浙西南高山地区种桃利弊及无公害栽培技术

高山地区种桃利多弊少,具有"人无我有,人有我优"的优势,市场前景广阔。分析了龙泉高山地区种桃的利弊因素,并从园地选择、肥水管理、病虫防治等方面阐述了无公害栽培技术。

“双关”称名之由来

双关是我国文学史上出现较早的传统修辞方式之一。大约从六朝民歌开始,就已经很常用了。例如,“高山种芙蓉”(子夜歌),以“芙蓉”谐“夫容”。“杀荷不断藕,莲心已复生”(读曲歌),以“藕”谐“偶”,“莲”谐“怜”。“昼夜常怀丝”(西曲歌·作蚕丝),以“怀丝”谐“怀思”。这类双关语,大多出现在男欢女爱的情歌里面,使作品委婉含蓄,风趣生动。刘禹赐的《杨柳枝》:“东边日出西边雨,道是无晴却有晴.《红楼梦》五回:“空对着山中高士晶莹雪,终不忘世外仙姝寂寞林”。都是运用双关手法当行出色的好例。徐芹庭曰:“双关之语,由来久矣。盖双关语者。

Population and conservation status of the Himalayan Griffon(Gyps himalayensis) at the Drigung Thel Monastery,Tibet,China

The Himalayan Griffon(Gyps himalayensis), occurring mainly in the Tibetan Plateau, is one of the scavengers of Old World vultures. As of now, knowledge about the Himalayan Griffon in China remains scarce. Estimates of its number, habitat, and conservation status were carried out in 2003, 2009 and 2102 in the Lhasa River Valley, where we paid particular attention to the population living at the Drigung Thel Monastery, Mzizhokunggar County. The resident species occupies alpine meadows in the daytime and roosts at the upper parts of cliffs at night between 4400–5000 m elevation. The number of individual birds of the Himalayan Griffon around the monastery was estimated as 230 in 2003, 250 in 2009 and 200 in 2012. This population is considered relatively stable, thanks to the current conservation measures by Buddhist monks and local people. Given the lack of any baseline information, it is difficult for us to recommend and provide any effective conservation measures.

Characteristics of Soil Seed Bank and Natural Regenerations in Pinus densata Natural Forest of Southeast Tibet

Pinusdensata is one of the main constructive species for coniferous forests in southeast Tibet. P. densata forests are important water conservation forests in the drainage basins of the middle and lower reaches of Yalu Tsangpo River, Nyang River and Parlung Zangbo River. In this study, with P. densata forest distributed in southeast Tibet as research object, the seed rain, soil seed bank, seed germination and natural regeneration of P. densata were monitored and ana- lyzed by field investigation, located monitoring and indoor experimental analysis. The results showed that the average intensity of the seed rain of P. densata was 249.30±78.42 seeds/m2, in which the intensity of full seeds was 168.09±56.36 seeds/m2, the intensity of seeds damaged by worms was 41.11±20.25 seeds/m2, and the intensity of empty seeds was 40.10±21.04 seeds/m2. The intensity of the seed rain exhibited a single-peak trend of increasing at first and decreasing then over time. The spatial distribution patterns in the whole seed falling process and at different seed falling time all exhibited clumping distribution, and within in certain range, with the distance from the seed tree increasing, the diffusion intensity of the seed rain was weakened, exhibiting approximately normal distribution. In average density of P. densata seeds in the soil seed bank of P. densata was 231 seeds/m2, in which 62.77% of seeds were distributed in the litter layer, and 37.23% of seeds were distributed in the soil layer, and about 8% of seeds were lost during the pro- cess from seed rain to soil seed bank. Field sowing observation showed that the accumulated germination rate curve of P. densata fitted with Logistics equation y= 91.404/（1＋e66194.449）. The height structure, basal diameter structure and age structure of seedlings and young trees of P. densata were all of reverse ＂J＂ type, indicating good natural regeneration of P. densata. This study would provide a science basis for protection and resource management of P. densata, and further enrich the eval- uation content of national ecological safety curtain of the Tibet plateau.

Study on Species Diversity of Alpine Vegetation with Different Altitudes in Daban Mountain

[Objective] The aim of this study is to investigate species diversity of alpine vegetation in different altitudes of Daban mountain. [Method] Plant communities were surveyed in three different altitudes （3 025 m,3 405 m,3 813 m） of Daban mountain,the eastern Qilian,and the richness or diversity index of vegetation in three different altitudes was comparatively analyzed. [Result] The species richness decreased with the gradual increase of altitude,and species diversity of plant communities was relatively lower in medium altitude. Furthermore,community similarity also decreased with the increase of altitude,and β diversity of communities had a significant change. [Conclusion] Environmental factor change caused by different altitudes and human disturbance are important reasons for the change of species distribution pattern in different altitudes.

