试论中德合作辽宁朝阳生态造林工程效益前景

朝阳市面积1.97万 km2,人口 330.84 万人。该地属于北温带半湿润半干旱大陆性季风气候类型区,年均降水量480~523mm,生长季(4~9月)降水量约占年降水量的91.6%,其中6~9月份降水量约占全年降水量的80.0%。年平均蒸发量为 1877. 8mm,春季(3 ~ 5 月)蒸发量为800.0mm以上,秋季(9~10 月)蒸发量为 400.0mm,这也是出现春旱的主要因素。年平均风速2.9m/s,最大风速 3~4m/s。年平均气温 8. 4℃左右,≥10℃年积温 3517.2℃。年平均日照2824.3h,无霜期平均148.9天。本区大部分地表由砂岩、片岩、石灰岩和花岗岩等岩石构成,属辽西低山丘陵区。森林以落…     

滇中华山松人工林的水文特征及水量平衡

根据滇中高原的华山松林集水区径流场连续 3a的降雨和径流观测数据 ,进行了华山松人工林的水文特征及水量平衡的研究。结果表明 :( 1)本区域降水量的季节分配不均 ,湿季 ( 6～ 10月 )降水量占全年的 80 % ,降水量主要由大于 10mm以上的降雨带来 ,且降雨强度大部分小于 5.0mm·h- 1。 ( 2 )集水区年平均降雨量 10 0 5.6mm ,在林冠作用面降雨量的分配中 ,林冠截留雨量 2 10 .6mm ,截留率 2 0 .9% ;穿透过林冠层的降雨 74 5.3mm ,树干茎流量 4 9.7mm ,分别占降雨量的 74 .2 %和 4 .9%。 ( 3)集水区径流的月变化滞后于降雨 ,总径流量 172 .2 9mm ,总径流系数 17.13% ,其中 ,地表径流 8.0 3mm ,地下径流 164.2 6mm ;地表径流主要集中在雨季产生 ,一次性降雨对地表径流的影响显著 (R =0 .91)。 ( 4 )土壤蓄水年变化量 11.2mm ,约占年降水量的 1.1% ,但月变化较大 ;系统水量最大的输出是蒸散 ,每年以气态形式返回大气的水量 82 2 .1mm ,占降水量的 81.8% ;在蒸散的水量中 ,林冠截留雨量的直接物理蒸发量 2 10 .6mm ,占总蒸散量的 2 5.6%。     

丘陵区保墒造林浅析

丘陵区保墒造林浅析彭维娴（甘肃省林业科学技术推广总站）甘肃中部黄土区一般为干燥的草原性气候，年平均降水量３２７．９ｍｍ，年蒸发量１３３２．７ｍｍ蒸发强烈，年平均气温为７℃－１３℃，年降水量多集中在夏秋两季，春季降雨仅占全年的１０％－２０％。经分析土壤...     

巴彦淖尔市沙区抗旱造林系列技术

乌兰布和沙区位于巴彦淖尔市西部,总面积506万亩,流沙约占沙区总面积的40%,年降水量62~201毫米,年蒸发量2380~3005毫米,是极干旱地区。全年8级以上大风日28~70天,平均风速每秒3米,最大风速每秒可达18米,风沙是该区的主要自然灾害。近几年来,巴彦淖尔市在乌兰布和沙区应用了先进的治沙技术,将造林时间从过去的4月份延长到5月中下旬,从过去的一     

广西不同林分区域降雨特征及其对地表水水质的影响研究

在广西松树、杉木、桉树人工林种植区建立10个监测区,连续2年收集各区域降雨量,并多次采集林区地表水用于监测DO、BOD_5和TN等水质指标,分析不同林分区域降雨特征及其对地表水水质的影响。研究结果表明,降雨量在不同区域分布不均衡,在不同月份分布亦不均衡,2015和2016年不同区域累积降雨量按从大到小的顺序排列为桂北桂中桂东桂南,降雨量主要集中分布在4～11月;按照降雨强度划分标准,降雨强度为大雨的累积降雨量及其占全年降雨总量比例均最高,降雨强度为小雨的降雨总天数及其占全年降雨总天数比例均最高;水质受暴雨和大暴雨的降雨量影响较大,受小雨、暴雨和大暴雨的降雨天数影响较大。     

元阳梯田水源区全福庄小流域降雨及径流特征

对元阳梯田水源区全福庄小流域进行了定位观测实验,收集了多年降水和径流资料,采用统计的方法分析了该地区降雨量与径流量的特征。结果表明:全福庄小流域降雨年度分布不均,年内主要集中在5~9月,以小雨最多,占总降雨场次的59.12%;研究区年径流深1429.58mm,径流量年内变化不明显,小流域一年四季常流水;降雨是产生径流的主要因素,但不是唯一因素。由小流域降雨和径流对比可知,全福庄小流域的森林植被对径流具有良好的调节功能。     

