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岷江上游干旱河谷是我国西部生态环境最恶劣的地区之一,尤其是二十世纪末大量的人为活动更加速了生态环境的恶化,有的地方甚至出现逆向演替.为了给该地区植被恢复与重建中的树种选择提供依据,本实验以杂谷脑河干旱河谷区域内,自然生长的白刺花(Sophora davidiana)、马鞍羊蹄甲(Bauhinia faberi var.microphylla)、刺旋花(Convolvulus tragacanthoides)和铁杆蒿(Artemisia gmelinii)为研究材料,通过大量抗旱生理指标对它们的抗旱性进行了研究,发现4种灌木不仅在不同的生理指标上表现有差异,而且相同树种的同一指标在不同的生长时期也有差异.同时,由于单一(部分)抗旱指标对林木抗旱能力很难准确评价,本文采用了主成分分析法对4种灌木的抗旱能力进行了综合评价,结果发现4种灌木的抗旱能力大小表现为:白刺花>马鞍羊蹄甲>刺旋花>铁杆蒿.这为在该地区与及其类似地区造林树种的选择中,尤其可以在作为先锋灌木树种的选择中,选择抗旱能力较强的马鞍羊蹄甲、白刺花等乡土树种提供理论依据. 相似文献
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以沙荒地葡萄栽培中配置的滴灌、喷灌、低压管灌和“U”型渠灌4种灌溉系统为供试对象，通过对各节水系统的节水率等5项主要性能指标开展试验调查，依据结果进行量化综合评价，筛选出滴灌是适宜干旱荒漠地区果树栽培的节水灌溉系统。分析了节水灌溉面临的问题，提出了推广节水技术、建设节水工程所应采取的措施及建议。 相似文献
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树木水分胁迫生理与耐旱性研究进展及展望 总被引：101，自引：5，他引：101
水分亏缺是一制约树木生长的重要环境因子，尤其是在干旱与半干旱地区。水分胁迫的影响表现在树木生长发育的许多方面，阐明在这些表现背后的生理生化、遗传、耐旱机制无疑有助于耐旱性品种选育。本文从ＤＮＡ转录及表达、光系统Ⅰ、Ⅱ（ＰＳⅠ、ＰＳⅡ）、气孔运动、树木生长适应与响应、水分利用效率、抗旱机制、耐旱性指标筛选及转基因耐旱植物等方面，对近几年来国内外一些试验结果进行了评述和探讨，并对耐旱性指标筛选、耐旱性工程植物等提出了自己的观点。 相似文献
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从水资源利用现状谈节水灌溉技术的重要性 总被引：1，自引：0，他引：1
我国从分利用率低，用水浪费，用水严重亏缺。内蒙古是我国水资源严重亏缺省（区）之一，农业灌溉用水量为１２６６亿ｍ＾３，占全区开发用水量的８７．９％，推广节水灌溉技术，提高水分利用率远较其他地区重要。推广以色列节水灌溉技术后，仅用现在的用水量，即可使灌溉面积由现在的０．０１亿ｈｍ＾２增加到０．０２ｈｍ＾２，并可使单产大幅度提高。 相似文献
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沙区主要造林树种节水灌溉制度的研究 总被引：5，自引：0，他引：5
在和田绿洲外缘新开发区 ,采用滴灌技术营造常规经济林、防护林树种 ,收集试验区基本气象资料 ,用彭曼公式估算和田地区 3～ 10月作物的蒸发蒸腾量 ,根据各树种生长期内的需水特性 ,计算耗水强度、灌水定额 ,确定各树种的灌溉周期 ,灌溉定额。借此来指导在干旱区采用先进滴灌设备节水造林工作。 相似文献
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毛白杨幼林节水灌溉效益分析 总被引：3，自引：0，他引：3
通过连续８ａ对毛白杨幼林的控水灌溉试验，对灌溉的经济效益及节水效益进行了研究，并对沙地毛白扬幼林的节水浇灌技术进行了分析。结果表明：灌溉不仅促进林木在短期内速生，而且具有长期持续的增产效益；春夏干旱期内灌溉具有很高的经济效益，且随时间的增加不断增长；灌溉的土壤水分阈值和灌溉时期是实现节水灌溉的两项重要指标。在生长季节，特别是林木生长的关键时期，使土壤水分维持在田间持水量的５０％－６０％以上，就可获 相似文献
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园林植物耐盐性评价体系建立、耐盐碱园林植物筛选及其在盐碱地园林绿化中的应用至关重要,可为盐碱地区园林绿化树种选择提供依据,以维持生物多样性和生态稳定性。文中从园林植物盐胁迫处理方式及处理时间、植物耐盐性评价指标、数据分析等方面对盐碱区景观绿化植物耐盐性评价进行讨论,发现评价中存在指标多、周期长、结果多样性等问题。同时从地域和形态习性的角度对景观绿化植物耐盐性鉴定进行了梳理,将我国常见的343种绿化植物按耐盐级别进行了分类,其中特耐盐植物80种、强耐盐植物103种、中度耐盐植物93种、轻度耐盐植物55种;南方耐盐植物明显多于北方,在耐盐植物种类和数量上,灌木多于乔木,而草本较少。概述了耐盐碱园林绿化植物的应用现状,对如何解决我国园林植物耐盐性评价、鉴定和在实际应用中的诸多问题,以及我国耐盐碱园林植物研究方向进行了展望。 相似文献
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随着城市园林绿地面积的增加,城市水资源出现短缺,再加上极端气候的影响,节水抗旱技术的开发和应用是城市园林发展的必然趋势。文章讨论有机覆盖基质技术、节水灌溉技术、保水剂、抑制蒸腾剂4种节水抗旱技术的应用,以期为以后城市绿化节水抗旱提供对策。 相似文献
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综述了油橄榄灌溉需水量研究的基本方法和典型模型,阐述不同亏缺灌溉策略在油橄榄灌溉中的应用,并分析和比较不同灌溉制度在油橄榄灌溉管理上的优劣,以期对我国油橄榄灌溉管理研究和油橄榄生产提供借鉴。 相似文献
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Mature shrubs can provide microhabitats that are beneficial to tree seedling growth and development. Sugar pine trees (Pinus lambertiana) grow in a narrow zone on the eastern slope of the Carson Range in extreme western Nevada, whereas Jeffrey pine (Pinus jeffreyi) is the dominant tree species in the region, an area extensively disturbed by wild fire. This study compares seedling establishment of sugar pine and Jeffrey pine relative to mature shrubs. In the fall of 2002 (cohort 1) and 2003 (cohort 2), 13,600 seeds of both species were planted in wire mesh enclosures, at three sites, under a variety of microhabitat treatments: under shade and in the open, under two species of shrub cover, and with and without plant litter. Seedlings