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Plants allocate biomass to different organs in response to resource variation for maximizing performance, yet we lack a framework that adequately integrates plant responses to the simultaneous variation in above‐ and below‐ground resources. Although traditionally, the optimal partition theory (OPT) has explained patterns of biomass allocation in response to a single limiting resource, it is well‐known that in natural communities multiple resources limit growth. We study trade‐offs involved in plant biomass allocation patterns and their effects on plant growth under variable below‐ and above‐ground resources—light, soil N and P—for seedling communities. We collected information on leaf, stem and root mass fractions for more than 1,900 seedlings of 97 species paired with growth data and local‐scale variation in abiotic resources from a tropical forest in China. We identified two trade‐off axes that define the mass allocation strategies for seedlings—allocation to photosynthetic versus non‐photosynthetic tissues and allocation to roots over stems—that responded to the variation in soil P and N and light. Yet, the allocation patterns did not always follow predictions of OPT in which plants should allocate biomass to the organ that acquires the most limiting resource. Limited soil N resulted in high allocation to leaves at the expense of non‐photosynthetic tissues, while the opposite trend was found in response to limited soil P. Also, co‐limitation in above‐ and below‐ground resources (light and soil P) led to mass allocation to stems at the expense of roots. Finally, we found that growth increased under high‐light availability and soil P for seedlings that invested more in photosynthetic over non‐photosynthetic tissues or/and that allocated mass to roots at the expense of stem. Synthesis. Biomass allocation patterns to above‐ and below‐ground tissues are described by two independent trade‐offs that allow plants to have divergent allocation strategies (e.g. high root allocation at the expense of stem or high leaf allocation at the expense of allocation to non‐photosynthetic tissues) and enhance growth under different limiting resources. Identifying the trade‐offs driving biomass allocation is important to disentangle plant responses to the simultaneous variation in resources in diverse forest communities.

Seagrass has long been known to be very sensitive to environmental changes, especially caused by human activities (anthropogenic disturbance) and has been used as a bioindicator for environmental condition. This research aimed to study interaction of Thalassia hemprichii measured and derived variables (metrics), at two locations i.e., inhabited island (high anthropogenic location) and uninhabited island (low anthropogenic location). Confirmative approach was conducted using a developed conceptual model based on preliminary studies, the conceptual model was analyzed in multivariate context using data from field observation. The result showed that Thalassia hemprichii dominated and have higher above ground biomass value in inhabited area which indicated high nutrient input, meanwhile uninhabited area showed a higher below ground biomass value. Above ground of Thalassia hemprichii that have direct effect on its biomass and below ground metrics was leaf width, meanwhile leaf length of Thalassia hemprichii have indirect effect on its biomass and below ground metrics. The result also indicated some different metric covariations which were influenced by the degree of Thalassia hemprichii density. Leaf length, leaf width, density, and percent cover of Thalassia hemprichii potentially could be used as components in multimetric index and bioindicator for environmental quality. Keywords: anthropogenic disturbance, path analysis, structural equation modeling, Thalassia hemprichii

This research estimates carbon sink and allocation in above- and below-ground biomass of a 12-year-old willow coppice plantation on fluvisol soil near the Vistula River (southern Poland). The plantation showed high C sink potential and sequestration rates. C sequestration by above-ground biomass was estimated at 10.8 Mg C ha−1 a−1. Accumulation in coarse roots was estimated at 1.5 Mg C ha−1 a−1 and in fine roots at 1.2 Mg C ha−1 a−1. Total C sequestered (above-ground biomass, coarse roots and fine roots) was estimated at 13.5 Mg C ha−1 a−1. These results confirm the potential of fast-growing plantations of willow to mitigate, over a short time span, the effects of high CO2 concentrations.

The below ground biomass of salt marsh species accounts for more than half of the total plant biomass in salt marsh systems, yet no biomass data exist for salt marsh species in South Africa. The aims of the current study were to compare the biomass allocation of Salicornia tegetaria in six estuaries and relate findings to their environmental conditions. The current study measured the physico-chemical variables of the sediment (moisture content, organic matter content, electrical conductivity, pH) and pore water (temperature, salinity, pH, depth) at Olifants, Berg, Langebaan, Heuningnes, Nahoon and Kwelerha estuaries. Above and below ground biomass and stem height measurements were also collected. The below ground biomass (1.51 ± 0.24 kg m−2) and root/shoot ratio (1.36 ± 0.17) was the lowest at Heuningnes Estuary with no significant difference at the remaining estuaries, suggesting that factors, such as geomorphology and sedimentological processes, could have a stronger effect on the biomass allocation in this species. Important drivers of biomass allocation were sediment pH, redox potential and pore water depth. The current study provides baseline information for S. tegetaria, an endemic salt marsh species, for which there is a paucity of data. This species plays a major role in the ecology of the lower intertidal zone, which will be vulnerable to sea-level rise.

