Stem Biomass Production Research Articles

Effect of shoot-bending on productivity and economic value estimation of cut-flower roses grown in Coir and UC Mix

Shoot-bending, a common cultural practice in cut-flower rose production, results in a canopy consisting of horizontally bent shoots in addition to upright shoots. Production of this bent canopy was compared with hedgerow canopy for two rose cultivars, ‘Kardinal’ and ‘Fire N Ice’. In conjunction with the two canopy styles, two soil-less horticultural systems with different growing media (Coir versus UC Mix) were tested in a 2×2 factorial experiment. We investigated the number and length of all harvested flowering shoots as indicators of productivity and quality, respectively, from September 1997 to August 1999. While bent canopy produced longer stems and higher biomass of individual flowering shoots in both cultivars, this also resulted in significantly fewer harvestable flowering shoots. The comparison between Coir versus UC Mix was not as conclusive. ‘Fire N Ice’ plants grown in Coir produced more harvestable flowering shoots than plants grown in UC Mix, while ‘Kardinal’ did not. Neither cultivar showed differences in stem length and biomass production of the flowering shoots between Coir and UC Mix. Calculation of market value using a linearly increasing value index with stem length showed that with ‘Fire N Ice’ the improvement in stem length achieved by bent canopy did not offset the economic loss due to the reduction in the number of shoots per square meter. For ‘Kardinal’ the increased quality as a result of shoot-bending did offset the reduced production. In neither case did the combination of bent canopy and Coir generate significant improvements in value. Bent canopy became economically feasible when both short-stem discount and long-stem bonus were applied together.

Marsh Sensitivity to Burning of Applied Crude Oil

This research note summarizes Spartina alterniflora and Sagittaria lancifolia sensitivity to oiling and in situ burning of applied oil. Experimental plots (2.4 m × 2.4 m × 0.6 m) were constructed in salt and freshwater marsh habitats and South Louisiana Crude (SLC) applied (2 l m −2) to stems and leaves of marsh plants of oil and oil/burn treatment plots. Burning was initiated mid-August when winds were calm and a 15–25 cm floodwater layer covered the marsh substrate. Vegetative responses (stem density, height, carbon assimilation and biomass production) were measured for approximately one year following the in situ burns. Application of oil and burning of SLC only had short-term detrimental effects on salt and freshwater marsh vegetation. About one year after burns, vegetative responses measured in oiled and oiled/burned plots approached or exceeded control (no oil or burn) values. Field results suggest, under our experimental conditions, in situ burning of spilled oil in S. alterniflora and S. lancifolia marshes may be a remediation operation to consider.

Effect of organic amendments and slow-release nitrogen fertilizer on willow biomass production and soil chemical characteristics

Lime-stabilized sewage sludge and composted poultry manure, at a rate of 250 m 3 ha −1 each, and slow-release N fertilizer (Scott's Osmocote) at 100, 200 and 300 kg N ha −1 , were applied to plots of willow biomass crops during the first season of a three-year growth cycle. Stem biomass production was measured annually and soil chemical characteristics were assessed at the end of the growth cycle. Average annual stem biomass production was 8– 11 Mg ha −1 in slow-release N fertilized plots corresponding to a yield increase of 7–33% relative to control plots. In organically amended plots, annual stem biomass production increased by 30–38% relative to control plots. The study suggests that organically amended willows grew at a slightly faster rate than slow-release N fertilized willows. Statistically, the relationship between slow-release N application rate and stem biomass production was not highly significant; applications of slow-release N in excess of 100 kg N ha −1 provided no additional yield benefits. Differences in soil characteristics were most strongly expressed in surface soil. The pH at 0– 10 cm depth was 1 and 2 units higher on lime-stabilized sludge and composted poultry manure plots, respectively. Concentrations of soil K, P and Mg were dramatically higher in the composted poultry manure soils. The highest soil organic matter and N levels were observed in the surface horizons of organically amended soils. Utilization of organic residuals increases biomass production, provides beneficial use for wastes, reducing production costs and contributing to the sustainability of biomass production systems.

