白蚁对不同园林木本树种的危害调查

当前随着我国园林化城镇建设的加速,白蚁对园林植物的危害具有日趋加重的趋势。本文对27种木本园林树种进行了蚁害调查,结果表明,受白蚁危害较为严重的园林树种主要有樟树、木荷、女贞、广玉兰、刺槐、加杨等树种,而柚、柏木、苦楝、擦木、喜树等树种较抗白蚁的危害。这一结果为我国南方园林抗白蚁树种的选择提供了可靠的依据。     

8个乡土树种抗逆性对比研究

在半干旱地区内蒙古中部3个不同造林立地类型对当地的8个乡土树种进行亚区造林对比试验,调查了被试树种在自然状态条件下的生长特征,应用PV技术测定了其水分生理指标,测定了抗寒及抗春季干旱风的等级,运用综合指标(成活、保存率、抗旱水分生理、耐寒性等)分析各树种的抗逆性和对不同立地条件的适应能力。结果表明:柄扁桃、桃叶卫矛、荆条和山杏(对照)抗逆性强,毛樱桃、山桃抗逆性较强,酸枣(山西种源)、欧李(山西栽培种)为中等,臭椿较差。     

铜仁地区冬青卫矛主要病虫种类及综合防治方法

冬青卫矛(Euonymus japonicus L.)是铜仁地区重要的观赏绿化树种,俗称大叶黄杨,为观叶常绿小灌木,具有较高的观赏性、生态性等许多优点。近年来,由于地域间的苗本交流频繁,忽视了对病虫害系统管理,使得病虫害严重发生,轻者影响长势和观赏性,重者造成植株死亡。为此,笔者于2004～2005年对本地区冬青卫矛病虫害种类进行了调查,并初步摸清了冬青卫矛的主要病虫发生规律。1调查方法调查在本地区的铜仁职业技术学院、师专、师范、铜仁一中、军分区、绿化休闲山庄、森林公园、烟厂、政府机关、花果山、河边公园等绿化地段进行。各处绿化带冬青卫…     

毛乌素沙地立地类型划分与抗逆树种筛选

文中通过对毛乌素沙地立地条件和经长期自然淘汰保留下来的树种生态适应性调查分析,将毛乌素沙地划分出7种立地类型,应用综合评价法对不同立地类型上的树种进行适宜性评价,为毛乌素沙地治沙造林树种选择与配置提供科学依据.评价结果为固定沙地上筛选出最优树种7种,适宜性由大到小分别为柠条、沙柳、杨柴、花棒、樟子松、沙棘、沙地柏,较适...     

基于生态需求的城市绿地系统生态设计方法与应用——以辽宁省海城市为例

文中分析了海城市绿地系统现状,指出该区域内绿地系统存在着总量低、空间分布不均匀、绿化配置结构单一、整体生态服务功能低下等问题。从满足滞纳粉尘、SO2净化和维持碳氧平衡等生态需求的角度出发,综合分析得出海城市绿地覆盖率应达到40%~45%才能基本满足改善城市生态环境的需要;提出在绿地总量控制的前提下,通过增加绿地面积、优化树种配植结构、合理布局绿地生态空间等措施,提高绿地生态系统的服务功能,以充分发挥绿地在改善海城市生态环境和维护城市生态安全中的作用。     

华家岭防护林带不同树种生长特征分析

以地处陇东黄土丘陵区的华家岭防护林带不同树种为研究对象,采用样地调查法,对不同树种、不同密度、不同林龄防护林的生长特征进行调查研究.结果表明:1)属幼龄林的22a生云杉纯林和20a生油松纯林的平均胸径、平均树高、单株蓄积量现已超过或接近了平均林龄37.5a的成(过)熟杨树纯林;2)华家岭防护林带中各类林分的平均胸径、平均树高均与林分密度呈负相关性.受林分密度的影响,区域内云杉×杨树混交林的生长状况略好于杨树纯林,云杉纯林和油松纯林的生长状况优于云杉×油松、云杉×落叶松混交林;3)华家岭云杉林在10a～15a、25a ～ 30a期间的胸径生长较为显著,20a～ 25a期间的树高生长较为显著.     

