Scavenging Wind Energy by Triboelectric Nanogenerators

To meet future needs for clean and sustainable energy, tremendous progress has been achieved in development for scavenging wind energy. The most classical approach is to use the electromagnetic effect based wind turbine with a diameter of larger than 50 m and a weight of larger than 50 ton, and each of them could cost more than $0.5 M, which can only be installed in remote areas. Alternatively, triboelectric nanogenerators based on coupling of contact‐electrification and electrostatic induction effects have been utilized to scavenge wind energy, which takes the advantages of high voltage, low cost, and small size. Here, the development of a wind‐driven triboelectric nanogenerator by focusing on triboelectric materials optimization, structure improvement, and hybridization with other types of energy harvesting techniques is reviewed. Moreover, the major applications are summarized and the challenges that are needed to be addressed and development direction for scavenging wind energy in future are highlighted.     

Patterns of Bat Fatalities at Wind Energy Facilities in North America

Abstract Wind has become one of the fastest growing sources of renewable energy worldwide, but widespread and often extensive fatalities of bats have increased concern regarding the impacts of wind energy development on bats and other wildlife. We synthesized available information on patterns of bat fatalities from a review of 21 postconstruction fatality studies conducted at 19 facilities in 5 United States regions and one Canadian province. Dominance of migratory, foliage- and tree-roosting lasiurine species (e.g., hoary bat [Lasiurus cinereus]) killed by turbines was consistent among studies. Bat fatalities, although highly variable and periodic, consistently peaked in late summer and fall, coinciding with migration of lasiurines and other species. A notable exception was documented fatalities of pregnant female Brazilian freetailed bats (Tadarida brasiliensis) in May and June at a facility in Oklahoma, USA, and female silver-haired bats (Lasionycteris noctivagans) during spring in Tennessee, USA, and Alberta, Canada. Most studies reported that fatalities were distributed randomly across turbines at a site, although the highest number of fatalities was often found near the end of turbine strings. Two studies conducted simultaneously in the same region documented similar timing of fatalities between sites, which suggests broader patterns of collisions dictated by weather, prey abundance, or other factors. None of the studies found differences in bat fatalities between turbines equipped with lighting required by the Federal Aviation Administration and turbines that were unlit. All studies that addressed relationships between bat fatalities and weather patterns found that most bats were killed on nights with low wind speed (<6 m/sec) and that fatalities increased immediately before and after passage of storm fronts. Weather patterns may be predictors of bat activity and fatality; thus, mitigation efforts that focus on these high-risk periods could reduce bat fatality substantially. We caution that estimates of bat fatality are conditioned by length of study and search interval and that they are biased in relation to how searcher efficiency, scavenger removal, and habitat differences were or were not accounted for. Our review will assist managers, biologists, and decision-makers with understanding unifying and unique patterns of bat fatality, biases, and limitations of existing efforts, and it will aid in designing future research needed to develop mitigation strategies for minimizing or eliminating bat fatality at wind facilities.     

Risk Analysis of Wind Energy Investments in Turkey

ABSTRACT

Wind energy is a reliable source for fulfilling energy demand. However, the wind power usage remains limited due to the investmental risks. Governments’ support on renewable energy compensates these risks partially. Traditional investment evaluation techniques that do not consider the compensations and risks associated with the wind energy investments are one of the main reasons for the limited usage of wind power. In this study a real option and Monte Carlo simulation–based methodology, which considers both risks and compensations associated with these investments, is proposed to evaluate wind energy investments. The model is applied to a wind turbine investment in Turkey in order to show the applicability of the proposed model. The results indicate that the option value created through wind energy investments due to the governmental compensations is very high; therefore the traditional investment techniques are not appropriate for evaluating wind energy investments.     