Biomass Partitioning and Growth Efficiency of Intensively Managed Pinus taeda and Pinus elliottii Stands of Different Planting Densities

Abstract The effect of planting density (740, 2,220, 3,700, and 4,440 trees/ha-1) on growth efficiency and biomass partitioning was examined in intensively managed stands of 4-yr-old loblolly (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.) stands on the Coastal Plain of southern Georgia. The primary objective of this study was to determine whether decreased partitioning of biomass to stem relative to other tree components limits stem biomass growth on a per hectare basis as stand density increases. Fourth growing season stem biomass production did not increase proportionally with planting density, indicating that stem biomass growth was limited at the higher stand densities. For both species, growth efficiency (stem biomass growth produced during the fourth growing season per unit of leaf biomass) was significantly lower for stands planted at 740 trees/ha-1 compared to the other stand densities. Similarly, the ratio of stem biomass growth: fine root biomass was significantly lower for the 740 trees/ha-1 stand. Within sites, planting density had no effect on the ratio of fine root biomass: leaf biomass for either species. Overall, these results indicate that partitioning to stem growth increased relative to foliage or fine roots as stand density increased. Therefore, the limitation in stem biomass growth on a per hectare basis that occurred as stand density increased was not due to changes in partitioning, but probably due to a limitation in net primary production. FOR. SCI. 47(2):224–234.

Potential of Salix as phytoextractor for Cd on moderately contaminated soils

Biomass production and Cd uptake in Salix (willow) is generally high. The aim of this study was to quantify the amounts of Cd in different plant and soil compartments in commercial Salix stands grown on different soil types and to use these data for estimation of the long-term effects of Cd removal by Salix at stem harvest on the soil Cd content by calculating Cd balances. Ten commercial short rotation willow coppice stands, planted with clone 78183 of Salix viminalis (L.) were investigated in order to include three different soil types with respect to pH. Stands with high stem biomass production generally had lower Cd concentrations in the plant and grew on more alkaline soils with low Cd availability when compared to stands with low stem biomass production. The highest output of Cd by Salix is therefore not necessarily achieved by stands with the highest yields or the highest Cd concentrations, as both these parameters have to be considered. The net removal of Cd from the plough layer by the Salix crop under different conditions varied between 2.6 and 16.5 g Cd ha−1 year−1. The long-term effects of Salix cultivation on soil Cd content, i.e. after 6–7 cutting cycles (25 years), were calculated and we reached the conclusion that there is a high potential in Salix to remove significant amounts of Cd at stem harvest. Salix can therefore presumably be used to counteract Cd pollution of agricultural soils in Sweden provided that the Cd in furnace ashes is taken care of.

Selection of Leucaena species for afforestation and amelioration of sodic soils

AbstractPerformance of three exotic species of Leucaena (L. diversifolia, L. shannonii and L. leucocephala) and one local selection of L. leucocephala was evaluated on sodic soil sites (pH 8.6–10.5) in order to select promising species for biomass production and reclamation of these soils. There were significant differences among three species with respect to their field survival (47.7–95.5 per cent), growth in terms of stem volume (40.8–118.6 m3 ha−1) and biomass production (24–70 Mg ha−1) after eight years of growth. L. leucocephala was rated as the most promising species irrespective of seed source, followed by L. shannonii. L. diversifolia could not perform well on these hostile soils. A definite improvement in physicochemical properties of soil particularly in surface layers (0–5 cm) was observed after eight years of plantations as compared to the same at uncultivated site. The soil pH and sodium content decreased followed by an increase in organic carbon, nitrogen and phosphorus content. However, efficiency of different species varied greatly to ameliorate these soils depending on quantity and quality of organic matter lying on the floor. L. leucocephala, irrespective of seed origin, showed greater promise for afforestation of sodic soils because of its potential to produce higher biomass per unit area and greater efficiency to ameliorate fertility status of these soils. The study revealed that matching of species to soil conditions is very important for a successful plantation programme and sustainable development of degraded soil sites. Copyright © 2002 John Wiley & Sons, Ltd.

