首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
垫状植物是高寒地区广泛分布的一类具有特殊形态的植物,被称为高寒生态系统工程师,其在高寒退化草地中的作用如何?本研究以位于西藏当雄念青唐古拉山脉南坡4500m的一处高寒退化草地为例,调查了垫状点地梅覆盖区域内外的物种多样性、土壤养分以及水分的差异。结果表明:垫状点地梅可以显著改善土壤养分,提高幅度大约为16%-48%,其中有机质和总氮(N)分别增加了16.2%和18.9%;局部土壤含水量提高约12%;样方内的物种丰富度(S)、Shannon-Wiener指数(H)和Simpson指数(D)都随着垫状点地梅盖度的增加而呈增加的趋势。垫状点地梅在退化草地中具有显著的改善土壤微环境和提高群落物种多样性的作用,应加强保育以促进高寒退化草地的恢复。  相似文献   

2.
Abiotic environmental factors have a major impact on the distribution and performance of plant species. In order to assess two major species–environmental relations in Sudano-Sahelian Acacia woodlands, we tested the relationship of soil and climate variables on plant diversity as well as on species responses.The indicator species values clustered in five vegetation units characterized by three to ten diagnostic species with woody species richness means varying from three to seven species per 0.09 ha. The NMS ordination explained 65% of the variation in species composition and revealed that soil properties, annual precipitations and temperature range structured the diversity of Acacia communities. Along the annual precipitations gradient, the response of Acacia polyacantha and Acacia hockii showed maxima in the wettest zone of our study area (more than 850 mm/year) whilst Acacia laeta showed a maximum response in the driest zone (below 500 mm/year). The unimodal response of A. hockii, Acacia gourmaensis and Acacia seyal to the soil available water gradient spanned their central borders, respectively from 13 to 18% (optimum 16%), 11–20% (optimum 15%) and 4–12% (optimum 7.5%).The response of Acacia communities and species to soil and climate gradients, makes them performant afforestation species in specific habitats of the Sudano-Sahelian zone.  相似文献   

3.
We studied the effect of ant herbivory on the establishment and survival of the annual plant Schismus barbatus. We hypothesized that ants may control this species when biomass of native plants is generally low during their vegetative period. We predicted that ant herbivory will decrease plant survival and reproduction. We tested our prediction with an insect exclosure experiment in a sandy desert of Northern-Central Monte.We found more than 12 000 established seedlings per square meter on early May, after two consecutive rain pulses of ca. 20 mm each. Overall, we found that almost 75% of recruited plants survived by the end of the cool season (September), and that 22–24% of the initially established plants survived as mature reproductive plants by the end of the growing season (December). Contrary to our expectation, insect herbivory did not affect plant establishment, plant survival or the proportion of flowering and fruiting individuals of S. barbatus.The large number of seedlings reported, the ability to exploit a temporal window free of plant competitors and enemies, and the availability of microsites where this species can succeed, all suggest that S. barbatus may have the potential to become an important plant invader in the Monte Desert.  相似文献   

4.
研究了科尔沁沙质草地放牧和封育下植被盖度、密度、丰富度与地上生物量关系的季节变化。结果表明:放牧和封育草地4月的植被盖度、丰富度和生物量均低于生长旺季8月,而4月植物密度要高于8月;封育草地生长季盖度高于放牧草地,6月和8月生物量高于放牧草地, 4月和6月植物密度则低于放牧草地。封育草地8月物种丰富度与生物量呈极显著的负线性关系（p<0.01）;放牧草地植物密度与生物量4月表现出极显著的正线性关系（p<0.01）、8月为极显著的负线性关系（p<0.01）。放牧草地优势植物糙隐子草4月的密度和生物量呈极显著的正线性关系（p<0.01）、8月为极显著的负线性关系（p<0.01）;黄蒿和狗尾草8月的密度和生物量均呈极显著的负线性关系（p<0.01）;猪毛菜4月和6月的密度和生物量呈极显著的正线性关系（p<0.01）。封育草地达乌里胡枝子、猪毛菜8月的植物密度和生物量呈极显著的正线性关系（p<0.01）。持续放牧和季节变化及其二者的交互作用对植被盖度、密度和生物量均有重要的影响（p<0.05）;放牧通过影响草地生长季中的优势植物密度变化和生物量积累,引起了草地植物密度和生物量关系的季节变化,也导致生长季物种丰富度和生物量无显著关系;封育草地植物的竞争导致了物种丰富度和生物量关系的季节变化。  相似文献   

