Dedicated biomass crops can enhance biodiversity in the arable landscape

Beyond biomass production: Enhancing biodiversity while capturing carbon in short rotation coppice poplar plantations

Biodiversity is essential for the functioning of ecosystems and the provision of services. In recent years, the role of plantations in mitigating climate change through carbon sequestration has been highlighted. In the Mediterranean area, high-density poplar plantations in short-rotation with resprouting management (SRC) have been established for biomass purposes on mostly irrigated agricultural land, coexisting with rainfed and irrigated agricultural crops. This study aims to assess the contribution of these plantations to this type of agroforest ecosystem in terms of biodiversity. For this purpose, both flora and fauna diversity were evaluated both within and outside of the plantation. Additionally, the accumulated carbon in the biomass, as well as in the accompanying vegetation within the plantation, was assessed. Different indices were used to evaluate both the intrinsic diversity of the forest plantation and the degree of substitution and complementarity between the different communities of the landscape. Our findings reveal distinct biodiversity patterns in the land-use scenarios sampled. Specifically, we observed significantly higher flora-species richness in SRC plantations than in the adjacent agricultural land, whereas fauna richness showed a similar but slightly higher level in the forested area. A moderate level of complementarity between land uses was found for insects and mammals (around 45 %), contrasting with high complementarity for birds (87 %) and flora (90 %). This suggests substantial turnover and replacement among these ecological environments. Our results indicate that a second rotation (4 year) plantation could accumulate a total of 61.6 Mg C ha-1, and even though adventitious flora represents <2 % of the total carbon accumulated, its importance in providing ecosystem services is considerable. Hence, these findings evidence the fact that SRC poplar plantations can enhance biodiversity in Mediterranean agroforest ecosystems and actively contribute to various provisioning ecosystem services, including carbon sequestration, reflecting a multi-objective approach that extends beyond biomass production.

Assessing the potential of poplar short rotation plantations to contribute to a low-carbon bioeconomy under water-limited conditions

Poplar short rotation coppice (SRC) systems are important for biomass production and for short-to medium-term carbon (C) sequestration, contributing to a low-carbon bioeconomy and thus helping to mitigate global warming. The productivity and profitability of these plantations are, however, challenged under restrictive irrigation associated with climate change. This study compares the above- and below-ground C sequestration potential and economic viability of a 12-year plantation cycle (4 rotations of 3 years each) under Mediterranean conditions with optimum irrigation (T1) and 50% irrigation reduction (T2), analysing other promising biomass uses in the form of bioproducts. A total of 138 trees of the highly productive hybrid ('AF2') in a SRC-trial were sampled monthly (first rotation). Additionally, data from an extensive poplar plantation network (30 sites) was used to complete data for the plantation cycle. The average C content for above- and below-ground biomass was 17.04 Mg C ha-1 yr-1 (T1), falling by 24% in T2. The net present value (NPV) in T1 (6461 € ha-1) was 52% lower under T2 conditions. Extra payments for C sequestration increased the NPV to 8023 for T1 and 4331 € ha-1 for T2. Roots represent an important C storage in the soil, accumulating 29.9 Mg C ha-1 (T1) and 22.8 Mg C ha-1 (T2) by the end of the cycle in our study. The mitigation potential is strongly fortified when the share of bioproducts in biomass end-use increases. Assuming a distribution of 50% bioenergy and 50% bioproducts, emission were reduced between -114 Mg CO2eq ha-1 (T1) and -88 Mg CO2eq ha-1 (T2) compared to BAU until end of the century. This scenario plays a crucial sink-effect role by storing C contained in biomass, which is not immediately released into the atmosphere.