Absract Study was conducted to ascertain the positive or negative allelospoly among Melia dubia-Aloe vera as components in silvi-medicinal land use [L1-M. dubia (2 × 2 m) + A. vera; L2-M. dubia (3 × 2 m) + A. vera; L3-M. dubia (4 × 2 m) + A. vera) and L4-sole A. vera] cropping systems. M. dubia spatial geometries resulted significant (P≤ 0.05) effect on quantitative and qualitative attributes of A. vera. Quantitative attributes viz., growth (plant height, mature leaf length, and small, mature and total leaves per plant) and biomass (above and below ground and total biomass, mature leaf, pulp, leaf peel and aloe latex) were significantly higher under M. dubia (2 × 2 m)-A. vera silvi-medicinal land use system (closer spacing) as compared to wider spatial M. dubia geometries and A. vera sole cropping. Growth and biomass decreased with increase in M. dubia spacing with minimum under sole crop of A. vera. No significant effect of silvi-medicinal and sole cropping systems was observed on A. vera below ground biomass. In A. vera pulp, through. Gas Chromatography-Mass Spectrometry, 11, 13, 9 and 9 different phytochemicals were detected in M. dubia (2 × 2 m) + A. vera; M. dubia (3 × 2 m) + A. vera and M. dubia (4 × 2 m) + A. vera) and A. vera sole cropping systems, respectively. Percentage of some of the phytochemicals [+(-salsolidine); cetyl alcohol, myristic acid, cyclopentane and 5-triazole, 3ethyl was less under closest spacing (2 × 2 m) and sole cropping system; however in wider spacing (3 × 2 and 4 × 2 m) percentage of these phytochemicals was higher. Intercropping of A. vera significantly affected the growth of M. dubia; however, there was no such effect on volume and biomass production when extrapolated to hectare basis. This study substantiate that M. dubia spatial geometries had positive allelospoly on A. vera growth, biomass and phytochemicals in A. vera pulp. Hence, tree spatial geometry is essential parameters to be considered for growing medicinal plants under agroforestry systems.

The present study was conducted in Central Research Institute for Dryland Agriculture (CRIDA), Hyderabad to develop the allometric equations for predicting the total biomass and carbon of Azadirachta indica in three different basal diameter classes (0–10 cm, 10–20 cm and 20–30 cm). The growth variables viz., tree height, basal diameter, DBH, crown height and crown width are maximum for neem under higher diameter class, whereas minimum under lower diameter class. The average total biomass of neem tree was recorded as 122.3 kg/tree and 338.8 t/ha in all three diameter classes. The allometric relationship between the variables in Azadirachta indica was highly significant with positive and high correlation. The highest and significant linear relationship was observed in tree height (0.992) followed by crown height (0.963) with above ground biomass. With below ground biomass, a strong and highly significant relationship was observed in tree height (0.988) followed by crown height (0.974) and DBH (0.967). The above ground variables (tree height, basal diameter, DBH, crown height and crown width) had highly significant linear relationship with predicted variable of total biomass. The highest and strongest coefficient observed between total carbon and tree height (0.991) followed by crown height (0.968) and DBH (0.957). And also, the significant relationship was found between the dependent variable (total carbon) and other independent variables viz., basal diameter (0.821), and crown width (0.910). Therefore, the result of this study may be useful to predict the amount of total carbon and biomass stored in Azadirachta indica plantation on area basis.

Elevated sediment delivery and resuspension in coastal waters from human activities such as shipping can have detrimental effects on seagrass health by limiting light penetration. Managing seagrasses requires knowledge of their light acclamatory abilities so guidelines for coastal activities (e.g. ship movements) that influence sediment dynamics can be created. Guidelines typically focus on ensuring that seagrasses are able to meet their minimal light requirements (MLR). MLRs can be achieved by different light regimes, but it remains unknown whether a chronically low yet stable light regime is less or more detrimental than a highly variable regime with periods of extreme low to no light. To test this, we compared the physiological and morphological responses of Thalassia hemprichii among three light regimes: an open control (30-40% ambient light), a shaded control with (11-15% ambient light), and a fluctuating shade (4-30% ambient light). The MLR for the T. hemprichii we studied was lower (4-10% ambient light) than previous reports (mean = 18%) illustrating enhanced light acclimation in Singapore's chronically turbid waters. Seagrass shoots in the shaded control, however, exhibited significantly more morphological stress symptoms, with reduced shoot growth and lower below ground biomass. These data suggest that for seagrass exposed to periods of acute light stress, energetic costs associated with photo-acclimation to more variable light regimes can be offset if the plant can meet its daily light requirements during periods of high light. Management of seagrass beds should incorporate regular light monitoring and move towards an adaptive feedback-based approach to ensure the long-term viability of these vulnerable ecosystems.

Replacing conventional monocultures with more diverse agroecosystems can positively impact environmental quality, but their adoption is limited, in part, due to inadequate understanding of how these systems operate regarding belowground competition. We examined how root competition between breadfruit (Artocarpus altilis) and māmaki (Pipturus albidus) affected aboveground performance. Our 2 × 3 factorial design consisted of two competition treatments and the three establishment treatments. Plants were grown together on either side of 47-gallon pots. For non-competition groups, a sheet of vinyl plastic was used to keep the roots of each species separate while maintaining above ground conditions. We used root cores to quantify the spatial allocation of root biomass to explore competition strategies of the two crops and measured biomass production to determine how growth was affected by competition. The two species demonstrated different responses to below-ground competition, with above ground biomass (AGBM) decreased for breadfruit but increased for māmaki. Below ground biomass increased for both plants under competition. Prior establishment enhanced māmaki's response to competition, while breadfruit's response to competition was exacerbated by post establishment and mitigated by simultaneous establishment. We suggest that māmaki's response is due to a more aggressive strategy that targets resource patches, while breadfruit is unable to compete within established māmaki zones and employs an avoidance strategy for root allocation.