5.
雅鲁藏布江源头区的植被及其地理分布特征   总被引：5，自引：1，他引：4  
雅鲁藏布江源头区是国家级重要生态功能区,该区域自然背景资料极为缺乏。2002—06和2002—11,结合遥感影像数据,对源头区主要河谷典型地理环境位点植被进行了2次地面踏勘。结果表明：源头区主要植被类型有高寒草原、高寒草甸、高寒灌丛以及高寒垫状植物和流石坡植物。高寒草原类型主要有紫花针茅(Stipa pur purea)草原、青藏苔草(Carex moorcroftii)草原、固沙草(Orinus thoroldii)草原、藏白蒿(Artemisia younghusbandii)草原、藏沙蒿(Artemisia weiibyi)草原。高寒草甸主要类型有高山嵩草(Kobresia pygmaea)草甸、藏北嵩草(Kobresia littledalei)、三角草(Trikeraia hookeri)草甸。高寒灌丛的主要建群种有小叶金露梅(Potentilla parvifolia)、金露梅(Potentilla fruticosa)和变色锦鸡儿(Caragana versicolor)。在雪线附近有由多种高寒植物组成的垫状植物群落和流石坡稀疏植物。对群落的物种组成,分布区的土壤、水分等生态要素以及植被地理格局进行了概括性描述。  相似文献   

6.
How species diversity–productivity relationships respond to temporal dynamics and land use is still not clear in semi-arid grassland ecosystems. We analyzed seasonal changes of the relationships between vegetation cover, plant density, species richness, and aboveground biomass in grasslands under grazing and exclosure in the Horqin Sandy Land of northern China. Our results showed that in grazed and fenced grassland, vegetation cover, richness, and biomass were lower in April than in August, whereas plant density showed a reverse trend. Vegetation cover during the growing season and biomass in June and August were higher in fenced grassland than in grazed grassland, whereas plant density in April and June was lower in fenced grassland than in grazed grassland. A negative relationship between species richness and biomass was found in August in fenced grassland, and in grazed grassland the relationship between plant density and biomass changed from positive in April to negative in August. The relationship between the density of the dominant plant species and the total biomass also varied with seasonal changes and land use (grazing and exclosure). These results suggest that long-term grazing, seasonal changes, and their interaction significantly influence vegetation cover, plant density, and biomass in grasslands. Plant species competition in fenced grassland results in seasonal changes of the relationship between species richness and biomass. Long-term grazing also affects seasonal changes of the density and biomass of dominant plant species, which further affects the seasonal relationship between plant density and biomass in grasslands. Our study demonstrates the importance of temporal dynamics and land use in understanding the relationship between species richness and ecosystem function.  相似文献   

7.
Krameria plants are found in arid regions of the Americas and present a floral system that attracts oil-collecting bees. Niche modeling and multivariate tools were applied to examine ecological and geographical aspects of the 18 species of this genus, using occurrence data obtained from herbaria and literature. Niche modeling showed the potential areas of occurrence for each species and the analysis of climatic variables suggested that North American species occur mostly in deserted or xeric ecoregions with monthly precipitation below 140 mm and large temperature ranges. South American species are mainly found in deserted ecoregions and subtropical savannas where monthly precipitation often exceeds 150 mm and temperature ranges are smaller. Principal Component Analysis (PCA) performed with values of temperature and precipitation showed that the distribution limits of Krameria species are primarily associated with maximum and minimum temperatures. Modeling of Krameria species proved to be a useful tool for analyzing the influence of the ecological niche variables in the geographical distribution of species, providing new information to guide future investigations.  相似文献   

