半干旱黄土高原生物结皮处理下集水造林的初步研究(英文)

集水措施是干旱半干旱地区解决因降雨少且季节间分配不均带来的水资源短缺的主要措施之一,有关微集水区防渗处理材料及其防渗效果的研究也已广泛开展。本文通过5 年(1992-1996)的野外试验对半干旱黄土高原微集水系统生物结皮覆盖对造林的影响进行了研究。结果表明,结皮接种3 年后,集水区表面大部分为结皮所覆盖,其集水功能已经部分地表现出来。在春季3 个典型时段内浅层土壤含水量与对照相比显著提高(0.05 水平),1m 土层内春季月均含水量均比对照提高了0.9%–6.04%。同时在研究期末(1996 年)结皮处理的样地内树木个体的树高(H)、胸径(DBH)和地径(DGL)均较对照有显著提高(0.05 水平),提高幅度分别为22.38%、17.34%和20.49%。作为一种生物防渗材料,生物结皮具有无污染、自我繁殖、使用期长和投入小等特点,因此很可以作为西部大开发中植被恢复的主要集水材料,进一步的工作应放在干旱环境下当地适宜结皮种类的选择及其快速繁殖技术上。     

Effects of landscape restoration on soil water storage and water use in the Loess Plateau Region,China

Large-scale vegetation restoration in China's Loess Plateau has been initiated by the central government for controlling soil and water losses in the past three decades. However, there is virtually no guidance for plant species selection for the restoration purpose. We investigated the effects of planting trees and shrubs, land-use conversions from croplands to pastures and native grasslands on soil water dynamics and water stresses by using long-term field measurements from 1986 to 1999 in the semi-arid loess hilly area. Our research has led to the following three major findings. Firstly, the amount of soil water storage within a 100 cm depth decreased as measured at both the beginning and the ending point of growing seasons regardless land cover types. The soil water replenishment by rainfall during rainy seasons was not sufficient to fully recharge the soil water storage. Landscape restoration through shrub planting may help retain more soil water than other land cover types. Secondly, the ratio of actual evapotranspiration (ET) and pan evaporation (PET) generally declined for all land cover types during the study period. Shrub lands had the largest ET/PET ratio, followed by native grassland, cropland/alfalfa, and pine woodland. The ET/PET ratio of native grasslands declined fastest, followed by pine woodlands, shrub lands, alfalfa, and croplands. Pine woodland's low ET/PET ratios were mainly caused by its higher runoff due to soil compaction resulted from soil desiccation. Lastly, we found that the soil water storage at the beginning of growing season was important in determining the ET/PET ratios. This study suggested that pine plantations may not be appropriate for landscape restoration in such a semi-arid loess hilly area while shrubs may be highly recommended.     

Soil respiration response to precipitation reduction in a grassland and a Mongolian pine plantation in semi-arid northeast China

Climate change is predicted to alter global precipitation regimes.However,the response of soil carbon and nitrogen cycles and soil microorganisms to precipitation reduction is poorly understood but is dependent on ecosystem type.To evaluate the impacts of reduced precipitation on soil respiration,soil inorganic nitrogen(i.e.,NH4^+–N and NO3^-–N),nitrogen mineralization,and soil microbial community composition,a precipitation manipulation experiment was initiated in a Mongolian pine plantation and a naturally restored grassland in semi-arid northeast China.Precipitation reduction led to decreases of soil respiration rates by 14 and 8%in 2014 and 2015 in the Mongolian pine plantation but no changes in the grassland.Soil inorganic nitrogen,ammonification and nitrification rate,and soil phospholipids fatty acids were not significantly changed by reduced precipitation but significantly differed between the two ecosystems and among growing seasons.Our results suggest that the impacts of precipitation reduction on soil respiration were different between the Mongolian pine plantation and the grassland,and that ecosystem type and growing season had more pronounced impacts on soil carbon and nitrogen cycles.     

