Contribution to the Cladonia mycota of Greece, including Cladonia graeca sp. nov.

From mid-elevation pine forest on the Aegean Sea island of Thasos 8 additional Cladonia species for the lichen mycota of Greece are reported.Most have a wide distribution in Europe and reach their southern limit in Greece.From schistose rock in the same area and on Evvia a new species is described,Cladonia graeca,which is probably related to C.macrophylla and C.decorticata but contains fumarprotocetraric acid instead of psoromic or perlatolic acid.     

Community Characteristics of Early Recovery Vegetation on Abandoned Lands of Shifting Cultivation in Bawangling of Hainan Island, South China

Shifting cultivation is a major form of agricultural practice in most parts of tropical regions worldwide. In places where the bush fallow period is excessively shortened or the period of cultivation is extended for too long, the rate of vegetation recovery and biodiversity on abandoned lands of shifting cultivation would decline. The recovery of the secondary plant communities could even be inhibited for a prolonged period because of grass occupancy. Because of the vital significance of the early recovery communities to secondary succession, we studied the community characteristics of early recovery vegetation on abandoned lands of shifting cultivation in Bawangling of Hainan Island. Measurements were made of the community composition and structure of early recovery vegetation. The sprouting abilities of different functional groups and different species in the same functional group, and the effect of the grass functional group on the composition and quantitative characteristics of tree and shrub functional groups were analyzed. Results indicated that only a few families, genera, or species apparently dominated in the early recovery vegetation on the abandoned lands of shifting cultivation and that deciduous species occurred with a rather high percentage in this early recovery community compared with the natural secondary or old growth forests. Smallsized individuals dominated the woody community. The abundance and basal area of sprouting stems for species in the tree functional group were greater than those of seeder stems, whereas the abundance and basal area of resprouters and seeders for species in the shrub functional group did not differ. The total abundance of stems for the community, stem abundances for species in tree or shrub functional groups, and for seeder or resprouter stems were all negatively correlated with coverage of the grass functional group. The mean sprouting ability in the tree functional group was greater than in the shrub functional group. The sprouting ability for different species in the same functional group was also significantly different.     

Plant biodiversity and its conservation strategy in the in-undation and resettlement districts of the Yangtze Three Gorges, China

The investigation on and conservation project of plant biodiversity in the inundation and resettlement districts of the Three Gorges region were carried out with the ongoing construction of the Three Gorges Dam. Based on the first-hand specimens collected for many years and the historical records, we found that there were about 1784 higher plant species, belonging to 762 genera of 170 families, which accounted for 59.19%, 75.30% and 85.85% of the total amount of species, genera and families in the Three Gorges region, including 27 species specific in these two districts. The shrub and grass communities were mostly distributed along the low-altitude river bank zone of the Yangtze River and were largely influenced by the dynamic water level of the Three Gorges reservoir area. The measurement of Shannon-Wiener and Pielou evenness indexes on 21 Pinus massoniana (Masson pine) communities distributed in the Three Gorges reservoir area was carried out, and results showed that the biodiversity of shrub layers was the highest, followed by grass layers, the middle, and tree layers, the lowest. Among the 11 typical shrub communities in this region, the abundance of shrub layers of Form. Rhus chinensis, Form. Cotinus coggygria var. cinerea, Form. Vitex negundo var. cannabifoliaand and Form. Coriaria sinica was relatively higher, which were 16, 26, 29 and 15, respectively. These four shrubs also showed high biodiversity index (H′), which were 1.791, 3.427, 2.949 and 1.718, respectively. Among the 9 grasslands mainly distributed along the river bank zone, 4 grassland communities with higher altitude (Form. Dicranopteris dichotoma, Form. Miscanthus floridutus, Form. Imperata cylindrica var. major and Form. Arthraxon hispidus) showed higher abundance and biodiversity, which were 1.697, 1.354, 1.144 and 1.018, respectively. Considering the inundation and resettlement districts, there were 22 vegetation types threatened by submersion, including 4 woody plant communities, 9 shrub communities and 9 grassland communities. The 6 shrub communities of Form. Securinega wuxiensis, Form. Bauhinia brachycarpa, Form. Geum aleppicum, Form. Distylium chinense, Form. Buxus henryi and Form. Myrsine africana would be fully submerged and part of Adianthum reniforme var. sinensis and Buxus ichangensis would be also submerged. At present, plant species conservation and monitoring stations in the Three Gorges region have been constructed, and more than 200 plant species have already been transplanted and conserved, including 37 threatened species listed in the China Plant Red Data Book and 11 local constructive species.     

