Wood Decomposition Rates Research Articles

The effects of invertebrates on wood decomposition across the world.

Invertebrates and microorganisms are important but climate-dependent agents of wood decomposition globally. In this meta-analysis, we investigated what drives the invertebrate effect on wood decomposition worldwide. Globally, we found wood decomposition rates were on average approximately 40% higher when invertebrates were present compared to when they were excluded. This effect was most pronounced in the tropics, owing mainly to the activities of termites. The invertebrate effect was stronger for woody debris without bark as well as for that of larger diameter, possibly reflecting bark- and diameter-mediated differences in fungal colonisation or activity rates relative to those of invertebrates. Our meta-analysis shows similar overall invertebrate effect sizes on decomposition of woody debris derived from angiosperms and gymnosperms globally. Our results suggest the existence of critical interactions between microorganism colonisation and the invertebrate contribution to wood decomposition. To improve biogeochemical models, a better quantification of invertebrate contributions to wood decomposition is needed.

Diversity and ecological significance of modern fungal non-pollen palynomorphs in a European lowland forest ecosystem

Fungal non-pollen palynomorphs (fNPPs) are microscopic structures occurring in various sediments. In paleoecological studies, they can serve as reliable indicators of vegetation types, grazing activities, and human impact, enriching the interpretation of fossil data. This study explores the composition and taxonomic richness of fNPPs in 85 moss samples from a European lowland forest. We found rich fungal diversity, with 95 morphological types, predominantly saprotrophs, favoring specific substrates, like wood, decaying bark, herbaceous plant remains, litter, and freshwater habitats. Key taxa, such as type HdV-96A, and cf. Hypoxylon (EMA-24), were prevalent across different forest types, especially in deciduous forests. We identified two primary gradients of fNPP composition. The first axis delineated samples by taxonomic richness, Shannon index, and canopy openness, showing similarities among deciduous forests. The second axis ordered samples by the proportion of fNPPs, volume of stumps, coarse woody debris, and herbs pollen richness, highlighting their connections. Forest management intensity had minimal influence on fNPP composition, indicating consistent composition along both ordination axes. Forest type and herbs pollen richness, significantly affected the taxonomic richness and Shannon diversity of fNPPs. Deciduous forests exhibited higher fNPP richness, compared to coniferous forests, linked to increased herbs pollen richness. However, fNPPs decreased with increasing volume of stumps, coarse woody debris, and canopy openness, demonstrating the complexities of forest management’s influence on fungal diversity. This study pioneers fNPP investigation in an old-growth temperate forest ecosystem, emphasizing the interplay of forest characteristics, herbs diversity, and dead wood components in shaping their composition and richness. It also reveals differences in fNPP assemblages between deciduous and coniferous forests, underscoring the importance of forest type in shaping fungal diversity. These findings highlight the need for detailed studies on microhabitats, dead wood decomposition rates, and specific forest impacts to comprehensively understand forest ecosystem dynamics.

Stem decomposition of temperate tree species is determined by stem traits and fungal community composition during early stem decay

