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1.
Two-year-old seedlings ofPinus koraiensis, Pinus sylvestriformis andFraxinus mandshurica were treated in open-top chambers with elevated CO2 concentrations (700 μL·L−1, 500 μL·L−1) and ambient CO2 concentrations (350 μL·L−1) in Changbai Mountain from June to Sept. in 1999 and 2001. The net photosynthetic rate, dark respiration rate, ribulose-1,5-bisphosphate
carboxlase (RuBPcase) activity, and chlorophyll content were analyzed. The results indicated the RuBPcase activity of the
three species seedlings increased at elevated CO2 concentrations. The elevated CO2 concentrations stimulated the net photosynthetic rates of three tree species exceptP. sylvestriformis grown under 500 μL·L−1 CO2 concentration. The dark respiration rates ofP. koraiensis andP. sylvestriformis increased under concentration of 700 μL·L−1 CO2, out that ofF. mandshurica decreased under both concentrations 700 μL·L−1 and 500 μL·L−1 CO2. The seedlings ofF. mandshurica decreased in chlorophyll contents at elevated CO2 concentrations.
Foundation item: This paper was supported by the National Natural Science Foundation of China (No. 30070158). Knowledge Innovation Item of
Chinese Academy of Sciences (KZCX2-406) and “Hundred Scientists” Project of Chinese Academy of Sciences.
Biography: Zhou Yu-mei (1973-) Ph. Doctor, Assistant Research fellow Institute of Applied Ecology. Chinese Academy of Sciences. Shenyang
110016. P.R. China.
Responsible editor: Song Funan 相似文献
2.
外源糖溶液和高浓度CO2处理对白桦叶片糖和蛋白质含量的影响 总被引:1,自引:0,他引:1
3年生白桦同时接受3种外源糖溶液(蔗糖、果糖、葡萄糖)和3种高浓度CO2(700、1400、2100μL·μL-1CO2)处理.处理1个月后,测定了叶片的总糖、蔗糖、果糖和蛋白质含量.结果表明:在700μL·L-1和1400μL·L-1 CO2下,外源糖溶液增加了叶片的可溶性糖和蛋白质含量,其中外源蔗糖的效果最好:外源糖溶液与2100μL·L-1CO2结合,会抑制叶片积累总糖和蛋白质:在700μL·L-1和1400μL·L-1CO2下,喷施葡萄糖、果糖的叶片在蛋白质含量上没有明显差别:同700、1400μL·L-1CO2相比,除喷施果糖植株外,2100μL·L-1 CO2明显增加了叶片的总糖、蔗糖、果糖和蛋白质含量:在喷施同种外源糖溶液的情况下,叶片的糖含量与CO2浓度呈正相关性.图6参7. 相似文献
3.
The net CO2 assimilation rate, stomatal conductance, RuBPcase (ribulose 1,5-biphosphate carboxylose) activity, dry weight of aboveground
and belowgroud part, plant height, the length and diameter of taproot ofPinus koraiensis seedlings were measured and analyzed after six-week exposure to elevated CO2 in an open-top chamber in Changbai Mountain of China from May to Oct. 1999. Seedlings were planted in four different conditions:
on an open site, control chamber, 500 μL·L−1 and 700 μL·L−1 CO2 chambers. The results showed that the total biomass of the seedlings increased whereas stomatal conductance decreased. The
physiological responses and growth to 500 μL·L−1 and 700 μL·L−1 CO2 varied greatly. The acclimation of photosynthesis was downward to 700 μL·L−1 CO2 but upward to 500 μL·L−1 CO2. The RuBPcase activity, chlorophyll and soluble sugar contents of the seedlings grown at 500 μL·L−1 CO2 were higher than that at 700 μL·L−1 CO2. The concentration 500 μL·L−1 CO2 enhanced the growth of aboveground part whereas 700 μL·L−1 CO2 allocated more carbon to belowground part. Elevated CO2 changed the carbon distribution pattern. The ecophysiological responses were significantly different between plants grown
under 500 μL·L−1 CO2 and 700 μL·L−1 CO2.
Foundation Item: This paper was supported by Chinese Academy of Sciences.
Biography: HAN Shi-jie (1956-), male, Ph. Doctor, Professor in Laboratory of Ecological Process of Trace Substance in Terrestrial Ecosystem,
Institute of Applied Ecology, Chinese Academy of Sciences.
Responsible editor: Chai Ruihai 相似文献
4.