中国地卷属地衣二新记录种

In addition to 25 species, 6 varieties and 17 forms of the lichen genus Peltigera accepted by Wei (1991), 2 species new to China in this genus are added to the Chinese lichen flora in present paper. Peltigera kristinssonii Vitik., Ann. Bot. Fennici 22: 291 (1985). Thallus folious, c. 10 cm in diam, upper surface gray-brown to brown, erect-tomentose and somewhat scabrous near the edge, glabrescent towards center, dull, lobes 1~1.5cm wide, 5~7 cm long, margins upturned to slightly downturned;…     

Impacts of variability of habitat factors on species composition of ichthyoplankton and distribution of fish spawning ground in the Changjiang River estuary and its adjacent waters

During June, August and October 2006, there were three multi-disciplinary surveys carried out in the Changjiang River estuary and its adjacent waters (122°00′–125°00′E, 27°50′–34°00′N) by R/V Beidou to study the species composition and abundance of ichthyoplankton (including fish eggs, larvae and juveniles), the spatial distribution of fish spawning ground and their relationship with habitat factors. There were 29, 29 and 25 grid stations sampled in the three cruises, respectively. The ichthyoplankton samples were collected by horizontally towing with a macro-plankton net (mouth diameter 80 cm, length 270 cm, mesh size 0.50 mm) at the sea surface, and the towing speed was 3.0 n mile/h at each sampling station. The towing lasted for 10 min. After hauling for each station, habitat factors including temperature and salinity were measured by Sea Bird-25 CTD. Samples were preserved in 5% formaldehyde solution immediately after sampling for analysis in laboratory. Since the trawl speed could not be accurately evaluated due to the effects of ocean currents and wind-induced wave, the amount of ichthyoplankton was evaluated by actual number of the sampling haul in each station. Ichthyoplankton collected were divided into three categories: dominant species, important species and main species by the index of relative importance (IRI). There are 71 species (including 1200 fish eggs and 2575 fish larvae and juveniles) collected during 3 cruises and 59 species have been correctly identified to species level, which belongs to 50 genera, 37 families and 9 orders; while 5 species can only be identified to genera level, 1 species only identified to family level and 6 species identified to order level. These 59 species identified to species level and 5 species identified to genera level are divided into three ecological patterns, i.e., brackish water species, neritic water species and coastal water species. Warm water species have 34 species in those 59 species identified to species level, accounting for 57.63%, warm temperature species have 25 species, accounting for 42.37%. According to the analysis of IRI, the dominant species are Engraulis japonicus (in June and August, that is important species in October), Scomber japonicus (in August), and Johnius grypotus (in October) during the survey; important species are Cynoglossus joyneri (in June and August), Trichiurus lepturus (in June, August and October), Gonorhynchus abbreviatus (in August), Stolephorus commersonii (in October), Saurida undosquamis (in October) and Saurida elongate (in October), and main species have 12 species in June, 9 species in August and 10 species in October, respectively. The amount of fish eggs and larvae of the dominant species, important species and main species (28 species) are 97.50% and 97.13% of the total amount of fish eggs and larvae, respectively, which are the important composition of fish eggs and larvae in the Changjiang River estuary and its adjacent waters.
In June and August of 2006, if compared with that in corresponding months in 1986, there are great changes in the habitat factors especially for temperature and salinity in the investigating areas: high salinity water from off-shelf is much closer to the coastal areas which results in the dramatic increase of sea surface salinity during all three surveys. Sea surface temperature, on the other hand, decreases distinctively in June, but significantly increases in August. The run-off of the Changjiang River greatly reduced due to the long-term drought in summer 2006, which is responsible for the great changes of habitat factors in the Changjiang River estuary and its adjacent waters. The habitat of the Changjiang River estuary is greatly changed, which consequently has significant influences on the spawning, breeding and the spatial distribution of spawning ground of neritic water species, such as Sardinella zunasi, Thryssa kammalensis, Thryssa mystax, Setipinna taty and S. commersonii ect, and coastal water species, such as Ilisha elongate and Konosirus punctatus ect.     