Study on Seed Plant Flora of Yunfeng Mountain,an Offshoot of Gaoligong Mountain Range

In this paper, the flora in an area of 35 km2 of Yunfeng Mountain, an off- shoot of Gaoligong mountain range, were sampled and analyzed. The results showed that Yunfeng Mountain had a high diversity in seed plants, which covered 92 families, 247 genera and 431 species. Among the seed plants, the gymnosperms covered 4 families, 5 genera and 7 species, while the angiosperms covered 88 families, 242 genera and 424 species. The seed plants in Yunfeng Mountain had rich distribution types, and they formed a flora dominated by tropical and subtropical plants.

Shrub Communities and Environmental Variables Responsible for Species Distribution Patterns in an Alpine Zone of the Qilian Mountains, Northwest China

Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the environmental factors that are responsible for the variations in species composition and richness of alpine shrublands using numerical methods. In the present study, we investigated vegetation and associated environmental variables from 45 sample plots in the middle Qilian Mountains of the northwestern China to classify different community types and to elucidate the species- environment relationships. We also estimated the relative contributions of topography and site conditions to spatial distribution patterns of the shrub communities using the variation partitioning. The results showed that four shrub community types were identified and striking differences in fioristic composition were found among them. Species composition greatly depended on elevation, slope, shrub cover, soil pH and organic carbon. The important determinants of species richness were soil bulk density and slope. No significant differences in species richness were detected among the community types. Topography and site conditions had almost equal effects on compositional variation. Nonetheless,a large amount of the variation in species composition remained unexplained.

Forest Biodiversity Assessment in Peruvian Andean Montane Cloud Forest

Cloud forests are unusual and fragile habitats, being one of the least studied and least understood ecosystems. The tropical Andean dominion is considered one of the most significant places in the world as regards biological diversity, with a very high level of endemism. The biodiversity was analysed in an isolated remnant area of a tropical montane cloud forest known as the "Bosque de Neblina de Cuyas", in the North of the Peruvian Andean range. Composition, structure and dead wood were measured or estimated. The values obtained were compared with other cloud forests. The study revealed a high level of forest biodiversity, although the level of biodiversity differs from one area to another: in the inner areas, where human pressure is almost inexistent, the biodiversity values increase. The high species richness and the low dominance among species bear testimony to this montane cloud forest as a real enclave of biodiversity.

Alpine Ecosystems of Northwest Yunnan,China:an Initial Assessment for Conservation

Implementing conservation actions on-the-ground is not a straightforward process,especially when faced with high scientific uncertainty due to limited available information. This is especially acute in regions of the world that harbor many unique species that have not been well studied,such as the alpine zone of the Hengduan Mountains of Northwest Yunnan (NWY),a global biodiversity hotspot and site of The Nature Conservancy’s Yunnan Great Rivers Project. We conducted a quantitative,but rapid regional-level assessment of the alpine flora across NWY to provide a broad-based understanding of local and regional patterns of the alpine flora,the first large-scale analysis of alpine biodiversity patterns in this region. Multivariate analyses were used to classify the major plant community types and link community patterns to habitat variables. Our analysis indicated that most species had small distributions and/or small population sizes. Strong patterns emerged with higher diversity in the more northern mountains,but beta diversity was high,averaging only 10% among sites. The ordinations indicated that elevation and geographic location were the dominant environ-mental gradients underlying the differences in the species composition among communities. The high beta diversity across the alpine of these mountains implies that conservation strategies ultimately will require the protection of large numbers of species over a large geographical area. However,prioritiza-tion should be given to areas where potential payoffs are greatest. Sites with high species richness also have a greater number of endemic species,and,by focusing efforts on these sites,conservation investments would be maximized by protecting the greatest number of unique species.

