of our rangelands.     

蓟运河故道消落带盐碱地土壤种子库特征

通过对蓟运河故道消落带的土壤种子进行萌发实验,确定了土壤种子库的物种组成、物种多样性指数和相似性指数,并对土壤种了库的物种特征进行了空间层次分析.结果表明:(1)蓟运河故道消落带土壤种子库共有16种植物,隶属于8科15属,其中藜科4种,菊科5种.3个区域土壤种子库物种相对多度和密度大小分布顺序为:洪淹区＞偶淹区＞常淹区.(2)不同区域种子库的Shannon—Wiener指数和Margalef丰富度指数随着水位的降低呈下降趋势,而生态优势度和Pielou均匀度指数有增大趋势.(3)种子库的空间分布特征明显,其中0--5 cm层种子数量最多,为623粒/m2;同时3个区域种子数量差异显著,洪淹区土壤种子库物种数量比偶淹区和常淹区分别多出253和353粒/,n2,而偶淹区土壤种子库物种数量与常淹区仅相差100粒/m2.     

地埋滴灌点源入渗土壤水分运动规律实验研究

通过室内砂土中进行地埋滴灌的实验,对地埋滴灌在砂土中的适应性进行初步研究,为田间试验布置提供依据。通过分析湿润锋的推移速率、特征点的土壤含水率变化规律,发现湿润锋推移速率先是径向大于垂向,随着灌水时间和灌水量增加,水平方向和垂向的湿润锋和含水率趋于平衡。根据对比滴灌带埋深15和20 cm特征点的含水率变化情况,得出埋深15 cm节水效果更好,更利于作物生长。实验还得出湿润比能作为滴灌灌水参数的指标,由于作物种植的间距和作物根系深度之比基本小于1.0,因此在田间实际灌溉中湿润比应控制在1.0左右。     

亚硝酸盐对海水COD测定的影响及消除方法的研究

研究了ＮＯ２对海水ＣＯＤ的影响，结果表明：海洋监测规范中ＣＯＤ的测定方法不适合于ＮＯ２较高的污染海水，比较了氨基磺酸与叠氮化钠对ＮＯ２的掩蔽效果及测定方法。认为在依次加热氧化，冷却后加入固体ＫＩ，然后加入０．２ｍＬ深度为５ｇ／Ｌ的ＮａＮ３再酸化，可以消除２ｍｇ／Ｌ以下的ＮＯ２－Ｎ的干扰作用，同时也提出了用氨基物具体操作方法。     

多层次防护林体系生态服务价值评价方法

利用对和田地区多层次防护林区的调查研究,进行了林区生态服务功能价值的估算。评估结果表明,在和田玉北的多层次防护林体系中,生态服务价值居第一位的是生物多样性保护,总价值为2.12×106元,占总比例的43.09%;位居第二位的是净化大气环境,价值1.08×106元,占总比例的21.95%;调节大气组分价值排在第三位,为19.35%;涵养水源价值占总比例的11.85%,固土保肥价值量最小,仅占3.76%;在不同的治沙工程措施中,与天然稀疏植被封育区、草方格固沙-人工林区和人工林区相比,多种植物配置区土壤肥力较高,单位面积的价值最高,达到了266.67元/hm2。     

马尾松防火道及果园化学除草试验初报

在马尾松的防火道上用5％森泰颗粒剂和25％森泰水剂、在桃树果园用65％草甘膦和41％春多多进行除草试验。结果表明：马尾松防火道用18．75kg／hm^2的森泰颗粒剂处理效果较好；桃树果园则以1500g／hm^2的草甘膦处理效果最好。