Impacts of variability of habitat factors on species composition of ichthyoplankton and distribution of fish spawning ground in the Changjiang River estuary and its adjacent waters

During June, August and October 2006, there were three multi-disciplinary surveys carried out in the Changjiang River estuary and its adjacent waters (122°00′–125°00′E, 27°50′–34°00′N) by R/V Beidou to study the species composition and abundance of ichthyoplankton (including fish eggs, larvae and juveniles), the spatial distribution of fish spawning ground and their relationship with habitat factors. There were 29, 29 and 25 grid stations sampled in the three cruises, respectively. The ichthyoplankton samples were collected by horizontally towing with a macro-plankton net (mouth diameter 80 cm, length 270 cm, mesh size 0.50 mm) at the sea surface, and the towing speed was 3.0 n mile/h at each sampling station. The towing lasted for 10 min. After hauling for each station, habitat factors including temperature and salinity were measured by Sea Bird-25 CTD. Samples were preserved in 5% formaldehyde solution immediately after sampling for analysis in laboratory. Since the trawl speed could not be accurately evaluated due to the effects of ocean currents and wind-induced wave, the amount of ichthyoplankton was evaluated by actual number of the sampling haul in each station. Ichthyoplankton collected were divided into three categories: dominant species, important species and main species by the index of relative importance (IRI). There are 71 species (including 1200 fish eggs and 2575 fish larvae and juveniles) collected during 3 cruises and 59 species have been correctly identified to species level, which belongs to 50 genera, 37 families and 9 orders; while 5 species can only be identified to genera level, 1 species only identified to family level and 6 species identified to order level. These 59 species identified to species level and 5 species identified to genera level are divided into three ecological patterns, i.e., brackish water species, neritic water species and coastal water species. Warm water species have 34 species in those 59 species identified to species level, accounting for 57.63%, warm temperature species have 25 species, accounting for 42.37%. According to the analysis of IRI, the dominant species are Engraulis japonicus (in June and August, that is important species in October), Scomber japonicus (in August), and Johnius grypotus (in October) during the survey; important species are Cynoglossus joyneri (in June and August), Trichiurus lepturus (in June, August and October), Gonorhynchus abbreviatus (in August), Stolephorus commersonii (in October), Saurida undosquamis (in October) and Saurida elongate (in October), and main species have 12 species in June, 9 species in August and 10 species in October, respectively. The amount of fish eggs and larvae of the dominant species, important species and main species (28 species) are 97.50% and 97.13% of the total amount of fish eggs and larvae, respectively, which are the important composition of fish eggs and larvae in the Changjiang River estuary and its adjacent waters.
In June and August of 2006, if compared with that in corresponding months in 1986, there are great changes in the habitat factors especially for temperature and salinity in the investigating areas: high salinity water from off-shelf is much closer to the coastal areas which results in the dramatic increase of sea surface salinity during all three surveys. Sea surface temperature, on the other hand, decreases distinctively in June, but significantly increases in August. The run-off of the Changjiang River greatly reduced due to the long-term drought in summer 2006, which is responsible for the great changes of habitat factors in the Changjiang River estuary and its adjacent waters. The habitat of the Changjiang River estuary is greatly changed, which consequently has significant influences on the spawning, breeding and the spatial distribution of spawning ground of neritic water species, such as Sardinella zunasi, Thryssa kammalensis, Thryssa mystax, Setipinna taty and S. commersonii ect, and coastal water species, such as Ilisha elongate and Konosirus punctatus ect.     

Variations in Growth, Photosynthesis and Defense System Among Four Weed Species Under Increased UV-B Radiation

Weed tolerance of UV-B radiation varies with species, and the radiation could affect weed ecology and management. Variations In growth, photosynthesis and defense system among four important agronomic weeds, Abutllon theophrastl Medlk, Amaranthus retroflexus L., Digitaria sanguinalis （L.） Scop and Chloris virgata Swartz, under Increased UV-B radiation （ambient and increased radiation at 2.7, 5.4 and 10.8 kJ.m^-2.d-1） were studied In the greenhouse experiment. After 2 weeks of radiation, the shoots＇ dry mass decreased with increasing UV-B radiation except for D. sanguinalis. The reduction in biomass was the result of changes in morphology and physiology. Higher levels of UV-B treatment decreased the leaf area, plant height, net photosynthetic rate and chlorophyll contents, while it increased the contents of wax and UV-B absorbing compound in all species, except for A. retroflexus, which did not increase significantly. The activity of superoxide dismutase, catalase, ascorbate peroxide and the content of ascorblc acid changed differently among the weed species as UV-B radiation increased. D. sangulnalls was the most tolerant and A. retroflexus the most sensitive to increased UV-B radiation. The results also show that the two grass species （D. sanguinalis and C. virgata） were more tolerant to UV-B radiation than the two broadleafed species （A. theophrasti and A. retroflexus）. The UV-B absorbing compound and leaf wax played Important roles against UV-B damages in the two grass weeds. The overall results suggest that weed community, competition and management will be altered by continuous ozone depletion.     

