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PubMed2000

[Optimized models of logging-tending system in cutting areas].

The comprehensive advantages of different logging-tending systems in Pinus massoniana forest cutting area were evaluated by set-pair analysis, based on the comparison of their economic and ecological benefits. The results showed that the optimized model for P. massoniana forests in Northern Fujian comprised 40% selective cutting, manual skidding, clear-cutting in ribbon, and natural regeneration with artificial aids, which could also be used in the nearby forests with conditions similar to the experimental area.

China↗

PubMed2000

[Simulation of potential responses of clear-cut of mixed coniferous and broadleaved Korean pine forest in Yichun to climate change by BKPF model].

The potential responses of forest succession in the clear-cut site of mixed coniferous and broad-leaved Korean pine forest (MCBLKPF) in Yichun, Heilongjiang Province to global climate change and elevated CO2 after 50 years by BKPF model were simulated. The results indicated that the densities of Pinus koraiensis and hardwood species(Fraxinus mandshurica, Tilia amurensis, Juglans mandshurica and Phellodendron amurense) would increase, while the densities of Larix olgensis, Betula platyphylla and Populus davidiana would decrease after 50 years. The stand densities would be slightly lower than those at the same age under the current climate condition. The stand productivity, total aboveground biomass and leaf area index will increase by 7-28%, 15-24% and 5-8%, respectively. Climate change would be beneficial to the forest succession from the clear-cut site to MCBLKPF.

Climate↗

PubMed2002

Effects of red-yellow soil acidification on seed germination of Chinese pine.

Acid treatments significantly change the physical and chemical properties of red-yellow soil by lowering its pH value and leaching out aluminum(Al) ions that are harmful to the growth of plants. The structure of soil will be damaged, resulting in higher viscosity, higher water retention rate and lower air permeability of the soil. The germination rate of Chinese pine(Pinus tobulacformic Carr.) seeds sowed in soil treated with sulphuric acid(H2SO4) decreased compared to that for untreated soil. The direct cause was the large amount of Al ions leached out because of low pH values(> or = 3.5). The added acid decreased the soil aggregation and increased the number of micro-aggregates(under 250 microns in diameter). Such changes increased the soil's viscosity, which tied the pine needles to the soil after the seeds had germinated and prevented the seedlings from fully developing.

Germination↗

PubMedDate not supplied

Jack pine growth and elemental composition are affected by saline tailings water.

In the processing of oil sands from Alberta's Athabasca formation, large quantities of alkaline, saline tailings and associated process-affected waters are produced. These waters may have a negative effect on plants used in reclamation of mined areas in this region of the northern boreal forest. In the present study, we examined the effects of process-affected water on the growth and elemental composition of jack pine (Pinus banksiana Lamb.) seedlings. Seedlings were grown in sand culture, and treated with tailings water to which mineral nutrients had been added. One-month-old seedlings were treated for 14 d, and all measured growth parameters were reduced. Growth and shoot elemental composition were also measured in seven-month-old seedlings that were treated for 10 wk with process-affected water. Shoots had significantly elevated levels of Na, Cl, S, P, B, and Sr, and significantly reduced levels of Fe, Mo, Ba, and K. The relationships between elemental composition and seedling growth and injury were examined using multiple regression. Growth rates, dry weights, and carotenoid content were reduced, but were not related to shoot elemental composition. Needle necrosis was positively related to tissue Na and Cl. Results indicate that reclamation planning must consider substrate Na and Cl levels when planting jack pine on tailings-affected sites.

Chlorine↗

PubMed2002

[N2O emission from trees under different light irradiances].

This paper firstly measured in situ N2O emission from branches and leaves of sun plants (Fraxinus mandshurica, Pinus koraiensis, Alnus hirsuta) and shade tolerant plants (Tilia amurrensis) under different light irradiances in closed chamber. Light irradiance had contrast effects on N2O emission flux from sun and shade-tolerant tree species. In the test sun plants, more N2O was emitted under weak light than under strong light. The emission rates decreased with increasing irradiances, and even absorption instead of emission of N2O was detected under strong light. In contrast to sun plants, in the shade tolerant plant T. amurrensis, there was more N2O emission under strong light than under weak light, and N2O absorption from environment was detected under weak light.

Fraxinus↗

PubMed2003

[Litterfalls of major forest stands at Baiyunshan scenic spot of Guangzhou].