were monitored for survival through two growing seasons. Even though more sugar pine seedlings emerged, more Jeffrey pine seedlings survived, and Jeffrey pine was the more drought tolerant species, better suited for the xeric climate found in the Carson Range. Litter slightly hindered seedling emergence but had no effect on survival and there was no significant species × litter interaction. Supplemental water facilitated survival in all treatments with highest survival in shade treatments. Sugar pine seedlings showed a significant increase in survival over Jeffrey pine seedlings with the addition of water, particularly in open treatments and more of both species survived under manzanita shrubs with water. The highest seedling mortality occurred when shrub canopy was removed, and seedlings experienced the effect of full sun and competition for soil water. For either species, microhabitat is a significant factor in determining success or failure in rehabilitation efforts after disturbance. 相似文献
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随着城市化的不断推进以及全球气候变化的加剧,高温、干旱等极端气候频发,对城市园林绿化造成重大影响。城市道路绿化作为城市绿地一种典型的带状绿地,其对高温干旱气候的响应机制尚不明确。以2022年南昌市所遭受的极端高温干旱气候为契机,对南昌市经开区十五条主次干道绿化树种进行受害特征调查分析,结果表明：(1)受高温旱害影响的植株分布呈现出一定的空间聚集性和规律性,南北向道路植物受灾较为严重,东西向道路植物受灾情况相对较轻;(2)随着树下铺装面积的增加,乔木、灌木受损情况呈上升趋势;随着铺装透水率的增加,乔木、灌木受损情况呈下降趋势;(3)乔木个体越大、长势越好,其抗干旱能力越强;(4)对耐旱性较差、小胸径及低矮的树种及时养护。适当增加南北朝向道路的人工浇灌及管护频次。选择透水性较好的铺装,并适当减少树下铺装的面积,以此来缓解高温干旱对城市道路绿化的影响。 相似文献
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Soil water affects transpiration response to rainfall and vapor pressure deficit in poplar plantation 总被引：2，自引：0，他引：2
Lixin Chen Zhiqiang Zhang Tonggang Zha Kangle Mo Yan Zhang Xianrui Fang 《New Forests》2014,45(2):235-250
Influences of environmental factors on transpiration are interactive. Sensitivities of transpiration responses to both evaporative demand and rainfall under contrasting soil water conditions constitute the physiological basis of the drought tolerance of trees. Such knowledge is practically significant for plantation management, especially for irrigation management. We therefore conducted a 6-year study on the transpiration of a poplar plantation in temperate China to elucidate the existence and pattern of the influence of the soil water over stand transpiration responses to (1) vapor pressure deficit (VPD), the major indicator of air dryness and (2) the rainfall, in terms of total amount and event size. The results showed that the response of plantation transpiration (E c ) to VPD was conditioned by soil moisture. There was a significant difference in the frequency distribution of maximum sap flux under contrasting soil relative extractable water. E c after rainfall of different sizes varied under similar VPD. The increasing occurrences of only large rainfall events led to enhanced total E c during the growing season, but prolonged rainless intervals did not lead to a continuous decrease of E c , suggesting appreciable supplements from the soil water were present to sustain transpiration. In addition, the balance of soil water between replenishment and extraction also conditioned the influence of rainfall over subsequent E c during the respective rainless intervals. Based on the E c responses to VPD and rainfall under different soil moisture levels, irrigation that directly replenishes the deep soil layers in order to alleviate water stress on transpiration during the small-rain event-dominated growing season is an effective and water-saving approach to guarantee trees survival during drought period. 相似文献