This study was carried out in order to explore and compare the correlation between each measured item of the above-ground and below-ground biomass of 13-year-old Pinus densiflora S. et Z. and prepare regression equations to identify differences of early growth characteristics on each slope aspect in the stand. The south-facing slope showed the highest above-ground and below-ground biomass, followed by the north-facing slope and ridge area. The root collar diameter showed the highest correlation between the biomass of the above-ground part and the below-ground part. In the linear regression equation on the root collar diameter and the biomass of the above-ground part and the below-ground part, the growth gradient was high in the south-facing slope and north-facing slope and low in the ridge area such that the biomass in the ridge area may well continue to be low in the future as the trees grow. The result of the study demonstrated that the differences in the growth environments associated with differences ...

To estimate above- and below-ground biomass in teak (Tectona grandis) plantations throughout Thailand, we developed general allometric relationships between tree size parameters (stem diameter and height) and tree biomass (of leaves, stems, and roots). Trees were harvested from 18 plantations within the native range of teak in Thailand and across the area covered by these plantations. Allometric equations for total above- and below-ground biomass showed no significant inter-site differences and high correlation coefficients (0.90–0.99). This similarity across sites may be due to similarities in wood density among different age and/or size of teak trees. The majority of previous biomass estimation models for teak trees gave higher estimated values for both above- and below-ground biomass, suggesting that they should not be applied within Thailand. To estimate belowground biomass using root: shoot ratio (RSR), we evaluated RSR among stands of various ages and sizes. We further identified differences in RSR between Thailand and other regions. Estimated RSR varied among stands and decreased significantly with stand age and average tree size. This relationship suggests that belowground biomass can be estimated from aboveground biomass using RSR. However, RSR values differed among countries and regions. In summary, general allometric equations and RSR value can be used to accurately estimate above- and below-ground biomass in teak plantations across Thailand.

Agriculture, and its impact on land, contributes almost a third of total human emissions of greenhouse gases (GHG). At the same time, it is the only sector which has significant potential for negative emissions through offsetting via the supply of feedstock for energy and sequestration in biomass and soils.Perennial crops represent 30% of the global cropland area. However, the positive effect of biomass storage on net GHG emissions has largely been ignored. Reasons for this include the inconsistency in methods of accounting for biomass in perennials. In this study, we present a generic model to calculate the carbonbalance and GHG emissions from perennial crops, covering both bioenergy and food crops. The model can be parametrized for any given crop if the necessary empirical data exists. We illustrate the model for four perennial crops e apple, coffee, sugarcane, and Miscanthuse to demonstrate the importance ofbiomass in overall farm GHG emissions.

Biomass is the component of living organism and mostly obtained from plants, animals, insects and the residue of all the mentioned organisms. Biomass is the key source of energy present in the form of organic matter. The study aimed to find out biomass and its variation in each component of Betula utilis D. Don (Birch Tree) with varying diameter at Kalam forest division Swat, Khyber Pakhtunkhwa (KPK) province, Pakistan. The biomass of different components was determined by non-destructive methods. Overall, 30 trees were selected from different diameter classes viz a viz up to 10, 11 - 20 and greater than 20 cm. Ten trees were selected from each class. The diameter of stem and large branches and their length were measured in the field. Later, the volumes of stem and branches were calculated and converted into biomass. The study revealed that stem contributes 42.65% biomass followed by large and sub branches as 39.22% and 13.54% respectively. Leaves contribute 4.59% only. The above tree biomass contribution by different components was arranged as stem was greater than large branches; these were greater than sub branches and the lowest was in leaves. The total above ground biomass of single tree was 20.59, 58.041 and 197.214 kg·tree-1 respectively for diameter up to 10, 11 - 20 and greater than 20 cm. The averaged biomass in all diameter classes was 91.95 ± 93.064 kg·tree-1. The total biomass of single tree of diameter class up to 10, 11 - 20 and greater than 20 cm was 24.71, 69.649 and 236 kg respectively. The below ground biomass of single tree of diameter class up to 10, 11 - 20 and greater than 20 cm was 4.11 ± 1.24 kg, 11.61 ± 3.56 kg and 39.44 ± 8.9 kg respectively. The biomass expansion factor was 1.34, 1.47, and 1.5 t·m-3 respectively for diameter classes up to 10 cm, 11 - 20 cm and greater than 20 cm respectively. The mean biomass expansion factor for all diameter classes was 1.44 t·m-3.

In the context of our work exploring the role of Sparganium erectum as a physical ecosystem engineer, we aimed to test our hypothesis that the root and rhizome biomass of this species would be largely confined to the uppermost sediment layers, thereby having the effect of reinforcing newly deposited material and facilitating the growth of in-channel macrophyte stands and sediment accumulations. Detailed measurements of the below ground structures of linear emergent macrophytes, in terms of their biomass and architecture, are complicated by difficulties associated with sampling in the highly saturated sediments that these morphotypes typically occupy. In this paper, we describe the development of an adapted ingrowth core method, which allows the extrusion of an undisturbed root-soil matrix from highly saturated environments. The approach combines an ingrowth core, which is commonly used to measure fine-root production in forest topsoil, with an outer casing that facilitates the retention of a sample representative of field conditions, and a laboratory protocol that enables extrusion and measurement of biomass at different depth increments. The new approach enabled detailed depth profiling of S. erectum, and confirmed our hypothesis by demonstrating that root and rhizome biomass was predominantly located in the 10 cm of sediment closest to the sediment–water interface throughout our study.