祁连山林草复合流域气象因子、土壤特性及其蒸发对比研究

土壤蒸发是森林生态系统水文循环的重要环节,也是流域水量平衡计算的难点,为此,在祁连山大野口流域对土壤特性、土壤蒸发和气象因子进行定位监测,对监测数据用相关系数法进行分析,结果表明:(1)林地比草地土壤年蒸发量低80.99%,林地土壤年蒸发量占降水量的54.16%,而草地占98.02%。在土壤蒸发旺盛期,林地和草地土壤蒸发量分别占全年的80.87%和85.47%;在土壤蒸发平稳期,林地和草地蒸发量分别占全年的19.13%和14.5 3%。(2)与各气象各因子相关性的平均值比较,林地比草低平均低出3.15%。(3)林地比草地土壤孔隙度、毛管孔隙度、非毛管孔隙度分别高出7.31%、7.63%、4.29%。本文通过林地和草地的土壤蒸发季节变化、土壤蒸发与气象因子相关性、土壤蒸发与土壤特性相关性等对比分析发现,虽然林地比草地土壤特性更有利于土壤蒸发,但气象因子是影响土壤蒸发的主成因子,林地形成的小气象环境抑制了土壤蒸发,使林地保持更多的水分供生长需要.本研究可为全面掌握森林生态水文学的水文循环机理和进行流域水量平衡计算提供科学依据和参考。     

谈黑龙江省西部干旱盐碱地雨季造林

我省造林一般都在春秋两季进行,但对西部干旱地区的盐碱地,这时造林往往成活率低,收不到成林效果。这是因为这个地区的气候特点是在春季造林时,气温高,近地层温度有时可高达40℃以上,昼夜温差变化大,降水量少,年平均降水量在400—450毫米,多集中在雨季(7～8月),占全年降水的58%以上,而造林季节(4～6月)降水量只占全年降水量的11%。蒸发量大,4～6月分的蒸发量约占全年的49%,使土壤干燥。春季干旱风大而持久,有时可持续到6月初,这样,就使林木在生长初期,加速了叶     

整地方式对油松幼林生长影响及水保效益研究初报

对不同整地方式的水土保持作用和油松幼林生长效果的观测研究表明:不同整地的水保能力以窄条梯田最大,其次是水平阶,鱼鳞坑最小,平均每年每平方公里的侵蚀模数分剐为51.8T、53.89T、57.3T、64.6T;径数模数分别为1.69×10~4m~3、1.75×10~4m~3、2.05×10~4m~3、2.54×10~4m~3。油松造林成活率、地径和高生长,以鱼鳞坑为最好,且三种整地方式均比不整地的好。单位面积投工量以窄条梯田最多,分别比水平阶、鱼鳞坑多45%、76%。不同整地方式及荒草地土壤含水量全年平均值差别不大,较荒草地有所提高,但四五月份含水量低于荒草土。     

森林对气候的调节作用

我区大部处于温带半干旱地区,年降水量一般在100—450毫米,且主要集中在夏季,约占全年降水的70％以上。全区森林覆盖率很不平衡,西部草原和荒漠地区多为无林或少林区,年蒸发量高于年降水量的数倍或数十倍,高达1500—3000毫米。加之每年春季,西伯利亚冷空气频繁进入我区,大风日数多达40天以上。大面积的植树造林,对改造干旱少雨、风大沙多的恶劣条件,调节气候,有着重要的作用,可以增     

木麻黄沿海防护林林内降水特征的研究

对木麻黄沿海防护林的林内降水特征的研究表明 :惠安木麻黄沿海防护林的林外年降水总量为 2 0 0 1 1mm ,年穿透降水量为 16 0 9 4mm ,占林外年降水量的 80 4% ,年树干径流量为 171 7mm ,占林外降水量的 8 6 % ,年林冠截留量为2 2 4 0mm ,占年降水量的 11 2 %。穿透降水与降水量以及树干径流与降水量之间存在着明显的直线相关关系 ,可分别描述为 y =0 8972x - 4 4974和 y =0 10 5 4x 0 2 5 4。     