Vascular plants distribution in relation to topography and environmental variables in alpine zone of Kedarnath Wild Life Sanctuary,West Himalaya

The present study was carried out in Tungnath alpine meadows of Kedarnath Wild Life Sanctuary, Western Himalaya from subalpine to upper alpine zone. A total of four summits were selected along an altitudinal gradient and sampled for detailed vegetation analysis using multi summit approach as per Global observation research initiative in alpine environments(GLORIA). Species richness, diversity, and evenness among four summits as well as the interaction between environmental variables with plant communities were assessed. Monthly mean soil temperature was calculated using data retrieved from geo-precision temperature logger in order to identify the trend of soil temperature among different season and altitudinal gradient and its implications to plant communities. Soil samples were analyzed fromeach summit by collecting randomized composite soil samples. The indirect non-metric multidimensional scaling(NMDS) and direct canonical correspondence analysis(CCA) tools of ordination techniques to determine the linkage between plant species from various sample summits and biotic/abiotic environmental gradients were used in the present study. The results of the study demonstrated increase in species richness as soil temperature increases, the ecotone representing summits were found most warm summits followed by highest species richness. Annual soil temperature increased by 1.43°C at timberline ecotone. Whereas, at upper alpine zone the soil temperature increased by 0.810 C from year 2015 to 2016. S?rensen's similarity index was found to be increased between subalpine and upper alpine zone with increase in the presence of subalpine plant species at upper alpine zone. Both the ordination tools separate the subalpine summit and their respective vegetation from summits representingtimberline ecotone and upper alpine zone. Soil p H, altitude, soil cation exchange capacity were found as the key abiotic drivers for distribution of plant species.

Effective Seed Distribution Pattern of an Upward Shift Species in Alpine Tundra of Changbai Mountains

The vegetation of alpine tundra in the Changbai Mountains has experienced great changes in recent decades. Narrowleaf small reed(Deyeuxia angustifolia), a perennial herb from the birch forest zone had crossed the tree line and invaded into the alpine tundra zone. To reveal the driven mechanism of D. angustifolia invasion, there is an urgent need to figure out the effective seed distribution pattern, which could tell us where the potential risk regions are and help us to interpret the invasion process. In this study, we focus on the locations of the seeds in the soil layer and mean to characterize the effective seed distribution pattern of D. angustifolia. The relationship between the environmental variables and the effective seed distribution pattern was also assessed by redundancy analysis. Results showed that seeds of D. angustifolia spread in the alpine tundra with a considerable number(mean value of 322 per m2). They were mainly distributed in the low elevation areas with no significant differences in different slope positions. Effective seed number(ESN) occurrences of D. angustifolia were different in various plant communities. Plant communities with lower canopy cover tended to have more seeds of D. angustifolia. Our research indicated reliable quantitative information on the extent to which habitats are susceptible to invasion.

Plant Communities and Factors Responsible for Vegetation Pattern in an Alpine Area of the Northwestern Himalaya

The study intended to describe the alpine vegetation of a protected area of the northwestern Himalaya and identify the important environmental variables responsible for species distribution.We placed random plots covering different habitats and altitude to record species composition and environmental variables.Vegetation was classified using hierarchical cluster analysis and vegetation-environment relationships were evaluated with Canonical Correspondence Analysis.Four communities,each in alpine shrub and meadows were delineated and well justified in the ordination plots.Indicator species for the different communities were identified.Maximum species richness and diversity were found in community IV among shrub communities and community II among the meadows.Studied environmental variables explained 61.5% variation in shrub vegetation and 59.8% variation in meadows.Soil variables explained higher variability (～35%) than spatial variables (～21%) in both shrubs and meadows.Altitude,among the spatial variables and carbon/nitrogen ratio and nitrogen among the soil variables explained maximum variation.About 40% variations left unexplained.Latitude and species diversity among the other variables had significant correlation with ordination axes.Study showed that altitude and C/N ratio played a significant role in species composition.Extensive sampling efforts and inclusion of other non-studied variables are also suggested for better understanding.

Herbage Production and Species Richness in Sub-alpine Grasslands of Different Soil Parent Material in Northern Greece

Several abiotic and biotic factors were investigated as possible predictors of local species richness in two sub-alpine grasslands of Jenna and Belles Mountains in Northern Greece.For species richness modelling a hierarchical modelling framework based on generalized additive models was adopted.The two sub-alpine grasslands differed in aspect,altitude and soil parent material(volcanic origin,mostly trachyte,and andesite(TA) for Jenna and metamorphic rocks,mostly gneiss(G) for Belles).12 fenced squared plots,16 m2 each,were used per grassland,where soil properties,herbage production,species presence and cover of grasses,legumes and forbs were estimated.Mean herbage production was significantly affected by slope and altitude,soil K content and floristic composition as expressed by an ordination axis.Soil p H,floristic composition and average herbage production were significant predictors of forbs and total species richness.For the former,soil N content and for the latter the occurrence of Agrostis capillaris,were also included as significant terms in the predictive model.Thepredictors for grasses species richness were N content,having a positive effect,and average herbage production.In all cases higher species richness was predicted for intermediate values of average herbage production.Differential responses were found between forbs and grasses.The predictors of their species richness were different while for the case of the common predictor(N) the responses of the two groups were also different(grasses species numbers increase and forbs species numbers decreased with increasing N).Maximum species richness of grasses was observed at relatively low production levels while forbs species richness maximized at relatively high production levels.

