Editorial

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2 pages, 644 KiB

Open AccessEditorial

Fast-Growing Trees Species—Opportunities and Risks for Sustainable Agricultural and Forest Land Use Systems

by Dirk Landgraf

Forests 2022, 13(6), 829; https://doi.org/10.3390/f13060829 - 26 May 2022

Cited by 1 | Viewed by 1379

Abstract

The cultivation of fast-growing tree species has noticeably increased worldwide in recent years [...] Full article

(This article belongs to the Special Issue Fast-Growing Trees Species—Opportunities and Risks for Sustainable Agricultural and Forest Land Use Systems)

Research

Jump to: Editorial

23 pages, 3966 KiB

Open AccessArticle

Establishment of a Laboratory Scale Set-Up with Controlled Temperature and High Humidity to Investigate Dry Matter Losses of Wood Chips from Poplar during Storage

by Albert Hernandez-Estrada, Ralf Pecenka, Sabrina Dumfort, Judith Ascher-Jenull, Hannes Lenz, Christine Idler and Thomas Hoffmann

Forests 2022, 13(3), 459; https://doi.org/10.3390/f13030459 - 15 Mar 2022

Cited by 3 | Viewed by 2146

Abstract

The aim of this work was to improve the understanding of dry matter losses (DML) that occur in wood chips during the initial phase of storage in outdoor piles. For this purpose, a laboratory scale storage chamber was developed and investigated regarding its [...] Read more.

The aim of this work was to improve the understanding of dry matter losses (DML) that occur in wood chips during the initial phase of storage in outdoor piles. For this purpose, a laboratory scale storage chamber was developed and investigated regarding its ability to recreate the conditions that chips undergo during the initial phase of outdoor storage. Three trials with poplar Max-4 (Populus maximowiczii Henry × Populus nigra L.) chips were performed for 6–10 weeks in the storage chamber under controlled temperature and assisted humidity. Two different set-ups were investigated to maintain a high relative humidity (RH) inside the storage chamber; one using water containers, and one assisted with a humidifier. Moisture content (MC) and DML of the chips were measured at different storage times to evaluate their storage behaviour in the chamber. Additionally, microbiological analyses of the culturable fraction of saproxylic microbiota were performed, with a focus on mesophilic fungi, but discriminating also xerophilic fungi, and mesophilic bacteria, with focus on actinobacteria, in two trials, to gain a view on the poplar wood chip-inhabiting microorganisms as a function of storage conditions (moisture, temperature) and time. Results show that DML up to 8.8–13.7% occurred in the chips within 6–10 storage weeks. The maximum DML were reached in the trial using the humidifier, which seemed a suitable technique to keep a high RH in the testing chamber, and thus, to analyse the wood chips in conditions comparable to those in outdoor piles during the initial storage phase. Full article

(This article belongs to the Special Issue Fast-Growing Trees Species—Opportunities and Risks for Sustainable Agricultural and Forest Land Use Systems)

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15 pages, 2160 KiB

Open AccessArticle

Impact of Different Pruning Practices on Height Growth of Paulownia Clon in Vitro 112^®

by Jiří Kadlec, Kateřina Novosadová and Radek Pokorný

Forests 2022, 13(2), 317; https://doi.org/10.3390/f13020317 - 15 Feb 2022

Cited by 8 | Viewed by 2155

Abstract

We focused on the ability of one-year-old and two-year-old plants of Paulownia Clon in vitro 112^® to sprout and grow branches, and on their pruning for their best possible growth on a plantation in Střelice u Brna. Furthermore, we carried out pruning [...] Read more.

We focused on the ability of one-year-old and two-year-old plants of Paulownia Clon in vitro 112^® to sprout and grow branches, and on their pruning for their best possible growth on a plantation in Střelice u Brna. Furthermore, we carried out pruning on selected parts that comprised: spring pruning; reduction in the angle between the stem axis and one new growing sprout; and year-long pruning. The sprouting capacity of Paulownia was high—up to 56% (one-year-old plants) and 50% (two-year-old plants). Branches grew on 34% of all one-year-old plants and on 57% of all two-year-old plants. The best possible spring pruning method seems to be the keeping of one stem sprout or one stump sprout for one-year-old plants and one stem sprout for two-year-old plants. The newly growing stem sprout should be formed by bandaging it to the stem, and, as a result of this, the angle between the stem and the sprout can be reduced to 20° in contrast to 50° when the sprout is not bandaged. Our results suggest that it is best to take off the lower ⅓ of the branches and leaves, which leads to faster height growth of the plant. Full article