晋西黄土区水土保持林地的土壤水分

2008年5月12 日-10月12日间采用EnviroSMART土壤水分定位监测系统,以每30 min监测1次的频度对晋西黄土区刺槐人工林地、油松人工林地、次生林地的土壤水分变化进行研究.结果表明:0～150 cm土层中次生林地蓄水量是刺槐人工林地的1.4倍,有整地措施的油松林地蓄水量与次生林地相近.人工林较次生林多消耗的土壤水分主要是深层的土壤水分,次生林主要依靠天然降水和消耗浅层土壤水分维持其生长.从表层到深层次生林地蓄水量逐渐增加,而有整地措施的油松人工林地蓄水量逐渐减少.随深度的增加各林地蓄水量的变幅逐渐减弱.0～150 cm土层的平均蓄水量8月最低.层次越深,蓄水量的最低值出现时间越晚.90～150 cm土层的蓄水量5-10月处于消耗状态.生长季刺槐人工林地0～150 cm土层耗水量为249.73 mm,油松林人工林地为248.09mm,次生林地为129.40 mm.刺槐人工林地最大的日耗水量为4.70 mm,油松林为4.77 mm,次生林为2.28 mm.刺槐与油松人工林地的耗水量明显大于次生林,因此,在干旱的黄土区应该模拟次生林营造水土保持林.     

Effects of soil drought on seedling growth and water metabolism of three common shrubs in Loess Plateau, Northwest China

The growth and water metabolism of three common shrubs on the Loess Plateau were studied under soil with different water contents. Results showed that water consumption of those species decreased with the increase in drought stress, and water consumptions of these shrubs were different: Forsythia suspensa was the greatest, and Syringa oblata was the lowest. The growth rate of new branches and leaf area of three species were the fastest under adequate soil water conditions, and were the lowest under severe drought. Under the same water conditions, the growth of F. suspensa was the fastest while that of S. oblata was the slowest. The water content, proline and chlorophyll content of different species changed with the increase in soil water stress. The leaf water content of Periploca sepium and F. suspensa was obviously higher than that of S. oblata, while the leaf proline content of F. suspensa and S. oblata was lower than that of P. sepium. The ratio leaf chlorophyll a: b of F. suspensa and S. oblata decreased with the decrease in soil water content. Although these three shrubs had different mechanisms in response to drought stress, they all had higher drought resistance and could adapt to the drought condition on the Loess Plateau. This paper provided some bases for choosing tree species on the Loess Plateau. __________ Translated from Acta Botanica Boreali-Occidentalia Sinica, 2007, 27(1): 91–97 [译自: 西北植物学报]     

黄土高原水土流失严重地区植被恢复策略分析

以晋西黄土高原地区为例，对黄土高原水土流失严重地区植被恢复的现状和前景进行了全面而细致的分析，提出土石山次生林区应实行“封山育林为主，辅之以人工措施”植被恢复策略。在土层浅薄、坡度较陡的生态脆弱地段，需要进行长期的植被封育；在土层深厚而且坡度平缓地段，可适当辅之以人工措施，包括人工抚育，以及补植或补造有经济价值的乡土树种等。当前土石山区次生林经营管理中急需解决的问题是提高林分质量，加强管护力度；黄土丘陵区应该实行封山禁牧或轮牧、围栏圈养以及陡坡地退耕等措施，这是植被恢复的前提和基础。同时，对黄土丘陵区恢复和建设森林植被的可能性进行了分析和探讨。最后指出只有转变农村传统的以破坏生态环境为代价的粗放生产经营方式，长期坚持植被封育和保护为主的策略，结合人工营造乡土树种为主的森林群落，晋西黄土高原地区才有可能恢复原来的森林植被景观，真正实现该地区的植被重建和水土流失的根治。     

黄土高原刺槐人工林根系分布与土壤水分的关系

对黄土高原丘陵沟壑区4种典型立地下刺槐人工林根系分布与土壤水分的关系进行了研究.结果表明:阴坡、半阴坡的细根(直径≤1 mm)在400 cm土层中的分布较为均匀,半阳坡和阳坡的细根集中分布在0~100 cm土层中,在200~400 cm土层中分布较少;各立地输导根(直径>1 mm)在分布深度上存在差异,阴坡和半阴坡输导根分布较深,阳坡输导根分布均较浅,半阳坡分布较阳坡为深;各立地下刺槐根系的水平分布均较广,水平根单向延伸最大均在8 m左右.不同立地条件下土壤水分状况的差异是各立地根系尤其是细根分布差异的主要原因之一;各立地细根分布范围对土壤水分变化有较大影响,同时根系分布也会影响到土壤水分的季节变化.     