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? Context
The knowledge of how shrub–seedling interactions vary with summer drought, canopy opening, and tree species is crucial for adapting forest management to climate change.? Aims
The aim of this study was to assess variation in shrub–oak recruitment associations along a south–north drought climate gradient and between two levels of canopy cover in coastal dune forest communities in a climate change-adapted forest management perspective.? Material and methods
Mapped data of associational patterns of seedlings of three oak species with interspecific pooled shrubs were analyzed using a bivariate pair correlation function in 10 (0.315 ha) regeneration plots located in forest and recent gap sites along the climate gradient. An index of association strength was calculated in each plot and plotted against a summer moisture index.? Results
The association strength increased with increasing summer drought from wet south to dry north and from closed forests to gaps.? Conclusion
Consistent with facilitation theory, our results suggest that climate change may shift associational patterns in coastal dune forest communities towards more positive associations, in particular in canopy gaps. In a perspective of climate change, foresters may need to conserve understory shrubs in gaps in order to promote oak species regeneration. 相似文献18.
Kitao Mitsutoshi Agathokleous Evgenios Harayama Hisanori Kitaoka Satoshi Uemura Akira Yazaki Kenichi Tobita Hiroyuki 《European Journal of Forest Research》2022,141(4):699-712
Improving drought tolerance of container seedlings of Japanese larch is of high importance to afforestation. We hypothesized that adequate nitrogen (N) and limited water supply would increase the tolerance of container seedlings to water-deficit stress, circumventing photoinhibition, by means of (i) enhanced photosynthetic capacity with higher leaf N and (ii) decreased water loss from leaves with lower biomass allocation into aboveground parts. Container seedlings of Japanese larch were grown under the treatment combinations of adequate (+?N: 300 mg N container?1) or limited (??N: 150 mg N container?1) N and adequate (+?W: daily irrigation) or limited (??W: twice-a-week irrigation) water. Then, seedlings were subjected to a progressive drought treatment. Higher leaf N was observed in container seedlings grown under?+?N and???W. During progressive drought, lower stomatal conductance and net photosynthetic rate were observed in leaves with higher leaf N at a given predawn leaf water potential. Furthermore, the maximum efficiency of PSII photochemistry (Fv/Fm) was lower in leaves with higher leaf N, suggesting that higher leaf N might impair intrinsic tolerance to drought at the leaf level contrary to expectations. Conversely,???N and???W seedlings with lower shoot biomass delayed soil drying as a whole-plant response via a reduction in leaf transpiration, leading to delayed photoinhibition as indicated by a decline in Fv/Fm. To circumvent stress at the initial stage of water deficit, lower leaf N via limited N regime and smaller shoot biomass driven by limited N and water regimes would be important.
