Mongolian Oak Forest Research Articles

三种温带森林大型土壤动物群落结构的时空动态

Soil macro-faunas are important decomposers in ecosystem and play a significant role in nutrient cycling and energy flow. In Maoer Mountain,the soil macro-faunas were investigated in three typical forest types(Korean pine plantation forest,Hard-wood forest and Mongolian oak forest). Our object was to explore the community structure,spatial and temporal dynamic of soil macro-fauna,and its impact factors in temperate forest. Soil samples were collected from the litter layer and the soil layers at depth of 0—10 cm and 10—20 cm. Sampling was carried out continuously from May to October in 2012. A total of 3604 individuals,belonging to 3 Phyla,6 Classes,17 Orders and 50 families were extracted and identified. Among them,the Lumbricidae,Enchytraeidae and Lithobiomorpha were the dominant communities. The results showed that:(1) for horizontal distribution,the decreasing order of individual density and biomass was Korean pine plantation,Hard-wood forest and Mongolian oak. The group number of soil macro-faunas was the largest in Hard-wood forest,and the least in Mongolian oak forest. The Shannon and richness indices of soil macro-faunas were the highest in Mongolian oak forest and the lowest in Korean pine plantation forest,but the trend in the dominance index was opposite.The evenness index was the largest in Mongolian oak forest and the least in Hard-wood forest;(2) for vertical distribution,the individual density,group number,biomass and diversity of soil macro-fauna were significantly affected by the soil layer(P0.001). The individual density distribution appeared significant surface-aggregation,and the maximum biomass of soil macro-fauna was found at depth of 0—10 cm. The group number showed a decrease trend with the increasing layer in Korean pine plantation forest and that of highest value in both Hard-wood forest and Mongolian oak forest occurred at 0—10cm depth,not the litter layer. The Shannon index decreased with the increasing soil depth,while the dominance index appeared the opposite trend;(3) the Shannon and dominance index of soil macro-fauna were significantly different among different months(P0.01). Individual density and group number were higher in May and September than other months,and biomass of soil macro-fauna was the largest in September;(4) the correlation analysis showed that the individual density,group number and biomass of the soil macro-fauna were positively correlated with total organic carbon(P0.05),there was the significantly negative correlation between the Shannon index and soil bulk density(P0.01). It can be conclude that there was obviously spatial and temporal heterogeneity in soil macro-fauna community structure and the total organic carbon was one of the important impact factors.

5种温带森林生态系统细根的时间动态及其影响因子

细根(直径≤ 2 mm)的生长和死亡动态及其影响因子是森林生态系统能量流动和物质循环的重要研究内容,但因受到研究方法的限制而了解甚少。于2010年5-10月采用微根管技术对东北东部山区5种温带森林生态系统的细根生长量(FRP)和死亡量(FRM)进行了动态跟踪测定,并同步测定了土壤温度(<em>T</em>s)、土壤湿度(<em>M</em>s)、叶面积指数(LAI)等相关因子。结果表明: 不同林型和取样时间的FRP和FRM均差异显著(<em>P</em> < 0.001)。杨桦林、硬阔叶林、兴安落叶松林、红松林、蒙古栎林的FRP和FRM分别为:(13.34±0.90) μm·cm^-2·d^-1(平均值±标准误)和(5.02±0.36) μm·cm^-2·d^-1、(13.04±0.82) μm·cm^-2·d^-1 和(6.85±0.32) μm·cm^-2·d^-1、(8.74±1.44) μm·cm^-2·d^-1和(5.05±0.61) μm·cm^-2·d^-1、(8.02±2.27) μm·cm^-2·d^-1和(3.88±0.35) μm·cm^-2·d^-1、(7.59±0.82) μm·cm^-2·d^-1和(3.88±0.61) μm·cm^-2·d^-1。所有林型生长季期间FRP的时间变化均呈现明显的单峰型,但峰值出现的时间却因林型而异。FRM随生长季的进程而逐渐增加,杨桦林和硬阔叶林FRM在8月初出现峰值,而红松林、兴安落叶松林和蒙古栎林的FRM峰值均出现在生长季末期。<em>T</em>s、<em>M</em>s和LAI对FRP和FRM均存在显著的正效应(<em>P</em> < 0.05),3个因子的综合作用对各个林型FRP和FRM变异性的解释率分别达68%和53%以上,表明这些温带森林生态系统细根生长和死亡的时间动态主要受土壤温湿度和叶面积变化的联合影响。;Production and mortality of fine roots (diameter ≤ 2mm) and influencing factors are important to energy flow and nutrient cycling in forest ecosystems, but remain poorly understood mainly due to the limitation of methodology. In this study, we used a minirhizotron technique to investigate the temporal dynamics in fine root length production (FRP) and mortality (FRM) of five representative forest ecosystems in Northeast China during the period between May and October of 2010. Soil temperature (<em>T</em>s), soil moisture (<em>M</em>s), and leaf area index(LAI)were simultaneously measured for each stand. The stands were aspen-birch forest dominated by <em>Populus davidiana</em> and <em>Betula platyphylla</em>, hardwood forest dominated by <em>Fraxinus mandshurica</em> and <em>Juglans mandshurica</em>, Mongolian oak forest dominated by<em> Quercus mongolica</em>, Korean pine (<em>Pinus Koraiensis</em>) plantation, and Dahurian larch (<em>Larix gmelinii</em>) plantation. The experimental design included five forest types, three 20 m×30 m replicate plots in each forest type. The results showed that the FRP and FRM were significantly (<em>P</em> < 0.001) affected by forest types, sampling times and their interactions. The FRP was (13.34±0.90) μm·cm^-2·d^-1(mean±SE), (13.04±0.82) μm·cm^-2·d^-1, (8.74±1.14) μm·cm^-2·d^-1, (8.02±2.77) μm·cm^-2·d^-1, and (7.59±0.82) μm·cm^-2·d^-1 for the aspen-birch, hardwood, larch, pine, and oak stands, respectively; and the FRM was (5.02±0.36) μm·cm^-2·d^-1, (6.85±0.32) μm·cm^-2·d^-1, (5.05±0.61) μm·cm^-2·d^-1, (3.88±0.35) μm·cm^-2·d^-1, and (3.88±0.61) μm·cm^-2·d^-1, correspondingly. The FRP showed a unimodal seasonal pattern with peaks varying with forest types. The FRM increased gradually as the growing season proceeded, and reached its maximum at the end of the growing season for all the stands except for the aspen-birch and hardwood stands where it peaked in early August. <em>T</em>s, <em>M</em>s, and LAI all exerted significant positive effects on FRP and FRM (<em>P</em> < 0.05), which, together, explained more than 68% and 53% of variability in FRP and FRM, respectively. These results illustrated that the temporal dynamics of fine root production and mortality in these temperate forest ecosystems were jointly influenced by changes in soil temperature, moisture and leaf area index.