Mangroves play an important role in the storage of carbon (C) and nitrogen (N) within estuarine systems, yet are being lost at an alarming rate throughout the tropics. In contrast, temperate mangroves have increased in area at many locations in recent decades. Field surveys, sediment sampling, allometry, and C and N analysis were used to determine total C and N stocks in five temperate Avicennia marina subsp. australasica forests in New Zealand. This is the first study developing allometric functions to estimate root biomass C and N stocks for A. marina. A. marina forests stored 117.1 ± 16.8 t C ha-1 and 15.4 ± 1.0 t N ha-1 in above and below ground biomass and sediment to 100 cm depth. Below ground biomass and sediment C and N stocks contributed 88 ± 3% and 99% ± 0.4% to total C and N stocks, respectively, emphasising the importance of below ground biomass and sediment in mangrove ecosystems. The results of this study can be used to inform management decisions for estuarine and coastal ecosystems, currently undergoing rapid changes in mangrove area.

Certainty over warming-induced biomass accumulation is essential for addressing climate change. However, no previous meta-analysis has investigated this accumulation across the whole of China, also unclear are the differences between herbaceous and woody species and across plant phylogeny, which are critical for corresponding re-vegetation. We extracted data from 90 field-based experiments to reveal general patterns and driving factors of biomass responses all over China. Based on traditional meta-analyses, a warmer temperature significantly increased above- (10.8%) and below-ground (14.2%) biomass accumulation. With increasing warming duration (WarmD) and plant clade age, both above-ground and below-ground biomass showed significant increases. However, for herbaceous versus woody plants, and the whole community versus its dominant species, responses were not always constant, the combined synergies would affect accumulative response patterns. When considering WarmD as a weight, decreases in total above-ground biomass response magnitude were presented, and the increase in below-ground biomass was no longer significant, notably, significant positive responses remained in tree species. However, if phylogenetic information was included in the calculations, all warming-induced plant biomass increases were not significant. Thus, it is still premature to speculate whether warming induces biomass increases in China, further long-term experiments are needed regarding phylogeny-based responses and interspecies relations, especially regarding woody plants and forests.

The objective of this work was to evaluate the effect of phosphorus doses in the growth of seedling of palm as well as to determine the content of macro and micronutrients from the below and above ground biomass through a tissue analysis. The assay was conducted in a greenhouse. The treatments were quantitative and equidistant, constituted by: T1- control (soil without P); T2-90 mg.dm -3 ; T3-180 mg.dm -3 ; T4-270 mg.dm -3 ; T5-360 mg.dm -3 ; T6-450 mg.dm -3 ; T7-540 mg.dm -3 ; T8-630 mg.dm -3 ; of P, respectively. 12 months after sowing, the following variables were evaluated: above ground height and biomass, below ground biomass and total. The nutritional analysis from below and above ground biomass was done to obtain the amount of macro and micronutrients. Results show that the growth of young palm plants was achieved to the analyzed parameters. Growth was obtained for height and it increased the aerial biomass of the plants to the doses of 540 mg.dm -3 of P, the answer was positive for the development of the below ground biomass to the doses of 450 mg dm -3 , and the development of total biomass was reached with the doses of 540 mg.dm -3 . For the macro tenors and micronutrients in the above ground biomass, the following sequence has been obtained, respectively: N> Ca> K> Mg> P>S; Fe> Mn> Zn> B> Cu, and for below ground: N> Ca> Mg> S> K> P; Fe> Mn> Zn> B> Cu, and the tenors of P didn't alter the tenors of nutrients in the plant.

Forest biomass is considered to have a large potential for temporary and long-term carbon storage as biomass. Enhancement of biomass increase via forest plantation establishment can be considered as an effective method of mitigation of atmospheric carbon dioxide. However, due to the difficulty of measuring the below ground biomass accumulation, most of the tree and forest related biomass studies have been conducted on the above ground components of the trees. Therefore the present study was conducted to identify the biomass accumulation over the age and its partition in above and below ground segments of young teak trees by destructive sampling. Teak trees of 55, 67, 79, 91 and 103 months growing in a single plantation in Puttlam was selected for this reason. Three trees of each age were randomly selected and carefully uprooted with the minimum damage to the roots. Then each tree was separated into main stem, primary, secondary and tertiary branches and roots and the weights were measured. Representative samples of each segment of the tree were oven dried at 72° C for three days. Then the biomass of each segment was calculated. The average total tree biomass increased from 28.430 to 79.760 kg from 55 to 103 months. Comparatively, the highest biomass was recorded in the main stem (63.5%) followed by primary branches (15.7%). The third highest biomass was recorded from the roots (11.7%) and the lowest biomass was recorded in tertiary branches (3.6%). A strong exponential relationship was observed between the tree age and whole tree biomass increase with the R2 of 97.7%. It further revealed that the biomass increase of teak is rising with a rapid rate even at the age of 10 years. Keywords: Tree biomass, Biomass partition, Teak

For lentil production to expand further in Australia, adaptation to the less favourable soils of the low to medium rainfall zones is required. To improve adaptation to these regions, varieties are required with increased tolerance to soil constraints such as high concentrations of boron (B), salinity and sodicity. To evaluate the range of B tolerance in lentil germplasm, 310 lines were screened in soil with a high concentration of B and tolerance was assessed at the seedling stage. A wide range in response to high concentrations of soil B was observed in the germplasm tested. Current Australian varieties were generally very intolerant to high concentrations of soil B. High levels of B tolerance was identified in germplasm originating from Afghanistan and Ethiopia. A subsequent experiment comparing lentils with different levels of B tolerance found that tolerant accessions (ILL213A and ILL2024) produced greater above and below ground biomass than intolerant accessions. The tolerant accessions had no significant yield loss under a high B treatment (extractable B = 18.20 mg/kg) compared to the control treatment (extractable B = 1.55 mg/kg). The large improvement in B tolerance, at soil concentrations typical of those found in the target regions, suggests there is potential to improve the tolerance level of adapted varieties and expand lentil production areas to regions with higher concentrations of soil B.

