共查询到20条相似文献,搜索用时 0 毫秒
1.
A study was conducted to test the correlation between biomass and elevation and the differences in concentration and storks of nutrients among five vegetation types (Felsenmeer alpine tundra vegetation-FA, Lithic alpine tundra vegetation-LA, Typical alpine tundra vegetation-TA, Meadow alpine tundra vegetation MA, and Swamp alpine tundra vegetation-SA) on alpine tundra of Changbai Mountains,Jilin Province, China in growing seasons of 2003, 2004 and 2005. The biomass of 43 mono-species and soil nutrients in alpine tundra ecosystem were also investigated. Dominant species from Ericaceae (such as Rhododendron chrysanthum and Vaccinium jliginosum var.alpinum) were taken to analyze organ biomass distribution. Result showed that the biomass and elevation had a significant correlation (Biomass=-237.3 In(Elevation) 494.36; R2=0.8092; P<0.05). No significant differences were found in phosphorus and sulphur concentrations of roots, stems and leaves among the five vegetation types. There were significant differences in nitrogen and phosphorus stocks of roots, stems and leaves and in sulphur stock of stems and leaves among TA, MA, and SA vegetation types (p<0.05). The nutrient stock of five vegetations was averagely 72.46 kg·hm-2, of which N, P, S were 48.55, 10.33 and 13.61 kg·hm-2, respectively. Soil N and S concentrations in meadow alpine tundra soil type was significantly higher than those in other four soil types (Cold desert alpine tundra soil, Lithic alpine tundra soil, Peat alpine tundra soil, and Gray alpine tundra soil). Phosphorous concentration in SA type was higher (p<0.05) than in other types. Soil nutrient stock (0-20cm) was averagely 39.59 t·hm-2, of which N, P, S were 23.74, 5.86, 9.99 t·hm-2, respectively. 相似文献
2.
Distribution patterns of vegetation biomass and nutrients bio-cycle in alpine tundra ecosystem on Changbai Mountains, Northeast China 总被引:1,自引:0,他引:1
A study was conducted to test the correlation between biomass and elevation and the differences in concentration and storks of nutrients among five vegetation types (Felsenmeer alpine tundra vegetation-FA, Lithic alpine tundra vegetation-LA, Typical alpine tundra vegetation-TA, Meadow alpine tundra vegetation-MA, and Swamp alpine tundra vegetation-SA) on alpine tundra of Changbai Mountains, Jilin Province, China in growing seasons of 2003, 2004 and 2005. The biomass of 43 mono-species and soil nutrients in alpine tundra ecosystem were also investigated. Dominant species from Ericaceae (such as Rhododendron chrysanthum and Vaccinium jliginosum var. alpinum) were taken to analyze organ biomass distribution. Result showed that the biomass and elevation had a significant correlation (Biomass-237.3 in(Elevation) +494.36; R^2=0.8092; P〈0.05). No significant differences were found in phosphorus and sulphur concentrations of roots, stems and leaves among the five vegetation types. There were significant differences in nitrogen and phosphorus stocks of roots, stems and leaves and in sulphur stock of stems and leaves among TA, MA, and SA vegetation types (p〈0.05). The nutrient stock of five vegetations was averagely 72.46 kg.hm^-2, of which N, P, S were 48.55, 10.33 and 13.61 kg·hm^-2, respectively. Soil N and S concentrations in meadow alpine tundra soil type was significantly higher than those in other four soil types (Cold desert alpine tundra soil, Lithic alpine tundra soil, Peat alpine tundra soil, and Gray alpine tundra soil). Phosphorous concentration in SA type was higher (p〈0.05) than in other types. Soil nutrient stock (0-20cm) was averagely 39.59 t.hm^-2, of which N, P, S were 23.74, 5.86, 9.99 t·hm^-2, respectively. 相似文献
3.
云南生物多样性的特点与保护现状 总被引:2,自引:0,他引:2
根据联合国第55届大会第201号决议,国际生物多样性日由原来的每年12月29日改为5月22日。中国是世界上生物多样性最丰富的国家之一。也是批准加入《生物多样性公约》最早的国家之一。云南是中国生物多样性最为丰富的省份。其生物多样性在全国占有举足轻重的地位。[编者按] 相似文献
4.
5.
森林生态系统健康及其内涵理解 总被引:6,自引:0,他引:6
本文粗略地介绍了生态系统健康的研究历史,并主要从管理目标途径、生态系统途径和综合途径三种思路对森林生态系统健康的定义、概念理解及森林生态系统健康的内涵理解进行了详细的探讨。为推动我国目前的森林生态系统健康研究,我们应该更多关注生态系统的特性。参16。 相似文献
6.