A modified ingrowth core method for measuring fine root production, mortality and decomposition in forests

The ingrowth core method is widely used to assess fine root (diameter < 2 mm) production but has many inherent deficiencies. In this study, we modified this method by adopting mini ingrowth cores (diameter 1.2 cm), extending sample intervals to a growing season, and developing new models to quantify the concurrent production, mortality and decomposition, and applied them to a secondary Mongolian oak (Quercus mongolica Fischer ex Ledebour) forest. Annual fine root production, mortality and decomposition estimated by our method were 2.10 ± 0.23, 1.78 ± 0.20 and 0.85 ± 0.13 t ha(-1), respectively, and 33.3% of the production was decomposed in the growing season. The production estimate using our method was significantly higher than those using two long-term ingrowth core (sample interval >2 months) methods. However, it was significantly lower than that using the short-term ingrowth core (sample interval <2 months) method, presumably due to the lower root competition and less decomposition occurring in the short-term cores. The fine root estimates using our method in the growing season were generally higher than those using the forward and continuous inflow methods but lower than those using the backward method. Our method reduces the disturbances in roots and soil, minimizes the sampling frequency and improves the quantification of fine root decomposition during the sample intervals. These modifications overcome the limitations associated with the previous ingrowth core methods. Our method provides an improved alternative for estimating fine root production, mortality and decomposition.

Carbon density and distribution of six Chinese temperate forests

Quantifying forest carbon (C) storage and distribution is important for forest C cycling studies and terrestrial ecosystem modeling. Forest inventory and allometric approaches were used to measure C density and allocation in six representative temperate forests of similar stand age (42-59 years old) and growing under the same climate in northeastern China. The forests were an aspen-birch forest, a hardwood forest, a Korean pine plantation, a Dahurian larch plantation, a mixed deciduous forest, and a Mongolian oak forest. There were no significant differences in the C densities of ecosystem components (except for detritus) although the six forests had varying vegetation compositions and site conditions. However, the differences were significant when the C pools were normalized against stand basal area. The total ecosystem C density varied from 186.9 tC hm(-2) to 349.2 tC hm(-2) across the forests. The C densities of vegetation, detritus, and soil ranged from 86.3-122.7 tC hm(-2), 6.5-10.5 tC hm(-2), and 93.7-220.1 tC hm(-2), respectively, which accounted for 39.7% +/- 7.1% (mean +/- SD), 3.3% +/- 1.1%, and 57.0% +/- 7.9% of the total C densities, respectively. The overstory C pool accounted for > 99% of the total vegetation C pool. The foliage biomass, small root (diameter < 5mm) biomass, root-shoot ratio, and small root to foliage biomass ratio varied from 2.08-4.72 tC hm(-2), 0.95-3.24 tC hm(-2), 22.0%-28.3%, and 34.5%-122.2%, respectively. The Korean pine plantation had the lowest foliage production efficiency (total biomass/foliage biomass: 22.6 g g(-1)) among the six forests, while the Dahurian larch plantation had the highest small root production efficiency (total biomass/small root biomass: 124.7 g g(-1)). The small root C density decreased with soil depth for all forests except for the Mongolian oak forest, in which the small roots tended to be vertically distributed downwards. The C density of coarse woody debris was significantly less in the two plantations than in the four naturally regenerated forests. The variability of C allocation patterns in a specific forest is jointly influenced by vegetation type, management history, and local water and nutrient availability. The study provides important data for developing and validating C cycling models for temperate forests.

