Seasonal Changes In Biomass Research Articles

Measuring Vegetation Heights and Their Seasonal Changes in the Western Namibian Savanna Using Spaceborne Lidars

The Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) with its land and vegetation height data product (ATL08), and Global Ecosystem Dynamics Investigation (GEDI) with its terrain elevation and height metrics data product (GEDI Level 2A) missions have great potential to globally map ground and canopy heights. Canopy height is a key factor in estimating above-ground biomass and its seasonal changes; these satellite missions can also improve estimated above-ground carbon stocks. This study presents a novel Sparse Vegetation Detection Algorithm (SVDA) which uses ICESat-2 (ATL03, geolocated photons) data to map tree and vegetation heights in a sparsely vegetated savanna ecosystem. The SVDA consists of three main steps: First, noise photons are filtered using the signal confidence flag from ATL03 data and local point statistics. Second, we classify ground photons based on photon height percentiles. Third, tree and grass photons are classified based on the number of neighbors. We validated tree heights with field measurements (n = 55), finding a root-mean-square error (RMSE) of 1.82 m using SVDA, GEDI Level 2A (Geolocated Elevation and Height Metrics product): 1.33 m, and ATL08: 5.59 m. Our results indicate that the SVDA is effective in identifying canopy photons in savanna ecosystems, where ATL08 performs poorly. We further identify seasonal vegetation height changes with an emphasis on vegetation below 3 m; widespread height changes in this class from two wet-dry cycles show maximum seasonal changes of 1 m, possibly related to seasonal grass-height differences. Our study shows the difficulties of vegetation measurements in savanna ecosystems but provides the first estimates of seasonal biomass changes.

Macrophytobenthos biomass in the Northwestern Cuban shelf, almost 50 years ago

Abstract This study presents for the first time a comprehensive review of the macrophytobenthos on the Northwestern Cuban shelf using data collected almost 50 years ago, and can be considered as a baseline for present and future studies. During 1972−1973 the total estimated fresh biomass was 1.88 million tons (686 tons km−2). Compared with seagrasses, seaweeds were 1.40 times more frequent but had a total biomass 2.86 times smaller. Frequency wise, 90 % of all seaweeds were Chlorophyta, while Phaeophyta, and Rhodophyta were 5 % each. Six Bryopsidales genera (Avrainvillea, Caulerpa, Halimeda, Penicillus, Rhipocephalus, and Udotea) comprised 73 % of 16 Chlorophyta species collected, and 80 % of their total fresh biomass. Turtle grass (Thalassia testudinum) leaves fresh weight was 96 % of all seagrasses biomass, and 71 % of the total macrophytobenthos biomass. The combined biomass of five Halimeda species and that of turtle grass leaves were 88 % of the total regional macrophytobenthos fresh biomass. Species presence was greatest on sand substrate, and least on reef rubble, with a total biomass greater at 1 m depth on organic mud mixed with sand. Of all species, only Halimeda spp. showed seasonal changes in biomass. The total biomass of macrophytobenthos was higher in the western larger and deeper Gulf of Guanahacabibes than in the eastern smaller and shallower Buenavista cays to La Mulata Port section of the shelf. The total macrophytobenthos biomass and that of some species showed significant correlations with depth. The eight most frequent macrophytes in the Northwestern Cuba shelf had similar Caribbean presence.

Зависимость дыхания стволов дуба разных классов роста от условий окружающей среды

Зависимость дыхания стволов дуба разных классов роста от условий окружающей среды

Foraging plasticity allows a large herbivore to persist in a sheltering forest habitat: DNA metabarcoding diet analysis of the European bison

Large herbivores that survived the Pleistocene/Holocene transition are hypothesized to have been forced to take refuge, as a result of environmental changes and human pressure, into forest habitats. Today, there is an open question of the degree to which extant large herbivores are well adapted to the forests that allowed for the herbivores’ persistence. We studied the diet of European bison (Bison bonasus), the largest terrestrial mammal in Europe, to gain insight into the foraging behaviour of a large herbivore, that appears to be primarily adapted to grazing but has been restored to forested habitats. The study population resided in the Białowieża Primeval Forests, Poland. DNA-based analysis of faecal samples revealed strong seasonal and spatial patterns in bison foraging, consistent between sexes. Bison fed on at least 105 different plant taxa. Woody species constituted 59.4% of DNA sequences, and forbs 33.6%. The two most abundant taxa were raspberry (Rubus idaeus) and European hornbeam (Carpinus betulus), which together comprised 31.0% of the dietary sequences and occurred in over 80% of faecal samples. Seasonally, the diversity of plants eaten by bison increased with increasing food availability. During high plant biomass in summer, bison consumed up to 40 different plant taxa. There was little overlap in the composition of the diet from month to month, reflecting the strong seasonality of vegetation abundance and/or its dietary quality. The results indicate high plasticity in bison foraging strategies and response to seasonal changes in biomass and the species composition of plants. Bison are browsers which continuously adjusts their diet with seasonal availability of easily digestible non-grass vegetation. We propose that dietary plasticity and micro-selection for open habitats (gaps and river valleys) within a forested landscape allowed bison to persist in sheltering forest habitats during the Holocene and accommodate to forest environments during species restoration.

