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.

Altitudinal changes in species richness, species diversity, species evenness, life-form spectrum, and community structure of arrow bamboo (Fargesia spathacea) were studied within 11 plots from 1 500 m to 2 600 m asl on Mount Shennongjia in Central China. From the lowest plot (1 680 m) to the highest one (2 570 m), vascular plants declined from 30 to 7 species, following a linear model ofY=55.99-1.83X (d.f.=9,F-value=48.64,r ²=0.84,P<0.001); species diversity, reduced from 3.13 to 1.78, following a linear model ofY=4.67–0.10X (d.f.=9,F-value=22.82,r ²=0.72,P=0.001); species evenness varied from 0.83 to 0.99, but presented little relationship to the altitude (r=0.112,P=0.742). In the life-form spectra, with the increase of altitude, the percentage of annual plants (r=0.60), underground bulb perennials (r=0.40), and big trees (r=0.35) tended to increase; shrubs (r=−0.52) and middle-sized trees (r=−0.45) tended to decline; perennial grasses (r=0.04) and semi-shrubs (r=0.03) were not strongly related to the altitudinal gradient. Arrow bamboo communities could be classified into five groups: bamboo under evergreen broad-leaved forest, under deciduous broad-leaved forest, under temperate coniferous forest, under cold-temperate coniferous and mixed forest, and pure bamboo community.

Eight kinds of phytoecdysteroids extracted from different parts ofAjuga multiflora Bunge (Labiatae) that were collected from different places at different time were tested for killing effects on the 2-instar larvae ofCryptorrhynchus lapathi L by adding them to the artificial diet of larvae. The experimental results indicated that adding 1–3-mL phytoecdysteroids to the artificial diet could lead 58%–100% of 2-instar larvae ofC. lapathi to death within 24 days. The phytoecdysteroids extracted from the whole plant ofA. multiflora which was collected before flowering time were much more effective than those extracted from the plants collected at flowering and after flowering periods, and the modified mortality rate of larvae reached 65.22%, 85.07%, and 98.11% at the dosage level of 1-mL, 2-ml, and 3-mL extracts, respectively. The extract made from root ofA. multiflora plant was more effective in killing efficiency than those from stem and leaves, and the average death rates of larvae were up to 100%, 98.20% and 98.32% at dosage levels of 1-mL, 2-mL, and 3-mL extracts, respectively. The killing speed of the extracted phytoecdysteroids was slower than that of triflumuron, hexaflumuron or deltamethrin emulsifiable concentrate. The mortality rate of larvae is closely related to the feeding duration on the diets containing phytoecdysteroids. Feeding on the diets with addition of phytoecdysteroids for 16 days, more than 80% of treated 2-instar larvae ofC. lapathi were led to death. The killing effect of the extracts was little affected by the growth areas ofA. multiflora plant and the adding way to artificial diet.

The relative potentials of either heartwood extracts (air dry extracts in 60 percent methanol) of very durable woods (Afzelia africana J.E. Smith;Erythrophleum suaveolens (Guill & Perr.) Brenam. Syn.E guinensis G.Don. orMilicia excelsa (Welw) C.C. Berg. Syn.Chlorophora excelsa (Welw) Benth.) or any of two proprietary wood preservatives (AWPA type “C”-Chromated Copper Arsenate (CCA) or 5 percent solution of AWPA Standard Designation P “9” type “C”—Pentanchlorophenol (Penta) in light oil solvent) to suppress attack on pressure treatedAntiaris toxicaria Lesch Sapwood by either any of three species of decaying fungi (Coridopsis Polyzona Klotzch;Lenzites trabea; orTrametes cingulata Fr.) under soil block exposure conditions were investigated and threshold values determined. Extract/preservative dosages were either 8.009; 24.778; 48.056; 96.111 or 144.167 kg m⁻³ (0.5; 1.5; 3.0; 6.0 or 9.0 1b/ft³). Exposure was for either 14 or 28 weeks and in accordance with ASTM D1413-72 Provisions. Conclusions reached were that at threshold values the ability of either any of the heartwood extracts or proprietary wood preservatives to suppress attack under conditions in this study was significant at 0.01. Relative efficacy of those biocides was dependent on fungal species. Neither any of the heartwood extracts nor any of the proprietary wood preservatives (except in the case ofTrametes cingulata attack on CCA treated wood at highest retention level) was able to confer “very durable” rating on treated wood. Possible reasons for the reduced relative durability of extracts visa vis native heartwood were advanced. At the highest retention level (144.167 kg m⁻³) there was no significant difference (at 0.05 level) between efficacy of each of the heartwood extracts and any of the proprietary wood preservatives (CCA or Penta).