Predicting Bald Eagle Collision at Wind Energy Facilities

Bald eagles (Haliaeetus leucocephalus) are currently protected in the United States under the Bald and Golden Eagle Protection Act of 1940 and Migratory Bird Treaty Act of 1918. Given these protections and the increasing development of wind energy throughout the United States, it is important for regulators and the wind industry to understand the risk of bald eagle collisions with wind turbines. Prior probability distributions for eagle exposure rates and collision rates have been developed for golden eagles (Aquila chrysaetos) by the United States Fish and Wildlife Service (USFWS). Given similar information has not been available for bald eagles, the current recommendation by the USFWS is to use the prior probability distributions developed using data collected on golden eagles to predict take for bald eagles. But some evidence suggests that bald and golden eagles may be at different risk for collision with wind turbines and the prior probability distributions developed for golden eagles may not be appropriate for bald eagles. We developed prior probability distributions using data collected at MidAmerican Energy Company's operating wind energy facilities in Iowa, USA, from December 2014 to March 2017 for bald eagle exposure rates and collision rates. The prior probability distribution for collision rate developed for bald eagles has a lower mean collision rate and less variability relative to that developed for golden eagles. We determined that the prior probability distributions specific to bald eagles from these operating facilities are a better starting point for predicting take for bald eagles at operating wind energy facilities in an agricultural landscape than those developed for golden eagles. © 2021 The Wildlife Society.     

Robust Thin Films‐Based Triboelectric Nanogenerator Arrays for Harvesting Bidirectional Wind Energy

Wind‐driven triboelectric nanogenerators (TENGs) play an important role in harvesting energy from ambient environments. Compared to single‐side‐fixed triboelectric nanogenerator (STENG) arrays for harvesting single‐pathway wind energy, double‐side‐fixed triboelectric nanogenerator (DTENG) arrays are developed to harvest bidirectional wind energy. Electrical performances of the STENG and DTENG can be improved due to sticky, abrasive, and electrical properties of the Ti buffer layers among Al, polytetrafluoroethylene (PTFE), and polyimide (Kapton), configuring in triboelectric PTFE/Ti/Al and Al/Ti/Kapton/Ti/Al thin films. Short‐circuit current (I _SC), open‐circuit voltage (V _OC), and frequencies of the STENG and DTENG increase with increasing wind velocity ranging from 9.2 to 18.4 m s²¹, revealing that the moderate I _SC, V _OC, frequencies, and output powers of the STENG and DTENG reach 67 μA, 57 μA, 334 V, 296 V, 173 Hz, 162 Hz, 5.5 mW and 3.4 mW with a matched load of 4 MΩ at airflow rate of 15.9 m s²¹, respectively. Compared with counterparts of the single‐pathway‐harvested STENG arrays, the I _SC, durability, and stability of the bidirectional‐harvested DTENG can be dramatically improved by a 4 3 1 array connected in parallel because of the improved device configuration, stickiness, and abrasion by adhering Ti buffer layers. The durable DTENG arrays present a step toward practical applications in harvesting bidirectional wind energy for self‐powered systems and wireless sensors.     

Influence of Behavior on Bird Mortality in Wind Energy Developments

ABSTRACT As wind power generation is rapidly expanding worldwide, there is a need to understand whether and how preconstruction surveys can be used to predict impacts and to place turbines to minimize impacts to birds. Wind turbines in the 165-km² Altamont Pass Wind Resource Area (APWRA), California, USA, cause thousands of bird fatalities annually, including hundreds of raptors. To test whether avian fatality rates related to rates of utilization and specific behaviors within the APWRA, from March 1998 to April 2000 we performed 1,959 30-minute behavior observation sessions (360° visual scans using binoculars) among 28 nonoverlapping plots varying from 23 ha to 165 ha in area and including 10–67 turbines per plot, totaling 1,165 turbines. Activity levels were highly seasonal and species specific. Only 1% of perch time was on towers of operating turbines, but 22% was on towers of turbines broken, missing, or not operating. Of those species that most often flew through the rotor zone, fatality rates were high for some (e.g., 0.357 deaths/megawatt of rated capacity [MW]/yr for red-tailed hawk [Buteo jamaicensis] and 0.522 deaths/MW/yr for American kestrel [Falco sparverius]) and low for others (e.g., 0.060 deaths/MW/yr for common raven [Corvus corax] and 0.012 deaths/MW/yr for turkey vulture [Cathartes aura]), indicating specific behaviors or visual acuity differentiated these species by susceptibility to collision. Fatality rates did not correlate with utilization rates measured among wind turbine rows or plots for any species except burrowing owl (Athene cunicularia) and mallard (Anas platyrhynchos). However, mean monthly fatality rates of red-tailed hawks increased with mean monthly utilization rates (r² = 0.67) and especially with mean monthly flights through turbine rows (r² = 0.92). Fatality rates increased linearly with rates of utilization (r² = 0.99) and flights near rotor zones (r² = 1.00) for large raptor species and with rates of perching (r² = 0.13) and close flights (r² = 0.77) for small non-raptor species. Fatalities could be minimized or reduced by shutting down turbines during ≥1 season or in very strong winds or by leaving sufficiently large areas within a wind farm free of wind turbines to enable safer foraging and travel by birds.     