Method of evaluation of response extent of forests to disturbances and its ap-plication —A case study of Qingyuan Experimental Station of Forest Ecology, Institute of Applied Ecology, Chinese Academy of Sciences

Based on the phenomena that disturbances for different forest types are different, an index system for evaluating the response extent of forests to disturbances (REFD) was constructed for Qingyuan Experimental Station of Forest Ecology, Institute of Applied Ecology, Chinese Academy of Sciences. Furthermore, REFD was also quantitatively evaluated for different forest types using the optimal distance method. Using the indices about diversity, productivity, stand structure, ecological function, stand health level, etc, of forest, with the broadleaf-Pinus koraiensis forest as target forest, REFD for eight existing forest types at Qingyuan Experimental Station of Forest Ecology were evaluated via the optimal distance method. The results show that REFD of the old growth forest and the broadleaf mixed forest is 0.317 8 and 0.398 9 respectively, which is the minimum among the eight forest types and with the nearest distance to the target forest. REFD for Mongolian oak forest, Fraxinus mandshurica forest, F. rhynchophylla forest and Juglans mandshuria forest is 0.426 2, 0.487, 0.498 3 and 0.501 6 respectively. However, REFD for Korean pine plantation and larch plantation is 0.635 8 and 0.686 4 respectively, which is the maximum among the eight forest types. These findings imply that the distance between the plantations and the target forest in the mountain regions of eastern Liaoning Province is the farthest.

Dynamics of fine roots in five Chinese temperate forests

We used a minirhizotron method to investigate spatial and temporal dynamics of fine roots (diameter < or =2 mm) in five Chinese temperate forests: Mongolian oak forest, aspen-birch forest, hardwood forest, Korean pine plantation and Dahurian larch plantation. Fine root dynamics were significantly influenced by forest type, soil layer, and sampling time. The grand mean values varied from 1.99 to 3.21 mm cm(-2) (root length per minirhizotron viewing area) for the fine root standing crop; from 6.7 to 11.6 microm cm(-2) day(-1) for the production; and from 3.2 to 6.1 microm cm(-2) day(-1) for the mortality. All forests had a similar seasonal "sinusoidal" pattern of standing crop, and a "unimodal" pattern of production. However, the seasonal dynamics of the mortality were largely unsynchronized with those of the production. The minimum values of standing crop, production and mortality occurred in March for all forests, whereas the maximum values and occurrence time differed among forest types. The standing crop, production and mortality tended to decrease with soil depth. The different spatiotemporal patterns of fine roots among the forests highlight the need for forest-specific measurements and modeling of fine root dynamics and forest carbon allocation.

Partitioning soil respiration of temperate forest ecosystems in northeastern China

Abstract Quantifying soil respiration components and their relations to environmental controls are essential to estimate both local and regional carbon (C) budgets of forest ecosystems. In this study, we used the trenching-plot and infrared gas exchange analyzer approaches to determine heterotrophic ( R H ) and autotrophic respiration ( R A ) in the soil surface CO 2 flux for six major temperate forest ecosystems in northeastern China. The ecosystems were: Mongolian oak forest (dominated by Quercus mongolica), aspen-birch forest (dominated by Populous davidiana and Betula platyphylla), mixed wood forest (composed of P. davidiana, B. platyphylla, Fraxinus mandshurica, Tilia amurensis, Acer amono, etc.), hardwood forest (dominated by F. mandshurica, Juglans mandshurica, and Phellodendron amurense), Korean pine ( Pinus koraiensis), and Dahurian larch ( Larix gmelinii) plantations, representing the typical secondary forest ecosystems in this region. Our specific objectives were to: (1) quantify R H and its relationship with the environmental factors of the forest ecosystems, (2) characterize seasonal dynamics in the contribution of root respiration to total soil surface CO 2 flux ( RC), and (3) compare annual CO 2 fluxes from R H and R A among the six forest ecosystems. Soil temperature, water content, and their interactions significantly affected R H in the ecosystems and accounted for 46.5%–78.8% variations in R H . However, the environmental controlling factors of R H varied with ecosystem types: soil temperature in hardwood and Dahurian larch forest ecosystems, soil temperature, and water content in the others. The RC for hardwood, poplar-birch, mixed wood, Mongolian oak, Korean pine, and Dahurian larch forest ecosystems varied between 32.40%–51.44%, 39.72%–46.65%, 17.94%–47.74%, 34.31%–37.36%, 33.78%–37.02%, and 14.39%–35.75%, respectively. The annual CO 2 fluxes from R H were significantly greater than those from R A for all the ecosystems, ranging from 337–540 g C·m −2·a −1 and 88‐331 gC·m −2·a −1 for R H and R A , respectively. The annual CO 2 fluxes from R H and R A differed significantly among the six forest ecosystems.