本文通过对干旱河谷封山育林区域与未封山育林区造林苗木生长状况和灌草群落特征对比,开展封山育林对干旱河谷区植被恢复成效研究。研究结果表明:在相同坡向和海拔梯度上,封山育林区造林苗木平均保存率和树高净生长量均极显著性高于未封山育林区,其差值变化幅度分别为21%(阴坡Ⅰ)~31%(阴坡Ⅲ)和42.7%(阳坡Ⅰ)~59.7%(阳坡Ⅱ);灌草平均盖度和高也表现为封山育林区高于未封山育林区,灌木和草本平均盖度差值变化幅度1.1%(阳坡Ⅰ)~26.7%(阳坡Ⅱ)和2.2%(阳坡Ⅰ)~18.5%(阳坡Ⅱ)之间;灌木和草本平均高度差值变化幅度8.2%(阳坡Ⅰ)~53.5%(阴坡Ⅲ)之间和17.9%(阴坡Ⅲ)~28.9%(阴坡Ⅱ)之间。 相似文献
7.
8.
IntroductionAsabranchofsystcn1scicnccs'ccos}'stc111scl1ginccr-ing,isdevelopcdfromtl1cpracticcofccoIogicalcl1gi-neeringforstudyandn1a11agcn1cl1tofecos}'Stcl11s.Itstheqandn1cthodolog}'arcl11ai11l}dcri\'cdfro111s}'s-temscnginceringands}'Stc11lsccoIog}'.II1tl… 相似文献
9.
Michael G. Messina Stephen H. Schoenholtz Matthew W. Lowe Ziyin Wang Dolores K. Gunter Andrew J. Londo 《Forest Ecology and Management》1997,90(2-3):201-215
Sustainable management of bottomland hardwood forest ecosystems requires a knowledge of responses to management impacts, including timber harvesting. The effects of clearcutting and partial cutting on woody vegetation regeneration dynamics, surface and groundwater quality, soil physical properties, and soil respiration were tested in a bottomland hardwood ecosystem in southeastern Texas, USA, through comparison with non-cut control areas. Overstory removal only slightly affected composition of woody vegetation regeneration 1 year after harvesting compared with pre-harvest composition. Initial composition in both cutting treatments appeared to be the strongest determinant of post-harvest composition, at least for the first year after harvesting. There were few significant differences in groundwater properties when harvesting treatments were compared with control areas during a 17-month period following harvest. Turbidity, temperature, electrical conductivity, dissolved O2, NH4-N, NO3-N, and PO4-P of streamwater did not vary significantly among treatments. Slight decreases in total and macroporosity were observed in association with higher bulk densities at 0–5 cm depth in the clearcut and partial cut treatments. Saturated hydraulic conductivity values did not decline significantly with treatment intensity. No significant differences among treatments in measured soil physical properties were observed at 5–10 cm depth. Although in situ soil respiration increased with harvest intensity, treatment had no significant effect on mineral soil respiration. In summary, most variables showed only slight response to harvesting, thereby indicating that harvesting practices can be conducted with minimal initial impacts on measured response variables. 相似文献
10.
管涔山生物多样性特征研究 总被引:2,自引:0,他引:2
从地理位置、地形地貌、气候、土壤与植被和地质特征5个方面阐述了管涔山的自然概况,并从物种多样性、生态系统多样性和遗传多样性3个方面介绍了管涔山的生物多样性特征,最后提出了管涔山生物多样性保护的重要意义。 相似文献
11.
INTRODUCTIONCoId-tCmPerateregioninnortheastofChinaisaindePendentrCgioninvegetationdit-isionofChina,andcalledcold-temPerateconifcrousforestregionl"'l.Itisthemostllorthcrnoneof8vopetationregionsofChina.Sincemiddleofl9centUry,scl1olarsfromRussiaandGerman3hadinvestigatedandcollcctedtheplantsinthisrcgion-suchasR.Maack(l857),C.J.Maximotvicz(l859).GRadde(l86o-l862),S.I.KorshinsLy(l892).B.L.Komarot'(l9ol)'V.I.Lipsky'(l9()l),B.Plaetschkc(l937)l=l.Thcseresearcl1csofplantin1'estigationan… 相似文献
12.