By the method of gradient pattern analysis, 24 plots were set at altitudes 700–2600 m with an interval of 100 m on the northern slope of Changbai Mountains. Two non-parametric estimating methods, jackknife and bootstrap, were used to estimate the numbers of species in the communities at different altitudes. Results showed that the estimated numbers of species from bootstrap were more close to the reality. By comparing the difference between estimated number of species and the number of observed species, rationality of critical sampling area for different communities were validated.

This study was conducted in Erdaobaihe River passing through the broadleaved and Korean pine forest located on the north slope of Changbai Mountain. In-stream large woody debris (LWD) in two segments of the river channel was investigated with base diameter, top diameter, length, and decay class. To study relationship between in-stream LWD and adjacent riparian forest, species of each log of LWD in segment 1 was identified, and the riparian forest was examined by setting a 32m×24m quadrat consisting of twelve 8m×8m small quadrats. The results showed that, in segment 1, in-stream LWD loading was 1.733 m³/100m or 10.83 m³·hm⁻², and in segment 2, it was 1.709 m³/100m or 21.36 m³·hm⁻². In-stream LWD in decay class III and IV were accounted for a high proportion, which was different from that in the broadleaved and Korean pine forest, and the possible reason might be different decomposing velocities due to different decomposing conditions. Logs of LWD in stream and living trees in riparian forest declined as diameter increased, and it was in a reverse J-shaped distribution except logs of LWD in segment 1 in the first diameter class. Volumes of LWD in stream and living trees in riparian forest increased as diameter increased, and it was in a typical J-shaped distribution. Loading and species component of in-stream LWD were correlative to status of riparian forest to a certain extent, and there also existed difference. Comparing the correlation and difference was helpful to study on dynamic of the riparian forest.

The precipitation distribution quantity of canopy in broadleaved/Korean pine forest was measured during the growing season (Jun.–Sept.) in 2001 in the Changbai Mountain, Jilin Province, P. R. China. Results indicated that the amounts of stemflow, throughfall, and interception were 37.39, 322.12 and 109.69 mm, accounting for 7.97%, 68.65% and 23.38% of the total rainfall, respectively. The rate of stemflow was higher in Jul. and Aug. than other months. The rate of throughfall dropped off from Jun. to Sept., however, rate of interception changed contrarily from 19.43% to 31.02% during the growing season. According to our analysis, the concentration of nutrient elements were arranged as Ca>Mg>N>K>Fe>P>Cu>Mn for rainfall, K>N>Mg>Ca>P>Fe>Mn>Cu for throughfall, and Mn>P>K>Cu>Fe>N>Mg>Ca for being leached through canopy. Nutrients concentration in stewflow and throughfall changed significantly when rainfall passed canopy, and concentration of all elements increased except for Ca and Mg.

The measurement and observation for this study were carried out at Forest Ecosystem Opened Research Station of Changbai Mountains (128°28′E and 42°24′ N, Jilin Province, P. R. China). Characteristics of Dominant time scales (DTSes) and dominant time scales contribution ratios (DCRs) across canopy-atmosphere interface and controlling factors were analyzed with multi-scale method. DTS of stream wise and lateral velocity components were larger than that of vertical velocity component. While DCR of vertical velocity component was larger than that of the stream wise and lateral velocity components. Effect of atmospheric stability on DCR and DTS was nonlinear. DTS under unstable conditions was larger than that under stable conditions; DTS and DCR were determined upon the original scales characteristics of upwind flow under strong stability. Canopy structure would influence DTS and DCR across canopy-atmosphere interface remarkably.