Comparisons were made of three different 15 N-feeding techniques, leaf, petiole and stem feeding, to identify the most efficient technique for labelling above-and below-ground plant biomass under controlled environment conditions. 15 N-urea (0.5%, 10 atom % excess 15 N) was applied to chickpea ( Cicer aritenium var. ICCV 5003) plants twice during early growth. Leaf feeding was found to be the most efficient in terms of 15 N-solution uptake (5.9 ml 48 h −1 ) and 15 N-enrichment at harvest, with 0.95, 0.41, 0.79, 0.67 and 0.22 atom % excess 15 N in the leaves, stems, grain, grain straw and clean root fractions, respectively. Solution uptake was low in the second stem feeding event due to blockage of the drilled hole, resulting in low 15 N-enrichment of leaves (0.29 atom % excess 15 N). Although petiole feeding resulted in more even relative enrichments among plant parts our results highlight the usefulness of leaf 15 N-feeding to estimate below-ground plant N and to trace the long-term fate of plant-derived N within the soil.

A dynamic model of regrowth in Typha angustifolia after cutting shoots above the water surface was formulated by characterizing the phenology and mobilization of resources from below-ground to above-ground organs after the cutting. The model parameters were determined by two cutting experiments to investigate the different strategies with flowering and non-flowering shoots after cutting in 2001 and by four cutting experiments to elucidate the regrowth characteristics after cutting on different days from June to September in 2002. A difference was evident both for flowering and non-flowering shoots and for each cutting day. From June to August, non-flowering shoots regrew immediately after cutting, but flowering shoots did not. The shoot regrowth height, number of leaves and shoot biomass were higher with the earlier cutting. The model was validated using the below-ground biomass observed in December 2002 and below-ground dynamics observed in 2003. In the low-flowering shoot zone of the stands, in which the percentage of flowering shoots was small (around 10%), the decrease in below-ground biomass became larger from June (20%) to August (60%). Cutting the high-flowering shoot zone (flowering shoots: 78%) in July 2001, just 1 week after peduncle formation, decreased the below-ground biomass by about 50%. In the low-flowering shoot zone, cutting just before senescence is better for decreasing below-ground biomass with a smaller rate of flowering shoots. The difference of below-ground biomass reduction in non-flowering shoots is mainly due to the decrease in downward translocation (DWT) of above-ground material to below-ground organs during senescence, because of the decrease in regrowth biomass. As for flowering shoots, the decrease in the photosynthate transportation from above-ground to below-ground organs and that of DWT are closely related because they cannot grow again within the season.

Synopsis The effect of the level of arbuscular mycorrhizal fungi (AMF) colonisation on the growth of Pterocarpus angolensis was studied. Mycorrhizal infected seedlings, showing either good or poor growth, under the same environmental conditions (temperature, humidity, light level) were analyzed for above and below ground biomass and Nand P concentration. The grouping was based on the number ofleaves and seedling size. All plants had AMF infection, with poor growth plants having a 7 5% infection and good growth plants 45%. The highly infected poor growth plants had fewer leaves, smaller total leaf area and total plant mass. The below ground plant component Nand P concentration of good growth plants was higher than in poor growth plants. There was however no difference inN and P concentrations of above ground components between the two groups. No nodules were recorded for good growth plants while plants in the poor growth group had nodules. There was no difference in the specific leaf mass and shoot:root ra...

ガマ, ヒメガマの各器官間のエネルギー輸送を考慮した生長モデルを作成した. モデルは, 群落中心部における地上部バイオマス, 地下部バイオマスの季節変化や, 湛水深に対する生長特性, 各器官の構成比, 地上部バイオマスと地下部バイオマスの比, により検証された. 老化期におけるバイオマスの変化を現地観測した結果, 穂付きの株と穂無しの株では, 器官の構成比の変化が大きく異なり, 栄養繁殖器官である地下茎の変化が全く対照的であることがわかった. 河川空間におけるガマ, ヒメガマ群落の拡大形態は, 植生地点の横断面形状や外力などの生育環境により大きく変化することが判明した.

This paper describes the results from a 4-year-old trial plantation of Bambusa vulgaris Schrad.ex.J.C.Wendl. grown in Goundampalayam area, Coimbatore, India. The growth, biomass accumulation and nutrient concentration were studied. The number of culms produced per clump varied from 28 to 46; their maximum length, and diameter at breast height (DBH) were 20 m and 3.5 cm respectively. The number of nodes per culm ranged between 20 to 34. The total biomass ranged from 277.3 t. DM ha−1 to 500.6 t. DM ha−1 with an average percent contribution of culms (66%), branches (26%) and leaves (3%). The ground biomass of rhizome contributed 5% to the total above and below ground biomass. The percent distribution of nutrients in different biomass components varied: The ordering of major element concentrations was K < N < Mg < Ca < P in branch, culm, rhizome but in leaves it was found to be N < K < Mg < Ca < P. The maximum amount of all nutrients was accumulated in the culms, followed by branches, rhizomes and le...