Abstract Dead trees are vital structural elements in forests playing key roles in the carbon and nutrient cycle. Stem traits and fungal community composition are both important drivers of stem decay, and thereby affect ecosystem functioning, but their relative importance for stem decomposition over time remains unclear. To address this issue, we used a common garden decomposition experiment in a Dutch larch forest hosting fresh logs from 13 common temperate tree species. In total, 25 fresh wood and bark traits were measured as indicators of wood accessibility for decomposers, nutritional quality and chemical or physical defence mechanisms. After 1 and 4 years of decay, we assessed the richness and composition of wood‐inhabiting fungi using amplicon sequencing and determined the proportional wood density loss. Average proportional wood density loss for the first year was 18.5%, with further decomposition occurring at a rate of 4.3% year−1 for the subsequent 3 years across tree species. Proportional wood density loss varied widely across tree species in the first year (8.7–24.8% year−1) and subsequent years (0–11.3% year−1). The variation was directly driven by initial wood traits during the first decay year, then later directly driven by bark traits and fungal community composition. Moreover, bark traits affected the composition of wood‐inhabiting fungi and thereby indirectly affected decomposition rates. Specifically, traits promoting resource acquisition of the living tree, such as wide conduits that increase accessibility and high nutrient concentration, increased initial wood decomposition rates. Fungal community composition, but not fungal richness explained differences in wood decomposition after 4 years of exposure in the field, where fungal communities dominated by brown‐rot and white‐rot Basidiomycetes were linked to higher wood decomposition rate. Synthesis: Understanding what drives deadwood decomposition through time is important to understand the dynamics of carbon stocks. Here, using a tailor‐made experimental design in a temperate forest setting, we have shown that stem trait variation is key to understanding the roles of these drivers; initially, wood traits explained decomposition rates while subsequently, bark traits and fungal decomposer composition drove decomposition rates. These findings inform forest management with a view to selecting tree species to promote carbon storage.

Drivers of wood decay in tropical ecosystems: Termites versus microbes along spatial, temporal and experimental precipitation gradients

Abstract Models estimating decomposition rates of dead wood across space and time are mainly based on studies carried out in temperate zones where microbes are dominant drivers of decomposition. However, most dead wood biomass is found in tropical ecosystems, where termites are also important wood consumers. Given the dependence of microbial decomposition on moisture with termite decomposition thought to be more resilient to dry conditions, the relative importance of these decomposition agents is expected to shift along gradients in precipitation that affect wood moisture. Here, we investigated the relative roles of microbes and termites in wood decomposition across precipitation gradients in space, time and with a simulated drought experiment in tropical Australia. We deployed mesh bags with non‐native pine wood blocks, allowing termite access to half the bags. Bags were collected every 6 months (end of wet and dry seasons) over a 4‐year period across five sites along a rainfall gradient (ranging from savanna to wet sclerophyll to rainforest) and within a simulated drought experiment at the wettest site. We expected microbial decomposition to proceed faster in wet conditions with greater relative influence of termites in dry conditions. Consistent with expectations, microbial‐mediated wood decomposition was slowest in dry savanna sites, dry seasons and simulated drought conditions. Wood blocks discovered by termites decomposed 16–36% faster than blocks undiscovered by termites regardless of precipitation levels. Concurrently, termites were 10 times more likely to discover wood in dry savanna compared with wet rainforest sites, compensating for slow microbial decomposition in savannas. For wood discovered by termites, seasonality and drought did not significantly affect decomposition rates. Taken together, we found that spatial and seasonal variation in precipitation is important in shaping wood decomposition rates as driven by termites and microbes, although these different gradients do not equally impact decomposition agents. As we better understand how climate change will affect precipitation regimes across the tropics, our results can improve predictions of how wood decomposition agents will shift with potential for altering carbon fluxes. Read the free Plain Language Summary for this article on the Journal blog.

Tree species richness increases spatial variation but not overall wood decomposition

Empirical evidence for the positive relationship between tree species richness and wood decomposition is weak, despite the greater numbers of decomposers in diverse stands. Tree species identity affects decomposition rates strongly by altering soil communities and micro-environments. It is therefore likely that tree species richness influences spatial variation rather than the mean rate of decomposition. We used a neighbourhood approach to test this hypothesis by quantifying decomposition rates and decomposer activities within deadwood, whilst measuring the surrounding micro-environments.Using the BEF-China experimental platform, we placed three fine branches from seven tree species across richness gradients for one and two years. As expected, plot species richness increased the spatial variation of wood decomposition of three species but decreased the mean rate of wood decomposition of two species. Neighbourhood trees altered wood decomposition in two ways. First, increasing amounts of leaf tannins reduced termite activities and the number of fungal fruitbodies. Second, higher species richness increased tree volumes and thus cooled the understory, which reduced the occurrence and feeding intensity of ectothermic termites. Neighbourhood species richness showed positive effects on decomposer activities (i.e. termite occurrence, fruitbody number and mycelium cover) after two years, probably by weakening resource limitation of deadwood biomass and increasing the stages of decay. Neighbourhood metrics had comparable (after 1 year) and even stronger effects (after 2 years) on decomposer activities than wood traits. Our study reveals that tree species richness promotes spatial variation in wood decomposition rates by enhancing environmental heterogeneity. Our results explain how young regenerating species-rich forests, where termites are the dominant decomposers, can maintain deadwood stocks and decomposer activities over relatively longer time spans.