(This article belongs to the Special Issue Fast-Growing Trees Species—Opportunities and Risks for Sustainable Agricultural and Forest Land Use Systems)

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15 pages, 21756 KiB

Open AccessArticle

Physiological Performance and Biomass Growth of Different Black Locust Origins Growing on a Post-Mining Reclamation Site in Eastern Germany

by Christian A. Lange, Dirk Knoche, Robin Hanschke, Sonja Löffler and Volker Schneck

Forests 2022, 13(2), 315; https://doi.org/10.3390/f13020315 - 15 Feb 2022

Cited by 5 | Viewed by 1889

Abstract

Black Locust/Robinia can play an important role in land reclamation due to its pronounced nitrogen fixation capability, fast initial growth and relative high drought tolerance. Hence, we set up a trial to test 12 Black Locust clones and three provenances growing on sandy [...] Read more.

Black Locust/Robinia can play an important role in land reclamation due to its pronounced nitrogen fixation capability, fast initial growth and relative high drought tolerance. Hence, we set up a trial to test 12 Black Locust clones and three provenances growing on sandy overburden material within the open cast lignite mine Welzow-Süd (South Brandenburg) in March 2014. Since then, biomass growth of the Black Locust trees was examined and physiological performance was studied on several occasions using chlorophyll a fluorescence and Dualex^® measuring technique. Plant physiological measurements revealed differences in photosynthetic vitality (PI_ABS), although the PI_ABS values followed a similar pattern and sequences across the plot. While the genotypes Fra3 and Roy show the highest photosynthetic vitality, the clones Rog and Rob display the lowest PI_ABS mean values. Chlorophyll and phenol content as well as the nutrition supply of the test trees vary depending on their origin and site conditions. The annual biomass growth rate corresponds to photosynthetic vitality and both depend on weather conditions during the growing season. After six years, the growing biomass amounts to 14.7 Mg d.m. ha⁻¹ for clone Rob and 44.8 Mg d.m. ha⁻¹ for clone Fra3, i.e., 2.5 to 7.5 Mg d.m. ha⁻¹ year⁻¹. Our data demonstrate a good correlation between biophysical parameters and biomass growth. We, thus, infer that physiological measuring methods can be combined to strengthen predictions regarding the physiological performance of Black Locust origins. Full article

(This article belongs to the Special Issue Fast-Growing Trees Species—Opportunities and Risks for Sustainable Agricultural and Forest Land Use Systems)

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20 pages, 7088 KiB

Open AccessArticle

Comparing the Effects of N and P Deficiency on Physiology and Growth for Fast- and Slow-Growing Provenances of Fraxinus mandshurica

by Xingtang Zhao, Xu Zhang, Zhang Liu, Yipin Lv, Tingting Song, Jinghong Cui, Tianchi Chen, Jianxia Li, Fansuo Zeng and Yaguang Zhan

Forests 2021, 12(12), 1760; https://doi.org/10.3390/f12121760 - 13 Dec 2021

Cited by 2 | Viewed by 1847

Abstract

With the continuous increase in atmospheric carbon dioxide emissions, nitrogen (N) and phosphorus (P) as mineral elements increasingly restrict plant growth. To explore the effect of deficiency of P and N on growth and physiology, Fraxinus mandshurica (hereafter “F. mandshurica”) Rupr. [...] Read more.

With the continuous increase in atmospheric carbon dioxide emissions, nitrogen (N) and phosphorus (P) as mineral elements increasingly restrict plant growth. To explore the effect of deficiency of P and N on growth and physiology, Fraxinus mandshurica (hereafter “F. mandshurica”) Rupr. annual seedlings of Wuchang (WC) provenance with fast growth and Dailing (DL) provenance with slow growth were treated with complete nutrition or starvation of N (N-), P (P-) or both elements (NP-). Although P- and N- increased the use efficiency of P (PUE) and N (NUE), respectively, they reduced the leaf area, chlorophyll content and activities of N assimilation enzymes (NR, GS, GOGAT), which decreased the dry weight and P or N amount. The free amino acid content and activities of Phosphoenolpyruvate carboxylase (PEPC) and acid phosphatase enzymes were reduced by N-. The transcript levels of NRT2.1, NRT2.4, NRT2.5, NRT2.7, AVT1, AAP3, NIA2, PHT1-3, PHT1-4 and PHT2-1 in roots were increased, but those of NRT2.1, NRT2.4, NRT2.5, PHT1-3, PHT1-4, PHT2-1 and AAP3 in leaves were reduced by P-. WC was significantly greater than DL under P- in dry weight, C amount, N amount, leaf area, PUE, NUE, which related to greater chlorophyll content, PEPC enzyme activity, N assimilation enzyme activities, and transcript levels of N and P transporter genes in roots and foliage, indicating a greater ability of WC to absorb, transport and utilize N and P under P-. WC was also greater than DL under N- in terms of the above indicators except the transcript levels of N and P assimilation genes, but most of the indicators did not reach a significant level, indicating that WC might be more tolerant to N- than DL, which requires further verification. In summary, WC was identified as a P-efficient provenance, as the growth rate was greater for the genetic type with high than low tolerance to P-. Full article