鼎湖山亚热带季风常绿阔叶林蒸散研究

运用Penman蒸散力公式和理论上导上导出的计算森林生态系统蒸散公式，对亚热睦带性群落鼎湖山季风常绿阔叶林的蒸散力和蒸散逐日进行计算，其结果表明：鼎湖山季风常绿阔叶林蒸散力年平均为９８７．５mm占同期降雨量的４７％，蒸散力最大的月分是７月，最小的月份是２月，这样基本上与近地面层的气温度变化规律相一致，而与同期的降雨量有所延迟。林外自由水面蒸发年平均为１１９４．５mm干季林内蒸散力明显小于林外自由水面的蒸发，而湿季两者又十分接近，因此，两者相比可用来作为该地区划分干湿季的一个参指标，理论公式法所计算出该系统的蒸散年平均为９５１．９mm,与蒸散力相当，占同期降雨量的４５．３％。鼎湖山季风常绿阔叶林总径流量年平均为１１０３．８mm，径流系数为０．５２，研究期间系统贮水量的变经年平均为３８．９mm.水量平均法所得的蒸散年平均为９６０．１mm与公式法计算所得的蒸散非常接近，３年的系统误差不到１５，因此，初步得出此公式是计算森林生态系统蒸散的一种值得推广的方法。     

坡地生态经济林水分研究

研究表明，黄土丘陵区旱坡地生态经济林在年降雨量达到331mm时，经济林(枣树)生长期的水分供需在理论上达到平衡状态。降雨量低于331mm时，经济林园水分出现亏损，水量平衡向负值倾斜。由于雨量分布不均，某一时期的旱害会影响整个生育过程。实际观测表明，当生态经济林平均单株土壤水分净集蓄量达到树体蒸发量的2倍时，经济林才能正常生长结果，而要达到这个集蓄量，年降雨量需大于400mm。当降雨量为298mm时，林地缺水随密度的加大而增加，4种密度株均缺水依次为—249．14kg、—354．56kg、—453．50kg和—640．95kg。     

薄山林场森林植被涵养水源价值评估

根据森林资源清查数据、降雨量、森林植被蒸散量,采用水量平衡法计算了薄山林场森林植被的涵养水源量,用“影子工程法”计算薄山林场森林植被涵养水源的经济价值。结果表明：薄山林场森林植被调节水量达到0．29亿m3／a,涵养水源的总价值为2．78亿元／a,其中针叶林与栎类调节水量与涵养水源价值较大;单位面积森林调节水量与涵养水源的价值,针叶林最大,栎类最小。     

Estimating water use of sclerophyllous species under East-Mediterranean climate: III. Tabor oak forest sap flow distribution and transpiration

The annual course of daily transpiration and the hydrological balance of a Tabor oak forest were determined. The study was done in a representative forest within the natural geographical range of the species in the lower Galilee region of Israel. The climate is sub-humid with a rainless dry season from May to October. A partial water balance of a 0.1 ha area supporting an average of 14 trees was calculated from: (a) soil water content (SWC) measured by a Neutron Probe at depths of from 0.2 to 8 m, and (b) daylight transpiration rate measured with sap flow sensors by the heat pulse technique.Soil–bedrock complex water content (%) in the first 2 m of the profile fluctuated strongly between 5 and 20% depending on the season. The water content increased with depth from about 10% at 2.0 m depth to more than 20% at 5.0 m depth. For depths exceeding 5.5 m seasonal fluctuations in water content were negligible and water content ranged from 30 to 35%. After a dry winter, water content generally decreased within the main root zone down to about 2.0 m depth. Monthly changes in water content (mm) were greatest at depths of 0.35–1.0 m. Only minor changes in the soil–bedrock complex water content were recorded at greater depths. After a very rainy winter (2002/2003), decreases in soil–bedrock complex water content in the upper 2 m were much larger than after a dry winter. Fluctuations of soil–bedrock complex water content in deeper regions were larger in the wetter year, probably the result of drainage.Sap velocity was measured at six depths in the sapwood, from 4 to 44 mm, at 8 mm intervals. Sap velocity declined with depth, hence, sap flux density too.Based on sap velocity measurements performed during 4 years, the annual average daily transpiration (T) was 0.796 mm/day. This sums up to 239 mm during ∼300 days of leaf carriage, i.e. 41.3% of the 578 mm average annual rainfall for the area in the last 50 years. In a relatively dry year (rainfall of 432.7 mm) total water withdrawal from the 8 m soil–bedrock profile was 81% of the annual rainfall; of this amount 69% were transpired by the oak trees (239.0 mm), or 55% of the annual rainfall. In a relatively wet year (annual rainfall 801.4 mm) total water withdrawal was 67%; of this amount 45% would be transpired by the oak trees, or 30% of the annual rainfall.     