Phylogeny of genus Glossina (Diptera: Glossinidae) according to ITS2 sequences

The flies of genus Glossina (Diptera: Glossinidae) are an important vector of African trypanosomiases which cause diseases in humans and animals. The ribosomal DNA Internal Transcribed Spacer-2 (ITS-2) region sequences from different Glossina species were PCR-amplified and analyzed in order to construct a molecular phylogeny for genus Glossina. Trees generated by parsimony confirmed the monophyletic taxonomic placement of genus Glossina where fusca group species formed the deepest branch followed by morsitans and palpalis groups, respectively. The placement of Glossina austeni by both the traditional morphological and biochemical criteria has been controversial. Results presented here, based on ITS-2 locus sequence analysis, suggest that Glossina austeni can be placed into a separate subgenerus which forms a sister-group relationship with the morsitans group species.     

DNA Barcode ITS Effectively Distinguishes the Medicinal Plant Boerhavia diffusa from Its Adulterants

Boerhavia diffusa (B. diffusa), also known as Punarnava, is an indigenous plant in India and an important component in traditional Indian medicine. The accurate identification and collection of this medicinal herb is vital to enhance the drug’s efficacy and biosafety. In this study, a DNA barcoding technique has been applied to identify and distinguish B. diffusa from its closely-related species. The phylogenetic analysis was carried out for the four species of Boerhavia using barcode candidates including nuclear ribosomal DNA regions ITS, ITS1, ITS2 and the chloroplast plastid gene psbA-trnH. Sequence alignment revealed 26% polymorphic sites in ITS, 30% in ITS1, 16% in ITS2 and 6% in psbA-trnH, respectively. Additionally, a phylogenetic tree was constructed for 15 species using ITS sequences which clearly distinguished B. diffusa from the other species. The ITS1 demonstrates a higher transition/transversion ratio, percentage of variation and pairwise distance which differentiate B. diffusa from other species of Boerhavia. Our study revealed that ITS and ITS1 could be used as potential candidate regions for identifying B. diffusa and for authenticating its herbal products.     

中国蜈蚣衣科地衣多样性及区系研究

该研究通过对山西管涔山和五鹿山等区域采集的蜈蚣衣科地衣300余份标本的鉴定分析,结合已有报道,从物种多样性、空间分布特点、生境类型及区系成分等方面对蜈蚣衣科地衣进行研究,以明确中国蜈蚣衣科地衣物种组成及区系特点。结果表明：(1)中国蜈蚣衣科地衣共有7属197种54变种,饼干衣属(Rinodina)占绝对优势,约占蜈蚣衣科地衣总种数的30.5%。(2)中国蜈蚣衣科地衣多分布于新疆,蜈蚣衣属(Physcia)是该科中分布最广泛的属,但其中有26.4%的物种仅分布于单一地区。(3)蜈蚣衣科地衣生境类型多样,有树生、石生、藓丛生、土生和多生境5种,以多生境地衣为主(48.5%)。(4)中国蜈蚣衣科地衣的地理成分复杂,同时伴随多种区系成分,但以温带性质显著(占43.1%),东亚特色明显。(5)仅分布于中国的蜈蚣衣科地衣共4属10种,且主要分布于中国东北、西北和西南地区。     

新疆阿勒泰山两河源自然保护区地面生地衣的物种多样性

阿勒泰山地是我国著名水系额尔齐斯河和乌伦古河的发源地,该山地地衣植物的研究在中国乃至中亚都占有非常重要的科学地位。新疆阿勒泰山两河源自然保护区位于阿勒泰山东段,气候在新疆最为潮湿,其地衣植物种类十分丰富。作者在该保护区选择6个植被带类型,即山地荒漠带、山地草原带、针阔混交林带、针叶林带、亚高山草甸带、高山草甸带,研究了其地面生地衣植物的物种多样性特征。结果表明:阿勒泰山两河源自然保护区地衣植物区系成分丰富而且复杂,共有地面生地衣植物5科6属46种,以石蕊科种类最为丰富,约32种。该地区不同植被带类型下地面生地衣植物物种的S?renson相似性系数在0.200–0.739之间,以针阔混交林和针叶林带的相似性为最高(0.739),针阔混交林和高山草甸带地衣植物物种相似性最低(0.200)。各植被带地衣优势种中白边岛衣(Cetrarialaeuigata)、林鹿蕊(Cladoniaarbuscula)、佐木氏珊瑚枝(Stereocaulonsasakii)、鳞地卷(Peltigeralepido-phora)、喇叭粉石蕊(Cladoniachlorophaea)、东方鹿蕊(Cladinagrisea)等的重要值在0.5以上,其余优势种的重要值均在0.5以下;山地森林带地衣植物物种多样性最为丰富,在整个阿勒泰山两河源自然保护区地面生地衣植物群落中占据优势地位,为该地区地衣植物多样性的分布中心,是地衣植物多样性保护的关键地区。     

