Short Rotation Research Articles

Improving Acacia smallholder plantation value chains in Thừa Thien Huế cooperative alliance, Vietnam

Acacia plantations in Vietnam have an important role in supplying the wood processing industry and generating income for small-scale forest owners. However, it is proving difficult to improve their incomes and reduce the vulnerabilities inherent to current production systems. To address this situation, a quantitative and qualitative value chain analysis was undertaken to understand the products and profits from small-scale Acacia plantations in Thừa Thiên Huế province in Vietnam. The results show that Acacia plantations are profitable, require low levels of inputs and have a short minimum rotation time of five years. Harvesting and transport costs account for a large proportion of total production costs. Traders play an important role in linking producers and processors. Most of the pro- ducts traded are Acacia logs for chipping and processing into other products and for saw-wood to produce timber for carpentry and domestic uses. Acacia logs with larger diameters of over 15 cm have a higher added value for wood processing companies producing furniture for export. Vulnerabilities include the highly fragmented value chain with little coordination and few information exchange mechanisms, and differences between ethnic groups that suggest a need for culturally sensitive intervention on value chains. Different options to increase profits – particularly for smallholder plantation owners – include product diversification, chain integration, and increased production to achieve efficiencies of scale.

Ascomycota and Basidiomycota fungal phyla as indicators of land use efficiency for soil organic carbon accrual with woody plantations

As soil fungi are major players in the carbon accumulation process, the two main fungal degraders in topsoil, Ascomycetes and Basidiomycetes, were investigated as indicators of land use effectiveness in increasing soil carbon accumulation and soil function. The study focused on the soil organic carbon content increase in a 20-year short rotation forest cycle with broadleaf woody plantations compared to a nearby arable cropping system. Total fungi, Ascomycota and Basidiomycota, were quantified in terms of DNA copy number, with specific probes using SYBR® Green I dye on the QuantStudio™ 3D digital PCR system (dPCR). Previously, next generation sequencing analysis using a general primer confirmed that Ascomycota and Basidiomycota were the most represented phyla and that fungal community composition significantly differed between treatments. A range of key soil enzyme activities for the C-cycle were also assessed. Total organic carbon content (TOC), microbial biomass in term of dsDNA and enzyme activities significantly increased in woody plantations compared to arable soil. The TOC increase differed significantly also between wood species, Salix and Robina gave the greatest increase (+30 and 20 % respectively), followed by Populus (+12), microbial biomass highly correlated with TOC showing the same trend. Total fungi, Ascomycota and Basidiomycota increased significantly in three woody plantations compared to the arable soil system. Ascomycota in the woody plantations increased two to four times (average 3144 n copies µl−1 of DNA) compared to the arable soil (1419 n copies µl−1); Basidiomycota were almost absent in arable soil (av. 94n copies µl−1) and increased five to six times in woody plantations (av. 490 n copies µl−1). Total fungi and ascomycetes correlated strongly with microbial biomass and TOC, whereas basidiomycetes did not. These findings showed that Ascomycota represent the largest portion of fungi in agricultural soils even after a 20-years short rotation forest cycle and they can be taken as indicators of carbon accumulation processes. Therefore, this study suggests that joining the Ascomycetes quantity in the topsoil to the Ascomycota:Basidiomycota ratio seems a good option when setting regional strategies for improving C accrual in farmland with the short-term afforestation.

Evaluating the impacts of SRC willows on phosphorus export from a temperate grassland micro-catchment