8.
施氮对高寒草甸草原植物群落和土壤养分的影响   总被引：3，自引：1，他引：2  
于2013-2014年在青藏高原东缘测定了不同梯度施氮后植物群落特征、牧草营养和土壤质量的变化,并分析了施氮后的经济效益。结果表明:(1)施氮显著增加了各功能群植物的高度和禾本科功能群植物盖度,而对莎草科和豆科植物盖度无显著影响;施氮显著增加了禾本科、莎草科、豆科和植物群落生物量,降低了杂类草盖度和生物量,其中施肥量为30.86～38.58 g·m-2时效果最为显著。(2)施氮显著增加了0～20 cm土层根系生物量;施氮当年显著增加了根冠比,施氮第2年根冠比无显著变化。(3)施氮不同程度降低了高寒草甸草原植物群落多样性,其中,施肥量在30.86～38.58 g·m-2时最低。(4)施氮不同程度地提高了禾本科、莎草科和杂类草植物的粗蛋白含量,降低了各功能群植物纤维含量;施氮不同程度提高了高寒草甸草原土壤养分和有机碳含量,其中在施肥量为30.86～38.58 g·m-2时最高。(5)施氮当年和第二年净收益均在施肥量为30.86 g·m-2时最大,分别为1 860元·hm-2和878元·hm-2。施氮缓解了青藏高原东缘高寒草甸草原植物生长的营养限制,提高了可食牧草产量,30.86～38.58 g·m-2可作为该区最佳施氮水平。  相似文献   

9.
Many arid basins in western North America are likely to experience future changes in precipitation timing and amount. Where shallow water tables occur, plant acquisition of groundwater and soil water may be influenced by growing season precipitation. We conducted a rainfall manipulation experiment to investigate responses of four common native plant species to ambient, increased, and decreased summer monsoon rainfall. We measured plant xylem pressure potentials (Ψ) and stable oxygen isotope signatures (δ18O) to assess effects of altered precipitation on plant water relations and water acquisition patterns. Reduced rainfall decreased Ψ more in the grasses Sporobolus airoides and Distichlis spicata than the more deeply rooted shrubs Sarcobatus vermiculatus and Ericameria nauseosa. E. nauseosa had little response to natural or experimental differences in available soil water. Plant xylem water δ18O indicated that S. airoides and D. spicata are almost entirely dependent on rain-recharged soil water, while E. nauseosa is almost entirely groundwater-dependent. Sarcobatus vermiculatus used groundwater during dry periods, but utilized precipitation from soil layers after large rainfall events. Persistent changes in precipitation patterns could cause shifts in plant community composition that may alter basin-scale groundwater consumption by native plants, affecting water availability for human and ecosystem uses.  相似文献   

10.
Eleven plant communities of the central Tibetan ecotone (31°20′-33°00′N/89°00′-92°10′E) between the Kobresia pygmaea grazing pastures of the eastern highlands and the open short grass steppe with cushion plants (“Alpine Steppe”) of the north-western highlands have been described on the basis of 189 plot-based floristically complete vegetation records. In parallel, remote sensing techniques distinguish four main land-use cover types. Our hypotheses are: (1) The plant communities of the central Tibetan highlands are grazing-adapted and resilient to degradation. (2) In contrast to grazing resilient plant functional types, the turf cover of the K. pygmaea pastures and the Kobresia schoenoides wetlands is degradable through desiccation, periglacial processes, soil-dwelling small mammals and livestock. Five grazing-related plant functional traits are introduced. Grazing tolerance is the prevalent functional type. Species with no specific protection against grazing make up not more than 6% of the total cover. Unpalatable plants cover up to 8%. Only the azonal K. schoenoides swamps - the indispensable winter grazing reserve - have been widely degraded and depleted by 75%, being replaced by Carex sagaensis grazing pastures. It can be foreseen that governmental policy of sedentarisation of nomads will lead to reduced grazing mobility and degradation of winter grazing reserves.  相似文献   