从1999年到2006年在中科院长白山森林生态系统定位站(42°24'N,128°28'E,海拔738m)对长期高浓度CO2熏蒸对土壤酶活性的影响进行了研究.采用开顶箱(OTC)的方式对红松和长白松进行高浓度CO2处理, CO2浓度分别受控于高浓度CO2箱(500 μmol·mol^-1)、对照箱(370 μmol·mol^-1))和裸地(370 μmol·mol^-1).经高浓度CO2(500 μmol·mol^-1)熏蒸8年后,土壤样品分别在2006年春季、夏季和秋季进行采集和分析.结果表明:在高CO2浓度(500 μmol mol^-1)条件下,转化酶活性除了红松夏季样品之外都是显著降低的;而脱氢酶活性却是增加的,但只有部分结果显著;长白松的多酚氧化酶活性都显著降低;过氧化氢酶活性在春季增加,而在其他季节均降低.总而言之,在高CO2浓度条件下,土壤酶的活性与树种有关. 相似文献
5.
Four-year-oldPinus sylvestriformis were exposed for four growing seasons in open top chambers to ambient CO2 concentration (approx. 350 μmol·mol−1) and high CO2 concentrations (500 and 700 μmol·mol−1) at Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences at Antu Town, Jilin Province, China
(42°N, 128°E). Stomatal response to elevated CO2 concentrations was examined by stomatal conductance (g
s), ratio of intercellular to ambient CO2 concentration (c
i/c
a) and stomatal number. Reciprocal transfer experiments of stomatal conductance showed that stomatal conductance in high-[CO2]-grown plants increased in comparison with ambient-[CO2]-grown plants when measured at their respective growth CO2 concentration and at the same measurement CO2 concentration (except a reduction in 700 μmol·mol−1 CO2. grown plants compared with plants on unchambered field when measured at growth CO2 concentration and 350 μmol·mol−1CO2). High-[CO2]-grown plants exhibited lowerc
i/c
a ratios than ambient-[CO2]-grown plants when measured at their respective growth CO2 concentration. However,c
i/c
a ratios increased for plants grown in high CO2 concentrations compared with control plants when measured at the same CO2 concentration. There was no significant difference in stomatal number per unit long needle between elevated and ambient CO2. However, elevated CO2 concentrations reduced the total stomatal number of whole needle by the decline of stomatal line and changed the allocation
pattern of stomata between upper and lower surface of needle.
Foundation Item: This research was supported by National Basic Research Program of China (2002CB412502), Project of Key program of the National
Natural Science Foundation of China (90411020) and National Natural Science Foundation of China (30400051).
Biography: ZHOU Yu-mei (1973-), female, Ph. Doctor, assistant research fellow, Institute of Applied Ecology, Chinese Academy of Sciences,
Shenyang 110016, P. R. China.
Responsible editor: Song Funan 相似文献
6.
Responses of soil microbial activities to elevated CO2 in experiment sites ofPinus sylvestriformis andPinus koraiensis seedlings were studied in summer in 2003. The results indicated the number of bacteria decreased significantly (p<0.05) under elevated CO2 forPinus sylvestriformis andPinus koraiensis. Amylase and invertase activities in soil increased forPinus sylvestriformis and decreased forPinus koraiensis with CO2 enrichment compared with those at ambient (350 μmol·mol−1). The size of microbial biomass C also decreased significantly at 700 μmol·mol−1 CO2. Bacterial community structure had some evident changes under elevated CO2 by DGGE (Denaturing Gradient Gel Electrophoresis) analysis of bacterial 16S rDNA gene fragments amplified by PCR from DNA
extracted directly from soil. The results suggested that responses of soil microorganisms to elevated CO2 would be related to plant species exposed to elevated CO2.
Foundation item: The study was supported by Major State Basic Research Development Program of China (2002CB412502) and the Knowledge Innovation
Project from Chinese Academy of Sciences (KZCX1-SW-01-03).
Biography: JIA Xia (1975), female, Ph. D. candidate of Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016,
P. R. China.
Responsible editor: Song Funan 相似文献
7.
The biomass and ratio of root-shoot ofPinus sylvestriformis seedlings at CO2 concentration of 700 μL·L−1 and 500 μL·L−1 were measured using open-top chambers (OTCs) in Changbai Mountain during Jun. to Oct. in 1999. The results showed that doubling
CO2 concentration was benefit to seedling growth of the species (500 μL·L−1 was better than 700 μL·L−1) and the biomass production was increased in both above-ground and underground parts of seedlings. Carbon transformation
to roots was evident as rising of CO2 concentration.