Willows (Salix SPP.) are increasingly being grown as a source of biomass which can be harnessed for energy production at a commercial scale as one example of a Short Rotation Coppice (SRC) crop. What is less widely understood is the role of the plants in reducing nutrient loads when planted as a nature-based solution to mitigate diffuse pollution from agricultural lands. Strategically planted woodland and forest can play a major role in Nature Based Solutions (NBS) approaches. SRC willows were planted in a 22-ha grassland micro-catchment located on a research farm in Northern Ireland, which is regularly grazed by cattle and sheep. The micro-catchment comprises a small ditch with upstream and downstream monitoring points where a pair of autosamplers were used to collect water samples for nutrient analysis. It was possible to reconstruct a timeseries of hourly discharge in the ungauged micro-catchment using the SHETRAN hydrological model. Subsequently, the modelled flows were used to estimate daily phosphorus (P) loads at both upstream and downstream monitoring points from the measured P concentrations. The nearly four years (June 2018–April 2022) of monitoring data allowed P loads to be calculated for pre-planting, juvenile trees and mature trees phases. A baseline scenario was run without any changes to the model; this evaluated the changes in P loads from the catchment. A further Post-Willows scenario “P–W” modified some model parameters and evapotranspiration to represent the land use change due to the willow plantation. The results from the baseline were evaluated and showed that (i) there was a statistically significant reduction in particulate P (PP) and total P (TP) concentrations at the outlet of the micro-catchment; (ii) a statistically significant reduction in PP and TP loads, indicating that the willows were reducing PP export (losses) probably by trapping fine sediment in the ditch. Results from the P–W scenario showed a smaller than expected decrease in discharge from the model results. The overall export of TP from the micro-catchment could be further decreased by additional planting of SRC willows, but the export of soluble forms of P did not decrease by a significant amount post-planting which is a recommendation for further study in mitigation programmes. The use of SRC willows in riparian buffer strips (RBS) which are a common form of NBS, has shown promising results in terms of trapping particulate forms of P. The layout of the RBS should also be carefully designed in terms of maximising the buffer strip width, here the areas planted was optimised to make best use of unproductive farmland. If the RBS can be designed to maximise the interception of runoff flowing downhill from agricultural fields then the removal rate should be even higher.

Design, implementation, and evaluation of a short rotation coppice system for wastewater treatment and resource recovery in India

Despite growing health concerns and increasing water scarcity, adequate wastewater treatment and reuse remains limited in India. Low-cost, decentralised, and nature-based on-site sanitation systems could play a key role in a circular water approach. This paper evaluates the performance of a Wastewater Fertigated Short Rotation Coppice (wfSRC) system based on willow, poplar, and bamboo species as a potential solution, offering low-cost, efficient water treatment, and high biomass production. Through a full-scale wfSRC pilot plant (250 m3·day−1 municipal wastewater on 6864 m2) established at Aligarh Muslim University, Uttar Pradesh, India, treatment capacities, biomass production rates, and contamination tolerance of different willow, poplar, and bamboo species were investigated. The chemical compositions of incoming wastewater, percolation water, soil, and biomass were monitored regularly. Despite the high load, all plant sections of the wfSRC system showed efficient removal of wastewater-originated pollutants. BOD5 and COD removal efficiencies were up to 99% and 95% respectively. Removal efficiencies for PO4-P reached 93% and for TN 91%. In general, total nitrogen and phosphate loads appear to be the limiting design parameters under the conditions at Aligarh to meet all discharge limits in India. Biomass production was projected to be >225 tDM·ha−1·yr−1 for bamboo, 65 tDM·ha−1·yr−1 for willow, and 206 tDM·ha−1·yr−1 for poplar. The pilot, conducted from March 2022 to June 2023, showcased how these densely planted agroforestry systems can effectively treat wastewater through natural processes such as oxidation, microbial degradation, and plant uptake. The findings demonstrate wfSRC's potential to serve as a nature-based, sustainable approach to wastewater treatment, particularly beneficial for suburban and rural areas in India and similar regions worldwide. This paper also provides recommendations for future implementation of wfSRC systems, emphasizing the need for careful planning regarding plant selection, system design, and operational strategies to maximize treatment efficiency and biomass production.

