非林地人参种植基地建设的优势分析

本文对非林地人参种植基地建设模式的多方面优势进行了分析,强调了非林地种植人参模式具有保护生态环境、解决宜参地资源枯竭;深化农业产业化调整,确保人参产业的可持续发展、实现人参产业的科学化,规模化,规范化管理,改善生产条件、降低生产成本;增加农业经济效益;推广GAP规范化管理,保证原药材质量,增加国际市场的竞争力、赶超世界先进水平,填补我国参业生产技术空白的多方面积极作用,强调了非林地种植人参的基地建设模式是提升人参种植的整体水平,从传统生产模式向现代新型生产模式发展的必由之路。

开发非林地人参种植 打造生态和谐特产业

本文针对近几年非林地人参产业发展的多方面研究、分析,重点对非林地人参作为未来人参种植的补充和主要耕作模式进行了阐述。加大非林地人参种植的投入力度,进而保持市场供求关系的同时,最大限度地减少对自然资源的破坏,从而做到人参种植与生态环境和谐发展的新常态。

江华县桉树种植存在的问题及对策

介绍了湖南省江华县发展速生丰产桉树林的现状,分析了桉树种植过程中存在的林地流转、林地租赁价格、林地合同、采伐指标、大众的认识和观念等问题,并针对这些问题,提出了建立林地流转交易机制、创建科学经营模式、规范林地合同、做好宣传工作并出台相关林地租赁政策等措施。

Spatial patterns in natural Picea crassifolia forests of northwestern China,as basis for close-to-nature forestry

Close-to-nature forest management has been proposed as an effective method for improving the quality of plantation forests. Knowledge of spatial distribution patterns, structure, and succession trajectories in natural forests can provide guidelines for the establishment of close-to-nature forest plantations. Such knowledge is lacking in natural spruce(Picea crassifolia) forests in the Qilian Mountains of China, impeding the establishment of production forests. We conducted a case study in the Qilian Mountains to analyze the relationships between the naturally-formed forest patches and terrain factors, spatial heterogeneity of stand characteristics, and stand structure following harvesting disturbance. Our results suggested that spruce plantations will be effective on the N, NE, and NW slopes, at elevations between 2700 and 3300 m, and on slopes ranging from 15° to 45°. Further, planted forest patches should occupy 64% of the slope area on semi-shady slopes(NE, NW). Spatial patterns in the studied forest exhibited a strong scale-effect, and an area of 0.25 ha could be used as the most efficient plot scale for the management of spruce plantations. Partial logging is an effective method for the conversion of spruce planted forests into nearnatural forests, and the intensity of partial logging can be determined from the negative exponential function relationship between stand density and DBH. Our results provided critical information for the development of spruce plantations and conversion of existing plantations.

STRATEGY OF MAIZE′S CONCENTRATING TO ADVANTAGE AREAS IN JILIN PROVINCE

Jilin Province is one of the main grain-producing provinces of China,which has dominant position in maize production,by the view of its advantages in policy,location,breed and market. And after entering WTO,some measures have been taken to enhance maize competitive ability. But there are some difficulties in concentrating production to maize advantaged areas. This paper expounds the basis that Jilin Province becomes the advantage area of maize,analyzes the problems and puts forward the supporting policy. Some strategic measures are proposed,as developing comparable advantages,carrying out the strategy of un-equilibrium development and cultivating advantaged product areas of maize to rapidly improve the international competitive ability and productivity of maize in Jilin Province,cast the agricultural predicament off and promote the agricultural development into a new stage.

Woody Species Diversity and Forest Structure from Lowland to Montane Forest in Hyrcanian Forest Ecoregion

Alborz Mountains host Caspian Hyrcanian forest ecoregion along the northern slopes and forest steppe ecoregion in highlands. Hyrcanian forest covers the southeastern part of Caucasus biodiversity hotspot and is of great biogeographic importance. Altitudinal pattern and correlation between woody species biodiversity （DIV）, forest structure （（stem density （DEN）, mean basal area （MBA） and mean height class （MHC）） and disturbance （DIS） were explored along 2,4oo m altitudinal gradient in Hyrcanian relict forest, Central Alborz Mountains. Vegetation changes from lowland forest （LoF） to mid- altitude forest （MiF） and montane forest （MoF） in this area. The altitudinal gradient was divided into twelve 200 m elevational belts. Point centered quarter method （PCQM） with 96 sampling points and 83 vegetation samples by plot method （PM） were used to record field data. Shannon-Wiener index and Pearson coefficient were used for diversity and correlation analysis. The results showed that DEN decreased linearly, MBA and MHC showed relatively hump shaped and DIS showed a reverse hump shaped pattern of change along altitudinal gradient. Woody species diversity decreased non-steadily from LoF to MoF. Transitional vegetations of Carpinus-Fagus and Fagus-Quercus represented higher diversity of woody taxa compared to adjacent homogenous communities. Significant correlation was observed between altitude and all parameters： DEN with MBA, DIS and DIV; MBA with DIS; MHC with DIS along with DIV; and DIS with DIV at the study area scale. Surprisingly,correlation between studied parameters differed within each vegetation type. Altitude probably acts as a proxy for human and environmental driving forces in this area. Stability of warm and wet condition, season length, soil depth along with forest accessibility probably influences the altitudinal pattern of the studied parameters. Disturbance affects forest structure and consequently diversity; especially in lowlands. The obtained results recommend using both forest biodiversity and mensuration data in management process of forest ecosystems.