阜新市主要园林树种叶片生态化学计量特征

以阜新市主要园林树种为研究对象,分析各树种叶片C、N、P化学计量特征。结果表明：园林树种叶片C、N和P含量分别为496~664 mg•g^-1、7.5~26.6 mg•g^-1和1.0~2.2 mg•g^-1,C/N、C/P和N/P分别为22.4~74.3、262~522和5.4~13.8,且叶片N含量与C/N和N/P之间显著相关（P＜0.001）。常绿针叶树种叶片N、P含量和N/P显著低于阔叶落叶树种（P＜0.05）,而C/N和C/P显著高于阔叶落叶树种（P＜0.05）;乔木树种叶片N含量和N/P显著高于灌木树种（P＜0.05）,而叶片P含量及C/N和C/P二者之间差异不显著（P＞0.05）,表明园林树种具有较高的储C能力及养分利用效率。根据叶片N/P发现,阜新市园林树种生长主要受N限制。     

天牛诱饵树种引诱星天牛效果调查

以宝鸡市植物园的月季作为诱饵树种,对天牛的引诱捕捉效果进行调查.结果表明,该园星天牛成虫出现的时间以6月份为主,6月中旬为羽化高峰期,在月季上捕捉到天牛成虫的数量占91％以上,在复叶槭上捕捉的天牛成虫占4.2％,其他树种上的天牛不足1％.月季可作为今后星天牛的首选诱饵树种,在月季园捕捉星天牛成虫是消灭天牛的有效措施.     

甘肃旱区5个经济林树种的苗期抗旱性综合评价

以核桃、枣、枸杞、沙棘和花椒5个树种的2年生苗木为试材,通过盆栽试验,测定了干旱胁迫处理下5个树种叶片的质膜透性、根系活力、丙二醛、叶绿素及渗透调节物质含量、抗氧化物酶活性等10个相关指标,并采用隶属函数法和灰色关联度法评价了5个树种的综合抗旱能力及各指标与树种抗旱性间的关系。结果表明:不同干旱处理下5个树种的抗旱性大小排列顺序不同,在对照处理下,核桃的隶属函数值最大,为0.5385,在重度胁迫下,则是花椒的最大,为0.5312。通过综合分析发现,5个树种的隶属函数值分别为花椒0.5610,核桃0.4992,枣0.4796,枸杞0.5028,沙棘0.5221,由此判断的5个树种抗旱性大小为:花椒枸杞沙棘核桃枣。在10个指标中,脯氨酸、膜透性、可溶性糖、可溶性蛋白、丙二醛和CAT 6项指标的关联度平均值可高达0.8562,可作为抗旱性鉴定的依据,而这6个指标代表的是渗透调节物质、酶活性系统和质膜过氧化3个体系,这些体系能充分反映5个经济林树种对干旱胁迫的适应性机制。     

晋西黄土区主要造林树种耗水量测算与分析

依据水量平衡原理,采用盆栽试验分别测算了晋西黄土区主要造林树种侧柏、刺槐、杏树和梨树在其生长季(4～10月)成熟单株树木的耗水量,并根据林地土壤水分动态及土壤水分特征曲线标定的各树种无效水界值,分析了各树种土壤水分供耗特点及其有效性.结果表明:①2002贫水年生长季降水量430.7 mm,试验树种同期耗水量约为430～470 mm,树木供耗失衡;2003丰水年降水量870.2 mm,耗水量约为450～510 mm,但降雨分配不均,5月和10月树木供耗也略有失衡.②不同树种年内土壤含水量变化趋势相近,而同月耗水量差异较大,同一树种不同月耗水量差异也较大,丰水年各试验地土壤水分状况要好于贫水年.③侧柏、刺槐、杏树和梨树无效水界值为8.0%,8.4%,9.4%和10.9%,侧柏较其它树种利用水分能力最强.贫水年林外单株树木土壤含水量在一段时间内低于对应树种的无效水界值,影响树木正常生长.单株树木依靠冬季和次年春季降水补充,生长季初期都能恢复到速效水水平.     