Modeling wood product carbon flows in southern us pine plantations: implications for carbon storage

BackgroundWood products continue to store carbon sequestered in forests after harvest and therefore play an important role in the total carbon storage associated with the forest sector. Trade-offs between carbon sequestration/storage in wood product pools and managed forest systems exist, and in order for forest sector carbon modeling to be meaningful, it must link wood product carbon with the specific forest system from which the products originate and have the ability to incorporate in situ and ex situ carbon synchronously over time.ResultsThis study uses elements of a life cycle assessment approach, tracing carbon from US southern pine timber harvests to emission, to create a decision support tool that practitioners can use to inform policy design around land- and bioproduct-based mitigation strategies. We estimate that wood products from annual loblolly and shortleaf pine timber harvests across the southern US store 29.7 MtC in the year they enter the market, and 11.4 MtC remain stored after 120 years. We estimate fossil fuel emissions from the procurement, transportation, and manufacturing of these wood products to be 43.3 MtCO2e year−1. We found that composite logs, used to manufacture oriented strand board (OSB), were the most efficient log type for storing carbon, storing around 1.8 times as much carbon as saw logs per tonne of log over 120 years.ConclusionsResults from our analysis suggest that adjusting rotation length based on individual site productivity, reducing methane emissions from landfills, and extending the storage of carbon in key products, such as corrugated boxes, through longer lifespans, higher recycling rates, and less landfill decomposition could result in significant carbon gains. Our results also highlight the benefits of high site productivity to store more carbon in both in situ and ex situ pools and suggest that shorter rotations could be used to optimize carbon storage on sites when productivity is high.

Historical Dynamic Mapping of Eucalyptus Plantations in Guangxi during 1990–2019 Based on Sliding-Time-Window Change Detection Using Dense Landsat Time-Series Data

Eucalyptus plantations are expanding rapidly in southern China owing to their short rotation periods and high wood yields. Determining the plantation dynamics of eucalyptus plantations facilitates accurate operational planning, maximizes benefits, and allows the scientific management and sustainable development of eucalyptus plantations. This study proposes a sliding-time-window change detection (STWCD) approach for the holistic characterization and analysis of eucalyptus plantation dynamics between 1990 and 2019 through dense Landsat time-series data. To achieve this, pre-processing was first conducted to obtain high-quality reflectance data and the monthly composite maximum normalized-difference vegetation index (NDVI) time series was determined for each Landsat pixel. Second, a sliding time window was used to segment the time series and obtain the NDVI change characteristics of the subsequent segments, and a sliding time window-based LandTrendr change detection algorithm was applied to detect the crucial growth or harvesting phases of the eucalyptus plantations. Third, pattern-matching technology was adopted based on the change detection results to determine the characteristics of the eucalyptus planting dynamics. Finally, we identified the management history of the eucalyptus plantations, including planting times, generations, and rotation cycles. The overall accuracy of eucalyptus identification was 90.08%, and the planting years of the validation samples and the planting years estimated by our algorithm revealed an apparent correlation of R2 = 0.98. The results showed that successive generations were mainly first- and second-generations, accounting for 75.79% and 19.83% of the total eucalyptus area, respectively. The rotation cycles of the eucalyptus plantations were predominantly in the range of 4–8 years. This study provides an effective approach for identifying eucalyptus plantation dynamics that can be applied to other short-rotation plantations.

Organic Amendments to Short Rotation Coppice (SRC) Plantation Affect Species Richness and Metal Accumulation of Spontaneously Growing Herbaceous Plants