Identifying indigenous tree species for land reforestation,forest restoration, and plantation transformation on Hainan Island, China

Selecting suitable species is the most important issue for bare land reforestation, degraded secondary forest restoration, and single-species plantation transformation. However, little information has been documented related to tree species selection for these silvicultural endeavors on tropical Hainan Island of Southern China. The present study employed Baisha County, the ecological core area of Hainan Island, as a case study area. We initially inventoried a slightly disturbed primary forest and attempted to produce diameter distribution curves for each tree species. Second, the tree species were classified into shade intolerant, opportunist, and shade tolerant species based on shape of their diameter distribution curves. Third, market value was determined for each tree species based on published literature and on-site investigations at local wood trading companies. Totally 118 tree species were encountered in the inventoried forest and 13 tree species present were finally identified as potential tree species for our silvicultural endeavor on Hainan Island, of which 3 species are shade intolerant, 5 species are opportunist and 5 species are shade tolerant. Additionally, we also selected 12 tree species that were not in the inventoried forest but were extremely economically valuable and ecologically important. This study should contribute to the formulation of a sustainable forest management strategy on Hainan Island and the methodology might be replicated in other tropical region where suitable species also need to be identified for silvicultural endeavor.

Above-ground Biomass Allocation in a Planted Forest in a Semi-arid Region of Northern Mongolia

Investigation of the above-ground biomass allocation patterns on Scots pine plantations is critical for quantifying the productivity and carbon cycle of forest ecosystems. We estimated above-ground biomass and net primary production of a 25-year-old Pinus sylvestris L. （Scots pine） plantation, in a semi-arid region of Mongolia. The above-ground biomass of sample trees was divided into stem wood, stem bark, live branches, dead branches and needles. Total biomass for the stand was only 18.03 Mg ha1, of which 47.6% was found in stem wood, 25.8% in live branches and 14.8% in needles. The growth rate of the Scots pine plantation in the study region was relatively low compared with other regions. In the study area, it was observed that the rate of biomass accumulation in the plantation was very slow; this can be explained by very limited growing conditions and intensive crown closure. The results from this study indicate that it may be necessary to carry out thinning to increase biomass production by reducing competition between trees in the Scotch pine plantation.

How Does the Blue C Stock Vary in Restored and Degraded Wetlands Across Land Cover Mosaics? Evidences from Medinipur Coastal Plain, India

Coastal wetlands are of paramount importance as major reservoirs of blue carbon(C),playing a crucial role in providing nature-based solutions to mitigate climatic changes.This research aimed to analyse the dynamics of total blue C(TBC)and its components;viz.soil organic C(SOC),below ground C,and above ground C;as well how they are influenced by land use/land cover(LULC)categories and wetland situations.Subsequently,study were identified as one restored wetland and another degraded wetland in the Medinipur Coastal Plain,India.The LULC categories were analyzed using Pleiades 1A and 1B satellite imagery,corresponding to the restored and degraded wetland,respectively.The quantification of SOC was based on point-specific sample data collected from both wetlands(nr=250;nd=84).Above ground biomass(AGB)was appraised employing allometric relationships involving field-measured dendrometric variables.Below ground biomass values were calculated using indirect allometric equations that take into account the AGB values.Integrating all the components,TBC stock of the restored and degraded wetlands were estimated at 246710.91 Mg and 7865.49 Mg,respectively.In the restored wetland,dense mangrove and open mangrove exhibited higher concentrations of blue C components,while other LULC categories demonstrated moderate to low densities.In the degraded wetland,the open mangrove category rechigh densities of C pools,whereas herbaceous vegetation,bare earth and sand,and waterbody exhibited lower concentrations.The results portrayed significant disparities(P<0.05)in blue C pools among different LULC categories in both wetlands.Furthermore,it was evident that wetland type and LULC category had notable(P<0.001)impacts on TBC dynamics,both individually and in combination.Overall,this research may aid in effective management of coastal wetlands as blue C sinks,emphasizing their significance as essential elements of climate mitigation strategies.