采用地形指数法选设高山冻板道的探讨

本文说明了利用地形指数法选设高山冻板道的具体方法.实践证明,此种方法是缩短集材距离.降低生产成本的一种有效方法.

关于高山陡坡冻板道选设的探讨

分析了利用地形指数法选设高山冻板道的具体方法。实践证明,该方法是缩短集材距离、降低生产成本的一种有效方法。

Spatial pattern of soil carbon and nutrient storage at the Alpine tun-dra ecosystem of Changbai Mountain, China

In August 2003, we investigated spatial pattern in soil carbon and nutrients in the Alpine tundra of Changbai Moun-tain, Jilin Province, China. The analytical results showed that the soil C concentrations at different depths were significantly (p<0.05) higher in Meadow alpine tundra vegetation than that in other vegetation types; the soil C (including inorganic carbon) concentrations at layer below 10 cm are significantly (p<0.05) higher than at layer of 1020 cm among the different vegetation types; the spatial distribution of soil N concentration at top surface of 0-10 cm depth was similar to that at 1020 cm; the soil P concentrations at different depths were significantly (p<0.05) lower at Lithic alpine tundra vegetation than that at other vegetation types; soil K concentration was significantly (p<0.05) higher in Felsenmeer alpine tundra vegetation and Lithic alpine tundra vegetation than that in Typical alpine tundra, Meadow alpine tundra, and Swamp alpine tundra vegetations.. However, the soil K had not significant change at different soil depths of each vegetation type. Soil S concentration was dramatically higher in Meadow alpine tundra vegetation than that in other vegetation types. For each vegetation type, the ratios of C: N, C: P, C: K and C: S generally decreased with soil depth. The ratio of C: N was significantly higher at 010 cm than that at 1020 cm for all vegetation types except at the top layer of the Swamp alpine tundra vegetation. Our study showed that soil C and nutrients storage were significantly spatial heterogeneity.

Carbon storage and flux for alpine tundra ecosystems in Changbai Mountains,Northeast China

This paper examined the carbon storage and flux of vegetation-litter-soil in alpine tundra ecosystems in Changbai Mountains. Approximately 17251 t·a-1 of carbon was yearly stored in the vegetation and 15043.1 t·a^-1of carbon flew into soil by litters. The vegetation-litter-soil ecosystem stored 452624 t·a^-1 of carbon, which was the important CO2 sink. The net carbon storage was currently 3146 t·a^-1 in vegetation-litter-soil ecosystem.

Soil Phosphorus Composition and Phosphatase Activities along Altitudes of Alpine Tundra in Changbai Mountains,China

Alpine tundra ecosystems have specific vegetation and environmental conditions that may affect soil phosphorus （P） composition and phosphatase activities. However, these effects are poody understood. This study used NaOH-EDTA extraction and solution ^31P nuclear magnetic resonance （NMR） spectroscopy to determine soil P composition and phosphatase activities, including acid phosphomonoesterase （AcP）, phosphodiesterase （PD） and inorganic pyrophosphatase （IPP）, in the alpine tundra of the Changbai Mountains at seven different altitudinal gradients （i.e., 2000 m, 2100 m, 2200 m, 2300 m, 2400 m, 2500 m, and 2600 m）. The results show that total P （TP）, organic P （OP）, OP/TP, NaOH-EDTA extracted P and AcP, PD, and IPP activities over the altitude range of 2500-2600 m are significantly lower than those below 2400 m. The dominant extracted form of P is OP （73%0-83%） with a large proportion of monoesters （65%0-72%）, whereas inorganic P is present in lower proportions （17%-27%）. The activity of AcP is significantly positively correlated with the contents of soil OP, total carbon （TC）, total nitrogen （TN）, and TP （P 〈 0.05）, indicating that the AcP is a more sensitive index for responding P nutrient storage than PD and IPP. Soil properties, P composition, and phosphatase activities decrease with increased altitude and soil pH. Our results indicate that the distribution of soil P composition and phosphatase activities along altitude and AcP may play an important role in P hydrolysis as well as have the potential to be an indicator of soil quality.

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.

印章鉴赏:易孺刻自用印

材质:高山冻尺寸:2.5cm×2.2cm×3.9cm印文:江(豇)豆红馆边款:余至爱豇豆红明眇,曾于燕市得一杨支瓶,一印泥合,因名。今物亡久矣,志之于石。《说文》无豇字,代以江,大厂。此篆刻以古玺为宗,章法大开大合,虚实对比强立,整体风格予人雄奇恣意、奇崛横肆之感。

印章鉴赏

吴朴刻闲章材质:高山冻尺寸:2.3厘米×2.3厘米×5.6厘米印文:黄米饭香青菜熟边款:辛卯八月,时客沪上,吴朴。此印作于1951年,印法端谨,工整秀雅,逸气横生。印面语句生动脱俗,令人心生向往。印钮为胡人洗象题材,古雅别致。下方胡人以黑巧取之,轻抚象体,妙趣横生。

Loss of total phenols from leaf litter of two shrub species: dual responses to alpine forest gap disturbance during winter and the growing season

Aims Alpine forest gaps can control understory ecosystem processes by manipulating hydrothermal dynamics.Here,we aimed to test the role of alpine forest gap disturbance on total phenol loss(TPL)from the decomposing litter of two typical shrub species(willow,Salix paraplesia Schneid.,and bamboo,Fargesia nitida(Mitford)Keng f.).Methods We conducted a field litterbag experiment within a representative fir(Abies faxoniana Rehd.)forest based on‘gap openness treatments’(plot positions in the gap included the gap center south,gap center north,canopy edge,expanded edge and closed canopy).The TPL rate and litter surface microbial abundance(fungi and bacteria)of the two shrub species were measured during the following periods over 2 years:snow formation(SF),snow cover(SC),snow melting(ST),the early growing season(EG)and the late growing season(LG).Important Findings At the end of the study,we found that snow cover depth,freeze–thaw cycle frequency and the fungal copies g−1 to bacterial copies g−1 ratio had significant effects on litter TPL.The abundances of fungi and bacteria decreased from the gap center to the closed canopy during the SF,SC,ST and LG periods and showed the opposite trend during the EG periods.The rate of TPL among plot positions closely followed the same trend as microbial abundance during the first year of incubation.In addition,both species had higher rates of TPL in the gap center than at other positions during the first winter,first year and entire 2-year period.These findings suggest that alpine forest gap formation accelerates litter TPL,although litter TPL exhibits dual responses to gap disturbance during specific critical periods.In conclusion,reduced snow cover depth and duration during winter warming under projected climate change scenarios or as gaps vanish may slow litter TPL in alpine biomes.