This project is supported by Chinese Academy of Sciences
Responsible editor: Chai Ruihai 相似文献
8.
温度对大叶桃花心木(Swietenia macrophylla King)幼苗叶片的光合影响 总被引:2,自引:0,他引:2
本文研究了大叶桃花心木(Swietenia macrophylla King)一年生幼苗在经过夜温处理后的光响应曲线和在饱和光强下的CO2反应曲线.结果表明:在大气CO2浓度下,叶片的最佳光合作用温度在25-31℃之间,而在饱和CO2浓度下为31-35℃.在25℃以下光合速率开始降低,主要是由于羧化效率的降低,而当温度超过31℃时,光合速率下降,是因为羧化效率的降低和呼吸速率的增加.CO2浓度对光合的促进作用在低温下受到抑制,这意味着未来在CO2浓度增高的情况下,高浓度的CO2对热带常绿植物光合的促进在冬天低温情况下表现不十分明显.图4参23. 相似文献
9.
Soil samples were taken from depth of 0–12 cm in the virgin broad-leaved/Korean pine mixed forest in Changbai Mountain in
April, 2000. 20 μL·L−1 and 200 μL·L−1 CH4 and N2O concentration were supplied for analysis. Laboratory study on CH4 oxidation and N2O emission in forest soil showed that fresh soil sample could oxidize atmospheric methane and product N2O. Air-dried soil sample could not oxidize atmospheric methane, but could product N2O. However, it could oxidize the supplied methane quickly when its concentration was higher than 20 μL·L−1. The oxidation rate of methane was increased with its initial concentration. An addition of water to dry soil caused large
pulse of N2O emissions within 2 hours. There were curvilinear correlations between N2O emission and temperature (r2=0.706, p<0.05), and between N2O emission and water content (r2=0.2968, p <0.05). These suggested temperature and water content were important factors controlling N2O emission. The correlation between CH4 oxidization and temperature was also found while CH4 was supplied 200 μL·L−1 (r2=0.3573, p<0.05). Temperature was an important factor controlling CH4 oxidation. However, when 20 μL·L−1 CH4 was supplied, there was no correlation among CH4 oxidization, N2O emission, temperature and water content.
Foundation item: This paper was supported by Chinese Academy of Sciences.
Biography: ZHANG Xiu-jun (1960-), female, Ph. Doctor, lecture in Laboratory of Ecological Process of Trace Substance in Terrestrial
Ecosystem, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110015, P.R. China.
Responsible editor: Song Funan 相似文献
10.
Photosynthetic induction responses of Pinus koraiensis seedlings grown in different light environments 总被引:2,自引:0,他引:2
The time processes of photosynthetic induction responses to various irradiances in Korean pine (Pinus koraiensis) seedlings grown in open-light environments and in understory of forest were studied in an area near the Research Station
of Changbai Mountain Forest Ecosystems, Jilin Province, China from July 15 to August 5, 1997. The results showed that at 200
μmol·m−2·s−1 photosynthetic photon flux density (PPFD) and 500 μmol·m−2·s−1 PPFD, the induction time for the photosynthetic rates of understory-grown seedlings to reach 50% and 90% steady-state net
photosynthetic rates was longer than that of the open-grown seedlings. The induction responses of open-growth seedlings at
500 μmol·m−2·s−1 PPFD were slower than those at 200 μmol·m−2·s−1 PPFD, but it was the very reverse for understory-growth seedlings, which indicates that the photosynthetic induction times
of Korean pine seedlings grown in the understory depended on the sunfleck intensity.
Biograph: ZHOU Yong-bin (1970-), female, associate professor of Shenyang Agricultural University, Shenyang 110161, P.R. China.
Responsible editor: Song Funan 相似文献
11.
12.
