The above-ground biomass and nutrient accumulation by poplar plantations were evaluated for pulpwood production in China. Experimental treatments applied in a split-plot design included four planting densities (1111, 833, 625 and 500 stems·hm⁻²), three rotation lengths (4a, 5a and 6a) and three poplar clones (I-69, NL-80351 and I-72). The highest biomass was achieved in the highest stocked stand (1111 stem·hm⁻²) at 6 of rotation age for both clone I-69 and clone I-72, which is about two times that in the stands of 500 stems·hm⁻² at 4 of rotation age. However, the highest occurred in the stand of 833 stems·hm⁻² at 6-year rotation for NL-80351. Ranking of the plantation biomass production by component was stem>branches>foliage>stem-bark and the production of the support components of the plantation was 10-fold that of the productive component, i.e., foliage. The pattern of accumulation of nutrients by the plantations was similar to the biomass. Nutrient accumulation in the plantations was in the order of Ca>N>K>Mg>P, but some differences existed in annual nutrient accumulation rates for four planting densities and three poplar clones. The mean annual accumulation of N and P in the plantations was 13.2 and 2.8 kg·hm⁻² in stem, 12.1 and 1.9 kg·hm⁻² in branch, and 98.5 and 9.5 kg·hm⁻² in foliage. The mean Ca, K and Mg accumulations were 28.2, 18.5 and 2.9 kg·hm⁻²·a⁻¹, 26.9, 11.0 and 2.3 kg·hm⁻²·a⁻¹ in branch, and 116.5, 81.3 and 16.1 kg·hm⁻²·a⁻¹ in foliage, respectively. Biomass utilization standards markedly affected the export of nutrients from the site. Whole tree utilization yields the most biomass and removes the most nutrients. Removal of stem with ≥10-cm diameter exports about half of the biomass, but N and nutrients removals are only 23% and 28% of the total, respectively. Removal of the entire stem provides about two-thirds of the total biomass and removes 31.1% total N and 37.5% total nutrients respectively. Including the branches in the removal increases biomass yield to 92% of the total, and nutrient removal is about 68% of the total.

Rates of fixation in chromated copper arsenate (CCA-C) treated red pine (Pinus resinosa Ait.) and southern pine (Pinus spp) sapwood specimens using retention of 1.5, 2.0, 6.4 kg·m⁻³ are compared at temperature (T) ranging from 70°C to 50°C and 5 different relative humidity (RH) conditions. The samples were investigated using the expressate method to follow chromium fixation. Red pine fixes faster than southern pine under all 11 post treatment schedules. The fixation rates for both species are not significantly different while the blocks were fixed under 6 fixation/drying schedules that differed only in the order of T/RH conditions applied. The rate of fixation of all samples in any fixation stage were reduced when the blocks were fixed under lower humidity conditions in spite of no change in chamber temperature. Some of this influence can be attributed to the effect of humidity on heat transfer into the wood and cooling of the wood surface.

Rhodiola sachalinensis growing in the different habitats, Xiaotianchi plot (altitude 1800 m), Tree line plot (altitude 2000 m) and Tianwenfeng plot (altitude 2325 m), of Changbai Moutain (northern slop) were transplanted to Harbin Experimental Forest Farm for measuring its characteristic of gas exchange. The study results indicated that the growth state and gas exchange characteristics ofRh. sachalinensis growing in different habitats varied markedly. The plants transplanted from Tianwenfeng plot had the highest values in net photosynthesis rate (Pn) and transpiration rate (Tr), those transplanted from Tree line plot shows the second, and those transplanted rom Xiaotianchi plot had the lowest values. The variance existed in transplanted plants was the same as shown in the field. From the result it can be extrapolated that the difference of Pn and Tr existed inRh. sachalinensis transplanted from different habitats is depend not only on the environmental factors, but on the variance of physiological characteristic of plant itself.

Genomic DNAs were isolated from both male and female plants ofAcer negundo L., by modified CTAB method of Doyle and Doyle for plant genomic DNA isolation and consequently tested with RAPD technique. Some sex-related specific oxyribonucleic acid bands were amplified by a group of decamer oligonucleotide random primers. This indicated that some genetic marks related to sexes of the species were found, which laid a foundation for sapling sex identification ofAcer negundo L.

This paper studied the sustainable development through a reasonable management of the social, economic and natural environment in a forested mountain area of northeast China. In order to show the local people how to manage their most important forest resource, we analyzed the life-history process of the key species and the influencing factors that were associated with the forest regeneration and sustainability. Pollination and fertilization were mainly affected by weather conditions. Light intensity under the forest canopy was the key factor that controlled seedlings growth and saplings survival. Periodic seeds setting caused the fluctuations of rodents and other related animals in the food chain. Squirrels played a very important role in the forest regeneration, theses animals were the absolutely indispensable components of the forest ecosystem. How to understand the co-evolutionary relationships among species in the forest ecosystems was very important for the conservation of biodiversity and maintenance of ecosystem itegrity. In conservation of the natural resources, we studied the social and economic environment of the forested mountain area. It is very hard to effectively protect the forest resources and maintain the normal life of the local people under the regime of the “unified administration and enterprise system”. Reforms are needed both in administrative institutions and in enterprise management. In the end, this paper proposed that we should not only protect the trees, the related animals, the ecological habitats, and the whole forest ecosystems, but also consider the human activities and their basic requirements so as to realize a sustainable development in the forested mountain areas.