Excess potentially toxic metals (PTMs) in soils require ad hoc approaches to salvage. Hence, this study explored the shoot accumulation of cadmium (Cd), lead (Pb), and zinc (Zn) by herbaceous plants growing under previously established Salix and Populus clones Short Rotation Coppice (SRC) with compost and sewage sludge applications in an abandoned metallurgical site, Podlesí, Czech Republic; PTM decontamination of soils. Soils within the SRC experimental site and outside considered as control were analyzed for their chemical properties by multi-analytical techniques. Shoots of spontaneously growing herbaceous plants under trees in the site and without trees in control were determined for pseudo-total Cd, Pb, and Zn contents. Moderately to slightly acid soils, high cation exchange capacity, and C/N ratio supported mineralization and relative mobility of total Cd (7.7–9.76), Pb (1541–1929), and Zn (245–320 mg kg−1) in soils. Although soil amendments improved chemical properties, compost application supported higher species richness than sewage sludge. Over 95% of plants accumulated Cd and Zn above the WHO threshold and green fodder in the Czech Republic, with 36% Pb above the regional limit (40 mg kg−1). Approximately 100, 50, and 6% of herbaceous species had Cd, Pb, and Zn accumulation, respectively, higher than published average upper limits in plants (0.2 Cd, 10 Pb, and 150 Zn mg kg−1). Dicots recorded higher Cd content, Tenacetum vulgare (L.), Hypericum maculatum (Crantz), and Cirsium arvense (L.); Stachys palustris (L.), Lamium perpereum (L.), and Campanula patula (L.) for Pb; Glechoma hederaceae (L.), C. patula, and C. arvense for Zn in all treatments. Appropriate soil amelioration of SRC-supported PTM mobility and excess herbaceous species shoot accumulation, growth, and richness.

Effect of no-till followed by crop diversification on the soil microbiome in a boreal short cereal rotation

Diversification of agricultural practices, including changes in crop rotation, intercropping or cover cropping, influence the soil microbiome. Here the impact of tillage and crop diversification on the soil microbiome is reported, being one of the few boreal studies. The field experiment consisted of four treatments with four replications all having a short cereal rotation practice namely an oat (Avena sativa) – spring barley (Hordeum vulgare) – wheat (Triticum aestivum) rotation for the past 10 years until spring 2018. During that period two of the treatments were conventionally tilled with moldboard ploughing whereas the other two were no-tillage treatments. From the growing season 2018 until fall 2020 the main crop in all treatments was spring barley. The first conventional tillage treatment was diversified with English ryegrass (Lolium perenne) as an undersown cover crop for the next three growing seasons. The first no-tillage treatment continued with spring barley only. The second conventional tillage and no-tillage treatment had winter rapeseed in rotation in 2019. Bulk soils were sampled in May 2018 before diversification and then in October 2018, 2019, and 2020. The results showed a clear effect of tillage on the beta-diversity of the soil microbiome and an increase in fungal richness. Barley monoculture interrupted with winter rapeseed resulted in a minor change of the fungal and bacterial community composition. Other fungal and bacterial alpha diversity measures did not react to tillage or diversification nor did the gene copy abundances involved in the N cycle. In conclusion tillage had a profound effect on the soil microbiome hindering impact of the diversification.

Early Dynamics of Carbon Accumulation as Influenced by Spacing of a Populus deltoides Planting

The fast-growing tree, eastern cottonwood (Populus deltoides), currently is being planted to catalyze native forest restoration on degraded agricultural sites in the southeastern United States. Many of these restoration sites are appropriate for short rotation woody crop (SRWC) culture that addresses climate mitigation objectives, but information needed to optimize climate mitigation objectives through such plantings is limited. Therefore, we established a 10-year experiment on degraded agricultural land located in the Mississippi Alluvial Valley, USA, aiming to quantify the dynamics of aboveground carbon (AGC) accumulation in a cottonwood planting of four replicated spacing levels (3.7 × 3.7 m, 2.7 × 1.8 m, 2.1 × 0.8 m, and (0.8 + 1.8) × 0.8 m) aligned with SRWC systems targeting various ecosystem services. Annual sampling revealed a substantial range in increments of AGC and year 10 carbon stocks among stands of different densities. Mean annual increments for AGC (MAIAGC) were similar for the two tightest spacing levels, peaking higher than for the other two spacings at about 7.5 Mg ha−1 y−1 in year 7. Year 10 AGC ranged between 22.3 Mg ha−1 for stands spaced 3.7 × 3.7 m and 70.1 Mg ha−1 for stands of the two tightest spacings, leading us to conclude that a spacing between 2.1 × 0.8 m and 2.7 × 1.8 m would maximize aboveground carbon stocks through year 10 on sites of similar agricultural degradation. Increments and accumulation of AGC on the degraded site trended lower than values reported from more productive sites but illustrate that quick and substantial transformation of the carbon stock status of degraded agricultural sites can be achieved with the application of SRWCs to restore forests for climate mitigation and other compatible ecosystem services.