Influences of temperature, humidity, and CO₂ concentration on the photosynthesis and respiration of three-year-oldBetula platyphylla was investigated. Light compensation point, saturation point and CO₂ compensation point were also determined. The results showed that the optimal temperature of photosynthesis and dark respiration was 24 °C and 30 °C, respectively, at ambient CO₂. When relative humidity was 80%,Betula platyphylla could maintain strong photosynthesis. There was no significant correlation between respiration and relative humidity. The light compensation and saturation point was 25 μmol·m⁻²·s⁻¹ and 1 375 μmol·m⁻²·s⁻¹, respectively. The CO₂ compensation point was 180 μL·L⁻¹. The results showed thatBetula platyphylla still had potential to assimilate CO₂ when CO₂ concentration was above 2 400 μL·L⁻¹.

Taihu Lake area is one of the most developed areas in agricultural production. Application of fertilizers and pesticides in large quantities greatly aggravate environmental pollution of this area, and water pollution has worsened to an unbearable condition. Two sampling farms (respectively 1 hm²) under rape-rice rotation and wheat-rice rotation were selected as studied ecosystem and a 5-yr-old Poplar forest and 8-yr-old Metasequoia forest were chosen in the selected areas. By collecting samples of Nitrogen, Phosphorus in water, crops and underground of forest, the transfer and loss of N and P (main water pollutants) in faming ecosystem were studied, and the effects of forest belts on non-point source pollution of agricultural lands was analyzed. The results indicated that the transfer and loss of N and P vary with means of rotation, types of crops and the amount of fertilizer application. Buffering forest belts betweens farmlands and ditches can effectively stop and purify such elements as N and P in soil runoffs, thus controlling non-point source pollution of agricultural lands. When the width ratio of farmland to forest belt is 100 to 40, 50.05% losing N, 29.37% losing P can be absorbed by forest under rape-rice rotation and 30.98% N, 86.73% P can be absorbed by forest under wheat-rice rotation. When the width ratio of farmland to forest belt is 150 to 40, 33.37% losing N, 19.58% losing P can be absorbed by the forest under rape-rice rotation, and under wheat-rice rotation 20.65% lost N and 57.82% lost P can be absorbed. There is only some purification effect when the width ration of farmland to forest belt is 200 to 40. Based on model of buffering forest belts, the width ratio of farmland to forest is determined between 100 to 40 and 150 to 40, because it not only can purify water, but also occupy less farmland. It is suggested that Poplars, with the characteristics of fast-growing and high value, are suitable to be planted as shelter-forest in Taihu Lake Watershed.

From the 1950s to 1960s, large area ofPopulus simonii shelterbelts system was established in northern area of Shanxi Province. For reconstructing the old shelterbelts, more attentions should be paid to selecting suitable tree species and design of logical shelterbelts structure. In order to provide a profound basis for the efficient establishment of shelterbelts, the study on function and structure of the farmland shelterbelts was conducted in Shuozhou and Datong areas, both are semi-arid areas in Northern Shanxi Province during 1996–2001. The wind-control effects of shelterbelts with different structures (close-spaced, wider-spaced, and widest-spaced) were investigated by portable wind vane and anemometer, wet and dry bulb thermometer, ground thermometer, glass service instrument. The results showed that the wind-control capacity of the shelterbelts during the leafing period should be thought as the criteria index in shelterbelts established. The wider-spaced shelterbelt that was made of 4–6 rows of trees, with a spacing of 2.0 m×3.0 m, had the best wind-control result.

In eastern area of Xiaoxing’an Mountains, Heilongjiang Province (44 ^o4′–47 ^o26 N′, 126 ^o33′–131 ^o41 E′) the diameter-class structure ofQuercus mongolica forest after different closed time was studied in the plots with different slope direction. Six repetitive plots within 5-year, 16-year and 24-year closedQ. mongolica forests were selected in sunny slope and shade slope, respectively. The area of each plot was 20m×20m. Diameter at breast height (DBH), tree height and canopy diameter of all the trees were measured. Six classes of diameter were determined as 2, 4, 6, 8, 10, and 12 depending on the range of DBH (0–3, 3–5, 5–7, 7–9, 9–11, and 11–13 cm). The results showed that: 1) After 5-year closed treatment, the population quantitiesQ. mongolica, Tilia mandshurica andUlmsis laciniata decreased with the increase in diameter class, which indicated they were healthy populations; 2) After 16-year closed treatment the tree number ofTilia mandshurica andUlmsis laciniata decreased because of canopy coverage increasing and became the associated species inQ. mongolica population; 3)Q. mongolica, after 24-year closed treatment, became dominant species; 4) Canopy coverage increased more rapidly in sunny slope than that in shade slope. Recession ofTilia mandshurica andUlmsis laciniata populations in sunny slope was more obviously than that in shade slope.