《Journal of Sustainable Forestry》2013,32(2):45-81
Abstract In this review article, the progress of Brazilian research on mineral nutrition and fertilization of native tree species is discussed, taking as reference the scientific knowledge regarding the exotic species of the genera Eucalyptusand Pinus. There is a great knowledge gap in the theoretical base needed to develop technologies on nutritional management of native species. The high diversity of species, with variable or unknown responses to nutrient supply, makes difficult to set up a standardized and efficient fertilizer recommendation. Nevertheless, taking into account the successional groups and the growth rate of species, it is possible to discriminate the levels of nutritional requirements and to define differential management strategies of fertilization. Relevant aspects for future research on this line are also suggested. 相似文献
13.
IntroductionSoilpropertiesdependonclimate,vegetationtypes,parentmaterials,landformandsoilderivedage(Bei-jingForestryCoIlege1982).VegetationpIaysasig-nificantroIeintheformationofsoiIparticuIarIyforthepropertiespfSurfBcesoil.PlantsabsorbselectivelynutrientfromsoilandbuiIdtheirbodies.ThenutrientpartofIitterdecomposedgradualIybymicrobeswouldraturntoground-TheroOtsystemOfplantaIsoplaysasignificantroleinsoiIproperties.EffectofpIantsonsoildependonthevegdstiontype,speciescomposi-tion,age,dens… 相似文献
14.
Forest management on many ownerships in North America and Europe has shifted toward the ecosystem management paradigm. The
associated shift toward multiple management objectives and focus on natural development patterns should also be reflected
in regeneration research efforts. As new information needs arise, research questions and approaches should be evaluated whether
they are still appropriate. Specifically, spatial and temporal scales of research studies need to be expanded to accommodate
complex sets of management objectives and constraints, rather than being focused on optimal tree regeneration. At the same
time, silviculturists are asked to utilize natural trends as a guide for management, but most natural disturbance studies
have focused on stand structures and not the regeneration processes. Criteria commonly used to describe disturbance regimes
need to be modified to better guide regeneration research efforts under the ecosystem management paradigm. 相似文献
15.
Estimation of fire severity by use of Landsat TM images and its relevance to vegetation and topography in the 2000 Samcheok forest fire 总被引:1,自引:0,他引:1
Byungdoo Lee Seon Young Kim Joosang Chung Pil Sun Park 《Journal of Forest Research》2008,13(4):197-204
The severity of the 2000 Samcheok forest fire was classified by using Landsat TM images, and the effects of vegetation structures
and topographic conditions on fire severity were analyzed. The estimated normalized difference vegetation index differences
between the pre and post-fire Landsat TM images were used as the criteria in determining the levels of fire severity–low,
moderate, and extreme. According to the results from fire severity estimation, of the 10,600 ha forest stands, 28% was severely
damaged by crown fires, 38% was moderately damaged, and the remaining 34% was damaged slightly by surface fires. The overall
accuracy of the fire severity classification was 83% (Kappa coefficient = 0.76). The results of χ
2-tests showed that fire severity differed significantly with the vegetation and topographic conditions as follows. The coniferous
stands, compared with the mixed and broad-leaved, were more vulnerable to fire damage; the higher the slope of fire sites,
the greater the fire damage; the south was the most vulnerable aspect; fire severity of coniferous forest stands increased
with increasing elevation. However, in the study area it was found that fire severity of broad-leaved forest stands were negatively
related to the elevation of the corresponding fire sites and affected more by vegetation conditions rather than by topographic
conditions. 相似文献
16.
Anna Filyushkina Niels Strange Magnus Löf Eugene E. Ezebilo Mattias Boman 《Scandinavian Journal of Forest Research》2016,31(1):99-110
The need to integrate non-market ecosystem services into decision-making is widely acknowledged. Despite the exponentially growing body of literature, trade-offs between services are still poorly understood. We conducted a systematic review of published literature in the Nordic countries (Denmark, Norway, Sweden and Finland) on the integration of non-market forest ecosystem services into decision-making. The aim of the review was two-fold: (1) to provide an overview of coverage of biophysical and socio-economic assessments of non-market ecosystem services in relation to forest management; (2) to determine the extent of the integration of biophysical and socio-economic models of these services into decision support models. Our findings reveal the need for wider coverage of non-market ecosystem services and evidence-based modelling of how forest management regimes affect ecosystem services. Furthermore, temporal and spatial modelling of ecosystem impacts remains a challenge. We observed a few examples of multiple non-market services assessments. Integration of non-market services into decision support was performed with either biophysical or socio-economic models, often using proxies and composite indicators. The review reveals that there is scope for more comprehensive and integrated model development, including multiple ecosystem services and appropriate handling of forest management impacts. 相似文献
17.