Gemmamyces bud blight of Picea pungens: a sudden disease outbreak in Central Europe

Due to its high tolerance to acid rain, the North American Colorado blue spruce (Picea pungens) has been among the most frequent substitute tree species used in reforestation programmes in spruce mountain forests in the Ore and Sudeten Mountains in the Czech Republic after destruction by sulphur dioxide pollution in the second half of the last century. This species was planted on more than 8800 ha of destroyed mountain forest stands in the Ore Mountains alone. New plantations prospered until a massive outbreak of the gemmamyces bud blight, first identified in 2009. The causal agent, Gemmamyces piceae, induced massive bud blight in infected trees – bud loss progressively increased to 70–80% or more, and because the trees were not able to replace the natural loss of older needles, they quickly withered and died. Many plantations disrupted by the pathogen had to be cut down. Although several resistant genotypes have been identified, the cultivation of this species in forest stands has no future in this area. Because this disease was also identified in several ornamental plantations in the area, the bud blight epidemic haunts public green space administrators and nursery and Christmas tree plantation owners. Other pathogens and pests, such as Lophodermium piceae, Sirococcus conigenus and Elatobium abietinum, have also been identified as involved in the damage to P. pungens.     

基于RS与GIS的包头市城市公园绿地休闲游憩服务半径研究

城市公园绿地是城市"社会-经济-自然"复合生态系统的重要组成部分,其休闲游憩服务半径是反映城市公园布局合理性的指标之一。以包头市建成区为典型的研究区,使用缓冲区分析法、引力模型法、费用加权距离法等结合调查问卷,分析了包头市公园绿地服务半径。结果表明:包头市公园绿地服务分布较合理,但布局仍有不足;问卷调查表明,包头市居民选择公园是为了锻炼身体和休闲游憩,距离因素是影响居民游园的主要因素。该研究为未来包头市城市规划提供了一个可供决策参考的依据。     

Spatial dynamics of aboveground carbon stock in urban green space:a case study of Xi’an,China

Greenhouse gas emission of carbon dioxide(CO2) is one of the major factors causing global climate change.Urban green space plays a key role in regulating the global carbon cycle and reducing atmospheric CO2.Quantifying the carbon stock,distribution and change of urban green space is vital to understanding the role of urban green space in the urban environment.Remote sensing is a valuable and effective tool for monitoring and estimating aboveground carbon(AGC) stock in large areas.In the present study,different remotely-sensed vegetation indices(VIs) were used to develop a regression equation between VI and AGC stock of urban green space,and the best fit model was then used to estimate the AGC stock of urban green space within the beltways of Xi’an city for the years 2004 and 2010.A map of changes in the spatial distribution patterns of AGC stock was plotted and the possible causes of these changes were analyzed.Results showed that Normalized Difference Vegetation Index(NDVI) correlated moderately well with AGC stock in urban green space.The Difference Vegetation Index(DVI),Ratio Vegetation Index(RVI),Soil Adjusted Vegetation Index(SAVI),Modified Soil Adjusted Vegetation Index(MSAVI) and Renormalized Difference Vegetative Index(RDVI) were lower correlation coefficients than NDVI.The AGC stock in the urban green space of Xi’an in 2004 and 2010 was 73,843 and 126,621 t,respectively,with an average annual growth of 8,796 t and an average annual growth rate of 11.9%.The carbon densities in 2004 and 2010 were 1.62 and 2.77 t/hm2,respectively.Precipitation was not an important factor to influence the changes of AGC stock in the urban green space of Xi’an.Policy orientation,major ecological greening projects such as "transplanting big trees into the city" and the World Horticultural Exposition were found to have an important impact on changes in the spatiotemporal patterns of AGC stock.     

