Impact of spruce forest on rainfall interception and seasonal snow cover evolution in the Western Tatra Mountains,Slovakia

The paper analyzes the impacts of the spruce forest on precipitation interception and evolution of snow cover in the mountain catchment of the Jalovecky creek, the Western Tatra Mountains, Slovakia. Both processes were monitored at the elevation of 1420 m a.s.l.. Interception was measured from the end of August 2006 until November 2008 by a network of 13 raingauges. Mean interception over the studied period in forest window was 23%. Mean values for the dripping zone under tree branches, near stems of the trees and under the young trees were 28%, 65% and 44%, respectively. With exception of forest window, the interception at the same characteristic positions was highly variable. Calculated daily precipitation thresholds needed to fulfill the storage capacity of the canopy were about 0.8–0.9 mm. Differences in snow accumulation and melt in the open area (elevation 1500 m a.s.l.) and in the forest were measured in winters 2003–2008. Snow depths (SD) and water equivalents (SWE) were typically smaller in the forest, although the differences were getting smaller towards the end of snow season. SD and SWE in the forest were higher than in the open area for a short time before the end of season in winters 2003 and 2005. The correlations between SD and SWE in the open area and in the forest explained about 90% of variability. The energy balance snow model UEB satisfactorily simulated the evolution of snow cover in the forest and in the open area.     

江西武功山两栖爬行动物资源调查及评价

2001年7月中旬～8月上旬,对江西武功山国家森林公园进行了20多天的野生动植物资源野外考察.公园内现已记录两栖类2目7科25种和爬行类3目9科37种,本次调查增加安福县爬行动物新记录7种：多疣壁虎、中国石龙子、黑背白环蛇、铅色水蛇、灰鼠蛇、乌梢蛇、银环蛇;增加武功山爬行动物新记录23种.动物地理区划属东洋界华中区东部丘陵平原亚区,动物区系组成以东洋界华中区与华南区共有种为主.两栖类东洋界种类占92.00%;生态类型以流水型9种和陆栖-静水型7种占优势.数量优势种为黑斑蛙、中华蟾蜍、黑斑肥螈、泽蛙、棘胸蛙、花臭蛙、华南湍蛙、三港树蟾、镇海林蛙和饰纹姬蛙.爬行类东洋界种类占75.68%,广布种占24.32%.数量优势种有石龙子、蓝尾石龙子、铜蜓蜥、赤链华游蛇、王锦蛇、虎斑颈槽蛇、赤链蛇、红点锦蛇、乌梢蛇、灰鼠蛇、尖吻蝮、竹叶青蛇等.公园内野生动物及其生境受人类干扰破坏大,当地群众保护意识有待增强,就此提出了保护对策.     

陇东子午岭林区野生有毒植物资源调查

经过三年的调查研究,首次报道了子午岭野生有毒维管植物66科127属170种.其中乔木10科 16属19种;灌木11科14属16种;木质藤本4科5属5种;多年生草本32科63属85种;一、二年生草本22科33属37科;草质藤本7科8属8种.并介绍了子午岭林区野生有毒植物的开发利用与保护建议.     

Positive interactions between alpine plant species and the nurse cushion plant Laretia acaulis do not increase with elevation in the Andes of central Chile

In alpine habitats, positive interactions among plants tend to increase with elevation as a result of altitudinal increase in environmental harshness. However, in mountains located in arid zones, lower elevations are also stressful because of scarce availability of water, suggesting that positive interactions may not necessarily increase with elevation. Here we analysed the spatial association of plant species with the nurse cushion plant Laretia acaulis at two contrasting elevations, and monitored the survival of seedlings of two species experimentally planted within and outside cushions in the semiarid Andes of central Chile. Positive spatial associations with cushions were more frequent at lower elevations. Species growing at the two elevations changed the nature of their association with cushions from neutral or negative at higher elevations to positive at lower elevations. Survival of seedlings was higher within cushions, particularly at lower elevations. The increased facilitation by cushions at lower elevations seems to be related to provision of moisture. This result suggests that cushion plants play a critical role in structuring alpine plant communities at lower elevations, and that climatic changes in rainfall could be very relevant for persistence of plant communities.     

青海祁连地区四川绢蝶成虫习性的初步观察

为了了解四川绢蝶的生活习性,2009年6月至8月对青海省祁连地区的四川绢蝶Parnassius szechenyii Frivaldszky进行了实地调查研究。研究结果表明,该绢蝶喜欢在位于山谷到山顶间的中偏上部飞行活动,并对树林和人工破坏的区域有着很强的回避作用;雄性绢蝶的被捕捉机率要远大于雌性的;绢蝶一般喜欢在无风、阳光充足、气温较高的天气活动,其年活动最高峰大约在每年的7月中旬,日活动最高峰在每天的13：00左右。     

Patterns of woody plant species richness in the Iberian Peninsula: environmental range and spatial scale