The present study aimed to compare the effect of various treatments on growth and biomass formation in Hedychium spicatum. The methodology consisted of the application of different organic substrates in five treatments of 100 seeds with three repetitions (T1: Pure Garden Soil (GS) (control), T2: Pure garden soil + Farmyard manure (FYM) (1: 1), T3: GS + Litter + FYM (2: 1: 1), T4: GS + FYM + Vermicompost (2: 1: 1), T5: GS + Litter + vermicompost (2: 1: 1). The variables recorded were Germination, and only was taken three Plants for Plant height, Number of leaves, leaf length, leaf width, above ground and below ground biomass. These data were analyzed with an anova (p

Annual (1990–91) mean values of total biomass of Thalassia testudinum (Banks ex Konig) at three stations in different environments in a Caribbean reef lagoon varied between 573 g dry wt m −2 (±167 SD) in a back-reef station, 774 g dry wt m −2 (±167 SD) in a coastal fringe and 811 g dry wt m −2 (±131 SD) in a mid-lagoon station. Corresponding ratios of mean above-ground to total plant biomass were 4.8% (±1.0 SD), 6.7% (±1.6 SD) and 8.6 (±2.0 SD) respectively. Production of above- and below-ground plant parts were calculated using the annual mean formation rates for leaves. The calculated annual mean total plant production (excluding root production) was 426, 1015 and 1116 g dry wt m −2 at the back-reef, coastal and mid-lagoon station respectively. Above-ground production accounted for 60.8%, 60.3% and 65.9% of the total production at these respective stations. Unimodal seasonal variations in blade length synchronized with earlier reported fluctuations in blade growth, whereas variations in number of blades per shoot reflected seasonal variations in blade initiation rates.

A 9-yr study was conducted on an alluvial clay loam at Swift Current, Saskatchewan to determine the effect of annual applications of urea-N (46-0-0) fertilizer on production, nutrient quality, N use efficiency, root mass, and root distribution of bromegrass (Bromus inermis Leyss.). Nitrogen was applied annually at the rates of 0, 50, 100, and 200 kg ha−1 N to an established stand of bromegrass. Plots were flood irrigated. Forage DM yields increased linearly with rate of N applied. In all years, the slope of the response was similar and averaged 24 kg DM kg−1 N. The average y-intercept value was 1794 kg DM ha−1. In years 1–4, the N concentration in the grass was depressed at low N rates but after 5 yr the N concentration increased at all N rates. Tissue [Formula: see text] levels over 100 ppm occurred at the 200 kg N rate after 3 yr. Applications of N reduced plant P in all years; the extent depended on N rate. Uptake of N increased with increasing N rate as did the apparent N recovery. Nitrogen rate had no effect on root mass or distribution. Root mass totalled 13 888 kg DM ha−1 to 105-cm depth. Approximately 36% of the root mass was in the top 7.5 cm, 11.9% in the 7.5- to 15-cm depth and 16.9% in the 15-to 30-cm depth. Estimates of the soil space occupied by roots indicate that they would occupy a large proportion of the available pore volume. It was concluded that producers growing bromegrass under irrigation on medium- to heavy-textured soils in southern Saskatchewan can consistently expect considerable increases in hay yield of good quality with N fertilizer at rates up to 200 kg N ha−1. While forage production increased linearly in response to N fertilization, root accumulation remained at a constant level. Further studies are needed to establish maximum yields and economic rates of N application. Key words: N rate, N recovery, roots, forage N, forage P

Revegetation is an important part of reclamation activities of mined land, partly due to potential CO2 absorption from theatmosphere, particularly through photosynthetic reactions. This research was aimed to calculate the amount of C absorbedby two major fast growing legume species in most reclaimed mined lands in Indonesia, mangium (Acacia mangium) andalbizia (Paraserianthes falcataria) at four years of age. Three tree samples of each species were destructively taken fromthe reclaimed mined land belong to PT Bukit Asam (PERSERO) Tbk, Tanjung Enim, South Sumatra to obtain plant biomassproduction of both above and below ground. The above ground plant biomass was separated into leaf, branches & twigs,and stem. All these components and the below ground biomass (roots) were then weighed for fresh weight determination.About 200 g of these tree components were dried in an oven at 70oC to obtain their dry weights, and then ground into 60mesh diameter for C analysis using wet destruction method of Walkley and Black. The results showed that up to the fourthyear, mangium sequestered C almost double of that sequestered by sengon stands, 21.66 and 10.35 kg C/tree respectively. Keywords: carbon sequestration, mangium, reclaimed lands, revegetation, sengon