Torrefaction of Portuguese woody biomasses and the evaluation of its properties

Torrefaction is an option for improving biomass properties for fuel application. Biomass undergoes chemical changes reflected on the upgrading of its properties as a biofuel, such as higher calorific power, lower O/C and H/C ratios, lower higroscopicity or better grindability. The objectives of this experimental study were to analyze the effects of torrefaction, under standard conditions of 265 ºC, and residence time of 15 minutes in a nitrogen atmosphere and during a total 1h45m heating period, on a set of sixteen woody biomasses coming from poplar short rotation coppice (SRC) and other Portuguese roundwoods. Average mass loss was higher than 40%. The set of poplar clones and common broom provided torrefied products with higher quality than the set of roundwood forest species. The results on other parameters for proximate and ultimate analysis corroborate this global picture. Correlation analysis showed a higher degree of interconnectedness between LHV and proximate analysis results, for poplar clones and common broom, comparatively with roundwood biomasses.

Growing Eucalypt Outside its Native Range: A Review on Suitability and Beneficial Role

Eucalypt is an industrial short rotation fast growing tree species (SRFGTs), having wide range regarding climatic and edaphic requirements in Indian subcontinent. Eucalyptus camaeldulensis, E. globulus, E. grandis, E. tereticornis and E. citriodora are the widely planted eucalyptus species for different purposes in the country. Oil extracted from E. globulus has medicinal value and used to inhibit the avian influenza virus H11N9, and has wide scope in cosmetics, perfume, food, beverages, phytotherapy and aromatherapy. Oil contain p-coumaric, gallic, gentisic, p-hydroxybenzoic, syringic and vanillic acids and catechol are the responsible for retarding seed germination growth and survival of Parthenium, Solanum lycopersicum, Lactuca sativa and Agrostis stolonifera. Burning of eucalypt leaves used as mosquito repellent and compound 1, 8 cineole of eucalypt oil damage and kills Pediculus humanus capitis and lice. Aqueous solutions extracted from different parts of eucalypt showed nematocidal properties. Maize, wheat, mustard, berseem, potato, lentil are agricultural crops widely grown under eucalypt based agroforestry systems. Wider spacing of eucalypt in block plantations or boundary plantation mostly adopted in the agroforestry systems. Eucalypt sequester carbon 6 – 43 Mg C ha-1 yr-1 under plantations and agroforestry systems. The species has potential to reclaim waterlogged sites and escalate soil health through improving soil physical, chemical and biological properties. In case of economic returns from eucalypt based agroforestry systems, it gives nearly 1.5 B:C ratio.

Control of weeds and sunflower broomrape (Orobanche cumana Wallr) in sunflower crops by crop rotation and tillage

ABSTRACT Agricultural production can be raised sustainably by a scientifically based crop structure. We determine the influence of the saturation of crop rotations with sunflower and basic soil tillage on the number and species composition of weeds, including the parasitic sunflower broomrape. The experiment included crop rotations with sunflower comprising 12.5, 20, 25, 33.3, 50 and 100%, and three systems of tillage: mouldboard plough, disking, and no-till. Compared with the mouldboard plough, disking and no-till left 1.3 to 1.5-times as many weeds. The greatest damage by sunflower broomrape was observed in the 2-field rotation of winter wheat – sunflower, and in continuous sunflower, with 16 and 32% of crop plants affected, respectively. Broomrape infestation was highest under the mouldboard plough where infestation was 1.2–1.6 times greater than under disking and no-till, respectively. The best oil seed yields (2.92 and 2.95t/ha) were achieved by 8- and 5-field rotations under the plough; the lowest in short rotations with a sunflower saturation of 50%, and with continuous sunflower, amounting to 1.75–2.21t/ha under the plough, 1.57–2.01t/ha with disking, and 1.49–1.95t/ha with no-till. Given market demand, it would be expedient to increase the proportion of sunflower in the structure of sown areas.