Potential Areas in Poland for Forestry Plantation

Plantations have many advantages when compared to natural or semi-natural forests, such as shortening production cycles, the production of wood with specific characteristics, and near-market production concentrations. The intensive development of this form of industrial wood production is practiced all over the world. The wood industry in Poland struggles in recent years, with a large shortage of wood. The deficit of wood has been accumulated for several years and is steadily increasing. One of the possibilities to change this trend can be development of fast-growing trees plantations. The main aim of this study was to determine the potential of land in Poland, which could be used for the cultivation of fast-growing trees plantations. The analyses took into account the area and marginal agricultural land. The potential plantation land areas were determined for poplar cultivar “Hybrid 275” and European larch (Larix decidua Mill.). The results show a possibility to generate a considerable area that can be developed into plantations of fast-growing trees in Poland. According to the analyses carried out for the purpose of this study, with only 5% use of the sown area and 5% use of forest lands, as well as the boscage (wooded land and bushy land), it is possible to obtain approximately 0.6 MM ha of land for fast-growing tree plantations. In the case of planting 50% of these lands with larch and 50% with poplar, and if a 50% capacity of the plantation is assumed, it will be possible to obtain nearly 6 MM m3 of wood per year.

Storage of Fine Woodchips from a Medium Rotation Coppice Eucalyptus Plantation in Central Italy

Eucalyptus spp. has received attention from the research and industrial field as a biomass crop because of its fast growth and high productivity. The features of this species match with the increasing demand for wood for energy production. Commonly, the wood used for energy production is converted in chips, a material susceptible to microbial degradation and energy losses if not properly stored before conversion. This study aims at investigating two outdoor storage systems of Eucalyptus wood chips (covered vs. uncovered), assessing the variation in moisture content, dry matter losses and fuel characteristics. The class size of the material was P16, which was obtained using a commercial chipper appositely searched to conduct the study. The results highlighted how the different storage methods were influenced by the climatic condition: the woody biomass covered showed the best performances in terms of dry matter losses achieving 2.7% losses vs. the 8.5% of the uncovered systems. However, fuel characteristics displayed minor changes that affected the final energy balance (∆En = −0.2% in covered; ∆En = −6.17% in uncovered). Particle size varied in both methods with respect to the start conditions, but the variation was not enough to determine a class change, which remained P16 even after storage.

Marginal Lands to Grow Novel Bio-Based Crops: A Plant Breeding Perspective

The biomass demand to fuel a growing global bio-based economy is expected to tremendously increase over the next decades, and projections indicate that dedicated biomass crops will satisfy a large portion of it. The establishment of dedicated biomass crops raises huge concerns, as they can subtract land that is required for food production, undermining food security. In this context, perennial biomass crops suitable for cultivation on marginal lands (MALs) raise attraction, as they could supply biomass without competing for land with food supply. While these crops withstand marginal conditions well, their biomass yield and quality do not ensure acceptable economic returns to farmers and cost-effective biomass conversion into bio-based products, claiming genetic improvement. However, this is constrained by the lack of genetic resources for most of these crops. Here we first review the advantages of cultivating novel perennial biomass crops on MALs, highlighting management practices to enhance the environmental and economic sustainability of these agro-systems. Subsequently, we discuss the preeminent breeding targets to improve the yield and quality of the biomass obtainable from these crops, as well as the stability of biomass production under MALs conditions. These targets include crop architecture and phenology, efficiency in the use of resources, lignocellulose composition in relation to bio-based applications, and tolerance to abiotic stresses. For each target trait, we outline optimal ideotypes, discuss the available breeding resources in the context of (orphan) biomass crops, and provide meaningful examples of genetic improvement. Finally, we discuss the available tools to breed novel perennial biomass crops. These comprise conventional breeding methods (recurrent selection and hybridization), molecular techniques to dissect the genetics of complex traits, speed up selection, and perform transgenic modification (genetic mapping, QTL and GWAS analysis, marker-assisted selection, genomic selection, transformation protocols), and novel high-throughput phenotyping platforms. Furthermore, novel tools to transfer genetic knowledge from model to orphan crops (i.e., universal markers) are also conceptualized, with the belief that their development will enhance the efficiency of plant breeding in orphan biomass crops, enabling a sustainable use of MALs for biomass provision.