A Large-Scale Mitigation Experiment to Reduce Bat Fatalities at Wind Energy Facilities

ABSTRACT Until large numbers of bat fatalities began to be reported at certain North American wind energy facilities, wildlife concerns regarding wind energy focused primarily on bird fatalities. Due in part to mitigation to reduce bird fatalities, bat fatalities now outnumber those of birds. To test one mitigation option aimed at reducing bat fatalities at wind energy facilities, we altered the operational parameters of 21 turbines at a site with high bat fatalities in southwestern Alberta, Canada, during the peak fatality period. By altering when turbine rotors begin turning in low winds, either by changing the wind-speed trigger at which the turbine rotors are allowed to begin turning or by altering blade angles to reduce rotor speed, blades were near motionless in low wind speeds, which resulted in a significant reduction in bat fatalities (by 60.0% or 57.5%, respectively). Although these are promising mitigation techniques, further experiments are needed to assess costs and benefits at other locations.     

Wind Energy Development and Wildlife Conservation: Challenges and Opportunities

ABSTRACT Wind energy development represents significant challenges and opportunities in contemporary wildlife management. Such challenges include the large size and extensive placement of turbines that may represent potential hazards to birds and bats. However, the associated infrastructure required to support an array of turbines—such as roads and transmission lines—represents an even larger potential threat to wildlife than the turbines themselves because such infrastructure can result in extensive habitat fragmentation and can provide avenues for invasion by exotic species. There are numerous conceptual research opportunities that pertain to issues such as identifying the best and worst placement of sites for turbines that will minimize impacts on birds and bats. Unfortunately, to date very little research of this type has appeared in the peer-reviewed scientific literature; much of it exists in the form of unpublished reports and other forms of gray literature. In this paper, we summarize what is known about the potential impacts of wind farms on wildlife and identify a 3-part hierarchical approach to use the scientific method to assess these impacts. The Lower Gulf Coast (LGC) of Texas, USA, is a region currently identified as having a potentially negative impact on migratory birds and bats, with respect to wind farm development. This area is also a region of vast importance to wildlife from the standpoint of native diversity, nature tourism, and opportunities for recreational hunting. We thus use some of the emergent issues related to wind farm development in the LGC—such as siting turbines on cropland sites as opposed to on native rangelands—to illustrate the kinds of challenges and opportunities that wildlife managers must face as we balance our demand for sustainable energy with the need to conserve and sustain bird migration routes and corridors, native vertebrates, and the habitats that support them.     

Firm Type,Feed‐in Tariff,and Wind Energy Investment in Germany: An Investigation of Decision Making Factors of Energy Producers Regarding Investing in Wind Energy Capacity

The development of renewable and sustainable energy is advanced by public financial support. This is particularly so in the German Energiewende, which seeks to replace nuclear and fossil electricity generation with wind, sun, and biomass. We study the impact of the (changes in the) feed‐in tariff (FIT) policy on the investment in wind electricity generation capacity in Germany in the period 2000–2014. We estimate a generic investment model that includes this support mechanism, the cost of capital, investment risks such as wind and price volatility, and manufacturing costs. We discuss specific features for different types of wind energy investors, such as the incumbents, small private investors, diversified companies, and independent power producers. We find that a change in the FIT has a negative impact on investment capacity regarding the generation of wind energy: A one monetary unit increase in the variation of the tariff is to be associated with a decrease by 0.17 megawatts of wind capacity installed. We argue that it is policy uncertainty that makes investors shy away from making real investments. We also argue that the drivers for wind energy investment can differ along different types of firms. For the traditional power producers, especially electricity price volatility, construction costs, and carbon prices seem to matter. But for the other investor types, the FIT is crucial indeed.     