Normalized Difference Vegetation Index as an Estimator for Abundance and Quality of Avian Herbivore Forage in Arctic Alaska

Tools that can monitor biomass and nutritional quality of forage plants are needed to understand how arctic herbivores may respond to the rapidly changing environment at high latitudes. The Normalized Difference Vegetation Index (NDVI) has been widely used to assess changes in abundance and distribution of terrestrial vegetative communities. However, the efficacy of NDVI to measure seasonal changes in biomass and nutritional quality of forage plants in the Arctic remains largely un-evaluated at landscape and fine-scale levels. We modeled the relationships between NDVI and seasonal changes in aboveground biomass and nitrogen concentration in halophytic graminoids, a key food source for arctic-nesting geese. The model was calibrated based on data collected at one site and validated using data from another site. Effects of spatial scale on model accuracy were determined by comparing model predictions between NDVI derived from moderate resolution (250 × 250 m pixels) satellite data and high resolution (20 cm diameter area) handheld spectrometer data. NDVI derived from the handheld spectrometer was a superior estimator (R2 ≥ 0.67) of seasonal changes in aboveground biomass compared to satellite-derived NDVI (R2 ≤ 0.40). The addition of temperature and precipitation variables to the model for biomass improved fit, but provided minor gains in predictive power beyond that of the NDVI-only model. This model, however, was only a moderately accurate estimator of biomass in an ecologically-similar halophytic graminoid wetland located 100 km away, indicating the necessity for site-specific validation. In contrast to assessments of biomass, satellite-derived NDVI was a better estimator for the timing of peak percent of nitrogen than NDVI derived from the handheld spectrometer. We confirmed that the date when NDVI reached 50% of its seasonal maximum was a reasonable approximation of the period of peak spring vegetative green-up and peak percent nitrogen. This study demonstrates the importance of matching the scale of NDVI measurements to the vegetation properties of biomass and nitrogen phenology.

几种根际微生物的时空分布的初步探究

根际微生物的活动在植物的根际营养中起着分解有机物、释放与贮蓄养分的积极作用。根际促生微生物可以通过影响植物根系形态及生理特征而影响植物对养分的吸收，根际生防微生物通过产生一些抗菌物质抑制病原菌在植物根际的生殖和发展。然而，由于土壤中微生物个体微小，数量多，分离和鉴定困难，土壤环境条件复杂等原因，限制了人们对根际微生物与植被相互关系的认知。因此，本研究选择五种具有代表性的植物，在不同季节取其根际土中的微生物置于酵母膏，琼脂，PDA，高氏一号四种培养基培养，运用菌落计数研究了同种植物微生物量随季节变化的规律及不同植物微生物类群结构的异同，试图解释根际微生物数量和结构与植被和季节的相互关系。 Rhizosphere microorganisms play an active role in the storage and release of nutrients and the decomposition of organic matter in the rhizosphere of plants. Rhizosphere microorganisms can affect plant growth and nutrient uptake by affecting the morphology and physiological characte-ristics of plant roots, and anti-microbial particles produced by some rhizosphere microorganisms can also inhibit the reproductive development of some pathogen in plant rhizospheres. However, soil microorganisms are small, large in number, difficult in isolation and identification, and complicated in soil environment conditions, which restrict the understanding of the relationship between rhizosphere microorganisms and vegetation. Therefore, in this study, five representative plants were selected and the rhizosphere soil extracts were cultivated into four different mediums, including yeast extract, pure agar, PDA, and Gause’s No.1 medium. Then, seasonal changes of biomass in each particular plant were studied by colony counting, and the similarities and differences between different plants’ microbial community structures were analyzed, trying to explain the correlation between rhizosphere microorganism number, community structure and plant types as well as environmental factors.