Bird and invertebrate communities appear unaffected by fracking traffic along rural roads despite dust emissions

The development of shale petroleum resources has industrialized rural landscapes. We investigated how traffic from energy development expands and intensifies the road-effect zone through increased dust exposure, and how birds and invertebrates inhabiting the road-effect zone in agricultural areas of the Bakken region might be affected by dust exposure. We used dust collectors, trail cameras, and sweep-netting at increasing distances from unpaved roads to determine dust deposition, relative bird abundance, and invertebrate abundance, respectively. We found that traffic associated with fracking along unpaved roads emitted substantial dust 180 m into adjacent crop fields. But neither bird abundance or behavior, nor invertebrate abundance or community composition, appeared to be affected by dust or traffic. These findings suggest that wildlife in previously intensified agricultural landscapes like crop fields are resilient to intensification from energy development, but the same might not be true for wildlife in previously undisturbed habitat.

Three-Dimensional Reconstruction of Soybean Canopies Using Multisource Imaging for Phenotyping Analysis

Geometric three-dimensional (3D) reconstruction has emerged as a powerful tool for plant phenotyping and plant breeding. Although laser scanning is one of the most intensely used sensing techniques for 3D reconstruction projects, it still has many limitations, such as the high investment cost. To overcome such limitations, in the present study, a low-cost, novel, and efficient imaging system consisting of a red-green-blue (RGB) camera and a photonic mixer detector (PMD) was developed, and its usability for plant phenotyping was demonstrated via a 3D reconstruction of a soybean plant that contains color information. To reconstruct soybean canopies, a density-based spatial clustering of applications with noise (DBSCAN) algorithm was used to extract canopy information from the raw 3D point cloud. Principal component analysis (PCA) and iterative closest point (ICP) algorithms were then used to register the multisource images for the 3D reconstruction of a soybean plant from both the side and top views. We then assessed phenotypic traits such as plant height and the greenness index based on the deviations of test samples. The results showed that compared with manual measurements, the side view-based assessments yielded a determination coefficient (R2) of 0.9890 for the estimation of soybean height and a R2 of 0.6059 for the estimation of soybean canopy greenness index; the top view-based assessment yielded a R2 of 0.9936 for the estimation of soybean height and a R2 of 0.8864 for the estimation of soybean canopy greenness. Together, the results indicated that an assembled 3D imaging device applying the algorithms developed in this study could be used as a reliable and robust platform for plant phenotyping, and potentially for automated and high-throughput applications under both natural light and indoor conditions.

Short rotation plantations policy history in Europe: lessons from the past and recommendations for the future

Short rotation plantations (SRPs) are fast-growing trees (such as willow (Salix spp.), poplar (Populus spp.) and Eucalyptus) grown closely together and harvested in periods of 2-20 years. There are around 50,000 hectares of SRPs in Europe, a relatively small area considering that there have been supportive policy measures in many countries for 30 years. This paper looks at the effect that the policy measures used in different EU countries have had, and how other external factors have impacted on the development of the industry. Rokwood was a 3-year European funded project which attempted to understand the obstacles and barriers facing the woody energy crops sector using well established methods of SWOT and PESTLE analysis. Stakeholder groups were formed in six different European regions to analyze the market drivers and barriers for SRP and propose ways that the industry could make progress through targeted research and development and an improved policy framework. Based upon the outcomes of the SWOT and PESTLE analysis, each region produced a series of recommendations for policymakers, public authorities, and government agencies to support the development, production, and use of SRP-derived wood fuel in each of the partner countries. This study provides details of the SRP policy analysis and reveals that each region shared a number of similarities with broad themes emerging. There is a need to educate farmers and policymakers about the multifunctional benefits of SRPs. Greater financial support from regional and/or national government is required in order to grow the SRP market. Introducing targeted subsidies as an incentive for growers could address lack of local supply chains. Long-term policy initiatives should be developed while increasing clarity within Government departments. Research funding should enable closer working between universities and industry with positive research findings developed into supportive policy measures.