The productions, seasonal dynamics, macronutrient contents and decomposition rates of the litterfalls of four typical stands, e.g., Pinus massoniana plantation, secondary evergreen broadleaved forest, Acacia mangium plantation and Schima superba-Acacia mangium plantation at the scenic Baiyunshan of Guangzhou were studied. The litterfall productions of four stands in 1998 were 8.34, 6.77, 6.31 and 11.54 t.hm-2, respectively. The seasonal dynamics of litterfall amounts demonstrated the single-peak model with the peak period in June and July. The total amounts of macronutrients returned to the forest land by means of litters in the four stands in 1998 were 26.30, 69.81, 54.9 and 152.24 kg.hm-2, respectively. The annual decomposition rates of the litterfalls were 24.4%, 53.4%, 52.4% and 57.4%.

Acacia↗

PubMed2003

[Application of succession study in tending and restoration of evergreen broadleaved forest].

The characteristics of synecology, population ecology and physio-ecology of main tree species Quercus fabri, Pinus massoniana, Castanopsis sclerophylla, Lithocarpus glaber, Schima superba and C. fargesii of evergreen broadleaved forest in Tiantong National Forest Park, Zhejiang Province were studied by comparative method. The successional process was clarified through the comparative studies of the synecological characteristics of these main tree species, the individual plant structure and renewability were discussed by comparative study of population ecological characteristics of main trees' populations, and the mechanism of replacement with each other of these main tree species was open out by comparative study of physio-ecological characteristics of these main trees. Based on the study of comparative ecology of the main dominant evergreen broadleaved forest series, the successional stage and direction and its management could be determined, and the theoretical basis for the planning and management of forest production, and the restoration, reconstruction, and exploiting under artificial disturbance could be offered.

Conservation of Natural Resources↗

PubMed2003

[The relationship between environmental change and stable carbon isotopes records from tree-ring in Mt. Helan].

The value of stable carbon isotope in plants is closely correlative with environmental factors. The stable carbon isotope chronology was attained from tree-ring alpha-cellulose in pine(Pinus tabulacformis), Mt. Helan. The relation between delta 13C series and precipitation from January to July was negatively correlative(r = -0.515, alpha = 0.05). And the delta 13C series was positive correlative with the average temperature from June to August(r = 0.427, alpha = 0.05). Also the atmospheric CO2 content relates to the delta 13C series in the tree-ring cellulose. It was easy to find the increasing trend of CO2 composition in the atmosphere from the tree rings. By the relation between the number of sunspot and delta 13C series, the more number sunspot was correlated with higher delta 13C value was found.

Air↗

PubMed2003

[Ecological restoration effects of typical manmade ecosystems and relationships between restoration variables in middle Yunnan area].

This paper studied the restoration effects of Pinus yunnanensis forest, mixed Eucalyptus maideni-Acacia meamsii forest, Eucalyptus maideni forest and restored natural vegetation in middle Yunnan area. The man-made forests consisting of different tree species had different effects on plant diversity, forest hydrology, soil surface erosion control, soil amelioration, and forest characteristics. Afforestation with native species promoted the plant diversity. Recovery Distance Index(RDI) was calculated for the evaluation of the forest restoration extent based on Principal Component Analysis (PCA). The restored natural vegetation P. yunnanensis forest, E. maideni forest, and A. mearnsii-E. maidensi forest would need correspondingly 29.14, 14.36, 34.23, and 11.03 years to recover to the ecological functions of zonal climax community. There were some relationships among forest recovery variables. Shannon-Wiener index, herbage coverage, community evenness, species diversity, soil available K, soil bulk density, biomass of herbage, woody plant coverage, timber volume of woody plant, soil total K, soil erosion, soil Si/V, littersfall, soil non-capillary porosity and through-fall were the main variables among the forest restoration variable dealt with in our work. Diversity played a central role in the restoration of ecosystem structure and functions.

Ecology↗

PubMed2003

[Height structures of dominant species of different subtropical evergreen broadleaved forest communities in Wanmulin Natural Reserve].

Based on the data of four subtropical evergreen broadleaved forest communities in Wanmulin Natural Reserve, whose dominant species were Tsoongiodendron odorum Chun, Cinnamomum micranthum Hayata, Castanopsis fabri Hance and Pinus massoniana, respectively, the height class and diameter class structures and the dynamics of height structure were analyzed. The results showed that the relationships between tree species, tree density, basal area at D. B. H, and height class (or diameter class) could be simulated by different equations. There was a significant positive correlation between tree species and tree density for different height class or different D. B. H. class. The structure dynamic analysis showed that the community of Tsoongiodendron odorum Chun was very unstable, and the species sharing degree in four communities was fairly lower, indicating that the dominant species were very obvious. The results could give a useful clue for the studies on endangered mechanism of rare species.

