海南岛尖峰岭热带林区牛肝菌类的研究

本文在第一期项目研究的基础上，进一步收集标本，整理并列出海南岛尖峰岭热带杯区牛肝菌５０种，隶属２科１２个属。其中食用牛肝菌１５种，药用牛肝菌７种，可形成菌根的牛肝菌２２种，有毒牛肝菌２种。其中，长柄条孢牛肝菌、黑紫牛肝菌和怪形牛肝菌属印度一马来亚区系的真菌，具热带成分，后两种亦是我国新分布种。文中从生态系统角度出发，对各类牛肝菌的生态环境条件及其分布特点等进行初步分析与探讨。

热带林区发展燃料人工林有损于气候和生物多样性保护

据MarketWatch网站2008年12月1日消息：在《保护生物学》杂志上发表的一篇研究报告发现，对于应对气候变化来说，保持热带雨林的完整比采用生物燃料人工林来取代它们更加可行。该报告是由7个国家的植物学家、生态学家和工程专家组成的国际研究小组完成的，它全面分析了热带林中的油棕榈人工林对气候和生物多样性的影响。

热带林业实验中心林区营林生产精细化管理措施

介绍了热带林业实验中心在营林生产实践过程中,切实做好选种源、工厂化轻基质网袋育苗、造林整地、定植、新造林抚育、卫生伐抚育、中龄林抚育、择伐等方面精细化管理工作的经验。

海南热带粘菌资料(Ⅰ)

报道采自海南五指山、尖峰岭等热带林区粘菌 2 8种 ,隶属于 6目 7科 12属。其中 ,有 7个中国新记录种和变种 ( 表示 ) ,有 8个种和变种是首次在海南采集到的 ( 表示 )。

亚热带森林岩溶区土壤CO_2迁移动态初步研究

贵州茂兰是研究森林覆盖下岩溶表层系统结构特征、运行规律的重要基地。本文初步研究了该地区碳迁移的若干特征 :(1)土壤剖面中CO2 浓度变化。秋、冬季土下CO2 浓度 ,5 0cm处始终高于 2 0cm处 ,而在春、夏季土壤剖面中CO2 浓度变化幅度大 ,2 0cm处的浓度时常高出5 0cm处。土下 2 0cm、 5 0cm处CO2 浓度在不同季节的变化趋势是夏季 (32 833× 10 - 6、 386 6 6× 10 - 6)春季 (2 4 4 16× 10 - 6,2 880 0× 10 - 6)秋季 (6 4 5 0× 10 - 6) ,142 16× 10 - 6>冬季 (3833× 10 - 6,8833× - 6) ,土下CO2 浓度变化趋势与温度和降雨量有较好的正相关关系。 2 0cm处的CO2 浓度变化与温度的相关系数r =0 89,与降雨量的相关系数r =0 70 ;5 0cm处的CO2 浓度变化与温度的相关系数r =0 6 9,与降雨量的相关系数r =0 6 6。 (2 )土壤呼吸释放CO2 的速率有类似的变化规律 :夏季为 339 6 8mg m- 2 h- 1、为 2 81 74mg m- 2 h- 1、秋季为 2 0 6 5 9mg m- 2 h- 1、冬季为 6 5 5 3mg m- 2 h- 1。年均排放量为 1 96kg m- 2 yr- 1。 (3)随水排泄HCO3 - 1是岩溶表层泉碳迁移的重要组分。表层泉水的HCO3 - 1浓度的季节变化与气温、月降雨量、土下 2 0cm处CO2浓度存在着负相关 ,其相关系数r =- 0 5 7、

Biomass, litterfall and the nutrient fluxes in Chinese fir stands of different age in subtropical China

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.), a fast-growing, ever-green conifer tree with high yield and excellent quality, is the most important tree species of timber plantations in subtropical China. We investigated the characteristics of biomass, litterfall and nutrient fluxes in the 8, 14 and 24 year-old stands, representing the young, middle-aged and mature stands. The results showed that Chinese fir plantations in central Fujian province had high productivity, and the proportion of stem mass in total biomass was between 50%-70%. Chinese fir was low nutrient-return tree species with litterfall. Nutrient withdrawal from senescing needles was a strong age-dependence for nitrogen, phosphorous and potassium in Chinese fir. With a management system of such short-rotation and continuously pure-crop planting, harvesting timber can lead to great nutrient loss, which may be one of the causes for site degradation.

河南省天然次生林类型划分

通过对河南省天然次生林资源评价，将全省天然次生林划分为２个天然次生林区，１５个次生林类型组，３４个天然次生林类型。并在此基础上划分出４个经营类型，为今后合理经营和天然次生林研究提供理论依据。

刚果河流域森林采伐量翻倍

尽管与其它亚洲和拉丁美洲国家相比，世界第二大热带林区的森林采伐量仍然处于较低水平，但最新的卫星监测数据也显示，自1990年以来，刚果河流域的森林年采伐量已经翻倍。

森林“世界之最”

森林面积最多的洲是拉丁美洲,森林面积占全世界森林总面积的24％,覆盖率达44％。森林面积最少的洲是大洋洲,森林总面积只占全世界森林总面积的2％,覆盖率只有11％。 森林面积最多的国家是俄罗斯,有森林面积4.8亿公顷。

森林世界之最

森林面积最多的洲是拉丁美洲，森林面积占全世界总面积的２４％，覆盖率达４４％；森林面积最少的洲是大洋洲，森林总面积只占全世界总面积的２％，覆盖率只有１１％；森林面积最多国家是俄罗斯，有森林面积４．８亿公顷。森林覆盖率最高的国家是圭亚那，高达８５％，比全...