Change of available soil moisture reserves in agrocenoses of winter wheat in short rotation crop rotations

The article presents the results of changes in available soil moisture in winter wheat crops in four short-rotation crop rotations. The research was carried out during 2012-2021 at the experimental field of the Belotserki National Agrarian University of the Kyiv region. The soil of the experimental field is a typical chernozem with a low humus content of average loamy humus in the 0–30 cm soil layer of 3,7–3,9 %. Four short-rotation crop rotations were studied (sunflower saturation 10 %); cereal grain (sunflower saturation 20 %); specialized seedbed (sunflower saturation 30 %); rowing (sunflower saturation 40 %). It was established that the reserves of available moisture for the period of winter wheat sowing were the highest in the grain-row specialized crop rotation, where wheat was sown after buckwheat with 257,2 mm in the 0–150 cm layer, 78,5 mm in the 0–50 cm layer. In the crop rotation in the 0–150 cm layer, they were 204,3 mm, in the 0–50 cm and 50–100 cm layers 59,4 and 52.4 mm, which is 19,1 and 15.0 less than in the grain-row crop rotation mm. During the crop rotation, the reserves of available moisture for the harvesting period were 1372 m3/ha, grain-rowing – 1154 m3/ha, specialized grain-rowing and row-rowing – 1327 and 928 m3/ha, which affected the total moisture consumption. The highest consumption of available moisture was observed during row crop rotation - 4029 m3/ha, while during crop rotation the available moisture reserves were 4032 m3/ha. The coefficient of moisture consumption was the highest in specialized and row-row crops – 97,8 and 90,7 m3/t, respectively, while for crop rotation – 70,7, grain-row crops – 85,2 m3, which was less than row crops by 5,5 and 20 m3/t.

Structure of aboveground phytomass of spruce and pine in short rotation plantation stands

Structure of aboveground phytomass of spruce and pine in short rotation plantation stands

Connectivity is the key to longer rural placement: Retaining students on rural longitudinal integrated clerkships

Purpose Recruitment and retention of medical practitioners to rural practice is an ongoing global issue. Rural longitudinal integrated clerkships (LIC) are an innovative solution to this problem, which are known to increase rural workforce. Crucially this association increases with time on rural placement. This study examines factors that promote retention in a Rural LIC. Methods A two-phased, sequential design qualitative study in a cohort of students enrolled in a rural LIC at Griffith University, Queensland, Australia. Phase I consisted of an open-ended questionnaire and phase II follow-up focus groups from the same cohort. Data was transcribed and analysed using an iterative, six-step thematic analysis process to identify salient themes. Results Twenty-four students were invited to participate, of which eight respond in phase I and thirteen participated in phase II. Participants described retention being driven by connectivity within three broad themes: current practice, future practice (immediate internship and career intention), and social networks. Participant proposals to increase connectivity were also suggested including peer-led solutions and short rotations in metropolitan hospitals. Conclusion Connectivity is key to retention on rural longitudinal integrated clerkships. Programs which enhance connectivity with current practice, future practice, and social networks will increase retention on rural medical programs.

Proportion of Nonindustrial Private Forest Lands That Potentially Can Be Leased to Bioenergy Enterprises to Grow Short Rotation Woody Crops