Response of wood decomposition to different forms of N deposition in subtropical forests

AimsWood decomposition plays an important role in ecosystem soil fertility and nutrient cycling, but how different forms of nitrogen (N) affect these biogeochemical processes is still unclear. The effects of N deposition on wood decomposition have been widely studied, but the decomposition process and biotic driver response to different forms of N have rarely been studied.MethodsIn this study, we conducted a two-year field factorial fertilization experiment with different N forms in a subtropical Chinese forest. Glycine and urea were selected as organic N (ON), and ammonium nitrate was selected as inorganic N (IN). Six different ratios (control, 0:10, 3:7, 5:5, 7:3, 10:0) of IN:ON with equal N amounts were uniformly added to the studied wood.ResultsWe found that both forms of N deposition, i.e., ON and IN, accelerated the wood decomposition rates across the four studied species, and the magnitude of the increase was species specific. Mixed fertilizer with ON and IN resulted in the highest responses in the wood decomposition rate, which was 1.73- and 1.48-fold higher than that in the control and in response to IN addition alone across species. The ON + IN treatment resulted in the highest faunal and microbial community abundance of the decomposing wood.ConclusionIn summary, our results indicate that different forms of anthropogenic N enrichment can promote wood decomposition through the modification of microbial and faunal communities in the wood decomposition process. Our results show that future studies need to consider N forms and components when estimating exogenous N deposition effects on the woody material nutrient cycle and terrestrial ecosystem carbon cycles.

Wood-decay type and fungal guild dominance across a North American log transplant experiment

We incubated 196 large-diameter aspen ( Populus tremuloides ), birch ( Betula papyrifera ), and pine ( Pinus taeda ) logs on the FACE Wood Decomposition Experiment encompassing eight climatically-distinct forest sites in the United States. We sampled dead wood from these large-diameter logs after 2 to 6 y of decomposition and determined wood rot type as a continuous variable using the lignin loss/density loss ratio (L/D) and assessed wood-rotting fungal guilds using high-throughput amplicon sequencing (HTAS) of the ITS-2 marker. We found L/D values in line with a white rot dominance in all three tree species, with pine having lower L/D values than aspen and birch. Based on HTAS data, white rot fungi were the most abundant and diverse wood-rotting fungal guild, and soft rot fungi were more abundant and diverse than brown rot fungi in logs with low L/D values. For aspen and birch logs, decay type was related to the wood density at sampling. For the pine logs, decay type was associated with the balance between white and brown/soft rot fungi abundance and OTU richness. Our results demonstrate that decay type is governed by biotic and abiotic factors, which vary by tree species. • Wood-decay types and wood-rotting fungal guilds were measured in large-diameter decayed logs. • White-rot processes dominated among a wide-range of temperate forest sites. • Decay type was related to the wood decomposition rate for aspen and birch dead wood. • Decay type was associated with wood-rotting fungal guild balance in pine dead wood.