Dogs Detect Larger Wind Energy Effects on Bats and Birds

As wind turbine-caused mortality of birds and bats increases with increasing wind energy capacity, accurate fatality estimates are needed to assess effects, identify collision factors, and formulate mitigation. Finding a larger proportion of collision victims reduces the magnitude of adjustment for the proportion not found, thus reducing opportunities for bias. We tested detection dogs in trials of bat and small-bird carcasses placed randomly in routine fatality monitoring at the Buena Vista and Golden Hills Wind Energy projects, California, USA, 2017. Of trial carcasses placed and confirmed available before next-day fatality searches, dogs detected 96% of bats and 90% of small birds, whereas humans at a neighboring wind project detected 6% of bats and 30% of small birds. At Golden Hills dogs found 71 bat fatalities in 55 searches compared to 1 bat found by humans in 69 searches within the same search plots over the same season. Dog detection rates of trial carcasses remained unchanged with distance from turbine, and dogs found more fatalities than did humans at greater distances from turbines. Patterns of fatalities found by dogs within search plots indicated 20% of birds and 4–14% of bats remained undetected outside search plots at Buena Vista and Golden Hills. Dogs also increased estimates of carcass persistence by finding detection trial carcasses that the trial administrator had erroneously concluded were removed. Compared to human searches, dog searches resulted in fatality estimates up to 6.4 and 2.7 times higher for bats and small birds, respectively, along with higher relative precision and >90% lower cost per fatality detection. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.     

风洞技术在昆虫化学通讯研究中的应用

综述了昆虫化学生态学中所使用的风洞技术。内容包括风洞的构造 ,风洞的工作条件 ,风洞操作中的技巧和数据采集 ,昆虫在风洞中表现出的典型行为特征以及一些需要注意的问题     

Use of Upland and Riparian Areas by Wintering Bald Eagles and Implications for Wind Energy

Weather can shape movements of animals and alter their exposure to anthropogenic threats. Bald eagles (Haliaeetus leucocephalus) are increasingly at risk from collision with turbines used in onshore wind energy generation. In the midwestern United States, development of this energy source typically occurs in upland areas that bald eagles use only intermittently. Our objective was to determine the factors that cause wintering bald eagles to occupy riparian areas and riskier, upland areas. We tracked 20 bald eagles using telemetry in the Upper Midwest (MN, IA, MO, WI, IL, USA) during winter 2014–2015 and 2015–2016 and evaluated habitat use by eagles in response to variation in weather and time of year. Eagles used riparian areas more when wind speed and atmospheric pressure were low. Exclusive use of uplands was more frequent during weather systems with low pressure and high humidity and after long periods of cold weather. There was a non-linear response to time of year (measured by days before migration) in the frequency of exclusive use of uplands or riparian areas. Probability of exclusive use of either landscape was generally constant within 95 days prior to migration. The probability of use of riparian areas, however, was markedly less during dates >100 days before migration. Our results suggest that eagles are most likely to be exposed to wind energy developments located in upland areas during low pressure systems, after long periods of cold weather, and several months before the onset of spring migration. This information helps to better understand the factors influencing bald eagle habitat use in winter and will be useful to managers and developers wishing to establish effective strategies to avoid, minimize, and mitigate take, and to survey for mortalities at wind energy developments. © 2020 The Wildlife Society.     

Indirect Effects of an Existing Wind Energy Facility on Lekking Behavior of Greater Prairie‐Chickens

Rapid expansion of the wind energy industry has raised concerns about the potential effects of anthropogenic disturbance on prairie grouse. While efforts have been made to address the effects of wind energy facilities on measures of fitness, their effect on the behaviors of prairie grouse has been largely neglected. To address these concerns, we investigated the effects of an existing wind energy facility in Nebraska that became operational in 2005 on the lekking behavior of male greater prairie‐chickens Tympanuchus cupido pinnatus between March and May 2013. Given the potential for disturbance caused by wind turbine noise to disrupt acoustic communication and thus behavior, we predicted that males at leks close to, compared to far from, the wind energy facility would spend more time in agonistic behaviors, and less in booming displays. Given the potential for wind turbine noise to reduce the number of females attending leks (hereafter ‘female lek attendance’), we also predicted that males at leks close to the wind energy facility would spend more time in non‐breeding behaviors and less time in breeding behaviors than males farther from the facility. Although we found no effect of the wind energy facility on female lek attendance, males at leks closer to the wind energy facility spent less time in non‐breeding behaviors than those at leks farther away. However, distance from the wind energy facility had no effect on time spent performing booming displays, flutter jumps, or in agonistic behaviors. Given that lekking behaviors of males influence mating success, our results may have consequences for the fitness of prairie grouse breeding in the vicinity of wind energy facilities.     