(This article belongs to the Special Issue Fast-Growing Trees Species—Opportunities and Risks for Sustainable Agricultural and Forest Land Use Systems)

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14 pages, 1856 KiB

Open AccessArticle

Targeted CRISPR/Cas9-Based Knock-Out of the Rice Orthologs TILLER ANGLE CONTROL 1 (TAC1) in Poplar Induces Erect Leaf Habit and Shoot Growth

by Matthias Fladung

Forests 2021, 12(12), 1615; https://doi.org/10.3390/f12121615 - 23 Nov 2021

Cited by 7 | Viewed by 2385

Abstract

Pyramidal-, erect- or upright-growing plant forms are characterized by narrow branch angles of shoots and leaves. The putative advantage of upright-leaf and shoot habit could be a more efficient penetration of light into lower canopy layers. Pyramidal genotypes have already been reported for [...] Read more.

Pyramidal-, erect- or upright-growing plant forms are characterized by narrow branch angles of shoots and leaves. The putative advantage of upright-leaf and shoot habit could be a more efficient penetration of light into lower canopy layers. Pyramidal genotypes have already been reported for various tree genotypes including peach. The paralogous rice ortholog TILLER ANGLE CONTROL 1 (TAC1) has been proposed to be the responsible gene for upright growth. However, it has not really been demonstrated for any of the pyramidal tree genotypes that a knock-out mutation of the TAC1 gene is causing pyramidal plant growth. By in silico analyses, we have identified a putative rice TAC1 ortholog (Potri.014G102600, “TAC-14”) and its paralog (Potri.002G175300, “TAC-2”) in the genome of P. trichocarpa. Two putative PcTAC1 orthologs in the P. × canescens clone INRA 717-1B4 were successfully knocked-out by applying a transgenic CRISPR/Cas9-approach. The mutants were molecularly analyzed and phenotyped over a period of three years in a glasshouse. Our results indicate that the homozygous knock-out of “TAC-14” is sufficient to induce pyramidal plant growth in P. × canescens. If up to twice as many pyramidal individuals were planted on short rotation coppices (SRCs), this could lead to higher wood yield, without any breeding, simply by increasing the number of trees on a default field size. Full article

(This article belongs to the Special Issue Fast-Growing Trees Species—Opportunities and Risks for Sustainable Agricultural and Forest Land Use Systems)

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26 pages, 2706 KiB

Open AccessArticle

Soil Carbon Modelling in Salix Biomass Plantations: Variety Determines Carbon Sequestration and Climate Impacts

by Saurav Kalita, Hanna Karlsson Potter, Martin Weih, Christel Baum, Åke Nordberg and Per-Anders Hansson

Forests 2021, 12(11), 1529; https://doi.org/10.3390/f12111529 - 06 Nov 2021

Cited by 5 | Viewed by 2565

Abstract

Short-rotation coppice (SRC) Salix plantations have the potential to provide fast-growing biomass feedstock with significant soil and climate mitigation benefits. Salix varieties exhibit significant variation in their physiological traits, growth patterns and soil ecology—but the effects of these variations have rarely been studied [...] Read more.