Early performance ofCasuarina junghuhnianaprovenances/land races at Lushoto, Tanzania

Summary A trial involving 21 provenances form Indonesia and 7 “local” seed sources of Casuarina junghuhniana was established at Lushoto, Tanzania in March 1997. At 22 and 48 months of age, the following characteristics were assessed: survival, root collar diameter (RCD ), breast height diameter (DBH) and height. The following were only assessed at 48 months of age: stem volume, biomass production and foliar nitrogen (N) and phosphorus (P) nutrient concentration and content. At all assessment occasions except for height (22 months of age), Nand P concentration and P content ( 48 months of age), significant provenance/land race variation was observed for the rest of the characteristics studied. At 48 months of age, the four best performing seed sources were: Mt. Bromo, East Java; Mt. Pohen, Bali; KARl, Muguga, Kenya andMt. Brumo, EastJ ava while the four worst performing ones were: Kapan, Kumpang, Timor; 25 km S.W.Soe, Timor; Noelmina River, Timor and Buat, Soe, Timor. Although these results are based on ea...

Canonical rules for plant organ biomass partitioning and annual allocation

Here we review a general allometric model for the allometric relationships among standing leaf, stem, and root biomass (M(L), M(S), and M(R), respectively) and the exponents for the relationships among annual leaf, stem, and root biomass production or "growth rates" (G(L), G(S), and G(R), respectively). This model predicts that M(L) ∝ M(S)(3/4) ∝ M(R)(3/4) such that M(S) ∝ M(R) and that G(L) ∝ G(S) ∝ G(R). A large synoptic data set for standing plant organ biomass and organ biomass production spanning ten orders of magnitude in total plant body mass supports these predictions. Although the numerical values for the allometric "constants" governing these scaling relationships differ between angiosperms and conifers, across all species, standing leaf, stem, and root biomass, respectively, comprise 8%, 67%, and 25% of total plant biomass, whereas annual leaf, stem, and root biomass growth represent 30%, 57%, and 13% of total plant growth. Importantly, our analyses of large data sets confirm the existence of scaling exponents predicted by theory. These scaling "rules" emerge from simple biophysical mechanisms that hold across a remarkably broad spectrum of ecologically and phyletically divergent herbaceous and tree-sized monocot, dicot, and conifer species. As such, they are likely to extend into evolutionary history when tracheophytes with the stereotypical "leaf," "stem," and "root" body plan first appeared.

Elevated atmospheric CO2 alters wood production, wood quality and wood strength of Scots pine (Pinus sylvestris L) after three years of enrichment

AbstractScots pine (Pinus sylvestris L.) trees were grown in open top chambers for three years under ambient and elevated CO2 concentrations. The trees were aged 3 y at the beginning of the CO2 exposure, and the effects of the treatment on total stem volume, stem wood biomass, wood quality and wood anatomy were examined at the end of the exposure. The elevated CO2 treatment lead to a 49% and 38% increase in stem biomass and stem wood volume, respectively. However, no significant effects of the elevated CO2 treatment on wood density were observed, neither when green wood density was estimated from stem biomass and stem volume, nor when oven‐dry wood density was measured on small wood samples. Under elevated CO2 significantly wider growth rings were observed. The effect of elevated CO2 on growth ring width was primarily the result of an increase in earlywood width. Wood compression strength decreased under elevated CO2 conditions, which could be explained by significantly larger tracheids and the increased earlywood band, that has thinner walls and larger cavities. A significant decrease of the number of resin canals in the third growth ring was observed under the elevated treatment; this might indicate that trees produced and contained less resin, which has implications for disease and pest resistance. So, although wood volume yield in Scots pine increased significantly with elevated CO2 after three years of treatment, wood density remained unchanged, while wood strength decreased. Whilst wood volume and stem biomass production may increase in this major boreal forest tree species, wood quality and resin production might decrease under future elevated CO2 conditions.

Use of wastewater as a nutrient solution in a closed gravel hydroponic culture of giant reed ( Arundo donax)

The objective of this experimental work was to examine the efficiency of giant reed ( Arundo donax L.), as a source of biomass production and as a biofiltering device for sewage effluents. Two giant reed populations were cultivated in a closed gravel hydroponic system, where pig's waste was used as a nutrient solution. The results showed that stem biomass production varied from 12 to 23 kg DM m −2 yr −1 , more than the ordinary production in the soil. According to stem analysis, for the first two years, there was an average infiltration rate of 31 g m −2 yr −1 total N, 7.5 g m −2 yr −1 total P, 18.8 g m −2 yr −1 K, 2.1 g m −2 yr −1 Ca, 2.1 g m −2 yr −1 Mg, 0.27 g m −2 yr −1 Fe, 0.02 g m −2 yr −1 Mn, 0.14 g m −2 yr −1 Zn and 0.08 g m −2 yr −1 Cu. During the third year, when a nutrient solution with added P was used, the average infiltration rate for most elements increased by 46% and for P by 169%.

