贵州麻若平台泥炭藓沼泽中泥炭藓持水特性及其与土壤营养元素关系研究

泥炭藓属（Sphagnum）植物的持水特性在泥炭湿地形成过程中起着重要作用,研究其与土壤营养元素之间的关系有助于地区湿地保护和退化湿地的修复。以贵州麻若平台分布的泥炭沼泽为对象,采用方差分析、相关性分析和冗余分析等方法对沼泽内泥炭藓的生物量、蓄水量、吸水率和土壤营养元素含量等进行研究。结果显示,该区域泥炭藓物种组成主要包括狭叶泥炭藓（Sphagnum cuspidatum Ehrh.）、多纹泥炭藓（Sphagnum multifibrosum X.J.Li&M.Zang）和卵叶泥炭藓（Sphagnum ovatum Hampe.）3种,狭叶泥炭藓为优势种,占泥炭藓总盖度的87.2%。沼泽中泥炭藓的生物量为（0.62 ±0.01）kg/m²,自然蓄水量为（9.42 ±0.45）kg/m²,饱和吸水率达1827.41%±34.56%,说明泥炭藓具有很强的持水能力。RDA分析表明,泥炭藓的生物量、饱和吸水量和饱和吸水率主要受沼泽土壤总钾、总磷、有效磷、有效氮、有效钾的影响,泥炭藓的鲜重、自然蓄水量和自然吸水率受土壤pH和水位的影响较大。泥炭藓的生物量、饱和蓄水量、饱和吸水率与土壤总钾含量呈正相关,与土壤总磷、有效磷、总钾、有效氮、总氮、有机质含量呈负相关,说明土壤总磷、有效磷、有效钾、有效氮、总氮、有机质对沼泽中泥炭藓的持水能力具有抑制作用。     

Perennial biomass cropping and use: Shaping the policy ecosystem in European countries

Demand for sustainably produced biomass is expected to increase with the need to provide renewable commodities, improve resource security and reduce greenhouse gas emissions in line with COP26 commitments. Studies have demonstrated additional environmental benefits of using perennial biomass crops (PBCs), when produced appropriately, as a feedstock for the growing bioeconomy, including utilisation for bioenergy (with or without carbon capture and storage). PBCs can potentially contribute to Common Agricultural Policy (CAP) (2023–27) objectives provided they are carefully integrated into farming systems and landscapes. Despite significant research and development (R&D) investment over decades in herbaceous and coppiced woody PBCs, deployment has largely stagnated due to social, economic and policy uncertainties. This paper identifies the challenges in creating policies that are acceptable to all actors. Development will need to be informed by measurement, reporting and verification (MRV) of greenhouse gas emissions reductions and other environmental, economic and social metrics. It discusses interlinked issues that must be considered in the expansion of PBC production: (i) available land; (ii) yield potential; (iii) integration into farming systems; (iv) R&D requirements; (v) utilisation options; and (vi) market systems and the socio-economic environment. It makes policy recommendations that would enable greater PBC deployment: (1) incentivise farmers and land managers through specific policy measures, including carbon pricing, to allocate their less productive and less profitable land for uses which deliver demonstrable greenhouse gas reductions; (2) enable greenhouse gas mitigation markets to develop and offer secure contracts for commercial developers of verifiable low-carbon bioenergy and bioproducts; (3) support innovation in biomass utilisation value chains; and (4) continue long-term, strategic R&D and education for positive environmental, economic and social sustainability impacts.     

The Financial Costs of Ecologically Nonsustainable Farming Practices in a Semiarid System

Nonsustainable ostrich farming practices have degraded large areas of the Little Karoo, a semiarid region in South Africa. The Little Karoo lies within the Succulent Karoo biome, a recognized biodiversity hotspot. A financial feasibility analysis was undertaken from a private landowner’s perspective to examine the costs and benefits of rehabilitating degraded areas thereby allowing farmers to shift their production focus from ostrich to sheep farming, a financially stable and relatively conservation‐compatible land use. Our aim was to raise awareness, at a private landowner level, to the opportunity costs incurred through unsustainable land use practices. We calculated and contrasted net present values for rehabilitation and no rehabilitation scenarios and investigated model sensitivities relating to seed costs, seedling survival and ostrich product prices. Rehabilitation was not found to be financially feasible for private landholders over 20 years. Seedling survival and associated seed costs were found to have strong controlling effects. Third parties need to contribute both financially and in terms of research outputs if sustainable land use practices are to be achieved in this area. This study elucidates the true costs associated with the unsustainable practice of ostrich farming and sounds a cautionary warning.     