11.
The arid rangelands of Syria cover over half of the nation's landmass. Punctuating this landscape are broad, dry basins, or wadis, and gentle landscape depressions that exhibit localized elevated vegetation productivity and unique edaphic and hydrologic properties. Historically, continuous heavy grazing and aggressive agricultural activities resulted in excessive ecological degradation within these sensitive environments. Information is needed to determine the influence of livestock grazing on plant communities in landscape depressions and the impact that this has on ecosystem resilience. The purpose of this research is to evaluate the effect of short-term sheep grazing on vegetation characteristics and plant community structure within depressions, and to provide recommendations for improved grazing management. Study plots were randomly located within paired topographic depressions located in northwestern Syria. Vegetation samples were collected along transects including plant biomass, plant density, herbaceous cover, and species diversity. In grazed plots, plant biomass was 49 g DM/m2 compared to 234.4 g DM/m2 in protected plots. Average plant density was 65 plants/m2 in grazed plots compared to 1013 plants/m2 in protected plots (P = 0.001). Herbaceous cover was 175% higher on protected sites compared to grazed plots. Average diversity (Shannon–Wiener index value) was 0.8 in grazed plots compared to 2.3 in protected plots. These results suggest that plant community structure will be impacted from short-term grazing and that a site's ability to positively respond to disturbance over time may be limited. We conclude that carefully planned grazing management should result in greater plant productivity and diversity.  相似文献   

12.
 对青藏铁路格尔木至安多段沿线不同海拔梯度下高寒植被与土壤特征进行研究。沿线高寒植被的主要分布种有91个,主要建群种为:紫花针茅(Stipa purpurea)、青藏苔草(Carex moorcroftii Falc)、藏异燕麦(Helictotrichon tibeticum)、黄芪(Astragalus)、棘豆(Oxytropis)、粗壮嵩草(Kobresia robusta Maximowicz)、矮嵩草(Kobresia robusta Maximowicz)等。高寒植被物种数、平均盖度、地下生物量和总生物量与海拔呈正相关性,而平均高度和地上生物量与海拔呈负相关性。沿线高寒植物群落主要可划分为海拔小于4 000 m的高寒荒漠植被、海拔4 000~4 500 m的高寒河谷灌丛植被、海拔4 500~4 700 m的高寒草原植被、海拔4 700~4 800 m的高寒垫状植被、海拔4 800~4 900 m的高寒草甸植被和海拔5 000 m左右的高寒沼泽和高寒流石坡植被。土壤全氮和有机质含量都与海拔高度呈正相关性,但全磷、全钾及pH值则在高海拔地区达到最低。沿线土壤颗粒组成主要以中、细沙(d＜0.4 mm)为主,占到了总含量的85%以上,因此,中、细沙是构成沿线土壤的最主要颗粒。沿线植被恢复比较有效的方法是选择紫花针茅、垂穗披碱草、燕麦、棘豆、黄芪、蒿草、梭罗草等当地草种,采取原生植物种子异地繁殖,再经沿线播种或栽培抚育,从而达到植被恢复的目的。该研究对青藏铁路沿线的植被恢复与植物防沙工程具有一定的指导意义。  相似文献   