黄土丘陵区杠柳叶片气体交换过程对土壤水分的响应

在半干旱黄土丘陵区,采用CIRAS-2型光合作用系统,在不同土壤水分条件下,对2年生杠柳的净光合速率、蒸腾速率、叶片水分利用效率、气孔导度和胞间CO2浓度等叶片气体交换参数的日变化进行了研究.结果表明:土壤水分的变化会影响到杠柳光合速率、蒸腾速率和水分利用效率的日变化过程.相对含水量为31.6%～84.9%时,杠柳可以维持较高光合生产力和较高的叶片水分利用效率,杠柳维持正常生理和生长过程所需的最低相对含水量为21.7%.据此认为:杠柳对土壤水分的适应范围较广,适宜栽植在黄土丘陵区水分较少的阳坡、陡坡.     

Review on Soil Moisture of Plantation Land in the Loess Plateau

Water is a crucial factor restricting vegetation restorationand conservation in the Loess Plateau (Zhang Leiming,et al, 2002). Annual rainfall is relatively low there, andits distribution is uneven on both the space and thetime scale. Water can be re-distributed in soil as thesoil layer is very deep (Hu Liangju, et al, 2000). It isdry on the mountain ridge and hilltop, but wet in thevalley. The characteristics of soil water distributionmake it difficult to conserve eco-environment in theLoe…     

陕西黄土高原苹果园土壤水分分异特征

采用定点监测法,对陕西省不同区域、生长年限、立地类型以及乔矮化果园的土壤水分分异特征进行研究.结果表明:陕西苹果园由南向北土壤贮水量逐渐降低,土壤水分亏缺加重;在干旱季节,北部丘陵沟壑区果园土壤水分亏缺度高达18.5％ ～47.5％,黄土残塬区为7.8％～20.3％,关中平原仅有1.2％～6.3％;在生长季内,随土壤深度增加,土壤含水量变异程度减弱;北部丘陵沟壑区的变化主要发生在2.2m以上土层内,CV值达12.67％ ～ 35.32％;黄土残塬区主要在1.8m以上土层内,CV值11.72％ ～24.54％;关中平原主要在1.2m以上土层内,CV值13.63％ ～20.76％;同一区域的果园土壤剖面贮水量随果树年龄增大而下降;在北部丘陵沟壑区,坡地的土壤水分含量最高,台地次之,梯田地相对较低;在残塬沟壑区,塬地的土壤水分含量最高,川地次之,台地相对较低;同一密度矮化果园的土壤含水量高于乔化果园,但栽培密度大的矮化果园土壤贮水量低于密度小的乔化果园.     

Effects of different vegetation restoration models on soil microbial biomass in eroded hilly Loess Plateau, China

Vegetation restoration is a key measure to improve the eco-environment in Loess Plateau, China. In order to find the effect of soil microbial biomass under different vegetation restoration models in this region, six trial sites located in Zhifanggou watershed were selected in this study. Results showed that soil microbial biomass, microbial respiration and physical and chemical properties increased apparently. After 30 years of vegetation restoration, soil microbial biomass C, N, P (SMBC, SMBN, SMBP) and microbial respiration, increased by 109.01%–144.22%, 34.17%–117.09%, 31.79%–79.94% and 26.78%–87.59% respectively, as compared with the farmland. However, metabolic quotient declined dramatically by 57.45%–77.49%. Effects of different models of vegetation restoration are different on improving the properties of soil. In general, mixed stands of Pinus tabulaeformis-Amorpha fruticosa and Robinia pseudoacacia-A. fruticosa had the most remarkable effect, followed by R. pseudoacacia and Caragana korshinkii, fallow land and P. tabulaeformis was the lowest. Restoration of mixed forest had greater effective than pure forest in eroded Hilly Loess Plateau. The significant relationships were observed among SMBC, SMBP, microbial respiration, and physical and chemical properties of soil. It was concluded that microbial biomass can be used as indicators of soil quality. __________ Translated from Journal of Natural Resources, 2007, 22(1): 20–27 [译自: 自然资源学报]     

黄土高原小流域水土保持与雨水利用技术措施研究

黄土高原气候干旱少雨，粮食产量低下，其原因不仅仅是天然降水不足，更主要的是（1）土质疏松，水土流失严重；（2）蒸发强烈，土壤深层蓄水有限；（3）作物水分利用效率低。基于国内有关专家学者的研究和鹿马岔流域治理经验，目前提高雨水利用率的有效技术主要有：1，改造坡地小地形，最大限度地拦蓄降水；2，调整农业用地结构，增加林草植被和其它形式的覆盖，减少地面蒸发，提高雨水利用效率；3，合理耕作，提高土地渗水保水能力；4，修筑蓄水窑窖，应用滴灌，渗灌技术发展庭院经济，建立雨水高效拦蓄利用系统。     