Seasonal variations in harvest index and bacoside A contents amongst accessions of Bacopa monnieri (L.) Wettst. collected from wild populations.

Bacoside A, a major active principle of Bacopa monnieri known for its cognitive effects is a mixture of saponins like bacoside A3, bacopaside II, isomer of bacopasaponin C and bacopasaponin C. Seasonal changes in biomass and bacoside A levels in fourteen accessions of B. monnieri were evaluated after maintaining these at a common site at Thapar University campus, Patiala (30°19'36.12″N and 76°24'1.08″E) for 1year. Harvestable biomass and total bacoside A contents varied significantly between the accessions and also in a particular accession during different seasons of the year. The maximum dry weight of plant (biomass 1.64g) and bacoside A levels (6.82mg/plant) were recorded in accession BM1. Harvestable biomass was highest during summer in accessions BM1 and BM7 (FW 4.2g/plant), whereas bacoside A levels were also highest during summer and in accession BM1 (6.82mg/plant). The lowest bacoside A level (0.06mg/plant) was recorded in accession BM14 during winter. Principal component analysis showed that samples of summer were positively correlated with both the components suggesting an appropriate time for the harvest.

Local hydrography and fishing drive life cycle strategies and population dynamics of the sea-bob shrimp Xiphopenaeus kroyeri in a coastal subtropical environment in Brazil

The sea-bob shrimp is a shallow-water species whose population dynamics along the southern and southeastern coasts of Brazil is influenced by the upwelling of the South Atlantic Central Water (SACW). Since the SACW does not reach our study area, we hypothesize that life cycle and distribution patterns are dominated by the local regime of estuarine plumes. Also, we would expect higher biomasses and larger individuals in autumn due to the closed fishing season. We conducted a survey for a year, consisting of 20 monthly trawling hauls. Spawning peaks occurred in spring and autumn, related to rainy periods with greater estuarine loads of particulate material and phytoplankton production. The relative abundance of larger individuals increased with depth, while juveniles concentrated at shallower sites. Size classes prior to the closed season were affected by increased fishing during summer due to tourist demand. Water transparency and bottom temperature were the main factors controlling the distribution and life cycle of sea-bob shrimp. Seasonal changes in biomass could be related to the inshore–offshore migrations of the type-3 life cycle, compounded by the impacts of fishing. Thus, fishing and local hydrography can drive life cycle and distribution patterns of the species, with important management implications.

Seasonal changes in phytoplankton biomass and dominant species in the Changjiang River Estuary and adjacent seas: General trends based on field survey data 1959–2009

The characteristics of seasonal variation in phytoplankton biomass and dominant species in the Changjiang River Estuary and adjacent seas were discussed based on field investigation data from 1959 to 2009. The field data from 1981 to 2004 showed that the Chlorophyll-a concentration in surface seawater was between 0.4 and 8.5 μg dm−3. The seasonal changes generally presented a bimodal trend, with the biomass peaks occurring in May and August, and Chlorophyll-a concentration was the lowest in winter. Seasonal biomass changes were mainly controlled by temperature and nutrient levels. From the end of autumn to the next early spring, phytoplankton biomass was mainly influenced by temperature, and in other seasons, nutrient level (including the nutrient supply from the terrestrial runoffs) was the major influence factor. Field investigation data from 1959 to 2009 demonstrated that diatoms were the main phytoplankton in this area, and Skeletonema costatum, Pseudo-nitzschia pungens, Coscinodiscus oculus-iridis, Thalassinoema nitzschioides, Paralia sulcata, Chaetoceros lorenzianus, Chaetoceros curvisetus, and Prorocentrum donghaiense Lu were common dominant species. The seasonal variations in major dominant phytoplankton species presented the following trends: 1) Skeletonema (mainly S. costatum) was dominant throughout the year; and 2) seasonal succession trends were Coscinodiscus (spring) → Chaetoceros (summer and autumn) → Coscinodiscus (winter). The annual dominance of S. costatum was attributed to its environmental eurytopicity and long standing time in surface waters. The seasonal succession of Coscinodiscus and Chaetoceros was associated with the seasonal variation in water stability and nutrient level in this area. On the other hand, long-term field data also indicated obvious interannual variation of phytoplankton biomass and community structure in the Changjiang River Estuary and adjacent seas: average annual phytoplankton biomass and dinoflagellate proportion both presented increased trends during the 1950s–2000s.