Effects of Chinese Fir，Loblolly Pine and Deciduous Oak Forests on Nutrient States of Soils in Northern Subtro－pics of China

This paper deals with a study on the effects of Chinese fir, loblolly pine and deciduous oak forests on thenutrient status of soils in northern subtropics of China, adopting the principle of forest ecology in the caseof similar climate and soil type. The experimental area was situated in the Xiashu Experimental Centre ofForest, where the soil is yellow-brown soil derived from siliceous slope wash. Sample plots of these 3 standswere established to study the nutrient status in litter, the amount of nutrient uptake by roots, the quantityof nutrient output by percolating water outside the deep layer of soil, and the seasonal dynamics of availablenutrient in surface soil. It was shown that the intensity of nutrient cycling in soil under deciduous oak wasthe highest, and the effect of oak in improving soil fertility was the best. The result of improving soil fertilityby Chinese fir was the most inferior, though the intensity of nutrient cycling under that stand was higherthan that under loblolly pine stand. The influence of loblolly pine on the improvement of soil fertility wasbetter than that of Chinese fir, in spite of its lowest intensity of nutrient cycling.

Comparative study on active soil organic matter in Chinese fir plantation and native broad-leaved forest in subtropical China

Active soil organic matter (ASOM) has a main effect on biochemical cycles of soil nutrient elements such as N, P and S, and the quality and quantity of ASOM reflect soil primary productivity. The changes of ASOM fractions and soil nutrients in the first rotation site and the second rotation site of Chinese fir plantation and the native broad-leaved forest were investigated and analyzed by soil sampling at the Huitong Experimental Station of Forestry Ecology (at latitude 26°48′N and longitude 109°30′E under a subtropical climate conditions), Chinese Academy of Sciences in March, 2004. The results showed that values of ASOM fractions for the Chinese fir plantations were lower than those for the broad-leaved forest. The contents of easily oxidisable carbon (EOC), microbial biomass carbon (MBC), water soluble carbohydrate (WSC) and water-soluble organic carbon (WSOC) for the first rotation of Chinese fir plantation were 35.9%, 13.7%, 87.8% and 50.9% higher than those for the second rotation of Chinese fir plantation, and were 15.8%, 47.3%, 38.1% and 30.2% separately lower than those for the broad-leaved forest. For the three investigated forest sites, the contents of MBC and WSOC had a larger decrease, followed by WSC, and the change of EOC was least. Moreover, soil physico-chemistry properties such as soil nutrients in Chinese fir plantation were lower than those in broad-leaved forest. It suggested that soil fertility declined after Chinese fir plantation replaced native broad-leaved forest through continuous artificial plantation.

Effect of Slash Burning on Nutrient Removal and Soil Fertility in Chinese Fir and Evergreen Broadleaved Forests of Mid-Subtropical China

A Chinese fir forest (Cunninghamia lanceolata, CF) and an evergreen broadleaved forest (EB) located inFujian Province, southeastern China, were examined following slash burning to compare nutrient capital andtopsoil properties with pre-burn levels. After fire, nutrient (N, P and K) removal from burning residues wasestimated at 302.5 kg ha-1 in the CF and 644.8 kg ha-1 in the EB. Fire reduced the topsoil capitals of totalN and P by about 20% and 10%, respectively, in both forests, while K capital was increased in the topsoils ofboth forests following fire. Total site nutrient loss through surface erosion was 28.4 kg (N) ha-1, 8.4 kg (P)ha-1 and 328.7 kg (K) ha-1 in the CF. In the EB, the losses of total N, P and K were 58.5, 10.5 and 396.3kg ha-1, respectively. Improvement of soil structure and increase in mineralization of nutrients associatedwith increased microbe number and enzyme activities and elevated soil respiration occurred 5 days after fire.However, organic matter and available nutrient contents and most of other soil parameters declined one yearafter fire on the burned CF and EB topsoils. These results suggest that short-term site productivity canbe stimulated immediately, but reduced subsequently by soil and water losses, especially in South China,where high-intensity precipitation, steep slopes and fragile soil can be expected. Therefore, the silviculturalmeasurements should be developed in plantation management.