Abstract Determining how much nonindustrial private forest (NIPF) land could potentially be allocated to growing short rotation woody crops (SRWCs) is critical for estimating the future supply of woody biomass for biofuels and overall bioenergy production. This study estimated the proportion of the land NIPF landowners would be willing to allocate to SRWC cultivation. In view of the bounded nature of the dependent binary variable [0,1] and model performance, a fractional logit regression model was used to estimate model parameters. The estimated proportion of land allocated to SRWCs was positively influenced by the rental rate per acre, owning land for investment or fee-access hunting purposes, and the landowner’s age. In contrast, size of the ownership, owning land for the production of agricultural products, and residing on the land negatively influenced the proportion of land allocated to SRWCs. Lease contract duration, location of the largest tract owned, owning land for personal recreation or ecosystem services, and landowner familiarity with the concept of alternative fuels production did not influence the proportion of land allocated to SRWCs. These results will contribute to a better understanding of SRWC biomass supply from NIPF land and provide important benchmark information for conducting feasibility analyses of biofuel and biopower manufacturing in Mississippi and other states with abundant woody feedstocks. Study Implications: To achieve targeted levels of bioenergy production and carbon dioxide (CO2) emission reductions and diversify NIPF landowner income, participation of NIPF landowners in woody biomass feedstock production will be critical, because they own a majority of forestland in the region. Moreover, they have diverse reasons for owning land which has extensive implications not only in terms of incentive types or monetary compensation levels they might require for cultivating SRWCs but also policies related to the development of the bioenergy sector in Mississippi, the location of individual bioenergy processing facilities, and feedstock types that will be developed. Thus, forest managers and biomass procurement foresters might need to decide whether to focus their efforts on maximizing the land area allocated to growing SRWCs or considering a mix of SRWCs at lower lease rates per acre and material obtained from thinnings, which might be more amenable to landowners who value environmental amenities.

Energy production and its characteristics from four tropical trees species planted in short rotation woody systems in Costa Rica

Short-rotation crop (SRC) systems with woody species have been planted in Costa Rica. However, information about different tree species and spacing is limited. The objective of the present study was to examine biomass production and the physical, energy, and chemical properties of feedstock of four tropical tree species (Cordia alliodora, Dipteryx panamensis, Gmelina arborea, and Tectona grandis) in 34-month-old plants planted at four spacings (0.5×1.0 m, 1.0×1.0 m, 1.0×2.0 m, and 2.0×2.0 m). The highest mortality rate (50%) was found in G. arborea; however, diameter, height, basal area, and biomass production in G. arborea plantations were higher than T. grandis, C. alliodora, and D. panamensis. Spacing effects on diameter, height, basal area, and biomass production were observed in 10-month-olds. Wide spacing presented the highest values in diameter and height, but the highest biomass production was found in the narrow spacing. Also, biomass distribution was different in D. panamensis in relation to other species. Specify gravity, density, and moisture content of biomass showed high variation between species and spacing, but the energy and chemical properties of biomass showed few differences. These results suggest that these four species were uniform in terms of their energy and chemical properties, regardless of the spacing used. Finally, three species (G. arborea, C. alliodora, and T. grandis) presented important potential for use in SRC systems. G. arborea was the species with the highest production but a high mortality rate.

Short Crop Rotation under No-Till Improves Crop Productivity and Soil Quality in Salt Affected Areas

Soil productivity and crop yield were examined in response to legume-based short crop rotation under conventional (CT) and no-till (NT) tillage practices in saline meadow-alluvial soils of the arid region in Bukhara, Uzbekistan. Compared with the CT treatment, crop yield was consistently higher under NT, i.e., winter wheat 9.63%, millet 9.9%, chickpea 3.8%, and maize 10.7% at the first experiment cycle during 2019–2021. A further crop productivity increase was observed at the second experiment cycle during 2021–2023 under NT when compared to CT, i.e., winter wheat 17.7%, millet 31.2%, chickpea 19.6%, and maize 19.1%. An increase in total phyto residue by 20.9% and root residue by 25% under NT compared to CT contributed to the improvement in soil structure and played a vital role in the sustained improvement of crop yields. In turn, the increased residue retention under NT facilitated soil porosity, structural stability, and water retention, thereby improving soil quality and organic matter content. Soil salinity more significantly decreased under NT than in CT, reducing salinity buildup by 18.9% at the 0–25 cm and 32.9% at the 75–100 cm soil profiles compared to CT. The total forms N and P were significantly increased under NT when compared to CT, while the efficiency of the applied crop rotation was essential. This study showed the essential role of the NT method with legume-based intensive cropping in the maintenance of soil health and crop yield, thereby touching on recent advances in agro-biotechnology and the sustainable land management of drylands.