Floating treatment wetland nutrient removal through vegetation harvest and observations from a field study

Nonpoint source pollution from urban areas has been identified as a leading contributor to impaired water quality. Floating treatment wetlands (FTWs) are cultivated plants growing on floating mats in open water. FTWs can be used to remove pollutants from runoff, but data on their effectiveness is limited. We conducted a field study of FTWs in a nutrient enriched urban wet pond to investigate vegetation biomass and phosphorus (P) accumulation/distribution, sustainability under ice encasement stress (which is a concern in temperate regions), and to assess the use of the FTW by species. Planted perennial macrophytes successfully adapted to stresses of the low dissolved oxygen (DO) concentrations (minimum: 1.2mg/L) in summer, ice encasement in winter, and relatively low nutrient concentrations in the water (median: 0.15mg/L TP and 1.15mg/L TN). Pickerelweed produced more biomass and demonstrated higher P removal performance (10.44g dry weight/plant and 7.58mg P/plant) than softstem bulrush (2.20g dry weight/plant and 1.62mg P/plant). Based on the observed seasonal changes in biomass and P, we recommend harvest of above-ground vegetation is conducted in June for maximum P removal or in September to prevent P release due to senescence. Submerged tissues of pickerelweed, softstem bulrush, and yellow iris (Iris pseudacorus) survived ice encasement and regrew in the second year. Additionally, plant diversity increased during the study period through recruitment of both native and exotic wetland plants. Systematic observation of wildlife activities indicated eight classes of organisms inhabiting, foraging, breeding, nursing, or resting in the FTWs. This study suggests above-ground plant harvest can enhance P removal, and that softstem bulrush, yellow iris, and pickerelweed can be sustained over winter on the FTW. Future study is recommended to investigate the feasibility of multiple vegetation harvest and document the possible habitat creation by the use of FTWs.

Biomass and carbon storage of Gracilariopsis lemaneiformis (Rhodophyta) in Zhanshan Bay, Qingdao, China

Marine macroalgae can absorb carbon and play an important role in carbon sequestration. As an important economic macroalga, Gracilariopsis lemaneiformis has the potential to significantly affect carbon absorption and storage in wave-sheltered intertidal reef systems. However, detailed knowledge on seasonal biomass changes and carbon storage of G. lemaneiformis is lacking, especially in many small and scattered ecosystems. Considering the influence of human activities on wild distribution of G. lemaneiformis, the understanding of seasonal dynamics of an economically important species in nature is necessary. In this study, we first investigated seasonal variations in biomass, coverage area, and carbon storage during low tide from August 2011 to July 2012 in Zhanshan Bay, Qingdao, China. Furthermore, we estimated the carbon storage potential of wild G. lemaneiformis using light use efficiency (LUE). The results show that the standing biomass and coverage area changed significantly with season. However, seasonal variations in carbon content and water content were not obvious, with an average content of 35.1% and 83.64%, respectively. Moreover, carbon storage in individual months varied between 0.67 and 47.03 g C/m2, and the value of carbon storage was the highest in August and June and the lowest in February. In Zhanshan Bay, LUE of G. lemaneiformis was only 0.23%. If it is increased to the theoretical maximum (5%–6%), the carbon storage will have an increase of at least 21 times compared with the current, which suggested that carbon storage of wild G. lemaneiformis had a high enhancement potential. The study will help to assess a potential role of G. lemaneiformis in reducing atmospheric CO2.

Seasonal changes in biomass and net production of Ecklonia kurome Okamura community off Gounoura, Iki Island, northern Kyushu, Japan

Seasonal changes in biomass and net production of <i>Ecklonia kurome</i> Okamura community off Gounoura, Iki Island, northern Kyushu, Japan

Distinctive copepod community of the estuarine turbidity maximum: comparative observations in three macrotidal estuaries (Chikugo, Midori, and Kuma Rivers), southwestern Japan

Copepods are considered to be a vital component connecting the unique macrotidal environment to the high productivity and high biodiversity of the Ariake Sea. To examine the spatiotemporal succession of copepod communities, we conducted monthly sampling (vertical hauls of a 100-μm mesh plankton net) in three neighboring macrotidal estuaries between 2005 and 2006. Irrespective of the season, three copepod communities were recognized in relation to the relatively long gradients of salinity and turbidity along the Chikugo and Midori River estuaries. The oligohaline community (salinity 1–10) was observed at higher turbidities (>100 NTU), whereas the freshwater (salinity 10) communities were associated with lower turbidities ( 10 mg m−3) in or close to the well-developed estuarine turbidity maximum (ETM) throughout the year. In the Midori River estuary, the oligohaline community lacked S. sinensis and showed a minimum biomass during winter (<10 mg m−3). In both estuaries, the freshwater community always remained at a small biomass (<1 mg m−3), whereas the meso/polyhaline community showed marked seasonal changes in biomass (0.1–657 mg m−3). The prevalence of higher salinities allowed only the meso/polyhaline community to occur in the Kuma River estuary. In summary, S. sinensis characterized the copepod community distinctive of the well-developed ETM, potentially serving as an important link to higher trophic levels during winter when copepods are scarce in other areas.