石林县是被誉为“天下第一奇观”的我国著名风景胜地,是典型的“中国南方喀斯特”地貌之一。由于特殊的地质地貌,土地石漠化较明显。土地石漠化防治对生态环境保护和全县经济发展具有重要意义。通过对石林县石漠化土地的现状调查,进行分析评价,提出石林县土地石漠化防治的措施。 相似文献
18.
David P. Turner William D. RittsZhiqiang Yang Robert E. KennedyWarren B. Cohen Maureen V. DuanePeter E. Thornton Beverly E. Law 《Forest Ecology and Management》2011,262(7):1318-1325
Carbon sequestration is increasingly recognized as an ecosystem service, and forest management has a large potential to alter regional carbon fluxes − notably by way of harvest removals and related impacts on net ecosystem production (NEP). In the Pacific Northwest region of the US, the implementation of the Northwest Forest Plan (NWFP) in 1993 established a regional socioecological system focused on forest management. The NWFP resulted in a large (82%) decrease in the rate of harvest removals on public forest land, thus significantly impacting the regional carbon balance. Here we use a combination of remote sensing and ecosystem modeling to examine the trends in NEP and net ecosystem carbon balance (NECB) in this region over the 1985-2007 period, with particular attention to land ownership since management now differs widely between public and private forestland. In the late 1980s, forestland in both ownership classes was subject to high rates of harvesting, and consequently the land was a carbon source (i.e. had a negative NECB). After the policy driven reduction in the harvest level, public forestland became a large carbon sink − driven in part by increasing NEP − whereas private forestland was close to carbon neutral. In the 2003-2007 period, the trend towards carbon accumulation on public lands continued despite a moderate increase in the extent of wildfire. The NWFP was originally implemented in the context of biodiversity conservation, but its consequences in terms of carbon sequestration are also of societal interest. Ultimately, management within the NWFP socioecological system will have to consider trade-offs among these and other ecosystem services. 相似文献
19.
通过调查中美洲有"小亚马逊"之称的哥斯达黎加热带雨林国家公园及其首都周边主要景观植被,详细记录了沟谷雨林、山地雨林和平原河岸雨林以及海滨及岛屿砂生环境中主要的植物种类;其城市绿化植物种类多样,首都圣荷西有"花城"美誉。热带特种作物及果树丰富,咖啡、香蕉等成为该国重要产业。调查研究发现,哥斯达黎加拥有如此丰富的植被资源是由于当地政府和原住民对其领地的物种和自然景观严加保护而留存至今的。 相似文献
20.
The effects of early vegetation management on the survival and growth of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] were examined 5 and 15 years after planting in the Oregon Coast Range. Our first objective was to document the effects of vegetation species competition upon key ecosystem properties. The second objective was to document the effects of vegetation removal during early Douglas-fir stand establishment upon long-term tree growth and on biomass production by vegetation components. Seven levels of manual vegetation removal were maintained for the first 5 years after planting: 0%, 25%, 50%, 75%, and 100% shrub removal; and 100% shrub removal combined with 50% or 100% herbaceous vegetation removal. Shrub and herb removal did not affect Douglas-fir survival at year five, but treatments providing less than 75% shrub removal significantly reduced Douglas-fir survival by year 15. Removing shrubs and herbs completely (100S + 100H) during the 5 years following tree planting allowed successful tree establishment, with a 366% increase in biomass accumulation per hectare for Douglas-fir in that treatment at the end of 14 years of growth. At 15 years stand age, even with shrub removal alone, a 304% gain in tree biomass per hectare was obtained compared to no vegetation removal (NVR). By stand age 15 years, any increase in the degree of understory removal beyond 75% did not contribute significantly to additional tree survival and growth. The understory vegetation on NVR treatment plots and the herbaceous vegetation on 100% shrub removal (100S) treatment plots, contained >90% and >80% of aboveground biomass N at 5 years, respectively, indicating possible competition for soil N. Soil moisture was not different among treatments at 5 years. Complete vegetation removal (100S + 100H) for 5 years resulted in a significant increase in soil bulk density (P < 0.05), a significant decrease in total soil C (P < 0.05) and no change in total soil N in the upper 15 cm of the mineral soil. By 14 years, however, only the soil bulk density remained greater (P < 0.05) on the 100S + 100H treatment. We conclude that greater tree survival and growth occurred with at least 75% shrub removal. Our results suggest that managers may have substantial flexibility in maintaining a partial understory component suitable for ecosystem productivity, canopy cover and wildlife habitat, while maintaining forests productive for timber resources. 相似文献