Review and proposals on vegetation restoration in the Loess Plateau, Northwest China

A group of scientists conducted a comprehensive investigation on ecological safety and water and soil erosion in the Northwest Loess Plateau, Northwest China. The data gathered was analyzed in terms of achievement, existing problems, and strategy and measures on vegetation restoration in the area. Since the policies of conversion from cropland to forest (CCF) and forbid grazing and cutting (FGC) were carried out, vegetation quality and coverage rate increased quickly in the Loess Plateau area, strengthening the concept of eco-environment protection. Environment harness measurements were optimized. The multiform investments on eco-environment and urbanization development in China will benefit vegetation restoration. However, there have been some persisting problems, such as the shortage of investment, instability of government policy, expectation of extravagant economic benefit, larger rate of plantation, and scarce technologies supporting vegetation restoration. Many key theories and practice problems require an urgent resolution. In the future, short-, mid-, and long-term goals for vegetation restoration should be clear, achievement should be expanded, and the natural restoration area should be increased. The benefit for the contractor on vegetation restoration should be ensured. Investment on vegetation building research work should be increased. __________ Translated from Scientia Silvae Sinicae, 2007, 43(1): 102–106 [译自: 林业科学]     

Factors affecting transpiration of Pinus tabulaeformis in a semi-arid region of the Loess Plateau

The effects of soil water and meteorological factors affecting transpiration of Pinus tabulaeformis were studied under different levels of soil water content to offer a scientific basis for increasing efforts in afforestation survival and management of soil water in forested land. Under artificial control methods for soil water and potting experiments, the transpiration rate (T _r) of P. tabulaeformis and environmental factors were measured using a portable steady porometer (Li-1600) and a speedy weight method (BP-3400) during a representative fine day in the growing season of 2004. The results indicated that the diurnal course of T _r and R _st of P. tabulaeformis displayed a double-peaked curve and a “W” curve under different levels of soil water content. Given a representative fine day, the T _r could be represented as a cubic relation with soil water content (SWC). The SWC which caused maximum T _r values of P. tabulaeformis was 17.7%, 19.8%, and 17.5% in July, August and October respectively. T _r was affected not only by physiological characteristics, but also by SWC and meteorological factors. T _r was significantly correlated with meteorological factors when the soil water was sufficient, but this correlation would decrease under conditions of serious water stress. Under such stress conditions, air temperature was the primary factor to affect T _r in July and August and photosynthetically active radiation (PAR) was the primary factor in October. When soil water is sufficient, the main factors affecting T _r were relative humidity (RH), air temperature (T _a) and leaf temperature (T _l) in July, August and October respectively. __________ Translated from Science of Soil and Water Conservation, 2007, 5(1): 49–54 [译自: 中国水土保持科学]     

渭北主要造林树种细根生长及分布与土壤密度关系

采用野外样地调查和盆栽试验的方法 ,研究了土壤密度对渭北主要造林树种细根生长及分布特征的影响。结果表明 ,在 0～ 10 0cm的深度内 ,不论是阴坡还是阳坡 ,油松林地的土壤密度均表现出随土层的加深逐渐增大的趋势 ;刺槐林地的土壤密度大于油松林地 ,且各土层间的差异不大。油松林地各土层土壤密度与不同径级根系长度存在显著的负相关关系。盆栽基质密度对不同树种苗木根系的生长和发育的影响虽各异 ,但在基质密度和孔隙度适中的条件下均生长良好 ,生物量达到最大。盆栽基质的密度对刺槐和油松根系的生长和发育的影响最显著 ;侧柏和山杏的细根生长发育受土壤密度的影响较小 ,其根系生物量在不同密度的基质中没有明显变化。     