Seasonal biomass changes at a newly constructed wetland in agricultural area

ABSTRACT The objective of this study was to present and evaluate the rate of biomass growth due to temperature changes and to identify the type of vegetation that best adapts to temperature changes in a surface flow constructed wetland (CW). The operation of the CW started in 2009 treating stream agricultural runoff from a watershed area of 221 ha which are mainly wet paddy fields. The CW is composed of seven connected cells which include a sedimentation zone, deep and shallow marshes. Five typical wetland plant species such as Acorus calamus, Oenanthe javanica, Phragmites australis, Phragmites japonica, and Typha orientalis were planted surrounding the CW. The water quality and plant biomass were monitored from April to December 2009. The mean inflow DO and pH concentration were 6.9 ± 2.0 mg/l and 7.0 ± 0.5, respectively during the whole season. The water and air temperature at the CW were not significantly different (Ta = 0.86Taw; n = 15; r = 0.91; p <0.0001). Based on the results, the optimum temperatu...

Seasonal biomass changes at a newly constructed wetland in agricultural area

Seasonal biomass changes at a newly constructed wetland in agricultural area

Seasonal changes in ciliate biomass and composition of the ciliate community in oligo-mesotrophic Lake Jasne (Iława Lake District, Poland)

Seasonal changes in ciliate biomass and composition of the ciliate community in oligo-mesotrophic Lake Jasne (Iława Lake District, Poland)Lake Jasne, also known as Lake Czyste, is a well-known oligo-mesotrophic water body located in the Iława Lake District, Poland. Between May 2009 and June 2010 ciliate biomass and community composition were studied on the basis of Lugol-fixed samples taken from the surface waters and the near-bottom zone. The mean annual ciliate biomass amounted to 0.58 μgC l-1in the surface waters and 1.46 μgC l-1in the near-bottom zone, and therefore, the ciliate biomass is amongst the lowest estimates observed in oligotrophic waters. In the surface waters typical bimodal seasonal changes in biomass were recorded with two peaks observed in spring and autumn. In the near-bottom zone the peak was recorded only in spring. The ciliate community was dominated by prostomatids (mainlyUrotrichaspp.), both in the surface waters (77% of biomass) and in the near-bottom zone (54% of biomass).

Fine root biomass dynamics and carbon storage along a successional gradient in Changbai Mountains, China

Fine root dynamics and net primary production were studied using the sequential soil coring method in an old-growth Korean pine (Pinus koraiensis Sieb.et Zucc.) mixed broadleaved forest, an 80-year-old stand of secondary birch (Betula platyphylla Suks.) in mixture with poplar (Populus davidiana Dode) and a 20-year-old stand of secondary birch and poplar in Changbai Mountains in Northeast China. The biomass and necromass of the fine roots in the 0- to 0.5-m soil layer were determined every month from May to October in three types of forest during 2002. The total and monthly production dynamics of the fine roots were calculated and analysed according to seasonal biomass changes along the successional gradient, as well as their carbon and nitrogen contents. The total production of the fine roots from the dominant tree species increased along the successional gradient, being 222.8, 569.1 and 672.3 g m−2 from the young forest through to the old-growth stage, respectively. As important soil carbon and nitrogen sources, the total carbon and nitrogen storages by fine root growth increased along forest succession in the Changbai Mountains.