Conservation of Natural Resources↗

PubMed2004

[Community characteristics in Hongchiba area of Wuxi County during ecological restoration after controlled burning].

This paper studied the species composition and the structure and species diversity of communities in Hongchiba area of Wuxi County after controlled burning and aerial-sowing afforestation. The results showed that after burning and afforestation, pure Pinus armandii forest was not developed, but various mixed needle board-leaved forests which comprised P. armandii and native board-leaved trees grew. Various native species contributed to the communities with great species diversity. Shannon-Wiener index was 2.305-3.145, ecological dominance was 0.063-0.151, and evenness was 0.600-0.749. The natural regeneration of P. armandii population was very poor, and there was a trend that P. armandii would be gradually replaced by other native board-leaved trees. It was demonstrated that P. armandii should not be taken as a unique afforest tree, and controlled burning was not a favorite ecological measure in subtropical area. Native trees should play more important roles in the process of ecological restoration.

China↗

PubMed2004

Investigation of heavy metals transportation from soil to the pine tree.

The Scots pine (Pinus sylvestris L.) is the most common tree in Lithuanian forests. Research on the impact of pollutants on pines allows us to evaluate pollutants in a major part of Lithuanian forests. Heavy metals (HMs) are among the major pollutants entering forest ecosystems in different ways: in their wet and dry form they come from local or distant sources of emission by being transported from seas alongside with nutrients and sea salt, washed up from the dead plants accumulated in soil, and together with mineral particles brought by wind or water. During the period of investigation, a decrease in the Cr concentration in pine rings is seen. High Zn concentrations (in 1987--1989 Zn concentration was 27.6 mg x kg(-1)) in the pine may be caused by emissions from heavy traffic. The results have shown that Mn has the highest concentration as compared with that of other HMs in the soil around the pine (at the depth of 30-40 cm, Mn concentration is 780 mg x kg(-1)). In comparison with other HMs, Cu and Zn have the largest factor of transport from the soil to the wood (0.39 and 0.49 respectively).

Ecosystem↗

PubMedDate not supplied

Recovery of cryopreserved embryogenic cultures of maritime pine--effect of cryoprotectant and suspension density.

Embryogenic cultures were obtained from seeds of open-pollinated maritime pine trees representing part of a breeding population. The aim of the present study was to develop and optimize a protocol for cryopreservation of Pinus pinaster somatic embryogenic tissue. The density of the embryogenic suspension and the type of pre-treatment significantly affected the recovery of cryopreserved embryogenic cultures, as evaluated by their survival and regrowth rate. An initial density of the suspension culture of 250 mg/ml improved the regrowth rate of the embryogenic lines. Pre-treatment with maltose 0.4 M significantly increased the regrowth rate when compared to the other tested carbohydrates. Also, the addition of DMSO in a mixture of PEG 4000 and sucrose (PSD solution), instead of DMSO alone, at the same final concentration, was clearly beneficial for recovery of cryopreserved tissues. This improved method for the cryopreservation of P pinaster embryogenic of cultures allowed the successful recovery of 97 percent of the lines stored in liquid of nitrogen.

Carbohydrates↗

PubMed2004

[Vegetation restoration in western Liaoning hilly region: a study based on succession theory and degradation degree of ecosystem].

Analysis with some habitat indexes of different succession stage, this paper quantitatively measured the degradation degree of degraded ecosystems in this region. The results showed that the average dissimilarities between natural Quercus forest, natural Chinese pine (Pinus tabulaeformis) forest and Populus-Quercus forest in Nanliuzhangzi forestry centre and Chinese pine plantations in Niuheliang region and Qitian forestry centre were 0.655, 0.665, 2.029 and 3.919, respectively, and as a whole, the dissimilarities represented the places of the forests in the process of ecosystem succession/degradation. It was also showed that most habitats were degraded to the stage between shrubbery and pioneer arbor forest, and closer to the succession stage of pioneer arbor forest. Some suggestions were made for the management of the existing plantation and the construction of mixed forest, e.g., to increase the proportion of shrubbery and pioneer arbor species, especially that of nitrogen fixation tree species. The plant species list of several main vegetation types in western Liaoning we offered could provide scientific reference for the vegetation restoration and the management of pure Chinese pine plantation in this region.