13.
The vascular vegetation of alpine talus slopes between 2035 and 3095 m altitude was studied at Lassen Volcanic National Park (California) in the Cascade Range. Taluses show a diverse flora, with 79 plant species; growth forms include coniferous trees, shrubs, suffrutices, herbs, graminoids, and ferns. Spatial patterns of plant distribution were studied along 40 point-intercept transects. Plant cover was low (0-32.7%) on all slopes, spatially variable, and showed no consistent trends. Sedimentological characteristics were determined by photosieving next to 1500 plants; this census indicated preferential plant growth on blocks and cobbles, with 43.2% and 23.3% of the plants growing on these stones, respectively; fewer specimens were rooted on pebbles (13%) or on stone-free gravel areas (20.5%). Growth forms displayed different substrate preferences: 92.5% of the shrubs and 83% of the suffrutices colonized blocks or cobbles, but only 57.2% of the herbs and 59.8% of the graminoids grew on large stones. Plants are associated with large clasts because (1) coarse talus is more stable than fine sediment areas, which are more frequently disturbed by various geomorphic processes, and (2) large stones help conserve substrate water beneath them while moisture quickly evaporates from fine debris.Root patterns were studied for 30 plant species; 10 specimens for each species were excavated and inspected, and several root growth ratios calculated. All species exhibited pronounced root asymmetry, as roots for most plants grew upslope from their shoot base. For 23 species, all specimens had 100% of their roots growing upslope; for the other 7 species, 92.2-99.3% of below-ground biomass extended uphill. This uneven root distribution is ascribed to continual substrate instability and resulting talus shift; as cascading debris progressively buries roots and stems, plants are gradually pushed and/or stretched downhill. Various disturbance events affect root development. Slope erosion following rubble removal often exposes plant roots. Debris deposition can completely bury plants; some may survive sedimentation, producing new shoots that grow through accumulated debris. Shrubs may propagate by layering, as adventitious roots develop along buried stems; or produce new clones along their roots. Slope processes may damage and transport plant pieces downhill; some species can sprout from severed, displaced root or stem fragments. Vegetation interacts with several geomorphic processes, including debris flows, grain flows, rockfall, snow avalanches, frost creep, and runoff. Larger plants may alter local patterns of debris movement and deposition, damming cascading debris on their upslope side and deflecting sediments laterally to plant margins, where they form narrow elongated stone stripes.  相似文献   

14.
为了研究新疆不同类型植被对气候变化的响应,以地带性划分的植被类型作为研究对象,1998-2012年为时间尺度,利用GIS的空间分析方法结合数学统计方法,分析了新疆各地带植被覆盖变化的时空分布特征;并采用"多元回归+残差插值"的方法,模拟了气温和降水量的空间分布;利用SPOT VGT/NDVI数据以及气候数据(气温和降水量数据),分析了5个不同地带植被的动态变化、年际变化和生长季内各月变化及其对气候变化的响应。结果表明:(1)新疆各地带植被覆盖度存在着显著差异,其中,温带北部草原地带高植被区和浓密植被区的范围较广,植被覆盖度较高,而高寒荒漠地带的极低植被区占该地带面积的一半以上,且植被覆盖度最低。(2)新疆各地带植被覆盖在近15 a间呈波动增加的趋势,5个地带的植被覆盖均有所改善,其中,高寒荒漠地带和暖温带半灌木、灌木地带的植被覆盖改善较为明显,其余3个地带均有少部分地区出现轻微改善现象。(3)温带半灌木、矮乔木荒漠地带,暖温带半灌木、灌木荒漠地带和温带半灌木、灌木荒漠地带4~10月的平均气温呈上升趋势,而温带北部草原地带、高寒荒漠地带对应的平均气温则出现下降趋势。5个地带的降水量在该时段内均表现为下降趋势。(4)基于年际尺度,新疆各地带植被NDVI与气温、降水量的相关性均不显著;基于月尺度,各地带植被NDVI受降水量的影响比气温大。同时,仅有暖温带半灌木、灌木荒漠地带植被NDVI与气温存在1个月的滞后性,其余4个地带对气温和降水均不存在滞后性。  相似文献   