Vegetation reconstruction of Bronze Age by using micro-scopic structure of charcoals

The microscopic structure of charcoals was determined in two sites of Bronze Age, Chifeng area by using the scanning electronic microscope. The results showed that these charcoals are all timbers of Mongolian oak (Quercus mongolica). It has powerful climatic indicative significance. Based on the assemblage of pollen composition, their eco-climatic index and character of community, the vegetation reconstruction of Bronze Age was obtained. The reconstruction showed that the zonal vegetation was Mongolian oak forest and Chinese pine forest in the loess hills in the Chifeng area, which suggested that the climatic condition was warmer and wetter at that time than present time.

The influence of heterogeneous habitats on the germination ofAcanthopanax senticosus seeds and the dynamics of its seed pool

Differences in germination ofA. Senticosus, an important shrub under the Korean Pine broad-leavd forest and its secondary forest in heterogeneous habitats and the dynamics of its seed pool have been studied by observations in location. The results showed that transformation rates from seeds to seedlings were in the following order: 16.8% in Larch plantations, 4.1% in Mongolian oak forests, 2.7% in Birch forests, 1.8% in Korean Pine plantations, and 0.5% in hard wood forests. The life-span of seeds was determined to be four years in the simulating seed pool under Larch plantations. The percentage of the seedling output was, 14.5% in the 2nd year, 10.1% in the 3rd year, and 1.8% in the 4th year. Other types of the seed output were those: decayed 33.1%, senescent, 22.3%, predated by mice 14.1%, which was variable due to the variation in the number of mouse, and only 1.17% were eaten by insects and ofher soil animals.

Studies on structure and functions of Mongolian oak forests

After the investigation and long-lenn research, the structure, succession, energy flow, nutrient and water cycles, productivity, etc. of Mongolian oak (Quercus mongolica) forest ecosystems are synthetically summarized. The oak, with a simple stand composition, naturally distributes at hilltops, where the soil is and and infertile and lots of tree species can not grow, and stabilizes for a long period for its high adaptive capacity and long longevity, but it will grow better in good sites. Compared with other forest ecosystems in temperate zone, the oak forest has not only more intensive biological cycles of nutrients but higher productivity as well. Among the nine elements determined, the concentrations of Ca and Zn are the highest and lowest, amounting to 41.99% and 0.0015%, respectively. In the vegetation, the largest nutrient pool is root system, making up 47.75%; and the trunk steps the following, 25.13%. Among the main secondary forest types in Maoershan region, the oak stands have not only highest biomass but best biomass structure for in which the biomass of tree stratum reaches 95.6% of the total of the stands and that of trunk does 68.9% of the total of the tree. The oak stands have high stemflow, which amounts to 15.6% of the precipitation and carries a lot of nutrients, and high evapotranspiration, which is as high as 504.1 mm and for which 77.45% of the total radiation (123.3 KJ. cm-2) is consumed as latent heat transfer in the growing reason. The clearculting of the oak stands will result in not only increasing the surface runoff and interflow percentage but also intensifying the loses of N, Ca. Mg and Fe. Finally, it is proposed to pay a great attention to cultivating, rejuvenating and even planting the oak as high yield timber and water conservation forests.

Oaks (Quercus spp.) in northeast China

There arc eight species and four varieties of oak in northeast China. This paper reports and describes the distribution and phylocoenogenesis of the Korean pine-broadleaved mixed forest and the mongolian oak formation. The close relationship between the flora of Ussuli—Amur region and Japan is discussed. Analyses of heat and energy balance, and biomass of mongolian oak forests arc provided. Many measurements indicate that, in a nonclosed stand, the wood production of a stand is positively correlated with leaf area index (LAI).