新疆北部小孢发属地衣初步研究

新疆北部山脉生态环境多样,是地衣生长分布的理想区域。作者根据多年的实地调查和前人研究资料,对新疆北部小孢发属（Bryoria Brodo＆D．Hawksw．）地衣的种类及其分布、地理成分和垂直分布进行了初步研究。结果表明,分布在新疆北部的小孢发属地衣共有10种,它们分别是钢灰小孢发B．chalybeiformis（L．）Brodo＆D．Hawksw．、刺小孢发B．cortfusa（D．D．Awasthi）Brodo＆D．Hawksw．、叉小孢发B．furcellata（Fr．）Brodo＆D．Hawksw．、暗褐小孢发B．知伽cem（Gyeln．）Brodo＆D．Hawksw．、绵毛小孢发B．1anestris（Ach．）Brodo＆D．Hawksw．、B．nadvornikiana（Gyeln．）Brodo＆D．Hawksw．、光亮小孢发B．nhidula（1’h．Fr．）Brodo＆D．Hawksw．、假暗褐小孢发B．pseudofuscescens（Gyeln．）Brodo＆D．Hawksw．、单一小孢发B．simplicior（Vain．）Brodo＆D．Hawksw．及毛状小孢发原亚种B．trichodesssp．trichodes（Michx．）Brodo＆D．Hawksw．等,主要分布在天山和阿勒泰山。新疆北部小孢发属地衣可划分为3种地理成分：（1）环北极-高山种Bryonachalybeiformis、鼠nhidula、且furcellata;（2）环低北极及北方种B．simplicior;（3）环北方种B．加唧cew、B．1anestris、B．nadvornikiana、B．pseudofuscescens。阿勒泰山和天山的小孢发属地衣具明显的垂直分布差异。     

The significance of the Northern Andes for lichens

Evaluation of the lichen flora of the Northern Andes must be based on a restricted number of better-known groups, probably less than 25% of the flora. This is because our knowledge of the taxonomy and distribution of lichens in the Tropics is still very incomplete. In the Andes, the groups with foliose and fruticose growth forms are particularly well represented; the crustose group seems less important. This is in contrast with the surrounding lowlands, where crustose is the dominant growth form. At higher taxonomic levels there is a resemblance in taxonomic composition with the cooler zones of the world, which disappears at the generic or sectional levels. A conspicuous morphological feature is the frequency of foliose lichens with linear, rhizinate, or ciliate lobes, probably an adaptation to very humid conditions. More than half of the species have a wide distribution throughout the Tropics or at least in the Neotropics. Among the more restricted taxa is a humid montane element. At the highest elevations a temperate element is apparent, usually with bicentric distribution in both hemispheres. Perhaps 10% of the species are known only from the region; local endemism is probably very scarce. A few taxa appear to be restricted to Ecuador and southern Colombia or Venezuela; so far, only a single species is known with certainty to be restricted to the humid paramos of Colombia. There are distinct affinities with the lichen flora of southeastern Brazil and the Caribbean-Central American area but not with the adjacent Guayana Highland.     

新疆地衣资源多样性研究进展

在生物多样性中,地衣是一类独特的生物。新疆地衣资源丰富,至今在新疆已定名的地衣有398种,隶属于98属;包括不完全真菌类地衣4属4、种。深入了解新疆地衣物种多样性和其生态环境及地衣的应用价值,有利于合理利用新疆的生物资源,有效保护生态环境。     

五种迁飞蛾类及非迁飞近似种前翅形状的数值分析

以翅面正投影周缘曲率为指标,对五种蛾类迁飞昆虫及与其近似的非迁飞昆虫的前翅翅形进行数值分析。结果表明,二者之间存在可以相互区别的差异：迁飞种类前翅前缘较平直,特别是前缘1/2处到翅尖的平均曲率绝对值显著小于非迁飞种类;而后缘1/2处到翅尖的平均曲率绝对值偏大,即这段后缘较弯曲,向外凸出,使翅外侧较宽阔。这种翅形特征较适合于利用气流进行远距离迁飞     