15.
Numerous human activities constitute threats to biodiversity. The effects of climate change, including increasing drought in already arid lands, pose an additional layer of uncertainty in the fate of rare species. In the case of plants, reintroduction is becoming an important active management practice in species conservation. We hypothesized that even under extreme drought inoculation with mycorrhizal fungi would increase growth rates of an endangered plant in experimental reintroduction. We selected a plant species, Abronia macrocarpa, and conducted the experiment in Texas while the area was experiencing mild and extreme drought intensities. Treatment plots were planted with seed inoculated with arbuscular mycorrhizal fungi and control plots were planted with seed coated with autoclaved inoculant. We analyzed measurements of growth and development of germinated plants. Mean number of leaves was greater in treatment plants (P = 0.005) and mean aerial diameter was larger in treatment plants (P = 0.02) than in control plants. Significantly improved growth suggests that inoculation is a viable technique to increase reintroduction success in plant species especially during periods of drought.  相似文献   

16.
In view of the repeatedly reported overstocking of the high-altitude pastures on Al Jabal al Akhdar, northern Oman, plant species abundance, cover and frequency, and herbaceous mass yield were studied in ungrazed versus heavily grazed areas of this mountain range. In addition, plant species selection by goats along a gradient of 1000–2000 m and spatial extent of pasture areas were investigated after abundant rainfall and a subsequent 6-months dry spell by means of manual observation and GPS/GIS tools.The substantially higher species diversity and herbaceous mass yield in the ungrazed area illustrate the production potential of these mountain pastures or, respectively, the biodiversity and productivity loss resulting from continuous grazing. The concentration of goats' selection on only a dozen herbaceous and ligneous species favours pasture encroachment with poisonous shrubs such as Nerium mascatense in the lower and Dodonaea viscosa in the higher altitudes. Given the spatially limited extent of pasture areas, these are exposed to high stocking rates. Therefore, grazing and feeding schemes need to be developed which reduce livestock pressure on the pastures, taking into account local property rights, herding skills and the recovery potential of the vegetation, which heavily depends on unpredictable rainfall events.  相似文献   

17.
Several environmental factors potentially influence the stable isotope compositions of plants, depending on species and local environment. Although several studies have discussed these aspects in C3 and C4 plants, only a few have attempted to identify the major drivers of δ13C, δ18O, and δ15N in CAM plants. In this study, stable isotopic ratios of CAM plants collected along an altitudinal transect in the Chisos Mountains/USA during two growth seasons, are used to understand major factors governing isotopic variability. A strong and significant relationship between δ13C and altitude, positive for agave at <1700 m and negative for both agave and cacti at >1500 m, suggests variable carbon isotope fractionation at different altitudes, which may be unique to CAM plants. Our data suggest that temperature primarily governs δ13C of the studied plants. The significant negative correlations observed between the δ18O of agaves and the recorded air temperature (0.59‰/°C) are similar to the δ18O of precipitation vs. temperature variability in global data. The δ15N variations suggest a similar N-source for both agaves and cacti, and reflect progressive changes in the dominant N-source across desert–grassland–woodland zones. We conclude that the stable carbon and oxygen isotope composition of agave reflects the climatic conditions along the elevation transect.  相似文献   

18.
The study was conducted to assess the status and trends of soil erosion and relate the perceptions of farmers on cattle productivity and botanical indicators to measured ecological conditions of rangelands in three altitude regions of southwest Ethiopia. A total of 342 farmers were interviewed. In addition, the ecological condition of rangelands was assessed. Severe soil erosion, ranked as the primary restriction to free-ranging livestock, occurred predominantly in the lower altitude region (LAR) (P < 0.05). More farmers in LAR witnessed an inadequacy of palatable plant biomass, grazable pasture as well as increased gully formation and expansion, which are strong indicators of soil erosion (P < 0.001). In addition to a decrease in grass cover and productivity of cattle, botanical composition, species richness and grazing capacity of herbaceous plants, less fodder trees and shrubs were observed (P < 0.05). There was a corresponding increase in the percentage of bare ground and soil erosion status along the degradation gradients (P < 0.05). The reported shift in botanical composition, and especially encroachment of invading plant species, can be attributed to soil erosion (P < 0.001). The results suggest that erosion is associated with reduced availability of feed resources and is related to altitude variation.  相似文献   