Aim Climate‐based models often explain most of the variation in species richness along broad‐scale geographical gradients. We aim to: (1) test predictions of woody plant species richness on a regional spatial extent deduced from macro‐scale models based on water–energy dynamics; (2) test if the length of the climate gradients will determine whether the relationship with woody species richness is monotonic or unimodal; and (3) evaluate the explanatory power of a previously proposed ‘water–energy’ model and regional models at two grain sizes. Location The Iberian Peninsula. Methods We estimated woody plant species richness on grid maps with c. 2500 and 22,500 km² cell size, using geocoded data for the individual species. Generalized additive models were used to explore the relationships between richness and climatic, topographical and substrate variables. Ordinary least squares regression was used to compare regional and more general water–energy models in relation to grain size. Variation partitioning by partial regression was applied to find how much of the variation in richness was related to spatial variables, explanatory variables and the overlap between these two. Results Water–energy dynamics generate important underlying gradients that determine the woody species richness even over a short spatial extent. The relationships between richness and the energy variables were linear to curvilinear, whereas those with precipitation were nonlinear and non‐monotonic. Only a small fraction of the spatially structured variation in woody species richness cannot be accounted for by the fitted variables related to climate, substrate and topography. The regional models accounted for higher variation in species richness than the water–energy models, although the water–energy model including topography performed well at the larger grain size. Elevation range was the most important predictor at all scales, probably because it corrects for ‘climatic error’ due to the unrealistic assumption that mean climate values are evenly distributed in the large grid cells. Minimum monthly potential evapotranspiration was the best climatic predictor at the larger grain size, but actual evapotranspiration was best at the smaller grain size. Energy variables were more important than precipitation individually. Precipitation was not a significant variable at the larger grain size when examined on its own, but was highly significant when an interaction term between itself and substrate was included in the model. Main conclusions The significance of range in elevation is probably because it corresponds to several aspects that may influence species diversity, such as climatic variability within grid cells, enhanced surface area, and location for refugia. The relative explanatory power of energy and water variables was high, and was influenced by the length of the climate gradient, substrate and grain size of the analysis. Energy appeared to have more influence than precipitation, but water availability is also determined by energy, substrate and topographic relief.     

Landslides and Their Contribution to Land‐cover Change in the Mountains of Mexico and Central America1

Landsliding is a natural process influencing montane ecosystems, particularly in areas with elevated rainfall and seismic activity. Yet, to date, little effort has been made to quantify the contribution of this process to land‐cover change. Focusing on the mountains of Mexico and Central America (M‐CA), we estimated the contribution of landsliding to land‐cover change at two scales. At the scale of M‐CA, we classified the terrain into major landforms and entered in a GIS historical data on earthquake‐ and rainfall‐triggered landslides. At the scale of the Sierra de Las Minas of Guatemala, we investigated Landsat TM data to map rainfall‐triggered landslides. During the past 110 yr, >136,200 ha of land in the mountains of M‐CA have been affected by landslides, which translates into disturbance rates exceeding 0.317 percent/century. In Sierra de Las Minas, rainfall associated with hurricane Mitch affected 1765 ha of forest, or equivalently, landslides triggered by storms of this magnitude transformed between 0.196 (return time of 500 yr) and 1.290 (return time of 75 yr) percent of forest/century. Although landsliding results in smaller rates of land‐cover change than deforestation, we hypothesize that it has a stronger impact on ecosystems, both in qualitative and quantitative terms, given its influence on vegetation and soil. Moreover, interactions between landsliding and deforestation may be altering the expression of this complex process such that the few protected areas in the mountains of M‐CA may represent the only possibility for the conservation of this process.     

黔中喀斯特城市遗存自然山体景观格局时空演变——以安顺市为例

城市遗存自然山体是山地城市中珍贵而脆弱的生态资源,对于维持城市生态系统稳定发挥着不可替代的作用,然而近年来高强度的城市建设对其产生严重的干扰和胁迫。以安顺市建成区为研究区域,在空间信息技术支持下,综合运用景观格局指数法和缓冲区分析法,分别从城市景观格局动态、城市遗存自然山体景观动态及城-山交互作用3个方面,对近10年快速城市化背景下,安顺市城市遗存自然山体景观格局时空演变进行定量化研究,旨在揭示其对城市扩张的响应规律。结果表明：1）城市整体景观破碎度递增,斑块丰富度密度递减,景观多样性、均匀度、优势度呈波动性变化;2）城市遗存自然山体斑块数量、类型面积、景观优势度递增,斑块形状趋于规则化,连通性递减,聚集度先减后增;3）城-山交互作用明显,主要表现为城市遗存自然山体因城市建设持续受损缩减及其吸引城市建设;4）城市遗存自然山体500 m缓冲区内平均城市建设用地占比及其平均城市人工园林绿地占比均与山体缓冲区距离呈显著负相关,且不同等级城市遗存自然山体斑块与缓冲区内城市建设用地相关程度表现为小型斑块 > 中型斑块 > 较大型斑块 > 大型斑块,与缓冲区内城市人工绿化相关程度表现为中型斑块最高、较大型斑块最低,城市遗存自然山体对城市建设及其人工绿化明显具有吸引作用。解析快速城市化背景下城市遗存自然山体景观动态变化规律及其与城市建设之间的交互作用关系,为城市遗存自然山体后续科学规划管理提供决策支持与理论依据,也可为今后进一步深入开展以其为研究对象的科研活动提供前期基础。     

秦岭山地植被净初级生产力及对气候变化的响应

基于1999~2009年的NDVI数据和气象数据,利用CASA模型对秦岭山地植被净初级生产力（Net primary productivity,NPP）进行模拟估算,并分析了秦岭NPP的时空变化特征及其对气候变化的响应。结果表明：1999~2009年11年间秦岭山地的平均年NPP为542.24 gC·m^-2·a^-1;研究期内秦岭NPP呈显著增长趋势（P<0.01）,2008年最高（718.77 gC·m^-2·a^-1）,2001年最低（471.78 gC·m^-2·a^-1）;四季对全年NPP的贡献率大小依次为夏季（49.90%）>春季（26.16%）>秋季（18.87%）>冬季（5.07%）;月NPP与温度和降水都显著相关,但与温度的相关性更高,月水平上温度对NPP的影响比降水大;生长季期间NPP与温度和降水的相关性在空间分布上都以正相关为主。