Carbon and water fluxes in Beech–Spruce model ecosystems in response to long‐term exposure to atmospheric CO2 enrichment and increased nitrogen deposition

1. We present data on the gas exchange of 32 Beech–Spruce model ecosystems including understorey species, which were planted on acidic or calcareous soil in 16 (half‐split) open‐top chambers in 1994 and were continuously exposed to the combinations of two CO2 concentrations and two wet nitrogen deposition rates for 3 years. 2. Instantaneous mid‐season net ecosystem carbon‐exchange rates (NEC) were determined during the day (11.00–16.00 h, NECd) and at night (22.00–02.00 h, NECn) with a mobile chamber in July 1996 and August 1997 for both soil types and, in addition, in August and September 1996 on acidic soil only. 3. Elevated CO2 increased NECd at all sampling dates on both soil types and under both N deposition rates. Increased nitrogen deposition stimulated NECd on acidic soil but not on calcareous soil, irrespective of the CO2 level. NECn was increased in elevated CO2 on both soil types (but more on the calcareous soil), but did not respond to increased nitrogen deposition in both years. The daytime instantaneous ecosystem evapotranspiration (ETd) was not significantly affected by the CO2 and nitrogen treatments at any sampling date. Year to year differences in NECn and ETd were small, but a doubling in NECd occurred throughout the observation period. 4. Elevated CO2 caused a small but significant increase in stem dry mass on calcareous soil only and increased nitrogen deposition stimulated stem biomass production on acidic soil only. Leaf area index was not affected by CO2, but was increased under high nitrogen deposition. 5. Our results suggest that nitrogen deposition and soil type are major co‐determinants of the carbon balance of forests in a future CO2‐rich world.

Utilization of sewage sludge in short-rotation energy forestry: a pilot study

Dewatered and non-dewatered sewage sludge from a secondary treatment plant was applied to plots planted with three Salix (willow) clones according to the Swedish short-rotation forestry concept. Stem biomass production was enhanced by the sludge application rate, which vaned between 2.5 and 20 t DS/ha/yr. Sludge metals in general accumulated in the soil within the layer in which the sludge was applied, whereas metal transportation below this point was less pronounced. Concentrations of nutrients and metals in plant tissues were not influenced by the sludge application rates, but decreased in general with stem and stand age. Improved sewage sludge quality in recent years is contributing to the possibilities of designing sustainable systems for sludge use on productive land—for instance, in short-rotation forestry for biofuel production.

Utilization of sewage sludge in short-rotation energy forestry: a pilot study

Dewatered and non-dewatered sewage sludge from a secondary treatment plant was applied to plots planted with three Salix (willow) clones according to the Swedish short-rotation forestry concept. Stem biomass production was enhanced by the sludge application rate, which varied between 2.5 and 20 t DS/ha/yr. Sludge metals in general accumulated in the soil within the layer in which the sludge was applied, whereas metal transportation below this point was less pronounced. Concentrations of nutrients and metals in plant tissues were not influenced by the sludge application rates, but decreased in general with stem and stand age. Improved sewage sludge quality in recent years is contributing to the possibilities of designing sustainable systems for sludge use on productive land—for instance, in short-rotation forestry for biofuel production.

Morphological adjustments of mature Quercus ilex trees to elevated CO 2

It is still not known whether mature forest trees respond to increasing atmospheric CO 2 concentrations in similar ways as seedlings do. Mature Mediterranean oaks ( Quercus ilex) growing in a CO 2 enriched atmosphere around natural CO 2 vents since the seedling stage showed a moderate, agedependent increase in stem biomass production, but had significantly lower biomass of 6-year-old branches, decreased branching, and lower leaf area per unit branch biomass, compared to control trees at a nearby unenriched site. Our data indicate that trees in natural forest stands morphologically adjust to increasing CO 2 and reduce CO 2-induced initial growth stimulations. Allometric adjustments such as reduction in leaf area may be regarded as a “down-regulation” of canopy photosynthesis and may be an effective mechanism for saving water.