The impact of biochar on wood-inhabiting bacterial community and its function in a boreal pine forest

Biochar is considered to be a possible means of carbon sequestration to alleviate climate change. However, the dynamics of the microbial community during wood decomposition after biochar application remain poorly understood. In this study, the wood-inhabiting bacterial community composition and its potential functions during a two-year decomposition period after the addition of different amounts of biochar (0.5 kg m−2 and 1.0 kg m−2), and at different biochar pyrolysis temperatures (500 °C and 650 °C), in a boreal Scots pine forest, were analyzed using Illumina NovaSeq sequencing combined with Functional Annotation of Prokaryotic Taxa (FAPROTAX). The results showed that the wood decomposition rates increased after biochar addition to the soil surface in the second year. Treatment with biochar produced at high temperatures increased the diversity of wood-inhabiting bacteria more than that produced at low temperatures (P < 0.05). The wood-inhabiting bacterial diversity and species richness decreased with decomposition time. The biochar treatments changed the wood-inhabiting bacterial community structure during the decomposition period. The pyrolysis temperature and the amount of applied biochar had no effect on the bacterial community structure but shifted the abundance of certain bacterial taxa. Similarly, biochar application shifted the wood-inhabiting bacterial community function in the first year, but not in the second year. The wood-inhabiting bacterial community and function were affected by soil pH, soil water content, and soil total nitrogen. The results provide useful information on biochar application for future forest management practices. Long-term monitoring is needed to better understand the effects of biochar application on nutrient cycling in boreal forests.

Analysis on the growth of fungal population and the interaction between population

The carbon cycle is an important part of the geochemical cycle of the Earth. As the primary decomposers of organic material in terrestrial ecosystems, fungi are critical agents of the global carbon cycle. Based on the two characteristics of a fungus, the growth rate of the fungus and the fungus’ tolerance to moisture, this article will establish a mathematical model to describe fungi and their role in the decomposition of ground litter (dead plant material) and woody fibers. First of all, the growth rate of a single fungus population was determined by modifying the Logistic population growth model. According to the hyphal extension rate of a fungus comprehensively measured by temperature and humidity changes, the effect of hyphal extension rate on wood decomposition rate is obtained. Next, this article uses the competitive ranking of fungi and the moisture niche width to determine the moisture tolerance of fungi and the influence of fungus moisture tolerance on wood decomposition rate. Integrating the hyphal extension rate and moisture tolerance of fungi, we established a wood decomposition rate model for a single fungus community. Based on this model and Lotka-Volterra model, this paper quantified and described the interaction between different types of fungi, and constructed a model of wood decomposition rate under the interaction of multiple fungal populations. Finally, the sensitivity and stability of the model are analyzed and tested. For the role and importance of biodiversity in the ecosystem, we conducted a more comprehensive study, and analyzed the role and principle of biodiversity in the process of environmental factors change.

Forest Resource Availability After Nuclear War or Other Sun‐Blocking Catastrophes

AbstractA global, sun‐blocking catastrophe like nuclear war, an asteroid strike, or a super volcano eruption spells disaster for most aspects of life as we know it. There have been many studies on how differing magnitudes of sun‐blocking catastrophes would affect the global climate, and many mention the effects of this cold, dark climate on forests and cropping systems. However, few studies have solely focused on the effects of nuclear winter on forests in terms of food, resources, and decomposition. Forests already provide over a billion people with food and fuel for their livelihoods. In this review, we connect how prehistoric catastrophes affected the world's forests to how a current‐day catastrophe may affect forest health, forest resource availability, and wood decomposition rates. We briefly discuss how forest resources may be used in this post‐catastrophe climate for food and fuel in an energy and fuel‐depleted world. We use this information to make policy and education suggestions to prepare for future catastrophes, build resilience from smaller local disasters, prepare for the many effects of climate change, and discourage nuclear weapon stockpiles.

Legacies of invertebrate exclusion and tree secondary metabolites control fungal communities in dead wood.

