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721.
记述在草Arthraxon hispidus (Thunb.) Makino(禾本科Poaceae)上发现的营自由生活的2种新瘿螨:草畸瘿螨Abacarus arthraxis sp. nov.和草花刺瘿螨Anthocoptes hispidus sp. nov.,二者均采自陕西秦岭山中。模式标本保存在安康学院农学与生命科学学院植物保护实验室。 相似文献
722.
《Basic and Applied Ecology》2014,15(5):435-443
Within Europe, mountain ecosystems are generally less invaded by exotic plant species than are lowland areas. This pattern is commonly attributed to climatic harshness, which limits invasive species presence, and higher propagule pressure and rates of disturbance in lowlands, which favours dissemination. However, the extent to which anthropogenic and natural disturbances contribute to invasive species presence in mountain and lowland environments remains unclear. We conducted field observations in a lowland and an upland region in France and measured environmental variables, estimated the natural and anthropogenic disturbance of plots invaded by Fallopia spp. and compared them to non-invaded plots. Based on generalised linear mixed models, the predictors of Fallopia spp. presence in the upland area only included anthropogenic elements such as the presence of a road or trail and frequentation by humans, whereas both anthropogenic parameters and natural components (light penetration, slope, presence of a road and of a watercourse) were retained as predictors for the lowland region. We calculated the odds of Fallopia spp. presence for the increase of one unit of each predictor. We conclude that the spread of Fallopia spp. in upland areas was mainly linked to human activity whereas dissemination of the species occurred both through humans and in natural ways in lowland areas, and this may be due to a more recent colonisation in the mountains. We therefore advise stakeholders to undertake actions in mountain areas to specifically limit the dissemination of exotic species by humans and to monitor areas of high invasion risk by exotic species, such as areas neighbouring trails and roads highly frequented by humans. 相似文献
723.
Stipa purpurea is among constructive endemic species in alpine meadow and steppe on the Qinghai–Tibet Plateau. To reveal the genetic diversity of this species and its relationship with geographic distribution pattern, we sampled eight populations across a northward transect with an increasing aridity gradient in the hinterland of Qinghai–Tibet Plateau. Their genetic diversity was quantified using eight intersimple sequence repeat (ISSR) primers. We found that S. purpurea had relatively low genetic diversity ( H e = 0.135) but significant genetic differentiation among populations ( G st = 0.391), indicating relatively more genetic diversity retained within populations. A Mantel test revealed a significant relationship between genetic and geographic distance in the S. purpurea populations. The genetic diversity tended to decrease with increasing latitude and longitude, while no significant relationship was found between genetic diversity and altitude, suggesting the possible influences of humidity and temperature on genetic diversity of alpine plant. We propose conservation measures for this plant on the plateau. 相似文献
724.
Nadia Corp Hitoshige Hayaki Takahisa Matsusaka Shiho Fujita Kazuhiko Hosaka Nobuyuki Kutsukake Michio Nakamura Miho Nakamura Hitonaru Nishie Masaki Shimada Koichiro Zamma William Wallauer Toshisada Nishida 《Primates; journal of primatology》2009,50(2):184-189
In 1998, four chimpanzees in the Mahale Mountains National Park, Tanzania, were observed wiping their mouths with non-detached
leaves or stalks of grass, or rubbing their mouths with a tree trunk or branch, especially while eating lemons. The number
of mouth-wiping/rubbing individuals increased to 18 in 1999. By 2005, 29 chimpanzees were documented wiping/rubbing their
muzzles in this way. Although it is difficult to determine whether the chimpanzees acquired this behavior as a result of trial
and error or social learning, the fact that chimpanzees at other sites perform this behavior with detached leaves or leafy
twigs much more often than with intact items suggests the possibility that cleaning with intact plant parts at Mahale spread
via social learning. 相似文献
725.
Middle-Late Devonian Radiolarians are recorded for the first time in the southern Ural Mountains in Bashkortostan, in a section of Kariukmas Mountain (Upper Eifelian) and on the southern slope of Argagan Mountain (Middle Frasnian). The new Late Eifelian assemblage is composed of 17 species of 11 genera, and Middle Frasnian radiolarians comprise 13 species of 7 genera of spherical, discoidal, pylomate, and spiny radiolarians. A new species, Primaritripus kariukmasensis, sp. nov., is described. The prevalence of discoidal forms in the oryctocenosis suggests shallow marine conditions in the Late Eifelian and Middle Frasnian basins. Two new biostratons, the Upper Eifelian beds with Primaritripus kariukmasensis and Middle Frasnian beds with Primaritripus chuvashovi, are established based on radiolarians. 相似文献
726.
Julie C. Pett-Ridge 《Biogeochemistry》2009,94(1):63-80
The input of phosphorus (P) through mineral aerosol dust deposition may be an important component of nutrient dynamics in
tropical forest ecosystems. A new dust deposition calculation is used to construct a broad analysis of the importance of dust-derived
P to the P budget of a montane wet tropical forest in the Luquillo Mountains of Puerto Rico. The dust deposition calculation
used here takes advantage of an internal geochemical signal (Sr isotope mass balance) to provide a spatially integrated longer-term
average dust deposition flux. Dust inputs of P (0.23 ± 0.08 kg ha−1 year−1) are compared with watershed-average inputs of P to the soil through the conversion of underlying saprolite into soil (between
0.07 and 0.19 kg ha−1 year−1), and with watershed-average losses of soil P through leaching (between 0.02 and 0.14 kg ha−1 year−1) and erosion (between 0.04 and 1.38 kg ha−1 year−1). The similar magnitude of dust-derived P inputs to that of other fluxes indicates that dust is an important component of
the soil and biomass P budget in this ecosystem. Dust-derived inputs of P alone are capable of completely replacing the total
soil and biomass P pool on a timescale of between 2.8 ka and 7.0 ka, less than both the average soil residence time (~15 ka)
and the average landslide recurrence interval (~10 ka). 相似文献
727.