The effect of papermill wastewater irrigation and gypsum soil amendments on sodium accumulation by cottonwood and soil

Gypsum soil amendments affected the concentrations of sodium in the stems and leaves of Populus seedlings irrigated with pulpmill effluent. Concentrations of sodium in the sapling tissues increased with gypsum applications which gave total calcium application rates of 175 mg Cal −1 wastewater (ww) and decreased as calcium application rates were increased to 625 mg Cal −1 ww. Conversely, stem biomass production decreased as calcium application rates increased to 175 mg Cal −1 ww and then increased as calcium application increased to 625 mg Cal t1̄ ww. This resulted in no significant differences across treatment in either total sodium uptake or removal of sodium from the soil by the Populus seedlings. Total sodium uptake by Populus was about 0.002% of wastewater inputs. Infiltration rate increased with the increasing gypsum application. Gypsum application rate was not associated with differences in the concentration and distribution of sodium in the soil profile but increased application rates were associated with decreased soil pH.

The effect of papermill wastewater and organic amendments of sodium accumulation by potted cottonwoods

In this experiment, the impacts of pulp mill effluent irrigation, Fraser cottonwood ( Populus deltoides ‘Fraser’) seedlings, and pulp sludge and manure soil amendments on sodium accumulation and distribution in the soil profile were evaluated during a 6 month greenhouse study. Sludge soil amendments and wastewater irrigation did not reduce stem biomass production of the cottonwood. Increased stem biomass production associated with manure soil amendments resulted in greater total uptake of sodium into stem material. This uptake was 0.002% of wastewater sodium inputs. In containers with seedlings, sodium concentrations were less in the surface horizon and more in the lower horizons than in containers with no seedlings. Infiltration rates and total sodium accumulation in the soil profile were not affected by the presence of Fraser cottonwood or the application of sludge or manure amendments to soil.

Establishment, Resource Acquisition, and Early Productivity as Determined by Biomass Allocation Patterns of Three Tropical Tree Species

Abstract Speed of stand establishment and rate of stem biomass production after canopy closure are two important criteria in the selection of species in the expanding field of tropical reforestation. How biomass allocation patterns determine establishment and stem production was studied in 0 to 2-yr-old plantations of Cedrela odorata, Cordia alliodora, and Hyeronima alchorneoides on fertile soil in the humid Atlantic lowlands of Costa Rica. The species were evaluated by: (1) their allocation of biomass to leaves and fine roots; (2) the resource-capturing capacity of the stands as expressed in leaf area, cover, fine-root length, and root distribution; and (3) biomass accrual and aboveground productivity. All species grew very fast: average stand heights at 2 yr ranged from 4 to 6 m, and some individuals were >12 m tall. Canopy closure and root-system overlap were fastest in Cordia, occurring within a year after planting. Cordia's rapid stand closure was achieved by its higher specific leaf area and specific root length, plus an architecture that distributed leaves and fine roots more widely. Maximum aboveground net primary productivities after canopy closure were 7.3, 4.9, and 3.3 g m-2d-1 for Hyeronima, Cordia, and Cedrela stands, respectively. High productivity of Hyeronima correlated with development of a high LAI coupled with a low leaf turnover rate. Cordia and Cedrela, on the other hand, had higher rates of leaf turnover, so a higher rate of leaf production was required to maintain a given leaf area; this, in turn, limited biomass allocation to production of stem biomass. Cedrela productivity was severely reduced by attacks of the stem-borer Hypsipyla grandella. Biomass allocation patterns that promoted rapid establishment of a tree stand, such as broad crowns, high specific leaf area, and high specific root length, did not lead to the highest levels of stem biomass production after canopy closure. Once stand closure is achieved, species having low rates of leaf turnover, high leaf area indices, and high density of fine roots are likely to be most productive. Fast-growing tropical tree species should be evaluated not just on initial growth but also on the stem production attained after stand closure. For. Sci. 41(4):689-708.