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[目的]以喀斯特断陷盆地小流域中典型植被恢复模式,即桉树(Eucalyptus maideni)林、冲天柏(Cupressus duclouxiana)林、马尾松(Pinus massoniana)林以及天然次生灌丛、高盖度车桑子(Dodonaea viscosa)灌丛和低盖度车桑子灌丛为研究对象,探究断陷盆地不同植被恢复模式土壤水分时空变异规律,为该地区植被生态恢复工作提供参考。[方法]利用自动气象观测系统和土壤水分传感器同步监测2016年5月—2017年4月期间小流域降雨量与各林地土壤水分,采用变异系数与克里金插值分析方法,对6种植被恢复模式林地的土壤水分时空异质性以及持续干旱条件下土壤水分衰减特征进行研究。[结果]表明:(1)同一植被类型不同土层雨季和旱季土壤体积含水量垂直变化趋势相同,且雨季土壤水分含量显著高于旱季(P0.05),均为中等变异(Cv:12.88%28.66%)。(2)同一乔木林雨季和旱季的土壤活跃层与次活跃层垂直分布不同,但同一灌丛雨季和旱季分布相同。(3)6种植被恢复模式土壤体积含水量均在降雨量较充足的8—9月达到最大值,其变化范围介于26.25%44.08%之间,在降雨量明显不足的3—4月达到最小值,土壤体积含水量介于9.48%17.47%之间。(4)3种乔木林0 30 cm土层、3种灌丛0 10 cm土层充分降雨后约10 d土壤水分恢复为降雨前1 d水平,低盖度和高盖度车桑子灌丛10 30 cm土层土壤水分降雨后15 d恢复为降雨前1 d水平,并且接近植物萎蔫系数。[结论]不同植被恢复模式间雨季、旱季和月均土壤体积含水量均表现为桉树林天然次生灌丛冲天柏林马尾松林高盖度车桑子灌丛低盖度车桑子灌丛。喀斯特断陷盆地季节性干旱和临时性干旱问题严峻,乔木林和灌丛经充足降雨,达到田间持水量后,在连续放晴天气下林地土壤水分可供植物10 15 d的消耗。 相似文献
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In afforestation, studies of forest edges seldom span the effects of planting design and the self-designing capacities of spontaneous vegetation. This study revisited experimental forest edge sections 16 years after their establishment to assess the impact of five design elements on (1) horizontal and vertical edge structure, (2) growth of planted species and species groups, and (3) spontaneous establishment of woody vegetation. The design elements were: exposure to direct solar radiation; edge typology (shrub mixture, mixture of trees and shrubs, no edge planting); width of edge planting (5 or 10 m); species mixture principle (intimate mixtures or single species grouping); and planting row position from outermost to interior planting row (max. 6 rows). The results demonstrate that edge plantings support significantly more spontaneous woody vegetation than stand boundaries without such edge plantings. This result was consistent across the different design elements. Position across the planting rows from the outermost to innermost row was the most influential design element for the development of planted seedlings. Planted tree and shrub species of similar shade tolerance had contradicting development, where light-demanding pioneer tree species had obtained dominant positions while shade-tolerant shrub species had outgrown more light-demanding species. These results demonstrate that important successional processes can be activated by establishing the initial components and structures of forest edges. When designing such edges, species should preferably be allocated to different row cohorts reflecting their growth form and shade tolerance. 相似文献