TIAN-TIAN FENG FRANK T. VAN MANEN NA-XUN ZHAO MING LI FU-WEN WEI 《The Journal of wildlife management》2009,73(6):852-858
ABSTRACT Because habitat loss and fragmentation threaten giant pandas (Ailuropoda melanoleuca), habitat protection and restoration are important conservation measures for this endangered species. However, distribution and value of potential habitat to giant pandas on a regional scale are not fully known. Therefore, we identified and ranked giant panda habitat in Foping Nature Reserve, Guanyinshan Nature Reserve, and adjacent areas in the Qinling Mountains of China. We used Mahalanobis distance and 11 digital habitat layers to develop a multivariate habitat signature associated with 247 surveyed giant panda locations, which we then applied to the study region. We identified approximately 128 km2of giant panda habitat in Foping Nature Reserve (43.6% of the reserve) and 49 km2in Guanyinshan Nature Reserve (33.6% of the reserve). We defined core habitat areas by incorporating a minimum patch-size criterion (5.5 km2) based on home-range size. Percentage of core habitat area was higher in Foping Nature Reserve (41.8% of the reserve) than Guanyinshan Nature Reserve (26.3% of the reserve). Within the larger analysis region, Foping Nature Reserve contained 32.7% of all core habitat areas we identified, indicating regional importance of the reserve. We observed a negative relationship between distribution of core areas and presence of roads and small villages. Protection of giant panda habitat at lower elevations and improvement of habitat linkages among core habitat areas are important in a regional approach to giant panda conservation. 相似文献
728.
HENDRIK MÜLLER MARK WILKINSON SIMON P. LOADER CHRISTIAN S. WIRKNER DAVID J. GOWER 《Biological journal of the Linnean Society. Linnean Society of London》2009,96(3):491-504
The external and musculoskeletal morphology of the head is described for an ontogenetic series of the scolecomorphid caecilian Scolecomorphus kirkii . The rostral region of foetuses and juveniles is expanded into large, posterolaterally pointing paraoral processes that are formed by the maxilla. Extraoral teeth are present on the underside of the rostrum and laterally on the paraoral processes. In the foetuses, teeth are covered by epidermal tissue. The endoskeletal part of the foetal skull is largely cartilaginous, but all of the dermal bones, with the exception of the squamosal, are present. The foetal chondrocranium is extensively developed and shows a peculiar, posterolateral process of the nasal capsule that is connected to the trabecula cranii by a transverse bar posterior to the choana, and extends further posterior beyond the level of the posterior end of the pila antotica. Only two mm. adductor mandibulae are present, together with two pterygoideus muscles that insert onto the lower jaw. The palatoquadrate and quadrate of foetuses and juveniles, respectively, are highly mobile. It is suggested that the derived head morphology of Scolecomorphus foetuses and juveniles is an adaptation to specialized postparitive feeding. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 491–504. 相似文献
729.
The new species Caesia sabulosa Boatwr. and J.C.Manning from deep sands along the West Coast of South Africa and sandy flats in the Cederberg and Bokkeveld Escarpment is described. It is distinguished by its extensively branched rhizome resulting in a robust, clump-forming habit, and unique ‘palisade’ root system of closely packed, hard, vertical roots; mostly larger flowers; erect fruiting pedicels; and details of the seed testa sculpturing. 相似文献
730.
Steven D. Leavitt Jason Hollinger Sara Summerhays Isaac Munger Jonah Allen Barb Smith 《Ecology and evolution》2021,11(16):11090
Lichens are major components of high altitude/latitude ecosystems. However, accurately characterizing their biodiversity is challenging because these regions and habitats are often underexplored, there are numerous poorly known taxonomic groups, and morphological variation in extreme environments can yield conflicting interpretations. Using an iterative taxonomic approach based on over 800 specimens and incorporating both traditional morphology‐based identifications and information from the standard fungal DNA barcoding marker, we compiled a voucher‐based inventory of biodiversity of lichen‐forming fungi in a geographically limited and vulnerable alpine community in an isolated sky island in the Colorado Plateau, USA—the La Sal Mountains. We used the newly proposed Assemble Species by Automatic Partitioning (ASAP) approach to empirically delimit candidate species‐level lineages from family‐level multiple sequence alignments. Specimens comprising DNA‐based candidate species were evaluated using traditional taxonomically diagnostic phenotypic characters to identify specimens to integrative species hypotheses and link these, where possible, to currently described species. Despite the limited alpine habitat (ca. 3,250 ha), we document the most diverse alpine lichen community known to date from the southern Rocky Mountains, with up to 240 candidate species/species‐level lineages of lichen‐forming fungi. 139 species were inferred using integrative taxonomy, plus an additional 52 candidate species within 29 different putative species complexes. Over 68% of sequences could not be assigned to species‐level rank with statistical confidence, corroborating the limited utility of current sequence repositories for species‐level DNA barcoding of lichen‐forming fungi. By integrating vouchered specimens, DNA sequence data, and photographic documentation, we provide an important baseline of lichen‐forming fungal diversity for the limited alpine habitat in the Colorado Plateau. These data provide an important resource for subsequent research in the ecology and evolution of lichens alpine habitats, including DNA barcodes for most putative species/species‐level lineages occurring in the La Sal Mountains, and vouchered collections representing any potentially undescribed species that can be used for future taxonomic studies. 相似文献