Nitrogen fertilization strategies in a short-rotation sycamore plantation

This study evaluates the effect of different nitrogen fertilization regimes in an American sycamore ( Platanus occidentalis L.) plantation on tree growth, fertilizer recovery by the trees, and nitrate leaching from the soil with the objective of determining the optimum application regime. A total of 450 kg N ha −1 was added as urea over a 3 year period at the following rates: a single dose shortly after planting (O1); 150 kg N ha −1 applied once every year (AE); applications of 50 kg N ha −1 three times per year (P); annual doses that increased with tree growth (AB: 50, 150, and 250 kg N ha −1). Aboveground biomass production, N accumulation in biomass, and soil solution chemistry were measured between 1989 and 1992 in three replicate plots per treatment and compared with those in unfertilized control plots. The O1 fertilization was inefficient because growth benefits were short-lived and were associated with excessive NO 3 leaching losses in the first year. Multiple fertilizer applications generally resulted in better growth, while soil solution NO 3 levels depended on the actual rate and frequency of fertilization. Nitrate leaching was greatest in the AE plots. The AB treatment, in which annual N additions increased commensurate with tree size, was optimum in terms of enhancing stem biomass production and reducing potential groundwater contamination. The reduction in fertilizer use efficiency and the increase in NO 3 leaching in the third year indicate that the input of 250 kg N ha −1 exceeded tree N retention capacity and should have been reduced to approximately one-half that rate. Increasing the frequency of fertilization from once per year to three times per growing season also decreased NO 3 leaching losses (i.e. improved N recovery) without measurable benefits to biomass production, and may therefore not be cost-effective in commercial operations.

UV‐B response of cucumber seedlings grown under metal halide and high pressure sodium/deluxe lamps

UV‐B‐sensitive (Poinsett) and ‐insensitive (Ashley) cultivars of cucumber (Cucumis sativus L.) were grown in growth chambers at 600 μmol m−2s−1 of photosynthetically active radiation provided by metal halide (MH) or high pressure sodium/deluxe (HPS/DX) lamps. Plants were irradiated 15 days from seeding for 6 h per day under 18. 2 kJ m−2 day−1 of biologically effective UV‐B (UV‐BBE) radiation. One of the most pronounced effects of UV‐B was a 27 to 78% increase in phenylalanine ammonialyase (PAL) activity. UV‐B also increased total polyamines. Catalase and superoxide dismutase varied greatly in their response to UV‐B. There were no interactive effects on PAL or catalase activity, or total polyamines. There was a UV × PAR source interaction for superoxide dismutase activity. UV‐B increased chlorosis and decreased height, dry weight and leaf area. Stem elongation, biomass production, leaf enlargement and chlorosis were greater under HPS/DX lamps than under MH lamps. Chlorosis was greater in Poinsett than in Ashley and in lower leaves than in upper ones. Aside from chlorosis, there were no interactive effects of UV‐B, PAR source or cultivar on any of the growth parameters measured, suggesting that the growth response of cucumber seedlings to UV‐B is unaffected by PAR source or cultivar. Similarly, except for SOD activity, the biochemical response to UV‐B was also not influenced by PAR source or cultivar.

Responses of two hybrid Populus clones to flooding, drought, and nitrogen availability. I. Morphology and growth

Repeated progressive drought and flooding stress were imposed on hybrid poplar clones Populus × euramericana 'Eugenei', and Populus tristis × Populus balsamifera ‘Tristis’ grown in pots in a greenhouse under two nitrogen levels. In both clones the rate of leaf initiation was promoted only in high-N plants subjected to minimum water stress. Water stress alone did not retard the rate of leaf initiation, but it significantly reduced leaf expansion of 'Eugenei', whereas only flooding led to smaller leaves in 'Tristis'. The addition of N stimulated leaf expansion, leaf chlorophyll and N concentrations, and leaf and stem biomass production across soil moisture levels, but the greatest effect of N was associated with minimum water stress. High N altered carbon allocation towards the aboveground portions, leading to lower root to shoot ratios. High N also appeared to stimulate initiation of fine roots. Soil moisture determined the amount of biomass that accumulated in roots, with highest root production in well-watered pots and lowest in flooded pots, with the droughted treatment in between. Leaves became thinner as soil moisture decreased from flooding. Stem biomass of 'Tristis' declined more under flooding than under drought, whereas 'Eugenei' displayed a greater reduction of stem biomass in droughty than in flooded soil. Key words: water stress, nitrogen, leaf and root morphology, root to shoot ratio, biomass, Populus, flooding.