梭梭和头状沙拐枣形态及生理生化特性对干旱胁迫的响应

目前,干旱和沙漠化等生态问题对植物的生存和适应提出新挑战。因此,探索植物的干旱适应策略对沙漠人工生态系统的维护和可持续发展具有重要意义。本研究采用灌溉(CK)和干旱(D)两个处理,研究塔克拉玛干沙漠防护林梭梭(Haloxylon ammodendron)和头状沙拐枣(Calligonum caput-medusae)生理生化和形态的适应情况。结果表明:形态上,两种植物的同化枝在干旱胁迫下均显著变短变细;生理上,两种植物在干旱胁迫下光合参数和羧化过程无显著变化,同化枝黎明水势显著降低,头状沙拐枣同化枝正午水势显著降低;生化上,两种植物的叶绿素a、叶绿素b、总叶绿素、光合酶含量在干旱胁迫下无显著变化。两种植物的初始荧光、最大荧光显著降低,梭梭的PSⅡ最大光化学效率显著升高。以上研究表明,两种植物以减缓同化枝生长和维持碳同化的方式抵御干旱。两种植物在干旱胁迫下光合色素活性降低,激发能力下降。头状沙拐枣稳定的叶绿素含量,使光化学系统免受损伤。

Damage by wind-blown sand and its control measures along the Taklimakan Desert Highway in China

Desertification is one of the most serious environmental problems in the world,especially in the arid desert regions.Combating desertification,therefore,is an urgent task on a regional or even global scale.The Taklimakan Desert in China is the second largest mobile desert in the world and has been called the''Dead Sea''due to few organisms can exist in such a harsh environment.The Taklimakan Desert Highway,the longest desert highway(a total length of 446 km)across the mobile desert in the world,was built in the 1990s within the Taklimakan Desert.It has an important strategic significance regarding oil and gas resources exploration and plays a vital role in the socio-economic development of southern Xinjiang,China.However,wind-blow sand seriously damages the smoothness of the desert highway and,in this case,mechanical sand control system(including sand barrier fences and straw checkerboards)was used early in the life of the desert highway to protect the road.Unfortunately,more than 70%of the sand barrier fences and straw checkerboards have lost their functions,and the desert highway has often been buried and frequently blocked since 1999.To solve this problem,a long artificial shelterbelt with the length of 437 km was built along the desert highway since 2000.However,some potential problems still exist for the sustainable development of the desert highway,such as water shortage,strong sandstorms,extreme environmental characteristics and large maintenance costs.The study aims to provide an overview of the damages caused by wind-blown sand and the effects of sand control measures along the Taklimakan Desert Highway.Ultimately,we provide some suggestions for the biological sand control system to ensure the sustainable development of the Taklimakan Desert Highway,such as screening drought-resistant species to reduce the irrigation requirement and ensure the sound development of groundwater,screening halophytes to restore vegetation in the case of soil salinization,and planting cash crops,such as Cistanche,Wolfberry,Apocynum and other cash crops to decrease the high cost of maintenance on highways and shelterbelts.

Growth and sustainability of Suaeda salsa in the Lop Nur,China

Extremely saline soils are very harsh environments for the growth and survival of most plant species, however, halophytes can grow well. The underlying mechanism of halophyte to resist high saline is not well understood by us. This study was conducted at the potash mine near the Lop Nur, China, where the effects of the halophyte Suaeda salsa L. on the saline-alkaline soils and its growth and sustainability were investigated. Four plots（in which the salt encrustation layers were removed）, with different soil treatments were evaluated：（1） undisturbed soil, with no additional treatment（T1）;（2） the slag soil zone, in which a 40-cm layer of slag was placed on the undisturbed soil surface（T2）;（3） slag＋sandy soil, in which a 20-cm layer of slag was placed in the lower layer and 20 cm of sandy soil, taken from an area about 70 km away from Lop Nur potash mine, where Tamarix species were growing, was placed in the upper layer（T3）; and（4） a 40-cm sandy soil layer taken from the area where Tamarix species were growing was placed on undisturbed soil（T4）. Soil nutrient contents increased in the four treatments, but salt content only decreased in the T1 treatment. Salt content in the T4 treatment increased over the two-year period, which may be partly attributed to salt deposition from wind-blown dust within the mine and salt accumulation within the surface soil（0–20 cm） in response to high evaporative demands. The S. salsa plants exhibited greater improvements in growth under the T4 treatment than under the T1, T2, and T3 treatments, which demonstrated that low levels of salinity are beneficial for the growth of this species. The T1 treatment was sustainable because of its low cost and superior soil improvement characteristics. Therefore, S. salsa plants not only reduced soil salinity and increased soil nutrient levels, but also ameliorated the plant growth environment, which would be beneficial for both the ecological restoration of the Lop Nur area and similar areas throughout the world.