During decomposition of organic matter, microbial communities may follow different successional trajectories depending on the initial environment and colonizers. The timing and order of the species arrival (assembly history) can lead to divergent communities through priority effects. We explored how assembly history and resource quality affected fungal communities and decay rate of decomposing wood, 1.5 and 4.5 years after tree felling. Additionally, we investigated the effect of invertebrate exclusion during the first two summers. We measured initial resource quality of bark and wood of aspen (Populus tremula) logs and surveyed the fungal communities by DNA metabarcoding at different times during succession. We found that gradients in fungal community composition were related to resource quality and we discuss how this may reflect different fungal life history strategies. As with previous studies, the initial amount of bark tannins was negatively correlated with wood decomposition rate over 4.5 years. The initial fungal community explained variation in community composition after 1.5, but not 4.5, years of succession. Although the assembly history of initial colonizers may cause alternative trajectories in successional communities, our results indicate that the communities may converge with the arrival of secondary colonizers. We also identified a strong legacy of invertebrate exclusion on fungal communities, even after 4.5 years of succession, thereby adding crucial knowledge on the importance of invertebrates in affecting fungal community development. By measuring and manipulating aspects of assembly history and resource quality that have rarely been studied, we expand our understanding of the complexity of fungal community dynamics.

Deadwood substrate and species-species interactions determine the release of volatile organic compounds by wood-decaying fungi

Wood-decaying fungi in the phylum Basidiomycota play a significant role in the global carbon cycle, as they decompose deadwood effectively. Fungi may compete for utilizable substrate and growth space by producing soluble metabolites and by releasing volatile organic compounds (VOCs). We determined the role of wood substrate (Scots pine or Norway spruce) on the generation of hyphal biomass, secreted metabolites and enzyme activities, wood decomposition rate, and fungal species-species interactions on VOC release. We studied one brown-rot species ( Fomitopsis pinicola ) and two white-rot species ( Phlebia radiata and Trichaptum abietinum ) cultivated individually or in combinations. Wood substrate quality influences VOC release by the wood-decaying fungi, with signature differences caused by the decomposition trait (brown rot or white rot) and species-species interactions. VOC release was higher in the cultures of Basidiomycota than in uncolonized sawdust. Fungal biomass, decomposition activity, iron reduction, enzyme activities, oxalate anion content, and oxalic acid production explained VOC release from decaying wood. • Species-species interactions of Basidiomycota accelerate sesquiterpene release. • Wood substrate quality affects VOC release. • VOC release depends on the decomposition trait and species-species interactions. • Decomposition activity, iron reduction and enzyme activities explained VOC release.

Stock of standing dead trees in boreal forests of Central Siberia

A significant part of carbon assimilated by forest is deposited in tree trunks. Growth and development of tree stands is accompanied by accumulation of standing dead trees (snags) due to natural tree mortality and as a result of the impact of exogenous factors. Carbon accumulated in these dead trunks is excluded from the fast turnover due to low rate of wood decomposition, so that snags can be considered as a pool of organic carbon with a slow rate of its return to the atmosphere. We estimated stock of snags on 54 sample plots, which represent the main types of forest ecosystems in the northern and middle taiga of Central Siberia. In the middle taiga, stock of snags varied from up to 7 m3 ha-1 in Siberian spruce forests to 20-42 m3 ha-1 in Scots pine forests. Larch forests in the northern taiga had the similar stock of snags as larch forests in the middle taiga despite significantly higher growing stock in the later. Snags contributed from 4 to 19% to the total stock of woody biomass in studied forests. This study indicated the significance of snags and can be used to estimate carbon budget of forest ecosystems of the region.

Fine Wood Decomposition Rates Decline with the Age of Tropical Successional Forests in Southern Mexico: Implications to Ecosystem Carbon Storage

Fine Wood Decomposition Rates Decline with the Age of Tropical Successional Forests in Southern Mexico: Implications to Ecosystem Carbon Storage

Urbanisation differently affects decomposition rates of recalcitrant woody material and labile leaf litter