Short-rotation coppice (SRC) Salix plantations have the potential to provide fast-growing biomass feedstock with significant soil and climate mitigation benefits. Salix varieties exhibit significant variation in their physiological traits, growth patterns and soil ecology—but the effects of these variations have rarely been studied from a systems perspective. This study analyses the influence of variety on soil organic carbon (SOC) dynamics and climate impacts from Salix cultivation for heat production for a Swedish site with specific conditions. Soil carbon modelling was combined with a life cycle assessment (LCA) approach to quantify SOC sequestration and climate impacts over a 50-year period. The analysis used data from a Swedish field trial of six Salix varieties grown under fertilized and unfertilized treatments on Vertic Cambisols during 2001–2018. The Salix systems were compared with a reference case where heat is produced from natural gas and green fallow was the land use alternative. Climate impacts were determined using time-dependent LCA methodology—on a land-use (per hectare) and delivered energy unit (per MJ_heat) basis. All Salix varieties and treatments increased SOC, but the magnitude depended on the variety. Fertilization led to lower carbon sequestration than the equivalent unfertilized case. There was no clear relationship between biomass yield and SOC increase. In comparison with reference cases, all Salix varieties had significant potential for climate change mitigation. From a land-use perspective, high yield was the most important determining factor, followed by SOC sequestration, therefore high-yielding fertilized varieties such as ‘Tordis’, ‘Tora’ and ‘Björn’ performed best. On an energy-delivered basis, SOC sequestration potential was the determining factor for the climate change mitigation effect, with unfertilized ‘Jorr’ and ‘Loden’ outperforming the other varieties. These results show that Salix variety has a strong influence on SOC sequestration potential, biomass yield, growth pattern, response to fertilization and, ultimately, climate impact. Full article

(This article belongs to the Special Issue Fast-Growing Trees Species—Opportunities and Risks for Sustainable Agricultural and Forest Land Use Systems)

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13 pages, 1304 KiB

Open AccessArticle

Potential Areas in Poland for Forestry Plantation

by Piotr Boruszewski, Agnieszka Laskowska, Agnieszka Jankowska, Marcin Klisz and Marcin Mionskowski

Forests 2021, 12(10), 1360; https://doi.org/10.3390/f12101360 - 07 Oct 2021

Cited by 7 | Viewed by 2070

Abstract

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. [...] Read more.

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. Full article

(This article belongs to the Special Issue Fast-Growing Trees Species—Opportunities and Risks for Sustainable Agricultural and Forest Land Use Systems)

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14 pages, 1802 KiB

Open AccessArticle

Site-Effects Dominate the Plant Availability of Nutrients under Salix Species during the First Cutting Cycle

by Piotr Koczorski, Bliss Furtado, Katarzyna Hrynkiewicz, Michelle Breezmann, Martin Weih and Christel Baum

Forests 2021, 12(9), 1226; https://doi.org/10.3390/f12091226 - 09 Sep 2021

Cited by 5 | Viewed by 2097

Abstract

Fast-growing willows (Salix spp.) provide alternative sources of renewable energy generation, but need an adequate nutrient availability in the soil for high biomass production. In general, species mixtures can be more nutrient-efficient than pure cultures, but this is scarcely known for Salix [...] Read more.

Fast-growing willows (Salix spp.) provide alternative sources of renewable energy generation, but need an adequate nutrient availability in the soil for high biomass production. In general, species mixtures can be more nutrient-efficient than pure cultures, but this is scarcely known for Salix spp. Therefore, this study evaluates the nutrient availability and P mobilization under two willow species, Salixdasyclados var. ‘Loden’ and S. schwerinii × viminalis var. ‘Tora’, grown as pure and mixed cultures at non-fertilized former arable sites in Germany (Stagnic Cambisol) and Sweden (Vertic Cambisol). The plant availability of potassium (K), magnesium (Mg) and phosphorus (P) and soil phosphatase activities in the topsoil were measured in spring of the year of planting (initial) and under 4 years-old stocks (one year after the first 3-year cutting cycle). The initial plant availability of the nutrients significantly differed between the sites and the two sampling dates at both sites. The plant availability of K and Mg was optimal to high at both sites and sampling dates, but rather low for P (after 4 years ≤5 mg P 100 g⁻¹ soil). The plant-available P and K content in soil significantly decreased within the 4 years of willow growth at both sites. The acid and alkaline phosphatase activity in the soil of the German site (Rostock) was significantly lower after 4 years of willow growth, but differed not significantly between the two sampling dates at the Swedish site (Uppsala). Higher activity of acid phosphatase compared to alkaline phosphatase was recorded in the soils at both test sites based on the site-specific soil pH (<7). The slight decrease of plant availability of P after 4 years of Salix growth in pure culture differed not significantly between the different species. Mixed growth did not decrease the plant availability of P within this period, although no significant difference in the biomass production of pure and mixed growth was observed. This was valid at both sites, and therefore, seems independent of the site-specific differences in soil and climate conditions. The general validity of the assumptions should be tested also for other species mixtures and soil conditions in the future before site-adapted growth designs can be recommended in biomass production of Salix. Full article

(This article belongs to the Special Issue Fast-Growing Trees Species—Opportunities and Risks for Sustainable Agricultural and Forest Land Use Systems)

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25 pages, 4306 KiB

Open AccessArticle

Effects of Leaf Loss by Artificial Defoliation on the Growth of Different Poplar and Willow Varieties

by Christiane E. Helbig, Michael G. Müller and Dirk Landgraf

Forests 2021, 12(9), 1224; https://doi.org/10.3390/f12091224 - 08 Sep 2021

Cited by 5 | Viewed by 2154

Abstract

The cultivation of fast-growing tree species in short rotation coppices has gained popularity in Germany in recent years. The resilience of these coppices to phyllophagous pest organisms is crucial for their profitable management, since the loss of a single annual increment can lead [...] Read more.