葡萄越冬防寒技术研究综述

葡萄冻害严重影响着我国北方葡萄的正常生产和品质,采取适宜的越冬防寒技术是确保葡萄产业健康发展的关键。通过查阅我国北方地区有关葡萄防寒越冬的相关方法和技术,以葡萄冻害入手,分别从覆盖保温被、保温膜、草帘等保温材料,埋土覆盖越冬防寒措施以及积雪覆盖的保温作用等多方面,分析对比了各防寒越冬技术的材料、原理、效果及优缺点。提出了以下建议:(1)葡萄安全越冬应采取因地制宜的措施,对于葡萄本身来说应采用综合的葡萄抗寒性锻炼,提高葡萄抗寒能力。(2)在探索不同地区切实有效、经济实惠的防寒越冬措施时,需要充分注重细节;不同覆膜技术和埋土技术应因地制宜,选择适合的安全越冬方式;在温度不是太寒冷的地区可采用机械埋土技术。(3)应该继续开发机械覆膜技术,以节约经济和劳力投入。(4)基于双层膜技术的保温效果及经济投入状况,以及自身在环保、耐磨以及人力投入较大等自身不足等特点,建议选择双层膜环保耐磨新材料,结合机械化覆膜新技术,在寒冷且风沙强烈的地区加以大力推广,这可能是未来葡萄防寒越冬措施的发展趋势。

膨润土在沙漠化防治和生态恢复中的应用前景

从膨润土的特性、资源分布、土壤改良作用、在固沙材料中的应用等多个方面,综述了膨润土及其产品在沙漠化防治中的应用前景及存在的问题,提出膨润土复合产品在沙漠化防治和生态恢复中的发展思路,即根据膨润土复合产品的实际功效、经济投入、环保特性及可持续性等,筛选出价格低廉、功能高效、可以大规模生产及推广应用的多种膨润土复合产品,将其分别应用于沙漠到绿洲过渡带的生态恢复、人工林沙产业、林草退化区、戈壁、公路铁路渠道工程等防沙领域,综合改善沙区生态环境,实现膨润土复合产品在沙漠化防治和生态恢复中的健康发展。

7种荒漠木本植物枝干与叶片光合特征及其影响因素

枝干光合作用广泛存在于荒漠生态系统的木本植物中,增加了荒漠植物固碳能力。本研究以同一生境下胡杨、新疆杨、灰杨、梭梭、红果沙拐枣、头状沙拐枣、沙冬青7种荒漠木本植物为对象,采用Li-6400XT便携式光合仪结合特制光合叶室(P-Chamber),监测不同植物的枝干、叶片光合特征,分析枝干光合速率及其与叶片光合的关系,并对枝干功能性状指标[含水量、干物质含量、叶绿素含量、水势、非结构碳水化合物(NSC)等]进行测定,确定影响枝干光合的主要因素。结果表明:7种植物的枝干光合速率为0.72~1.71μmol·m^(-2)·s^(-1),其中最大的为灰杨,最小的为梭梭,可抵消枝干呼吸释放CO_(2)的57%~83%;7种植物的叶片光合速率为12.80~22.54μmol·m^(-2)·s^(-1),其中梭梭和沙冬青叶片光合速率显著低于其他5种荒漠植物;枝干光合速率与叶片光合速率存在显著正相关关系;枝干水分利用效率是叶片水分利用效率的2.2~7.7倍;枝干叶绿素含量、NSC含量、枝干呼吸速率及叶片光合速率是影响枝干光合的主要因素。

Functional zoning in national parks under multifactor trade-off guidance:A case study of Qinghai Lake National Park in China

Functional zoning is an important mechanism for achieving national park planning and management objective.Better functional zoning is of great significance to the protection of ecosystem legitimacy and integrity,the appropriate utilization of resources,community integration,and feasible management.In the present study,the proposed Qinghai Lake National Park is the research object.Based on the critical goal of ecological protection,the importance of ecosystem service functions and the ecological sensitivities were evaluated.The results showed that the ecosystem service functions and the ecological sensitivity of the whole region are high.Among them,lake,river and wetland as the most strictly protected ecosystems account for the highest proportion.Then this study divided the proposed Qinghai Lake National Park into five functional areas through grid calculations,spatial analysis and multifactor trade-off.The results indicated that the goal of functional zoning for national park is to maximize the overall utility of park protection value and its comprehensive functions based on its spatial units with different functions,management and control requirements.The zoning scheme addresses the lack of sustainable development in Qinghai Lake National Park due to ecological environmental changes and single-resource zoning with resource protection as the primary goal.This study can serve as a reference for spatial functional zoning methods of national land parks,nature reserves and other natural protected areas.