Behavioral Responses of Bats to Operating Wind Turbines

Abstract Wind power is one of the fastest growing sectors of the energy industry. Recent studies have reported large numbers of migratory tree-roosting bats being killed at utility-scale wind power facilities, especially in the eastern United States. We used thermal infrared (TIR) cameras to assess the flight behavior of bats at wind turbines because this technology makes it possible to observe the nocturnal behavior of bats and birds independently of supplemental light sources. We conducted this study at the Mountaineer Wind Energy Center in Tucker County, West Virginia, USA, where hundreds of migratory tree bats have been found injured or dead beneath wind turbines. We recorded nightly 9-hour sessions of TIR video of operating turbines from which we assessed altitude, direction, and types of flight maneuvers of bats, birds, and insects. We observed bats actively foraging near operating turbines, rather than simply passing through turbine sites. Our results indicate that bats 1) approached both rotating and nonrotating blades, 2) followed or were trapped in blade-tip vortices, 3) investigated the various parts of the turbine with repeated fly-bys, and 4) were struck directly by rotating blades. Blade rotational speed was a significant negative predictor of collisions with turbine blades, suggesting that bats may be at higher risk of fatality on nights with low wind speeds.     

高寒沙地人工林的气流场特征与防风功能

人工造林是高寒沙地极具生态修复效益与生态挑战的治沙技术。该研究选取青海湖沙地8~10年生的沙棘、乌柳、樟子松和小叶杨人工林作为观测对象,采用手持气象仪结合样方调查方法观测林地2008~2018年的风况环境的时空变化,分析植株附近气流场和防风功能的植物种、高度层和年变化。结果表明：(1)植株株后的气流降幅(20%~85%)和植株有效防护距离(1.0~10.0 m)存在显著的植物种和高度层差异,乌柳和小叶杨(50%~85%,3.5~8.0 m)均大于沙棘和樟子松(20%~65%,1.0~2.0 m)。(2)植株附近流速的方位差异表现为株前>株侧>株后,流向上的方位差异较小;多株植物间的南北通道和中心区成为气流高速区。(3)人工林地植物的防风功能主要表现在中下层(风速降幅18%~76%),且表现为樟子松>乌柳>沙棘>小叶杨,在10年间增长了5%~15%,对应各林地地表输沙率近6年降低了30%~90%,临界起沙风速增大2.0~3.0 m/s。研究发现,人工林的防风机制主要为营造植株不同部位的令流速流向差异来削减风能,4种人工林植物的适宜造林规格为1.0~2.0 m。     

On the Transport of Nematodes by the Wind

The possible effectiveness of atmospheric transport of nematode forms (dry larvae or eggs) as a means for introducing new species to a given environment is examined. Given the measured sedimentation velocities for a range of forms (0.1 ≥ Ws ≥ 0.6 mps), the necessary conditions on the wind speed required for natural erosion are defined. With these results scenarios for lofting, transport, and diffusion of these forms are examined using relevant gaussian plume models. Results indicate that on rare occasions individuals can be deposited up to 40 km from their original location. Redepositions up to 5 km per erosion event should be fairly common occurances when dry loose soil conditions or dry tillage operations combine with optimal atmospheric conditions and the presence of significant numbers of nematodes at the surface.     