Application of mathematical modelling techniques for evaluation of radionucleide accumulation levels in biota

In the majority of the cases associated with radioactive contamination of the environment, forest and lake ecosystems as natural filters and radionuclide storages relate to critical ecosystems. These two types of natural ecosystems as well as meadow prevail in the areas where NPP are located. To solve the entire complex of radioecological problems, the authors have developed the models for 137Cs and 90Sr migration in forest ecosystems that take into account the transformation processes of 137Cs and 90Sr in a soil-litter system, age- and season-specific dynamics for the tree layer and seasonal biomass changes in the understory, as well as radionuclide entering into food chains. A mathematical model for the migration of varied kinds of admixtures is developed and enhanced on the pattern of the 90Sr, 106Ru, 125Sb, 137Cs, 144Ce radioactive micro-admixture in lake ecosystems. The model takes into account the fact that micro-admixture withdraws out of the water both as a result of molecular/ ion-exchanging sorption on the boundary of the bottom sediments/ water layer and as a result of the detritus-forming process. When describing a vertical radionuclide migration in bottom sediments through a diffusion equation, the increase in the bottom sediment layer is considered. The authors have developed the mathematical models describing a long-term behavior of 90Sr and 137Cs in meadow ecosystems and taking into account basic processes that define the 90Sr and 137Cs biological accessibility for root absorption as well as the transformation processes in soil. For the assessment of biological effects of a radiation factor on the biota, a complex of dosimeter models is developed to evaluate the internal/ external doses to biota taking into account different geometry of the exposure source of ionizing radiation. The represented mathematical models were successfully used during an environmental expertise performed for a number of Russian NPP and also when assessing environmental effects from the implementation of countermeasures in the Mayak facility region, as well as the effects of radioactive contamination in the Bryansk Region resulted from the Chernobyl accident. The complex of mathematical migration and dosimeter models developed by the authors may be used to solve theoretical or applied radioecological issues with regard to the investigation of radionuclide behavior peculiarities in different ecosystems, as well as the evaluation of radiation impacts on organisms, populations or entire ecosystems. Besides, the models can be parameterized for specific forest/ water/ meadow ecosystems in varied situations associated with nuclear pollution of environment.

Seasonal changes in biomass of macrophytes stranded on Yoro Beach along a sargassacean forest in Wakasa Bay, Sea of Japan

Macrophytes stranded on a beach provide food and habitat for many kinds of animals and play important roles in coastal ecosystems. Macrophytes stranded on a sampling beach (56 m long) along a sargassacean forest (400 m long and 88 m wide) were collected every 10 days from late April 2003 to late May 2004. The weight of macrophytes stranded per meter of beach amounted to 1733 g dry wt/m per year. Sargassacean plants were dominant and constituted 72.9% (1263 g dry wt/m per year) of whole stranded macrophytes. Large numbers of macrophytes were stranded just after heavy winter storms and the maximum weight of stranded macrophytes in winter was 407 g dry wt/m. Stranded macrophytes also increased in May to July; the deterioration period of sargassacean species in this region, and the maximum weight in this period was 233 g dry wt/m. The number of sargassacean plants stranded with holdfast increased only in winter. These results suggest that winter storms have an important role in stranding sargassacean plants at Yoro Beach.

陸域生態系のＣＯ２吸収と地球環境

A five-year strategic project (S-1 project), which was organized to clarify the carbon dynamics of terrestrial ecosystems in East Asia was conducted from April 2002 to March 2007 with financial support from the Ministry of Environment, Japan. It had four themes. The first was a bottom-up approach using micrometeorological and ecological techniques to measure carbon dioxide fluxes at sixteen tower sites in Japan and East Asia. The second was a top-down approach using. an inverse model based on atmospheric CO2 concentration data finely measured at six western Siberian sites. The third was a modeling approach driven by data-based quality-controlled data from the first theme and artificial satellite data. The fourth and final theme synthesized the results of the three themes mentioned above following a systems approach, which led to a comprehensive conclusion.The main results obtained by the many principal investigators of the S-1 project are summarized below.1. Characteristic seasonal changes of Net Ecosystem Production (NEP) were obtained from ten tower flux sites including forest and grassland sites.2. Annual NEP values obtained by micrometeorological and ecological techniques showed almost satisfactory agreement at the six forest sites, although those obtained by the micrometeorological technique were usually higher than ones obtained by the ecological technique.3. A satisfactory agreement was obtained for seasonal changes of biomass at a paddy field site between results obtained by micrometeorological and ecological harvesting techniques.4. Seasonal changes of NEP in western Siberia estimated by an inverse model showed a similar pattern to those of an ecological process-based model, Sim-CYCLE, but there was a fairly large difference between the estimated annual values of the two models.5. Gross Primary Production (GPP) and Net Primary Production (MPP) maps of a spacially high resolution drawn by Sim-CYCLE revealed a characteristic pattern reflecting the diverse vegetation types in East Asia. This region was estimated to be a net carbon sink, with 57 Tg carbon on an annual average during the six years from 2000 to 2005, although annual values fluctuated greatly due to weather conditions.