Efficient use of timber is a vital concern problem, especially in these regions where the forestry coverage ratio is decreasing. Studies on physical modification of wood have been taken more attention due to the increasing attentions on environmental protection. Thermal modification is emphasized and developed quickly in developing countries, especially in European countries. A large number of researches have been conducted and some industrial production plants have been built. This paper reviewed the history of heat treatment, exemplifies the industrial developments in several European countries, summarized the basic principle of heat treatment and describes the environmental characteristics. The properties of heat-treated wood and its usage are also summed up.

As the most important type or component in the terrestrial ecosystems, forest ecosystem makes its role obviously prominent and important on environment and human being. It possesses non-substitutable functions in the process of sustainable development. However, due to the complexity of the forest ecosystem and the relatively delay or lack of the related research technology, the science is still in the case of immature and questions. This paper summarized and reviewed briefly the development and the present case of the forest ecology, then pointed out the existing problems in the forest ecosystem researches. In the end, we discussed several fields that need to pay more attention to in future researches.

Many researches have been carried out on the taxonomy ofBetula in northeast of China, but the classification of species and subdivision of species had some divergences at all times, which led to a disorder for developing and utilizing resources ofBetula. In this paper, species and subdivision ofBetula were classified not only according to the wax sample ofBetula but also the comprehensive taxonomy of population characters, geographical distribution, and the habitat. The conclusion supported the Fu Pei-yuns’ (1995) viewpoint of the taxonomy ofBetula in the northeast of China. ButB. mandshurica (Regel) Nakai should be considered as one single species, the name ofB. platyphyla Suk. varphellodendroides Tung should be the synonym ofB. platyphyla varplatyphyla, andB. ermanii Cham. var.yingkiliensis liou et Wang should be incorporated intoB. ermanii Cham.B. ovalifolia Rupr should not be regarded as a variety ofB. fruticosa Pall. but as one single species.

Most of forest birds have the characteristics for habitat selection. The purpose of this study is to clarify the vegetation structure in breeding area of Siberian rubythroat (Luscinia calliope). In Daecheongbong peak, Mt. Seoraksan national park, South Korea from May to August, 2001, breeding population of Siberian rubythroat and the dominant species in breeding area of Siberian rubythroat (Luscinia calliope) were surveyed by line transect method along the ridge in the Daecheongbong peak area. Number of individuals and location of song posts were observed and recorded. According to the survey results, the study area was classified into high, middle and low density areas. Those birds selected the forest area of dominant species for Erman’s birch and dwarf Siberian pine as habitat and preferred the shrubs area with the lower height and higher coverage.

The various behaviors of four Amur tigers in captivity were investigated in March from 1998 to 2001 in Harbin Zoo. The results showed that the behavior could be divided into 5 major types: moving, resting, sleeping, eating and other behaviors (including drinking, urinating, grooming, playing, standing). Of all behavioral models, sleeping and moving behaviors alone accounted for 75.18% and were two major behavioral models of all behaviors. Resting, eating and other behaviors accounted for 24.82%. Apart from eating, one male and two female individuals have similar peak periods of 4 major behaviors (one peak period in the daytime, and one peak period at night), similar to that of wild Amur tiger. However, one female individual have two clear peak periods at night.

The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on automatic seedling classification (ASC), the seedling grading theory, traditional grading methods, the background and the proceeding of ASC techniques are described. The automation of the measurement of seedling morphological characteristics by photoelectric meters and computer vision is studied, and the automatic methods of the current grading systems are described respectively. And the further researches on ASC by computer vision are proposed.