Untersuchungen zur Bekämpfung von Beifußblättriger Ambrosie (Ambrosia artemisiifolia L.) mit herbiziden Wirkstoffen

Measures for the control of A.??artemisiifolia have to be adjusted to allow for the plant density in the stands. In Brandenburg and Saxony numerous locations of A.??artemisiifolia with low density of the species have been reported. For those stands eradication arrangements are scheduled and also practicable. Furthermore there are, especially in Brandenburg, agricultural areas with a high density of A.??artemisiifolia. The goal in these locations is the control of further spread, combined with the reduction of allergean potential. Approaches to the control A.??artemisiifolia are demonstrated by testing of herbicides in different agricultural crops. High efficacy (up to 100%) was reached in maize using approved herbicides. The active substance imazamox showed the highest efficacy against A.??artemisiifolia in peas. Cultiviation of tribenuron-tolerant sunflower varieties and the use of tribenuron-methyl offers the opportunity to eliminate the competition of A.??artemisiifolia even in strongly infested areas. In grass land and public green space the active substance clopyralid controls A.??artemisiifolia well. Non-selective active substances like glyphosate and glufosinate are appropriate to control A.??artemisiifolia in non-crop areas. Organic farming shows a reduction of A.??artemisiifolia taking adequate agricultural measures. However further spread of A.??artemisiifolia cannot be prevented in organic farming.     

基于分类回归树分析的棉花种植面积提取——以库、新、沙三县为例

以研究区2012年的HJ卫星CCD影像为数据源,通过物候历和主要农作物的光谱特征分析,确定棉花识别最佳时相。采用分类回归树分析（CART）的决策树方法提取棉花种植面积信息,并以农田实地调查样点和统计数据为参考对提取的棉花种植面积结果进行评价。结果表明,基于HJ-CCD数据,使用CART算法的决策树可以较好地提取棉花覆盖信息,最终提取的棉花种植面积总量精度为94．29％,位置精度为88．57％;本研究采用的决策树方法,操作方便、容易实现,分类结果较为实际,基本满足棉花种植面积遥感监测的需求,可对棉花种植面积估算和种植结构分析提供一定的参考。     

Metabarcoding and development of new real‐time specific assays reveal Phytophthora species diversity in holm oak forests in eastern Spain

The evergreen holm oaks (Quercus ilex subsp. ilex and Q. ilex subsp. ballota) are the most representative tree species in the Iberian peninsula and the main tree species in oak‐rangeland ecosystems (dehesas). Oak decline in western, central and southern parts of Spain has been associated with root rot caused by Phytophthora cinnamomi for decades. However, Phytophthora species such as P.  quercina and P. psychrophila have recently been found associated with Quercus decline in eastern Spain where calcareous soils are predominant. Soil and root samples from two Quercus forests presenting decline symptoms in two different geographical areas in eastern Spain (Carrascar de la Font Roja and Vallivana) were analysed by amplicon pyrosequencing. Metabarcoding analysis showed Phytophthora species diversity, and revealed that an uncultured Phytophthora taxon, named provisionally Phytophthora taxon ballota, was the predominant species in both areas. In addition, a real‐time PCR assay, based on the pyrosequencing results, was developed for the detection of this uncultured Phytophthora taxon, and also for the detection of P. quercina. TaqMan assays were tested on soil and root samples, and on Phytophthora pure cultures. The new assays showed high specificity and were consistent with metabarcoding results. A new real‐time PCR protocol is proposed to evaluate the implication of different Phytophthora spp. in oak decline in eastern Spain.     