2004年5月至9月,研究了长白山白桦林土壤呼吸以及根系呼吸对土壤呼吸的贡献随土壤温度和土壤湿度的季节变化,研究结果表明:土壤总呼吸、断根土壤呼吸和根系呼吸在生长季内有相似的季节变化趋势,夏季潮湿而且温度较高,呼吸速率也较高,春季和秋季温度较低,呼吸速率也较低。2004年5月至9月,土壤总呼吸、断根土壤呼吸和根系呼吸的平均值分别为4.44,2.30和2.14μmol·m^-2s^-1,三者与土壤温度均呈指数相关,与土壤湿度呈线性相关,三者的Q10值分别为2.82,2.59和3.16,这与其他学者的结果相似。根系呼吸是土壤呼吸的一个重要组成部分,2004年5月至9月,根系呼吸对土壤总呼吸的贡献在29.3~58.7%之间。根据Q10模型估算的土壤总呼吸、断根土壤呼吸和根系呼吸的全年平均值分别为1.96、1.08和0.87μmol·m^-2s^-1,即741.73、408.71和329.24gC·m^-2·a^-1,全年根系对土壤总呼吸的贡献为44.4%。土壤呼吸和土壤温度之间的关系模型是了解和预测长白山白桦林生态系统潜在的随森林管理和气候变化而变化的有用工具。 相似文献
13.
The photosynthetic response of 12-year oldPinus sylvestriformis to elevated CO2 and its influential factors were tested and analyzed in the forest region of Changbai Mountain in 1999. Trees grown at the
natural condition were controlled at three levels of CO2 concentration (350 μL·L−1, 500 μL·L−1 and 700 μL·L−1) by CO2 rich settlement designed by us. Net photosynthetic rates (NPR), temperature, relative humidity, stomatal conductance, intercellular
CO2 concentration and photosynthetic active radiation (PAR) were measured at 6:00, 8:00, 10:00, 14:00, 16:00 and 18:00 hours
a day. Experimental results showed that the NPR ofPinus sylvestriformis increased by 32.6% and 123.0% at 500 μL·L−1 and 700 μL·L−1 CO2 concentration respectively, compared to ambient atmospheric CO2 concentration (350 μL·L−1). The relations between NPR and influential factors, including temperature, relative humidity, intercellular CO2 concentration and photosynthetic active radiation, were analyzed respectively by regression analysis at different CO2 concentrations.
Foundation Item: This project was supported by Chinese Academy of Sciences.
Biography: WANG Chen-rui (1970-), male, Assistant Research Fellow in Institute of Applied Ecology, Chinese Academy of Sciences.
Responsible editor: Chai Ruihai 相似文献
14.
Eco-physiological responses of seedlings of eight species,Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica andAcer mono from broadleaved/Korean pine forest, to elevated CO2 were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998–1999).
Two concentrations of CO2 were designed: elevated CO2 (700 μmol·mol−1) and ambient CO2 (400 μmol·mol−1). The study results showed that the height growth of the tree seedlings grown at elevated CO2 increased by about 10%–40% compared to those grown at ambient CO2. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration
and chlorophyll content to elevated CO2 varied with tree species. The broad-leaf tree species were more sensitive to the elevated CO2 than conifer tree species. All seedlings showed a photosynthetic acclimation to long-term elevated CO2.
Foundation item: The project was supported by National Key Basic Development of China (G1999043400) and the grant KZCX 406-4, KZCX1 SW-01
of the Chinese Academy of Sciences
Biography: WANG Miao (1964-), maie, associate professor in Institute of applied Ecology, Chinese Academy of Sciences, Shenyang 110016,
P. R. China.
Responsible editor: Song Funan 相似文献
15.
Muehlewbeckia complera was introduced to China in 2002 as indoor-hanging ornamental foliage plant. The experiment of the shade tolerance for this
species was carried out in different light intensities (0.14–946.00 μmol·m−2·s−1). After 40 days in experimental areas, leaf photosynthentic characteristics indexes ofM. complera in different photosynthesis active radiation (PAR) were measured with LI-COR6400 apparatus, such as the light compensation
point, light saturation point, and maximum net photosynthesis rate, at the same time, the increments of total leaf area and
leaf amount were measured. The results showed that the optimum light intensity range forM. complera was from 9.26 μmol·m−2·s−1 to 569.00 μmol·m−2·s−1 (463–28150 lx, relative humidity (RH) for 46–60%, temperature at 16–22°C). Under this condition, leaf photosynthetic efficiency
was tiptop. AlthoughM. complera belonged to the moderate sun-adaptation plant species, the plant growth was inhibited when PAR increased to the level of
569.000 μmol·m−2·s−1 or above.M. complera could sprout new leaves in photosynthesis active radiation of 0.16–19.22 μmol·m−2·s−1 (8–961 lx), or 10 μmol·m−2·s−1 for above 6 h.
Foundation item: This study was supported by the Research Foundation of Northeast Forestry University.
Biography: YUE Hua (1962-), female, Associate professor in Northeast Forestry University, Harbin 150040, P. R. China.