Litter decomposition is a fundamental ecosystem process and service that supplies nutrients to the soil. Although decomposition rate is influenced by litter quality, climatic conditions, the decomposer community and vegetation type in non-urban ecosystems, little is known about the degradation of different organic matter types in urban settings. We investigated the decomposition rates of recalcitrant (wood sticks for 4 years) and labile litter (green tea leaves in pyramid-shaped teabags for 3 years) in urban habitats that differed in level of management and disturbance. We found that recalcitrant woody material decomposed slower in urban habitat types (ca. 60–75% mass loss after 4 years in remnant spruce forests, park lawns, ruderal habitats) than in natural to semi-natural spruce forest soils (84% mass loss) outside the city. Labile tea litter, however, decomposed faster in typical open urban habitats (70% mass loss after 3 years in park lawns, ruderal habitats) than in forested habitats (60% mass loss in semi-natural and remnant spruce forests), with a remarkable dichotomy in decomposition rate between open and forested habitats. We suggest that the slower rate of wood decomposition in the city relates to its depauperate saprotrophic fungal community. The faster rate of labile litter decomposition in open habitats is difficult to explain, but is potentially a consequence of environmental factors that support the activity of bacteria over fungi in open habitats. We propose that the reintroduction of decaying woody material into the urban greenspace milieu could increase biodiversity and also improve the ability of urban soils to decompose an array of organic material entering the system. This reintroduction of decaying woody material could either occur by leaving cut logs – due to management – in urban remnant forests, which has been shown to be accepted as natural features by residents in Fennoscandian cities, and by placing logs in urban parks in ways that communicate their intentional use as part of urban landscape design and management.

Microbial and environmental controls on wood decomposition in deciduous forests of different ages

Wood decomposition is regulated by microbial community and soil conditions and plays an important role in global carbon cycling. Among many factors, local conditions, associated with forest age and the leaf litter adjacent to decaying wood may directly and indirectly influence microbial colonization and rate of decay. In this study, wood sticks with and without leaf litter were buried in young (50–70 years), old (120–150 years) and uncut (over 200 years) forests at the Smithsonian Environmental Research Center (SERC), Maryland, USA to test hypotheses about woody and foliar litter interaction during decomposition and whether decay rates are associated with differences in microbial community and soil properties. At the early stages of decomposition, wood mass loss in the young forests was significantly higher than that in other two forests but was not different between old and uncut forests. Adjacent foliar litter increased functional diversity of wood colonizing fungi, and enhanced decay in old and uncut stands. Factors, significantly correlated with decomposition, included fungal community composition, soil moisture, pH and C:N ratio. This study highlights the importance of local factors, such as land use and forest age affecting wood decomposition rates.

The wood decomposition system and community diversity of fungi

Fungi are critical agents of the global carbon cycle, however, our ability to link fungal community composition to ecosystem functioning is constrained by a limited understanding the wood decomposition rates of fungus. Here we examined the wood decomposition rate of fungus and the impact of fungal community diversity on the wood decomposing. To understand the relationship between the wood decomposition rate and the traits of fungi, we introduced 37 types of fungus into the wood decomposition system and set the growth rate and moisture tolerance of fungus as the explanatory variables. In addition, we constructed the competition, parasitic and symbiotic model based on Malthus-block growth comprehensive to analyze and predict the interactions between different fungus. The entropy weight-TOPSIS model was established to understand the biodiversity of fungus and obtain the relative dominance degree which can reflect the advantages and disadvantages of different fungus. The ARIMA model was used in five different environments to predict the impact of fungal community diversity on the overall efficiency of wood decomposing. Our research can not only help us to better understand the fungus community, but also significant for improving the quality of climate and the carbon cycle.