Bird Mortality in the Altamont Pass Wind Resource Area,California

Abstract The 165-km² Altamont Pass Wind Resource Area (APWRA) in west-central California includes 5,400 wind turbines, each rated to generate between 40 kW and 400 kW of electric power, or 580 MW total. Many birds residing or passing through the area are killed by collisions with these wind turbines. We searched for bird carcasses within 50 m of 4,074 wind turbines for periods ranging from 6 months to 4.5 years. Using mortality estimates adjusted for searcher detection and scavenger removal rates, we estimated the annual wind turbine–caused bird fatalities to number 67 (80% CI = 25–109) golden eagles (Aquila chrysaetos), 188 (80% CI = 116–259) red-tailed hawks (Buteo jamaicensis), 348 (80% CI = −49 to 749) American kestrels (Falco sparverius), 440 (80% CI = −133 to 1,013) burrowing owls (Athene cunicularia hypugaea), 1,127 (80% CI = −23 to 2,277) raptors, and 2,710 (80% CI = −6,100 to 11,520) birds. Adjusted mortality estimates were most sensitive to scavenger removal rate, which relates to the amount of time between fatality searches. New on-site studies of scavenger removal rates might warrant revising mortality estimates for some small-bodied bird species, although we cannot predict how the mortality estimates would change. Given the magnitude of our mortality estimates, regulatory agencies and the public should decide whether to enforce laws intended to protect species killed by APWRA wind turbines, and given the imprecision of our estimates, directed research is needed of sources of error and bias for use in studies of bird collisions wherever wind farms are developed. Precision of mortality estimates could be improved by deploying technology to remotely detect collisions and by making wind turbine power output data available to researchers so that the number of fatalities can be related directly to the actual power output of the wind turbine since the last fatality search.     

我国西南地区风速变化及其影响因素

基于110个台站日风速观测资料,对我国西南地区1969—2009年风速时空变化及其影响因素进行研究,结果表明:1969—2009年西南地区平均风速以0.24 m s-110a-1的速率显著降低,其中1969—2000年平均风速以0.37 m s-110a-1速率降低,而2001—2009年却以0.55 m s-110a-1的速率升高,各季节、非季风和季风期风速变化趋势与年序列相似。空间分布上,1969—2009年风速降低台站主要位于高海拔区,降低幅度呈现西高东低趋势。1969—2000年风速降低台站主要位于西藏高原、横断山区和云南高原。2001—2009年风速增加台站主要位于云南高原、横断山区和四川盆地。风速这种变化趋势一方面受大气环流影响,西风环流和季风环流风速的减弱可能是2000年之前风速降低的重要原因,而纬向风的加强则对2000年以来风速增强有重要贡献。另一方面,区域变暖是风速降低的关键诱因。     

Risk Management Model of a Micro-Grid Wind Farm

Micro-grid operation mode, which is the combination of a power grid and distributed generation, is the main way for saving investment, reducing energy consumption, and improving a power system's reliability and flexibility, but it has many risks in the process of implementation. In this article, the micro-grid generation structure of a wind farm was established, a processing flow chart of an intelligent management system was drawn, and a risk management model of a micro-grid wind farm was built from the angle of cost risk, including construction of cost risk and operation cost risk models. The construction cost risk model, grid-connected operation, and isolate-operation cost risk model of a micro-grid wind farm were set up by using a mathematical model that consisted of an objective function and constraint conditions. The accuracy of the model was verified through empirical analysis. This provides a reference and mirror for solving grid-connected wind energy problems and gives an important basis for wind energy risk policy-making, and for avoiding the risks in the process of planning, design, and operation management of a wind farm.     

沙蒿与油蒿灌丛的防风阻沙作用

沙蒿与油蒿广泛分布于我国沙漠地区,是沙地植被的重要建群种和优势种。在腾格里沙漠南缘半流动沙地,实测了两种典型固沙植物沙蒿与油蒿的防风阻沙作用,从灌丛空间构型对比分析了其防风阻沙机制。结果表明,沙蒿与油蒿灌丛均具有明显的降低风速作用,但油蒿灌丛较沙蒿灌丛具有更显著的防风作用,而且对灌丛后不同位置、近地面不同高度层风速的降低程度明显不同。在灌丛后6倍株高范围内,沙蒿灌丛对50cm高度风速降低程度显著大于20cm,而油蒿灌丛对近地面20cm高度层风速降低程度显著大于50cm。在相同风速下,油蒿灌丛后20cm高度平均风速是沙蒿灌丛的1/2,而50cm高度平均风速与沙蒿灌丛相近。同时,沙蒿灌丛阻沙作用弱,而油蒿灌丛具有明显的阻沙作用,单株积沙体积达到45.2±16.1dm3,积沙重量达到72.1±25.7kg,油蒿灌丛积沙量大小与灌丛结构间存在显著的正相关。研究表明,紧密型结构的油蒿灌丛是较松散型结构沙蒿灌丛更为理想的防风固沙植物,其灌丛分枝数多、分枝角度小、生物量大且多分布在近地面层是具有显著防风阻沙作用的根本原因,该结论可为干旱区防风固沙植被建设物种选择提供依据。