Responsible editor: Zhu Hong 相似文献
16.
Forest soil is a huge reserve of carbon in the biosphere. Therefore to understand the carbon cycle in forest ecosystems, it
is important to determine the dynamics of soil CO2 efflux. This study was conducted to describe temporal variations in soil CO2 efflux and identify the environmental factors that affect it. We measured soil CO2 efflux continuously in a beech secondary forest in the Appi Highlands in Iwate Prefecture for two years (except when there
was snow cover) using four dynamic closed chambers that automatically open after taking measurements. Temporal changes in
soil temperature and volumetric soil water content were also measured at a depth of 5 cm. The soil CO2 efflux ranged from 14 mg CO2 m−2 h−1 to 2,329 mg CO2 m−2 h−1, the peak occurring at the beginning of August. The relationship between soil temperature and soil CO2 efflux was well represented by an exponential function. Most of temporal variation in soil CO2 efflux was explained by soil temperature rather than volumetric soil water content. The Q
10 values were 3.7 ± 0.8 and estimated annual carbon emissions were 837 ± 210 g C m−2 year−1. These results provide a foundation for further development of models for prediction of soil CO2 efflux driven by environmental factors. 相似文献
17.
ZHOULi DAILi-min SUBao-ling 《林业研究》2003,14(3):213-216
Embryo of lilacs (Syringa L) culture in vitro and the rapid propagation were studied. The orthogonal experiments, including the selection of basal medium, embryo age and other factors such as sugar, benzyladenine (BA), naphthalene acetic acid (NAA) and glutamine (Gln), were carried out. The results indicated that the optimal medium for embryo culture was Monnier medium supplemented with NAA (0.001 mg.L^-1), BA (0.1 mg.L^-1), sugar (50 g.L^-1), and Gin (400 mg.L^-1), with a germination rate of 91.7% at least; the optimal embryo age was 50 d; and Gln had significant effects on the germination rate of embryo.Moreover, the optimal medium for subculture was MS BA (2 mg.L^-1) NAA (0.001 mg.L^-1) Gln (0.5 mg.L^-1), with the propagation coefficient of 3.6 at least. 相似文献
18.
The N2O emission rates, photosynthesis, respiration and stomatal conductance of the dominant tree species from broadleaf/Korean
pine forest in Changbai Mountain were measured by simulated water stress with the closed bag-gas chromatography. A total of
five species seedlings were involved in this study, i.e.,Pinus koraiensis Sieb. et Zucc,Fraxinus mandshurica Rupr,Juglans mandshurica Maxim,Tilia amurensis Rupr, andQuercus mongolica Fisch. ex Turcz.. The results showed that the stomatal conductance, net photosynthetic rate and N2O emission of leaves were significantly reduced under the water stress. The stoma in the leaves of trees is the main pathway
of N2O emission. N2O emission in the trees mainly occurred during daytime. N2O emission rates were different in various tree specie seedlings at the same water status. In the same tree species, N2O emission rates decreased as the reduction of soil water contents. At different soil water contents (MW, LW) the N2O emission rates ofPinus koraiensis decreased by 34.43% and 100.6% of those in normal water condition, respectively. In broadleaf arbor decreased by 31.93% and
86.35%, respectively. Under different water stresses N2O emission rates in five tree species such asPinus koraiensis, Fraxinus mandshurica, Juglans mandshurica, Tilia amurensis, andQuercus mongolica were 38.22, 14.44, 33.02, 16.48 and 32.33 ngN2O·g−1DW·h−1, respectively.
Foundation item: This project was supported by the National Natural Science Foundation of China (No. 30271068), the grant of the Knowledge
Innovation Program of Chinese Academy of Sciences (KZ-CX-SW-01-01B-10), and the Special Funds for Major State Basic Research
Program of China (No. G1999043407)
Biography: Wang Miao (1964-), male, associate professor in Institute of Applied Ecology, Chinese Academy of Science, Shenyang 110016,
P. R. China.
Responsible editor: Song Funan 相似文献
19.