西藏地衣物种多样性的海拔梯度分析

根据西藏地衣分类和区系的文献资料,对西藏地衣物种多样性的海拔梯度进行了分析。267个分类群按照生长型或者基物被分为六组。每一组地衣的物种丰度随海拔增加呈现单峰曲线形式的变化。多数组物种丰度的峰值出现在海拔3400~3900m之间,对应于山地寒温带针叶林带的上半部分,比尼泊尔对应类群出现极值的海拔要高。此植物带谱内复杂的生态系统可能是物种多样性高的主要原因。壳状地衣物种丰度的峰值出现在5100~5400m区间则可能是因为该区内高大的树木的消失以及具有充裕的阳光。西藏的地衣物种多样性远低于尼泊尔,两地共有的物种数量很少。对西藏地衣物种多样性的调查不充分应当是其主要原因,因此今后中国地衣学工作者应当加强西藏地衣多样性的研究。     

The conservation of ground layer lichen communities in alvar grasslands and the relevance of substitution habitats

Semi-natural calcareous grasslands (alvars) are biodiversity hotspots in Northern Europe, particularly for herb layer plants. In the last century, traditional management has ceased, and the area of grasslands has declined due to extensive encroachment. We were interested in the drivers of ground layer (alias terricolous or epigeic) lichen communities. Our survey consisted of 86 habitat fragments in western Estonia, covering four types of historic alvar grasslands and three types of alvar-like habitats. We found that the ground lichen communities were primarily soil-type-specific, but were also affected by historic disturbances and land use change. In contrast to knowledge about herb layer communities, for which shrub encroachment has been shown to be main driver, the increased density of the herb layer and the reduced diversity of microhabitats were major drivers for the ground layer lichen community. These drivers caused a decrease in species richness, but only within the species of conservation value, and also led to a shift in the composition of lichen growth form from the dominance of squamulose and crustose towards fruticose lichens. We conclude that the traditional practice of restoring alvars by cutting shrubs is insufficient to maintain ground layer lichen biodiversity. Alvar maintenance practices should include grazing, which creates various small-scale ground disturbances and increases microhabitat heterogeneity. Alvar-like habitats originating from large-scale historic disturbances appeared to be suitable for calcicolous epigeic lichens, and can therefore be considered to be temporary substitution habitats, i.e. refugia for the regional species pool.     

Germination and seedling establishment of two annual grasses on lichen-dominated biological soil crusts

Biological soil crusts dominated by lichens are common components of shrub-steppe ecosystems in northwestern US. We conducted growth chamber experiments to investigate the effects of these crusts on seed germination and initial seedling establishment of two annual grasses; the highly invasive exotic Bromus tectorum L. and the native Vulpia microstachys Nutt. We recorded germination time courses on bare soil and two types of biological soil crusts; one composed predominantly of the lichen Diploschistes muscorum (Scop.) R. Sant. (lichen crust) and the other comprised of an assortment of lichens and mosses (mixed crust). Final germination on the lichen crust for both grass species was about a third of that on the bare soil surface. Mean germination time (MGT) was 3–4 days longer on the lichen crust compared with the bare soil. In contrast, there was no difference in germination percentage or MGT between the mixed crust and bare soil, and results were similar for both grass species. For both species, root penetration of germinating seeds on the lichen crust was lower than on the bare soil or mixed crust surfaces. The combined effects of the lichen crust on germination and root penetration resulted in an overall reduction in seedling establishment of 78% for V. microstachys and 85% for B. tectorum relative to the bare soil treatment. Our results clearly demonstrate that lichen-dominated biological soil crust can inhibit germination and root penetration, but the extent of these effects depends on the composition of the crust. Responsible Editor: Tibor Kalapos     

新疆天山西部山脉森林生态系统地衣群落结构的初步研究

 根据多年的研究资料并采用聚类分析方法对分布在天山西部山脉的地衣群落结构进行了研究。结果表明,分布在该地区的地衣种类形成了6种群落:1) 土星猫耳衣（Leptogium saturninum)＋矮石蕊(Cladonia humilis)＋兰灰蜈蚣衣（Physcia caesia）群落;2）黑穗石蕊（Cladonia amaurocr