Land cover change and carbon stores in a tropical montane cloud forest in the Sierra Madre Oriental,Mexico

Tropical montane cloud forest is one of the ecosystems with the highest biomass worldwide, representing an important carbon store. Globally its deforestation index is –1.1%, but in Mexico it is higher than –3%. Carbon estimates are scarce globally, particularly in Mexico. The objective of this study was to simulate future land-cover scenarios for the Sierra Madre Oriental in Mexico, by analyzing past forest cover changes. Another objective was to estimate stored carbon in the two study areas. These objectives involve the generation of information that could be useful inputs to anti-deforestation public policy such as the REDD+ strategy. Remote sensing was used to measure land cover change and estimate carbon stocks. Satellite images from 2015, 2000 and 1986 were used, and Dinamica EGO freeware generatedmodels of future projections. Between 1986 and 2015, 5171 ha of forest were converted to pasture. The annual deforestation rates were –1.5% for Tlanchinol and –1.3% for the San Bartolo Tutotepec sites. Distance to roads and marginalization were highly correlated with deforestation. By 2030, an estimated 3608 ha of forest in these sites will have been converted to pasture. Stored carbon was estimated at 16.35 Mg C ha-1 for the Tlanchinol site and 12.7 Mg C ha-1 for the San Bartolo site. In the Sierra Madre Oriental deforestation due to land cover change(–1.4%) is higher than levels reported worldwide. Besides having high values of stored carbon(14.5 Mg C ha-1), these forests have high biodiversity. The models' outputs show that the deforestation process will continue if action is not taken to avoid the expansion of livestock pasturing. This can be done by paying incentives for forest conservation to the owners of the land. The results suggest that REDD+ is currently the most viable strategy for reducing deforestation rates in tropical montane cloud forests in Sierra Madre Oriental.

Effects of Alternative Nitrogen Management Regimes on Production of Eucalyptus in Tropics and Sub-tropics

This paper presents the effects of alternative nitrogen management regimes on production of Eucalyptus in tropics and sub-tropics carried out in autumn, 2011. The aim of the study was to review alternative nitrogen management regimes that could enhance the positive effects and reduce negative effects of different Eucalyptus species in the perspective of smallholders. Literature review was used to survey the alternative nitrogen management regimes on eucalyptus trees. There was a significant improvement （P ≤ 0.01） in mean annual increment （MAI） as measured at seven years of Eucalyptus tereticornis in the plots planted with only legume, pueraria and stylosanthes, compared to that of the control on altitude 150 m and rainfall of 2,000 mm at the age of seven years, The MAI of Eucalyptus urophylla and Eucalyptus camaldulensis in plots planted with beans and rice shows a significant improvement （P ≤ 0.05） over the control treatment. Only the plots treated with nitrogen fertilizer 550 kg/ha showed significant improvement （P ≤ 0.05） in terms of MAI of Eucalyptus nitens, compared to the control treatment. In general, it can be concluded that as these alternative management regimes enhance productivity of Eucalyptus woodlots, the challenge for the small-scale farmers is on how to manage them sustainably. Therefore, forest policies that take consideration of increasing production of Eucalyptus and managing biodiversity with reference to these alternative management regimes should be developed in tropics and sub-tropics.

Responses of Earthworms to Organic Matter at Different Stages of Decomposition

This study was conducted to examine the responses of earthworms to soil organic matter and litter at different decomposition stages and their contributions in litter decomposition processes in southern subtropical areas of China. Two plantations were selected as the study sites: Site I was dominated by the exotic endogeic earthworm species Ocnerodrilus occidentalis; Site II was dominated by epigeic species Amynthas corticis. After the fallen litter and earthworms were removed or expelled, four treatments were set up as: reserving the top soil (0–5 cm, equal to H layer) (H), removing the top soil and adding fresh litter (Le), removing the top soil and adding semi-decomposed litter (Li), and a control with no top soil nor any litter (CK). Five randomized blocks that were enclosed with nylon nets on the top were set up in each site, and then the four treatments were arranged randomly in each block. After 2–3 months, earthworms were collected using the formalin method. The results showed that Ocnerodrilus occidentalis preferred Treatment H though it was found in Treatments Le and Li as well; Amynthas corticis preferred Treatment Li though sometimes it also appeared in Treatment H; and Amynthas sp., another epigeic species, was mainly present under Treatment Le and only appeared in Treatment H occasionally. These findings confirmed that earthworm species belonging to different ecological groups had different responses to organic matter at different decomposition stages. The impacts of earthworm communities dominated by O. occidentalis mainly appeared at the later periods of litter decomposition.

Linking Markets to Smallholder Agro-forestry Farmers as a Strategy for Poverty Alleviation in the Tropics

The objective of the study was to assess factors affecting market participation of agro-forestry smallholder farmers in Uganda. Primary data on household, farm and marketing characteristics were collected from 153 farming households using a semi-structured, pre-tested questionnaire. The determinants of market participation were assessed using the Probit model. Descriptive statistics showed that a combination of crop, livestock and tree products were marketed by farmers. The main products included maize, cassava and coffee （crops）; firewood and poles （tree products）; and birds and goats （livestock products）. Results from the Probit model showed that farm size, household size, education level, access to credit and extension visits had positive and statistically significant effects on market participation of farmers in agro-forestry products＇ markets. Age of farmer had a negative and statistically significant effect on the participation. Emphasis on improving the quality and coverage of extension services, extending credit facilities to farmers and intensifying agro-forestry training among farmers are suggested as avenues to enhance participation of farmers in agro-forestry products＇ markets.