Developing indicators for biodiversity monitoring in short rotation tree plantations

Global biodiversity loss has increased societal expectation to businesses to assess and manage their dependencies on biodiversity and transparently report their biodiversity impacts. Various global frameworks have been developed to manage risks and|or report the impacts. The metrics and indicators of the global frameworks are generic in nature and do not necessarily capture local biodiversity impacts. Stora Enso has publicly declared in our Sustainability Strategy an ambition to have a net positive impact on biodiversity. For short rotation plantations Stora Enso has set an objective to develop granular, yet practical and applicable indicators for monitoring and reporting biodiversity impacts and developments over time. The selection of indicators needs to reflect the connection between biodiversity management actions and outcomes, i.e. that: i) there are purposeful biodiversity measures in place that ii) result in monitorable outcomes. Hence Stora Enso in collaboration with the joint venture partners in Veracel and Montes del Plata has developed biodiversity indicators adapted to the local conditions for the Eucalypt plantations in Brazil and Uruguay, respectively. The overarching goal is to have indicators that reflect that the environmental and biodiversity measures that are integrated in the management of the plantations have real and measurable effects promoting landscape level biodiversity. The selected biodiversity indicators meet the following criteria: Science-based, measurable and quantifiable, reliable, recurrent, and cost-effective monitoring to follow trends over time. With biodiversity indicators in place, Stora Enso wishes to further the development of adaptive biodiversity management. This means to continuously monitor biodiversity management performance, via the indicators, to enable further adaptation and development of biodiversity positive actions. The indicators will be publicly published to provide full transparency. In preparation for launching the indicators in the fall 2023, the intention at this conference is to present the indicators and consult with the audience on their purposefulness.

Development of comprehensive calibration models for pulp traits by near infrared spectroscopy (NIRS) for pure species and hybrids of Corymbia and Eucalyptus

Corymbia hybrid has emerged as a complimentary pulpwood in India along with Eucalyptus camaldulensis and eucalypt hybrids for enhancing the profitability of the industry and the income of farmers. Near infrared spectroscopy (NIRS) offers a rapid non-destructive method for estimating wood and pulp traits of short rotation trees. Development of NIR calibration models in Corymbia is essential for quick selection and rapid advancement of pulp wood traits. A study was carried out to develop a combined calibration curve for pure E. camaldulensis and Corymbia species and their interspecific hybrids. Wood samples were extracted from four-year-old 300 trees of Corymbia torelliana (CT), C. citriodora (CC), C. variegata (CV) and E. camaldulensis (EC) and their interspecific hybrids from progeny evaluation trials at three different locations in south India. The wood logs and powdered core samples were analyzed for kraft pulp yield (KPY), lignin and S|G ratio by wet chemistry and NIRS method. The KPY values of CC and CV ranged from 44 to 52%, whereas CT, a maternal parent in CT x CC|CV hybrids, had a narrow range of 38-46.5%. However, the interspecific hybrids of CT x CC|CV exhibited a range with higher values from 48.5 to 50.5%, indicating a narrow scope for predicting hybrids from that of parent’s standard calibration curves. The estimated values in pure species of Corymbia for lignin content ranged from 22.7 to 29.2 % and 1.9 to 3.1 for S|G ratio, while in hybrids it was 25.6 to 29.4 for lignin. The correlation coefficients for cross-validation of KPY in CC, CV, CT and their hybrids were 0.8, 0.81, 0.89 and 0.72, respectively, and root mean square errors (RMS) were 0.8, 0.55, 0.73 and 0.31, respectively. When CC and CV samples were pooled to generate a common prediction model, the correlation coefficients were 0.8 for KPY, 0.75 for lignin and 0.83 for S|G ratio, with RMS of 0.68 for both KPY and lignin, and 0.12 for S|G ratio. Corymbia hybrids were evaluated with 99% accuracy using a combined prediction model of pure Corymbia species and hybrids. The method was validated with 80 samples of pure species and hybrids with a RMS of less than 1.0. We also attempted in developing a combined prediction model for different species of Corymbia, Eucalyptus, and their hybrids with minimum prediction errors.