China↗

PubMed2004

[Mechanism analysis of optimized model of conversion from farmland to forestland in the hill-gully sub-region of Loess Plateau].

Conversion from Farmland to Forestland Program (CFF) is one of the six great ecological forest programs in China. This study covered the CFF model area of the hilly-gully sub-region of loess plateau, and introduced system dynamics and other latest theories and methodologies. Based on the analysis of five modules including that of the site observation of field stations and extensive investigations, and over 10000 original data obtained in the fields of natural science, social science and economics, the operational mechanism of the optimized model was studied. The optimized operational models integrated maximized ecological, economic and social benefits, while sustainability concepts were proposed for typical CFF sites: The Pinus tabulaeformis + Platycladus orientalis + Zanthoxylum spp. + Robinia pseudoacacia model at the eroded flat ridges of the middle reaches of the Yellow River. The result showed that the ecological, economic and social benefits of the optimized model reflected by main indexes were the best or better, and in the other models, either individual one was the best or others were not. From the viewpoint of comprehensive comparison of three great benefits, the optimized model was most excellent, and had eminent difference comparing to other ones through F test. The relationship between ecological and social benefit was eminent positive correlative. Social benefit was the same with economical one at some degrees. The relationship between ecological and economical benefit was more complicated. On the whole, they were positive correlative, but the economical benefit was not the greatest when the ecological one was the greatest. In general, from the viewpoint of largest comprehensive benefit, the three great benefits were not all the best, indicating that the combination of the modules must be reasonable. In order to achieve the ultimate goal of CFF, we must choose the optimized combination of ecological, economical and social benefits, and can't only pursue any one maximum of three great benefits.

China↗

PubMed2005

[Relationship between plant community succession and fertility variation of mountain yellow soil in east Chongqing].

Based on the analyses of soil physical and chemical properties, this paper studied the relationship between plant community succession and fertility variation of mountain yellow soil in east Chongqing. The results showed that the values of integrated soil fertility index of Pinus massoniana, Cunninghamia lanceolata, deciduous oak, Camellia sinensis and evergreen broad-leaved forest soils were 0.1256, 0.2085, 0.3514, 0.2479 and 0.9329, respectively, implying that soil development had a close relation to plant community succession.

Cunninghamia↗

PubMed2005

[Experience model for self-thinning process of even-aged pure stands].

Based on the famous -3/2 power rule and generalized Schumacher growth equation, a mathematical model for the density change of even-aged pure stands with time during self-thinning process was presented, and the genetic algorithms was used to fit this nonlinear model. With the collected data from Populus tremula var. davidiana, Pinus yunnanensis and Cunninghamia lanceolata even-aged pure stands, the new model was verified and compared with other models. The results showed that the new model could fit observed data very well, and was very useful in practice. The surplus square, mean relative error, mean absolute error and surplus standard deviation of the new model were all smaller than those of other models, indicating its good qualification in describing stand density change during self-thinning process and its useness in studying forest self-thinning rules. The study also showed that genetic algorithms could give a better global convergence, and be used to estimate the parameters of nonlinear models in ecology, biology and forestry.

Algorithms↗

PubMed2005

[Scanning electron microscopic observations of Monochamus alternatus antennal sensilla and their electroantennographic responses].

With scanning electron microscope (SEM), this paper observed the shape, category, amount and distribution of the main antenna sensilla of adult Monochamus alternatus, and tested their electroantennographic (EAG) responses to the main volatiles of Pinus spp.. There were seven types of antennal sensilla, i. e., sensilla trichoid, sensilla basiconica, sensilla digit-like, sensilla rod-like, sensilla bottle-like, sensilla bud-like and sensilla chaetica, among which, sensilla trichoid and sensilla basiconica were the most abundant on the antenna surface, and each of them could be divided into three subtypes. Two subtypes of sensilla digit-like could also be observed. The II and III subtypes of sensilla trichoid and I and II subtypes of sensilla basiconica had deep longitudinal grooves on their surface, the typical characteristics of olfactory receptor. The comparison of the EAG response of different parts of Monochamus alternatus antennae to alpha-Pinene showed that each volatile and their compounds could provoke significant EAG responses of both females and males. The dose-response test showed that there was a certain rule in the EAG responses of M. alternatus.

Animals↗