The cultivation of fast-growing tree species in short rotation coppices has gained popularity in Germany in recent years. The resilience of these coppices to phyllophagous pest organisms is crucial for their profitable management, since the loss of a single annual increment can lead to uncompensable economic losses. To study the effects of leaf loss on the growth of poplar and willow varieties that are frequently cultivated under local conditions, three sample short rotation coppices including five poplar (Populus spp.) and three willow (Salix spp.) varieties were established in a randomized block design with four artificial defoliation variants and, on one site, with three different variants regarding the number of defoliation treatments. After up to three defoliation treatments within two growing seasons, the results show negative effects of leaf loss on the height growth and the fresh weight of the aboveground biomass of plants. Our data also suggests a lasting effect of defoliation on plant growth and re-growth after the end of the treatment. In general, defoliation had a greater impact on the growth of poplars than on willows. We conclude that even minor leaf loss can have an impact on plant growth but that the actual effects of defoliation clearly depend on the site, tree species, and variety as well as the extent and number of defoliations, which determine the ability of plants for compensatory growth. Full article

(This article belongs to the Special Issue Fast-Growing Trees Species—Opportunities and Risks for Sustainable Agricultural and Forest Land Use Systems)

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20 pages, 5456 KiB

Open AccessArticle

Short-Rotation Coppice Managed According to Ecological Guidelines—What Are the Benefits for Phytodiversity?

by Felix Zitzmann and Michael Rode

Forests 2021, 12(5), 646; https://doi.org/10.3390/f12050646 - 19 May 2021

Cited by 3 | Viewed by 2833

Abstract

In recent years, the impact of short-rotation coppice (SRC) on biodiversity has been a regular subject of research and ecological guidelines have been developed to make biomass cultivation on SRC more compatible with biodiversity concerns. However, since these guidelines are only implemented voluntarily [...] Read more.

In recent years, the impact of short-rotation coppice (SRC) on biodiversity has been a regular subject of research and ecological guidelines have been developed to make biomass cultivation on SRC more compatible with biodiversity concerns. However, since these guidelines are only implemented voluntarily by farmers, there are barely any SRC that are managed according to ecological guidelines. Consequently, knowledge about their importance for farmland biodiversity and about the impact of different measures for increasing biodiversity remains scarce. Therefore, three experimental SRC, which are managed according to ecological guidelines and thus include stands of different tree species (varieties of poplar (Populus) and willow (Salix), rowan (Sorbus aucuparia), silver birch (Betula pendula)) and different growth-stages within the same site, were investigated with regard to their importance as habitat for vascular plants. Species numbers and species composition were compared with the following habitat types: afforestations (AFO), young (HE-Y) and old hedges (HE-O), field margins (FM) and arable land (AL). Furthermore, different stand types (i.e., stands with different tree species and growth-stages, headlands, clearings) within these SRC were surveyed and compared. Species numbers of SRC were similar to HE-Y, AFO and FM and significantly higher than in AL and HE-O. The composition of plant communities in SRC differed considerably from the other farmland habitats, especially from AL, HE-O and FM. Within the SRC, most stand types had similar species numbers. Only the non-harvested poplar stands were particularly species-poor. Harvesting led to increased species numbers. This increase was significant for the poplar stands but only moderate for the willow stands. With regard to their species composition, the different stand types differed considerably in many cases. We conclude that SRC, which are managed according to ecological guidelines, can be an additional measure to promote phytodiversity in agricultural landscapes as they contain relatively high species numbers (of mainly common and adaptable species) and support distinct plant communities that differ from other farmland habitats. Therefore, measures such as the cultivation of different tree species or sectional harvesting could be offered as agri-environmental schemes to further increase the ecological sustainability of biomass production on SRC. Full article

(This article belongs to the Special Issue Fast-Growing Trees Species—Opportunities and Risks for Sustainable Agricultural and Forest Land Use Systems)

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