19.
The retreating snowfields and glaciers of Glacier National Park, Montana, USA, present alpine plants with changes in habitat and hydrology. The adjacent and relic periglacial patterned ground consists of solifluction terraces of green, vegetation-rich stripes alternating with sparsely vegetated brown stripes. We established georeferenced transects on striped periglacial patterned ground for long-term monitoring and data collection on species distribution and plant functional traits at Siyeh Pass and at Piegan Pass at Glacier National Park. We documented species distribution and calculated the relative percent cover(RPC) of qualitative functional traits and used 16 S rRNA from soil samples to characterize microbial distribution on green and brown stripes. Plant species distribution varied significantly and there were key differences in microbial distribution between the green and brown stripes. The rare arctic-alpine plants Draba macounii, Papaver pygmaeum, and Sagina nivalis were restricted to brown stripes, where the RPC of xeromorphic taprooted species was significantly higher at the leading edge of the Siyeh Pass snowfield. Brown stripes had a higher percentage of the thermophilic bacteria Thermacetogenium and Thermoflavimicrobium. Green stripes were co-dominated by the adventitiously-rooted dwarf shrubs Salix arctica and the possibly N-fixing Dryas octopetala. Green stripes were inhabited by Krummholz and seedlings of Abies lasiocarpa and Pinus albicaulus. Prosthecobacter, a hydrophilic bacterial genus, was more abundant on the green stripes, which had 6,524 bacterial sequences in comparison to the 1,183 sequences from the brown stripes. While further research can determine which functional traits are critical for these plants, knowledge of the current distribution of plant species and their functional traits can be used in predictive models of the responses of alpine plants to disappearing snowfields and glaciers. This research is important in conservation of rare arctic-alpine species on periglacial patterned ground.  相似文献   

20.

The retreating snowfields and glaciers of Glacier National Park, Montana, USA, present alpine plants with changes in habitat and hydrology. The adjacent and relic periglacial patterned ground consists of solifluction terraces of green, vegetation-rich stripes alternating with sparsely vegetated brown stripes. We established georeferenced transects on striped periglacial patterned ground for long-term monitoring and data collection on species distribution and plant functional traits at Siyeh Pass and at Piegan Pass at Glacier National Park. We documented species distribution and calculated the relative percent cover (RPC) of qualitative functional traits and used 16S rRNA from soil samples to characterize microbial distribution on green and brown stripes. Plant species distribution varied significantly and there were key differences in microbial distribution between the green and brown stripes. The rare arctic-alpine plants Draba macounii, Papaver pygmaeum, and Sagina nivalis were restricted to brown stripes, where the RPC of xeromorphic taprooted species was significantly higher at the leading edge of the Siyeh Pass snowfield. Brown stripes had a higher percentage of the thermophilic bacteria Thermacetogenium and Thermoflavimicrobium. Green stripes were co-dominated by the adventitiously-rooted dwarf shrubs Salix arctica and the possibly N-fixing Dryas octopetala. Green stripes were inhabited by Krummholz and seedlings of Abies lasiocarpa and Pinus albicaulus. Prosthecobacter, a hydrophilic bacterial genus, was more abundant on the green stripes, which had 6,524 bacterial sequences in comparison to the 1,183 sequences from the brown stripes. While further research can determine which functional traits are critical for these plants, knowledge of the current distribution of plant species and their functional traits can be used in predictive models of the responses of alpine plants to disappearing snowfields and glaciers. This research is important in conservation of rare arctic-alpine species on periglacial patterned ground.

  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号