黄土高原和六盘山区森林面积增加对产水量的影响

[目的]定量评价黄土高原地区造林对流域产水量的影响,指导林水协调的林业发展和森林管理。[方法]综合分析多年在黄土高原、泾河流域、六盘山区开展的森林产流影响的多尺度研究结果。[结果]在黄土高原区域尺度,林地平均年径流(16 mm)比非林地(39 mm)减少59%;在典型流域尺度(泾河干流上游流域),森林年均产水量(76 mm)比自然草地减少51%,其中,半湿润土石山区的森林年均产水量(88.8 mm)比自然草地减少58%;在典型小流域尺度(半湿润的香水河小流域),完全覆盖森林后的年均产流比无森林覆盖情景减少59%。森林增加导致的年产流减幅在干旱地区和干旱年份会更大,并可能超过100%,如年降水量低于450 mm的黄土流域、半干旱的泾河上游黄土区的林地及半干旱的叠叠沟小流域的坡面乔木林分样地,其年产水量常为零或负值,即需消耗土壤水分和坡上汇入径流等维持生存。低度间伐不能显著减少森林蒸散耗水。[结论]在黄土高原研究的小流域、流域和区域空间尺度内,造林减少年产流量的平均幅度都在50%~60%以上,且随干旱程度的增加可达到100%,并因消耗降水外的其他水源而出现负产流。需依据水分承载力合理选择待恢复植被类型和确定森林覆盖率,这是保障区域供水安全和实现林水协调管理的基本途径。     

黄土区人工林草植被深层土壤干燥化研究进展

黄土高原地区深层土壤干燥化(土壤干层)是人工林草植被过度耗水导致土壤水分负平衡的结果。概述土壤干层的研究进展,包括土壤干层的特征、类型、量化指标、成因、分布、危害及其缓减对策,指出当前研究中存在的问题,对今后研究提出建议。     

沙棘的水土保持功能及其在治理和开发黄土高原中的作用(英文)

研究表明 ,5～ 7年生沙棘林冠层可截留降水 8 5%～ 4 9 0 % ,并降低雨滴动能 ;枯枝落叶层重5 4 6t·hm- 2 ,其最大持水量可达 15 31t·hm- 2 ,有 1cm厚枯枝落叶层覆盖地表 ,即可基本控制水土流失 ;根系可以提高土壤的抗冲性和抗蚀性 ,与无根系土壤相比 ,可减少土壤冲刷量 55%～ 88% .据1988～ 1994年雨季径流小区测定 ,沙棘林在栽植后 4～ 5年可充分发挥水土保持作用 ,与农地相比 ,可减少地表径流量 87 1% ,减少土壤流失量 99 0 % .此外 ,它还可以每 4～ 5年提供薪材 10～ 30t·hm- 2 ,提高土壤中有机质和氮素含量 115%和 90 % ,生产沙棘果实 50 0kg·hm- 2 .所有这些表明了沙棘在治理黄土高原水土流失和改善人民生活条件 ,在实现由“恶性循环”向“良性循环”转变等方面 ,具有十分重要的作用 .目前 ,黄土地区已建立起若干利用沙棘固坡、防洪、解决燃料短缺和综合治理小流域的成功典型     

陇东黄土高原水土流失现状以及防治策略

陇东黄土高原位于甘肃省东部,是中国黄土自然地理最典型的地区,也是我国水土流失最大的水土区,同时也是黄河泥沙的主要输入区之一。从陇东区内水土流失现状入手,针对陇东黄土高原生态环境脆弱、水土流失严重、水资源短缺等实际的特点,概述了水土流失产生的自然和人类活动的主要因素,并对其发展趋势进行了分析,在此基础上提出了水土流失的治理措施和防治对策,对治理黄河流域水土流失、改善生态环境具有一定的理论价值。     

陕北黄土高原人工刺槐林生长与土壤干化的关系研究

通过对陕北黄土高原南北 6个人工刺槐林样地进行标准地调查 ,结合树干解析与土壤含水量资料 ,分析了人工刺槐林树高、胸径、材积等指标的生长状况与土壤含水量亏缺的关系。结果表明 ,土壤含水量的亏缺程度与刺槐林的生长有明显的一致性。南部的宜君降雨充沛 ,土壤含水量基本没有亏缺 ,没有产生明显的土壤干化现象 ,相应刺槐林的生长状况良好 ,没有产生衰退迹象。随着降雨量的减少 ,从富县开始 ,土壤含水量发生了严重程度不一的亏缺现象。富县样地因水分亏缺而形成的干化层已影响到了人工刺槐林的生长 ,林分已有了衰退的迹象。样地吴旗、安塞、绥德和米脂则土壤含水量亏缺严重 ,形成了明显的土壤干化层 ,并且严重影响到了人工刺槐林的生长和发育 ,导致人工刺槐林成为低效低产林 ,限制了林分的生态防护效益 ,说明这些地区属于不适宜人工刺槐林生长的分布区。