In this paper, the biomass productivity and nutrient cycling in an agroforestry system of coconut (Cocus nucifera) interplanted with pineapple (Ananas comosus) had been studied. The result showed that the biomass productivity of this ecosystem was 47 460 kg...hm²...a⁻¹, which was 4.3 times as much as that of pure coconut plantation. In the biological cycling of N, P. K elements, the total annual retention was 559.470 kg...hm⁻², the annual return was 410.745 kg...hm⁻², the annual uptake was 970.475 kg...hm⁻², respectively. The average circulation rate in three nutrient elements (N, P, K) was 42.32%, which was 27.53% more than that in pure coconut stands. Coconut interplanted with pineapple was proved to be one of optimum cultural patterns, which had the higher biomass productivity, and better usage efficiency of environment resources in tropical areas.

In order to increase its hardness and gravity as well as dimension stability, the technology of hot-compressing onPaulownia wood was studied. The main factors of affecting the spring back of the compressedPaulownia samples were discussed. It was discovered that every factor in the experiment had obvious effects on wood hardness and dimension stability of compressed wood. When the MC (Moisture Content) of experimental specimens was 13.89%, it was useful to spray water on the surface of samples before hot pressing. The best result was the recovery of compression set could decrease from 90.69% of untreated wood to 45.51% of soaking specimens into PF (Phenol Formaldehyde) water solution. The hot pressing time was 8 min at 190°C.

The statistical ecology develops rapidly with the advancement of analyzing technology and method. This paper made a review about statistical ecology in China in following aspects: data collection, spatial and time patterns analysis, species-abundance and species-area relations, population dynamic, species affinity, community similarity and community cluster analysis, and community ordination.

Soil animal communities of Secondary forest,Platycladus forest andQuercus acutissima forest in Confucian graveyard of Qufu were investigated. 3583 specimens were collected, belonging separately to 5 Phylums, 11 Classes and 23 Orders. Two dominant groups and 9 common groups account for 94.45% of the total numbers. The soil animals in these three forest habitats differ in composition, ecological distribution and important indices. The dominant groups of soil animals in the three forests were the same, but other groups differ more greatly. Diversity index (H′) and evenness index (E) of soil animal in Secondary forest are the highest, and yet dominance index (C) inQuercus acutissima forest is the highest. Most soil animals in each forest habitats congregate to the surface soil layer. Their sorts and individual numbers are all layer I>II>III. It is very similar for composition of soil animals in the three forests.

Different types of plantations were observed in Baishilazi National Nature Reserve, Liaoning Province, for 34 a. The environmental quality ofAbies holophylla plantations was analyzed under different cutting systems. Analysis factors included soil erosion rate, humification degree of litters, and water hold capacity. The surface soil loss of clear cutting area was 19000t·km⁻²·a⁻¹ more than that of selective cutting area. The content of soil organic matter in board-leaved—Abies holophylla forest was 4.62% more than that in pure stand, and the water hold capacity of the mixed forest was 1.43 time of that of pure stand. The mixed forest of board-leaved—Abies holophylla by selective cutting can upgrade the ecological environment quality.

Wood composites can generally be classified in three parts: laminated composites, mixed composites and penetrated composites. Every part has its own characteristic and can be further divided. This paper introduces the history and the state of development of wood composites in China. The research about glue-laminated timber is rare and the industry hardly comes to being. A great of achievements have been obtained in mixed composites and it is well industrialized. Many studies on scrimber have been done and the Chinese researchers are looking for a feasible way to develop the scrimber industry in China. Chinese researchers also spent so much energy in studying wood plastic composites (WPC), but it has not been industrialized due to the high cost.

The food availability, composition of the diets and selective grazing of the Mongolian gazelle (Procapra gutturosa) were studied in Hulunber Grassland in Nei Monggol. The food availability of Mongolian gazelle showed seasonal changes. The plant biomass was higher in spring and summer than that in autumn and winter. The fecal compositions of the gazelle demonstrated that fibrous parts occupied 62.4%, 74.8%, and 66.0% in spring, autumn, and winter, respectively. The Mongolian gazelle preferred to grazeCompositeae, Leguminosae, Allium spp. and other forbs in spring and autumn, while the grasses, such asAneurolepidium chinense andStipa spp. were selectively feeding in winter.

The NDT detection of knobs of logs and timbers was conducted by using computer video technique. The key detection points were taken from these knobs for mathematics description. It can make the drawing of these knobs quantitatively and establish corresponding mathematics models. Using the grayness of pictures and cartoon treatment made the mathematics reappearance of the knobs become more access to video pictures.