Island size affects wood decomposition by changing decomposer distribution

Island biogeography theory describes the relationship between island size, isolation and biodiversity, but it does not address the effects on ecosystem processes such as wood decomposition. Wood decomposition rates can be expected to increase with decomposer diversity, which increases with island size and decreases with increasing island isolation. However, island size and isolation effects on wood decomposition may also act by impacting substrate composition, forest composition and biotic interactions among decomposers. In this study, branch‐wood decomposition rates of three locally dominant tree species deployed at 154 plots on 15 islands in Thousand Island Lake, China, were measured over one year. The results showed that decomposition rates in coarse‐mesh bags where both termites and fungi were allowed access increased with island size for the two tree species preferred by the termites. By contrast, decomposition rates in fine‐mesh bags which only fungi could access decreased with island size for the two tree species preferred by fungi. The positive effects of island size on termite feeding activity were mediated by a higher deadwood diversity, a more diverse forest composition and a higher soil moisture content, with forest composition shaping soil moisture. For fungal diversity, the negative effects of island size were attributable to a higher soil moisture content and termite feeding activity. Island isolation decreased fungal diversity but increased wood decomposition rates. Our study indicates that island size affects wood decomposition by altering the distribution of decomposers and their relative contributions to wood decomposition. Size–decomposition relationship further depends on the affinity between substrates and decomposer taxa. In general, our results show that ecosystem processes may be affected by island size and isolation, but the patterns are more complex than expected from the island biogeography theory. This discrepancy is largely due to the different responses and trade‐offs among different functional groups.

Deadwood volume and quality in recreational forests: the case study of the Belgrade forest (Turkey)

Aim of the study: The aim of this study is to understand quantitative and qualitative characteristics of deadwood in recreational forests.Area of study: Belgrade forest in the North of Istanbul city (Turkey).Material and methods: The data has been collected through a stratified sampling scheme that has randomly located 50 clusters formed by 3 sample plots each (150 sample plots).Main results: The results show an average deadwood volume of 16.49 m3 ha-1 (81.5% in logs, 16.4% in snags, 2.1% in stumps). The highest volume of deadwood is in oldest forests (age over 180 years) with an average value of 20.39 m3 ha-1, followed by forests with 61-120 years with 15.77 m3 ha-1. Concerning forest management objectives, the results show that average deadwood volume is 13.66 m3 ha-1 in the forest section managed for water resource conservation and 21.14 m3 ha-1 in the forest section managed for recreational purposes.Research highlights: Deadwood management in the recreational forests must consider both biodiversity conservation and recreational attractiveness of an area.Keywords: forest management; forest types; forest accessibility; stand age; wood decomposition rate.

Various effects of the expression of the xyloglucanase gene from Penicillium canescens in transgenic aspen under semi-natural conditions

BackgroundRecombinant carbohydrases genes are used to produce transgenic woody plants with improved phenotypic traits. However, cultivation of such plants in open field is challenging due to a number of problems. Therefore, additional research is needed to alleviate them.ResultsResults of successful cultivation of the transgenic aspens (Populus tremula) carrying the recombinant xyloglucanase gene (sp-Xeg) from Penicillium canescens in semi-natural conditions are reported in this paper for the first time. Change of carbohydrate composition of wood was observed in transgenic aspens carrying the sp-Xeg gene. The transformed transgenic line Xeg-2-1b demonstrated accelerated growth and increased content of cellulose in wood of trees growing in both greenhouse and outside in comparison with the control untransformed line Pt. The accelerated growth was observed also in the transgenic line Xeg-1-1c. Thicker cell-wall and longer xylem fiber were also observed in both these transgenic lines. Undescribed earlier considerable reduction in the wood decomposition rate of the transgenic aspen stems was also revealed for the transformed transgenic lines. The decomposition rate was approximately twice as lower for the transgenic line Xeg-2-3b in comparison with the control untransformed line Pt.ConclusionA direct dependence of the phenotypic and biochemical traits on the expression of the recombinant gene sp-Xeg was demonstrated. The higher was the level of the sp-Xeg gene expression, the more pronounced were changes in the phenotypic and biochemical traits. All lines showed phenotypic changes in the leave traits. Our results showed that the plants carrying the recombinant sp-Xeg gene do not demonstrate a decrease in growth parameters in semi-natural conditions. In some transgenic lines, a change in the carbohydrate composition of the wood, an increase in the cell wall thickness, and a decrease in the rate of decomposition of wood were observed.