空间竞争指数在华北土石山区天然次生林的应用

为了揭示森林群落内林木竞争关系,对比分析不同空间竞争指数的特点与关系,采用大小比数和开敞度对木兰围场国有林场管理局域内天然次生林林木竞争强度进行定量分析。研究结果显示:研究区天然次生林林分内各树种大小分化较为明显,平均大小比数为0.476;林分内不同种群和林木个体生长空间分配并不均匀,差异较大,全林分开敞度为0.282,处于不足状态;树种大小比数与开敞度呈负相关关系,但其相关性显著程度存在差异。大小比数与开敞度计算结果存在差异,且这一差异主要受控于两种指数对参照木与相邻木距离的不同处理方法。大小比数全面考虑了参照木与相邻木之间的大小关系,但忽略了参照木与相邻木之间的干扰程度随二者距离增大而降低的特性;开敞度虽然考虑了参照木与相邻木之间的距离,却又将参照木与相邻木抽象为没有大小的点与线,忽略了二者之间的大小关系。     

二歧法与多歧法结合应用于树木分类检索表的编制——以《乌鲁木齐园林树种分类检索表》编制为例

以《乌鲁木齐园林树种分类检索表》的编制为例,探讨了传统植物检索表在应用中存在的检索障碍。通过实地调查、文献查阅,并根据多年的教学、科研实践中野外采集、分类、鉴定所积累的第一手资料,采用二歧法和多歧法相结合,不按分类系统直接划分的方法编制了《乌鲁木齐园林树种分类检索表》,对传统的按分类系统,且只用二歧分类法编制检索表的格式进行了改良。该方法的主要优点：① 对于某一区域植物的检索鉴定,不受分类系统位置和分类单位等级的限制,便于使用;② 二歧法与多歧法相结合,更便于检索表的编制和应用,编排的种类过多时篇幅相对少,降低因植物种类多而产生的编排难度;③ 检索表选用简便通俗而稳定的性状特征,在整个生长季节对各种树木的鉴定几乎都不会出现因缺乏树种观察器官而产生的检索障碍。本检索表将会给该地区大中专院校的教学、科研和园林工作带来极大的方便。     

Objectives and Integrated Approaches for the Control of Brown Tree Snakes

The inadvertent introduction of the brown tree snake (Boiga irregularis) to Guam has resulted in the extirpation of most of the island's native terrestrial vertebrates, has presented a health hazard to small children, and also has produced an economic problem. Management of brown tree snakes is aimed at a number of objectives, the foremost of which has been to deter its dispersal through Guam's cargo traffic to other locations. Another objective is to reclaim areas on Guam for reintroduction of native wildlife. A related objective is the protection of small sensitive sites on Guam from brown tree snake intrusion, such as power stations or nesting trees and caves. A fourth objective is to contain and capture incoming brown tree snakes at destinations vulnerable to their introduction. A final objective is to control incipient populations in other areas beyond their native range. A number of control tools have been developed, or are being developed. The efficacy of each control method depends on the situation to which it is to be applied. The control methods are described individually and the suites of methods most suited to each management objective are discussed.     

Potential host range of four Phytophthora interspecific hybrids from Clade 8a

In recent years several interspecific hybrids have been reported in the plant pathogenic oomycete genus Phytophthora. Due to the large genotypic and phenotypic changes, these hybrids might have broader or more limited host ranges compared with their parental species. It is crucial to understand the host range of Phytophthora hybrids to minimize the economic losses caused by their infection. The potential host range of four hybrids belonging to Clade 8a of the Phytophthora phylogenetic tree was investigated in this study. Thirty species of herbaceous plants as well as eight species of woody plants were inoculated and monitored for any symptom of infection. In addition, the detached twigs of 32 tree species, fruits of six plant species, tubers of potato, and roots of carrot and sugar beet were investigated for susceptibility to these hybrids. Almost all hybrids caused severe rot on all tested fruits, tubers, and roots, although different isolates showed different pathogenicity on detached tree twigs. All hybrids tested had a different host range compared with their parental species: they were able to infect plants outside the host range of their parents, infect hosts of both parental species, although these parents did not have overlapping hosts, or, in some cases, they were not able to infect hosts infected by the parents.