Water use in a Grevillea robusta–maize overstorey agroforestry system in semi-arid Kenya

Novel approaches involving a combination of sap flow measurements of transpiration and allometric estimates of biomass production were used to determine seasonal water use by trees and crops in agroforestry systems. The results were used to test the hypothesis that agroforestry may improve productivity by capturing a greater proportion of annual rainfall than annual crops. Grevillea robusta A. Cunn., which is reputed to have a deep rooting habit, was grown in semi-arid Kenya either as sole stands or in combination with maize (Zea mays L.). Water use by individual trees and maize plants was determined using constant temperature heat balance gauges and scaled to provide stand-level estimates of transpiration based on linear relationships (r²>0.70) between sap flow and leaf area across a range of tree ages and environmental conditions. Maximum stand-level transpiration rates for grevillea ranged from 2.6 to 4.0 mm per day, consistent with previous studies in similar environments. Biomass production by grevillea was closely correlated with stand-level transpiration (r²>0.69–0.74), suggesting that non-destructive estimates of biomass increments can be used to provide reliable estimates of seasonal transpiration. Cumulative water use by grevillea over the 4.5-year observation period was comparable in the sole tree and agroforestry treatments, reaching a maximum utilisation of annual rainfall of 64–68% 3–4 years after planting. Approximately 25% of the water transpired by the trees was used during the dry season, indicating that they were able to utilise off-season rainfall, comprising 16% of the total annual rainfall, and residual water remaining in the soil profile after the cropping period. During the 1995 long rains, when 221 mm of rain was received, transpiration by sole maize was <50% of precipitation, compared to ca. 85% by the trees in the sole grevillea and agroforestry treatments. These results confirm that agroforestry systems may greatly increase rainfall utilisation compared to annual cropping systems. However, careful consideration of the tradeoffs between the loss of crop production and the additional value provided by tree products is essential.     

Water table levels at different drainage intensities on deep peat in Northern Norway

This report comprises a 10-year study on the effects of ditching-systems on water table levels in deep peat. The following factors have been tested: ditch depth, ditch distance, vegetation type, surface fall, permeability of peat, air temperature, evaporation and rainfall.Correlation and multiple regression analyses showed that mean water table level midway between ditches for the growing season (June—September) could be predicted with good precision (R = 0.74 – 0.87) by: ditch depth, logarithm (e = 2.7183) of ditch distance, rainfall, permeability and initial water table level on 1 June (autocorrelation factor).Multiple regression tests on orthogonalized variables showed that ditch depth is very important. On unfurrowed peatland this factor reduced total variation in the annual mean water table levels from 1 June to 30 September by 26.2%. On furrowed peatland, logarithm of ditch distance, ditch depth and rainfall each accounted for between 15.1 and 17.2% of the variance.Proper drainage for afforestation in Northern Norway could be attained by an effective ditch depth of 0.8 m and ditch distances from 9 to 25 m. This rather broad range depends on regional variation in mire types, permeability of surface peat layers and rainfall.     

Water yield changes as a result of silvicultural treatments in an oak ecosystem

Interception loss represents an important factor of water balance. The reduction of interception loss through silvicultural treatments to the benefit of water yield is very important for countries with large periods of limited rainfall like Greece. In the context of climate change and its possible effects on water availability, oak ecosystems can play a significant role in water production, as they comprise the largest part of the forested area in Greece. The objective of this study is to investigate the relationships between water interception changes, as a result of different forest management treatments, and water yield. For this reason, experimental watersheds have been established for the study of the hydrological impacts of thinning and clearcutting in an oak ecosystem in northern Greece. Two watersheds were used as control while different combinations of thinning (removal 50% of basal area) and clearcutting treatments were used in the other three study watersheds. Canopy annual interception amounted for 9.0%, 6.7% and 1.8% of the total precipitation in the untreated, thinned and clearcut plots respectively. The practiced thinning and clearcutting operations increased the available amount of water by a mean annual average of 13.2 mm and 42.8 mm respectively compared to the control watersheds. The total water surplus represented 29.5%, 30.9% and 33.9% of the average annual precipitation for the control, thinned and clearcut plot respectively. Surface flow was very low even during large rainfall events, possibly due to the soil and bedrock attributes and the topography of the area. Analogous silvicultural treatments can increase water availability but they should incorporate reduced-impact logging and skidding practices and thus cause the least possible soil disturbance, by carefully selecting the best suited wood harvesting systems and methods.     

金塔柽柳在甘肃沙区的气候适宜性分析

选取年均降雨量、年均蒸发量、年均气温、年日照时数、极端高温、极端低温、相对湿度和≥0℃积温等8个气候因子作为金塔柽柳在甘肃沙区的气候适宜性栽培条件,以金塔县的金塔柽柳为固定样本,以甘肃沙区的景泰县、民勤县等15个县市区的气候资料为依据,用模糊相似优先比法进行分析,将15个县市区划分成4类金塔柽柳的适宜性区域：适宜区、较适宜区、基本适宜区、不适宜区。