Wenjie Wang Huimei Wang Yuangang Zu Xueying Li Takayoshi Koike 《Frontiers of Forestry in China》2006,1(2):125-135
The temperature coefficient, Q
10 (fractional change in rate with a 10°C increase in temperature) describes the temperature sensitivity of soils, roots, and
stems, as well as their possible performance in global warming processes. It is also a necessary parameter for the estimation
of total CO2 efflux from each element. A number of studies have focused on Q
10 values to date; however, their conclusions are not universal and do not always agree. A review of these reported Q
10 values therefore becomes necessary and important for a global understanding of the temperature sensitivity of different forest
types and elements. The aims of our present paper are, first, to find the frequency distribution pattern of soils, roots,
and stems (branches) and compare their temperature sensitivity; then, to find the Q
10 differences between conifer and deciduous tree species and the effect of methodology on Q
10 values; finally we want to give a perspective on future Q
10-related studies. We found that most Q
10 values of each element were concentrated in a relatively narrow range despite a total data distribution over quite a wide
range. For soil respiration, the median Q
10 value was 2.74 and the center of the frequency distribution was between 2.0 and 2.5 with a percentage of 23%. Most of the
data (>80%) were within the range from 1.0 to 4.0. The median Q
10 value for root respiration was 2.40 and the center of the frequency distribution was from 2.5 to 3.0 with a percentage of
33%. Most of the results (>80%) ranged from 1.0 to 3.0. For stem respiration, the median Q
10 value was 1.91 and the frequency distribution was concentrated between 1.5 and 2.0. Over 90% of the data ranged from 1.0
to 3.0. Obvious differences in Q
10 value were found between different elements, stem < root < soil including root < soil excluding root. The differences between
woody organisms of stems, roots, and soils excluding roots were statistically significant (p<0.05), indicating that heterotrophic respiration from microorganism activity may be more sensitive to global warming. The
duration of the period with leaves slightly affects the temperature sensitivity of woody organisms since the Q
10 values for root and stem of coniferous evergreen trees did not differ significantly from deciduous trees (p>0.10). CO2 analytical methods (soda lime absorption method, IRGA (Infra-read gas analysis), and chromatograph analysis) and root separation
methods (excised root and trenched box) slightly affected the Q
10 values of soil and root respiration (p>0.10), but an in vitro measurement of stem respiration yielded a significantly higher Q
10 value than an in vivo method (p<0.05). In general, although the Q
10 values of non-photosynthetic organisms stayed within a relatively conservative range, considerable variation between and
within elements were still detectable. Accordingly, attention should be paid to the quantitative estimation of total CO2 efflux by Q
10-related models. In future studies, the biochemical factors and the environmental and biological factors controlling respiration
should be emphasized for precise estimation of total CO2 efflux. The difficulty is how to clarify the underlying mechanism for fluctuations of Q
10 values for one specific habitat and element (e.g. temperature acclimation or adaptation of Q
10 values) and then allow the Q
10 values to be more conservative for representation of temperature sensitivity in global warming processes.
__________
Translated from Acta Phytoecologica Sinica, 2005, 29(4) [译自:植物生态学报, 2005, 29 (4)] 相似文献
20.
Shoji Hashimoto Nobuaki Tanaka Tomonori Kume Natsuko Yoshifuji Norifumi Hotta Katsunori Tanaka Masakazu Suzuki 《Journal of Forest Research》2007,12(3):209-221
Soil CO2 production seasonality at a number of depths was investigated in a temperate forest in Japan and in a tropical montane forest
in Thailand. The CO2 production rates were evaluated by examining differences in the estimated soil CO2 flux at adjacent depths. The temperate forest had clear temperature seasonality and only slight rainfall seasonality, whereas
the tropical montane forest showed clear rainfall seasonality and only slight temperature seasonality. In the temperate forest,
the pattern of seasonal variation in soil respiration was similar at all depths, except the deepest (0.65 m–), and respiration
was greater in summer and less in winter. The contribution of the shallowest depth (around 0.1 m) was more than 50% of total
soil-surface CO2 flux all year round, and the annual mean contribution was about 75%. CO2 production mostly appeared to increase with temperature in shallower layers. In contrast, in the tropical forest, soil CO2 production seasonality appeared to differ with depth. The CO2 production rate in the shallowest layer was high during the rainy season and low during the dry season. Soil CO2 production at greater depths (0.4 and 0.5 m–) showed the opposite seasonality to that in the shallower layer (around 0.1 m).
As a result, the contribution from the shallow depth was greatest in the tropical forest during the rainy season (more than
90%), whereas it decreased during the dry season (about 50%). CO2 production appeared to be controlled by soil water at all depths, and the different ranges of water saturation seemed to
cause the difference in seasonality at each depth. Our results suggest the importance of considering the vertical distribution
of soil processes, particularly in areas where soil water is a dominant controller of soil respiration. 相似文献