Tree Population Dynamics of Three Altitudinal Vegetation Communities on Mount Cameroon(1989-2004)

Changes in permanent sample plots in the lowland,submontane and montane forests on Mount Cameroon(4,095 m above sea level),an active volcano,are described for 15 years from 1989 to 2004.Throughout the study period,the stocking level of trees with a diameter at breast height(DBH) ≥ 10 cm in the three forests were lower than in pan-tropical stands suggesting a significant impact of volcanic and human-related activities on the vegetation communities on the mountain.Annual mortality rates in the submontane and montane forests were consistent with those reported for comparable altitudinal ranges in the Blue Mountains of Jamaica.The annual mortality rate was higher in the lowland forest than other lowland sites included.Divergence between recruitment and mortality rates was large suggesting that the three vegetation communities have not reached their climax.The seven-year difference in half-life of large trees(with a DBH ≥ 50 cm) in the submontane and montane forests suggests an altitudinal effect on turnover of larger trees that in turn contributes to the frequent small stature of high altitude forests.There was little evidence of an altitudinal effect on species turnover and growth rate.This finding supports generalizations about the zero effect of growth on the stature of high altitude trees.Understanding forest dynamics is crucially important in the management of tropical montane environmentsand in this instance particularly so given the recent creation of the Mount Cameroon National Park.

High seed losses in mountain birch(Betula pubescens ssp.tortuosa)and developmental,ecological,and environmental correlates

Plants typically experience great losses from their reproductive potential represented by ovule production to the post-dispersal crop of viable seed.We examined seed density and viability in a founder population of mountain birch(Betula pubescens ssp.tortuosa),aiming to quantify losses at different stages and examine potential selection forces on the reproduction success of the founder generation of an isolated population.At the time of the study(2017-2020),the population had recently reached reproductive maturity,following its colonization around 1990 through long-distance dispersal onto an early successional outwash plain in southeast Iceland.Seed densities were high,but 89% of apparently intact seeds did not contain an embryo,despite being visually indistinguishable from filled seeds.Externally evident losses amounted to about 45% of the total seed crop and were mostly due to predation by the gall midge Semudobia betulae.When all losses were accounted for,2.7% of the seed crop remained viable and germinated.Pollen limitation may partially explain the high incidence of empty seeds.Excessive flower production is compatible with the predator satiation hypothesis but cannot explain pre-dispersal losses.Another adaptation to predation,masting,appears poorly developed in Iceland.Our results suggest the presence of constraints on the reproduction potential of the new island population,that are more limiting than in neighbouring populations,and we discuss their developmental,ecological,and environmental correlates.

山歌

高原多山,山上有数不清的树木林子,山中有叫不出名字的鸟儿、蝉儿。高原人天天在深山里与流云、小鸟、山花作伴。高兴了。

Functional diversity and redundancy of subalpine meadows subjected to anthropogenic disturbances

Aims The aims of this study were to assess how functional diversity(FD)and functional redundancy respond to subalpine meadow ecosystem degradation under anthropogenic disturbance and how species contribute to functional redundancy along the disturbance gradient.Methods The study was carried out in the subalpine meadow in Mount Jade Dragon,which is located at the southeastern edge of the Tibetan Plateau.Four disturbance intensities[no disturbance(ND),weak disturbance(WD),moderate disturbance(MD)and severe disturbance(SD)]were identified.Species richness,soil properties and five key plant functional traits were assessed along the disturbance gradient.Simpson’s diversity index,FD based on the Rao algorithm,functional redundancy,community-weighted mean of each functional trait and species-level functional redundancy were determined.Important Findings Unimodal change pattern of FD and functional redundancy along the disturbance gradient were found in the present study,with their maximum in MD and WD,respectively.Species diversity showed a decreasing trend with increasing disturbance intensity.As disturbance intensified,species with traits related to conservative growth strategies,such as low specific leaf area(SLA)and high leaf dry matter content(LDMC),decreased,whereas species with resource acquisitive strategies,such as small plant,high SLA and low LDMC,increased in the community.At the species level,species showed species-specific roles in functional redundancy.Notably,some species were important in the community in terms of their unique function.For instance,Ligularia dictyoneura in ND and Potentilla delavayi in MD and SD.