Biomass partitioning by arid-zone dwarf shrubs between above- and below-ground fractions could be influenced by plant adaptations to herbivory. The response of potted Indigofera spinosa and I. cliffordiana to heavy and moderate top defoliations, compared to non-defoliated controls, was investigated. Relative growth rates of plants (Weeks 1–8), number of lateral shoots (Weeks 5–13), total number of leaves and leaf area (at Week 13), clipped biomass (CB) at Weeks 8 and 11 as well as residual biomass (RB), total above-ground biomass (TAGB) (i.e. the sums of CB and RB) and total root biomass (TRB) by treatments at Week 13 were greater in I. cliffordiana than in I. spinosa . Clipping reduced the shoot-root ratio (S:R) in I. cliffordiana but not in I. spinosa . For I. spinosa , plants defoliated at moderate intensities produced more root biomass (22.9%) than at heavy regimes (17.6%) or the controls (12.9%). In I. cliffordiana , below-ground biomass as a fraction of the combined biomass was less in control plants (16.5%), compared to moderate (18.2%) and heavy defoliation treatments (26.5%). The two dwarf shrub species compensated at different intensities for above- and below-ground biomass: I. spinosa at moderate defoliations and I. cliffordiana at heavy defoliations. Keywords: biomass allocation, compensatory growth, Indigofera cliffordiana, I. spinosa , shoot:root ratio African Journal of Range & Forage Science 2006, 23(3): 159–164

This study is part of a larger project aimed at quantifying the biomass and biomass increment of an experimental beech stand aged 30 years, and comparing the carbon sequestration in trees to carbon fluxes. The below ground part of trees is expected to play an important role in carbon sequestration. A method has been developed to estimate the biomass and biomass increment of coarse, small and fine roots of trees from root system excavations of sampled trees of different crown classes. The biomass and biomass increment of broken root ends during excavation was estimated from the diameter of the roots at the broken points. Equations were then established relating the biomass and biomass increment of the different root categories to tree DBH. These equations were then used to estimate the root biomass and biomass increment of the experimental stand from stem inventory, for the different root categories. Trees from dominant and codominant crown classes contribute for more than 80% to below ground biomass and biomass increment of the stand, Cette étude fait partie d'un projet plus vaste ayant pour objectif l'estimation de la biomasse aérienne et souterraine d'un peuplement expérimental de hêtre de 30 ans et de son accroissement, pour comparer la quantité de carbone séquestrée annuellement dans les arbres aux flux de carbone mesurés par les échanges gazeux. La partie souterraine des arbres paraît jouer un rôle important dans la séquestration du carbone. Une méthode a été développée pour estimer la biomasse et l'accroissement en biomasse des racines de différentes catégories de grosseur grâce à l'extraction du sol de systèmes racinaires d'un échantillon d'arbres représentatif des différentes classes de statut social du peuplement. La biomasse et l'accroissement en biomasse des parties de racines cassées lors de l'extraction du sol ont pu être estimés, pour chaque catégorie de racine, à partir du diamètre des racines au niveau de la cassure. Des relations ont ensuite été établies entre la biomasse racinaire et son accroissement, pour chaque catégorie de racines, et le diamètre de l'arbre à 1,30 m. Ces équations ont été utilisées pour estimer les biomasses au niveau du peuplement à partir de l'inventaire des arbres. Les arbres dominants et codominants du peuplement contribuent pour plus de 80 % à la biomasse souterraine du peuplement et à son accroissement

Little knowlegde is attributed to below ground growth of mature trees (Hardley and Smith 1987). Some work has been done to classify the distribution of the roots and to group adaptive processes caused by a long exposure to NaCl. the tree species into three main classes (horizontal root, tap root and heart root). Other studies were concerned with the length of the root branches and the calculation of below ground biomass. In this study, the root installation data were examined and whenever possible, related to age at the root/shoot interface. The root/shoot interface represents the zone between the roots and the trunk and gives the exact age of the trees (Telewski 1993).

In this contribution the results of the total herb layer biomass (above-ground + below-ground) of the natural and seminatural forest ecosystems in Slovakia are presented. The basic values, total biomass (W T ), above-ground biomass (W A ), below ground biomass (W R ) and their mutual ratio (R B =W A /W R ) are as follows (in t.ha -1 , dry weight): Oak forests W T 2.85, W A 1.38, W R 1.46, R B 1:1.06; Beech forests W T 0.47, W A 0.17, W R 0.30, R B 1:1.75; Mixed deciduous forests W T 1.20, W A 0.45, W R 0.75, R B 1:1.67; Mixed coniferous forests W T 1.83, W A 0.67, W R 1.16, R B 1.172; Coniferous forests W T 1.53, W A 0.40, W R 1.14, R B 1:2.91.

Total biomass increments were determined for three adjacent 22-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) plantations in the Oregon Coast Range that had widely different early growth rates. Estimated total aboveground biomass of the stands, designated slow, intermediate, and fast, was 98.7, 148.7, and 203.7 Mg•ha−1, respectively; estimated mean biomass increment in the 5 years previous to sampling was 8.9, 12.6, and 12.3 Mg•ha−1•year−1. The slow stand had a greater proportion of aboveground biomass in branches and a smaller proportion in stem wood than the intermediate and fast stands. Differences in biomass increment were primarily due to stem rather than crown growth. Total below ground biomass was highest in the fast stand, the difference being due to roots >5 mm in diameter; weight of roots 5 mm comprised about 77% of the total root system in those stands and 90% in the fast stand. Increment of roots >5 mm was 2.2, 2.5, and 3.0 Mg•ha−1•year−1 in the slow, intermediate, and fast stands. The ratio of productivity to total leaf nitrogen suggests that nitrogen is a principal limiting resource in the intermediate stand. The fast stand, with a leaf area index 50% greater than the others, is probably limited by light. The slow stand has anaerobic soils during at least part of the year, which may restrict rooting depth and thereby induce water stress during summer drought.

The distribution of tree biomass and the allocation of production was measured in four stands of lodgepole pine (Pinuscontorta var. latifolia Engelm.), two growing on sites with xeric soil moisture regimes and two on sites with mesic soil moisture regimes. At the time of sampling the stands were 70–78 years old. Aboveground biomass ranged from 116.5 Mg•ha−1 on one xeric site to 313.1 Mg•ha−1 on one mesic site. Stem biomass represented 68 and 73% of total tree biomass on the xeric and mesic sites, respectively. Total root biomass represented between 20 and 28% of total lodgepole pine biomass. Fine and small roots (−1•year−1 on the xeric sites to 11.9 Mg•ha−1•year−1 on the mesic sites. Stemwood production represented 20 and 27% of total net primary production on the xeric sites and 35% on both mesic sites. Belowground production represented 38 and 46% of total net primary production on the two mesic sites (4.5 and 5.5 Mg•ha−1•year−1, respectively) and 55 and 66% on the two xeric sites (4.3 and 6.3 Mg•ha−1•year−1, respectively). Fine and small roots represented 82–94% of belowground production. Production allocation was in the following order: fine and small roots > stems > foliage > coarse roots > branches, for all but the wettest site, where stem production exceeded fine and small root production.

Above and below ground biomass of Avicennia marina (Forsk.) Vierh. was studied in a mangrove community near Sydney, Australia. Data were obtained for seedlings (0–80 cm) and established trees (≥ 200 cm) growing in two nearby sites. Estimates were made of total mangrove biomass and its components: roots and pneumatophores; trunks and branches: leaves and petioles. The sites studied differed in average tree size (277 kg v. 97 kg) and in seedling biomass (0.12 km m-2 v. 0.02 kg m-2) but not in total biomass (29.2 kg m-2 v. 27.3 kg m-2). The partitioning of biomass of Avicennia marina in this temperate mangrove community was similar to that of Rhizophora mangle in a tropical mangrove community.

Excavation to a depth of 1 m of a 3 x 4 m portion of a clone of Quercus gambelii revealed the presence of a massive underground system of lignotubers, interconnecting rhizomes and roots. Lignotubers comprised the greatest proportion (72%) of the total below ground biomass (81 t/ha). Lignotubers are distinctive in appearance: they are an enlarged stemlike structure with numerous clusters of adventitious buds on the surface. Anatomically, they are comparable to the above ground stems with growth rings. Lignotubers are lobed and distorted, giving the appearance of a burl. Rhizomes are round to I-beam in shape with a star-shaped pith, distinct annual rings, bud traces, and branch gaps. There were also clusters of adventitious buds on rhizomes, although not as dense as those on the lignotubers. Roots are oval in cross section with discernible growth rings, no pith, and no bud traces. The lignotuber is the most important regenerative underground structure, but the rhizome appears to be the primary means of clone expansion.

Loblolly pine seedlings of five half-sib families were grown under ambient, subambient (approximately 0.6 × ambient), and elevated [ambient + 60 ppb O3 (120 μg m−3)] O3 levels for one growing season in open-topped chambers. Diameter and height of the seedlings were measured periodically over the growing season, and above ground and below ground biomass were determined at harvest. Significant genetic differences were found in above ground volume (D2H) 1 mo after 03 fumigation began and continued until harvest. Biomass of secondary needles and coarse and fine roots also differed significantly among families. Elevated O3 resulted in significantly decreased D2H and secondary needle biomass relative to seedlings grown in ambient air. Seedlings receiving subambient O3 levels were intermediate in size, but were not significantly different from seedlings fumigated at ambient O3 levels. Root and stem biomass did not differ significantly among treatments. A significant interaction of O3 and genotype was detected, suggesting that the response of loblolly pine to O3 is influenced by genotype.

With the continuing deposition of atmospheric nitrogen (N), N has become a major factor affecting ecosystem carbon (C) balance and N cycles. However, it is still unclear how increasing N deposition alters above- and below-ground biomass allocation, especially among different order roots. Pinus tabuliformis Carriere is an important native species in the Loess Plateau of China, as well as the preferred species for artificial afforestation in this area. One-year-old P. tabuliformis seedlings were treated with six different N concentrations (0, 0.02, 0.04, 0.08, 0.16, and 0.32 g N kg−1 soil year−1) for 3 years. Individual P. tabuliformis seedlings were separated into leaves, shoots, and roots in May 2011. Variations in leaf morphology, root characteristics, and their biomasses were investigated. (1) The highest N fertilizer level (0.32 g N kg−1 soil year−1) significantly decreased leaf area, root length, and specific root area. (2) Lower levels of N significantly reduced root length, root diameter, and specific root area in the first- and second-order roots. (3) Leaf biomass increased significantly in the higher N treatments (0.02–0.08 g N kg−1 soil year−1). However, total seedling biomass under the highest treatment decreased significantly due to excessive N. Biomass of the roots and leaves in the 0.04 g N kg−1 soil year−1 treatment increased compared with that in the control. (1) The lower-order roots (and leaves) were more sensitive than the higher-order roots (and stems) to N application. (2) The specific root area to specific leaf area ratio might be more suitable than area or biomass indices in explaining the utilisation of N by plants. (3) The functional balance hypothesis did not adequately explain the distribution of photosynthetic products among P. tabuliformis organs, but the source-sink relationship hypothesis did. This indicates that roots were the main sink and received a greater distribution of photosynthetic products.