Values and perceptions of landowners within remaining breeding territories of Eurasian Curlew Numenius arquata in Ireland

Habitat loss and degradation have been identified as some of the main threats to breeding Curlew (Numenius arquata) across much of Europe. In Ireland, marginal habitats such as rough or wet grasslands and peatlands have been fragmented or degraded by activities including afforestation, drainage and intensification. The management implemented by landowners directly affects Curlew breeding territories. However, the values and perceptions held by landowners whose lands contain Curlew breeding territories, or the factors driving the decisions behind farming practices in these areas are rarely considered when looking at the causes of changes in these bird populations. This study, as part of the Curlew Conservation Programme established in 2017, gathered data through the distribution of questionnaires to landowners found within three kilometres of Curlew breeding territories in Ireland. In this study, we identify the current land uses being employed in Curlew breeding territories, and query future projections of land use in these areas. We investigate landowners’ perceptions of the requirements to sustain favourable environments for breeding Curlew. We also explore landowner values with respect to farming. The landowners in this study identified habitat loss and predation as the main drivers for Curlew declines. The majority of farming systems in this study were cattle rearing, the sustainability of which is under threat across Ireland. The results indicate that these landowners are not financially motivated, however, the availability of financial aid and expert advice are listed by landowners as requirements for traditional farming practices to continue. These results give an insight to the lifestyle, values and perceptions owners of land adjacent or within Curlew breeding territories. This information can be used to design Curlew conservation programmes that align with these values.     

Spectroscopic properties of dissolved humic substances - a reflection of land use history in a fen area

The elemental composition and spectroscopic properties of dissolved fulvic acids isolated from different sampling media (topsoil, ground and surface water) of a natural fen area (high portion of organic soils) were examined to reveal the effects of land use history. These effects need to be known if dissolved humic substances are to be a major factor in identifying the impact of present and future changes in land use. Dissolved fulvic acids (topsoil, groundwater) from highly degraded peatlands (due to a long-term agricultural use) exhibit lower C/N ratios, higher absorption in the UV spectra, and higher absorption at 1,620 cm^–1 in the FTIR spectra compared with fulvic acids from relatively intact peatlands. These properties illustrate that long-term agricultural use with high inputs results in increased aromatic structures and a further humification of dissolved fulvic acids due to very strong peat decomposition compared with relatively intact peatlands. Synchronous fluorescence spectra also indicate the higher level of aromatic structures within fulvic acids isolated from sites with long-term agricultural use (high peat decomposition) compared with a land use history resulting in a lower peat decomposition. The different sources of fulvic acids in surface water (precipitation, runoff, interflow, groundwater) are the main reason for these effects not being detected in fulvic acids isolated from surface water. Short-term changes in land use characterized by a transition from crop farming to an unimproved grassland were found not to affect the spectroscopic properties of dissolved fulvic acids. A humification index deduced from the synchronous fluorescence spectra is proposed. We have strong evidence that dissolved humic substances indicate changes in the environmental conditions (both anthropogenic and natural) of wetlands with a high proportion of organic soils.     

On the after‐use and restoration of abandoned extracted peatlands in the Baltic countries

In the Baltic countries (Estonia, Latvia, and Lithuania), mires directly affected by peat extraction cover almost 90,000 ha. Of these, over 26,200 ha have already been extracted and are abandoned. The main aim of this article is to give an overview of the extent of extracted peatlands in the Baltics, the legislative background around the land‐use options, and the directions of after‐use of peatlands since the middle of the 20th century. We also critically review results from restoration of abandoned extracted peatlands and assess whether they are on a trajectory toward reinitiation of paludification and functioning mire ecosystems. Almost all currently existing abandoned extracted peatlands in the Baltics were abandoned during and shortly after the Soviet period (1940–1991) without any restoration measures. The rest of the extracted areas were mostly afforested, converted into agricultural lands, berry plantations, or water bodies. The after‐use was mostly experimental, lacking systematic, proper assessment of outcome, cost and benefits, and side effects. The data are scarce but it could be estimated that only <10% (Estonia and Lithuania) and <20% (Latvia) of the total area of abandoned extracted peatlands were used for some purposes after peat extraction. Recently, several trials aimed at restoring the mire vegetation and ecosystem functions have been started in abandoned extracted peatlands in all three countries. In the coming years, the restoration of extracted peatlands in the Baltics will start on much bigger areas within different projects and initiatives cofinanced by the European Union.     

Structure of microbial communities in <Emphasis Type="Italic">Sphagnum</Emphasis> peatlands and effect of atmospheric carbon dioxide enrichment

Little is known about the structure of microbial communities in Sphagnum peatlands, and the potential effects of the increasing atmospheric CO2 concentration on these communities are not known. We analyzed the structure of microbial communities in five Sphagnum-dominated peatlands across Europe and their response to CO2 enrichment using miniFACE systems. After three growing seasons, Sphagnum samples were analyzed for heterotrophic bacteria, cyanobacteria, microalgae, heterotrophic flagellates, ciliates, testate amoebae, fungi, nematodes, and rotifers. Heterotrophic organisms dominated the microbial communities and together represented 78% to 97% of the total microbial biomass. Testate amoebae dominated the protozoan biomass. A canonical correspondence analysis revealed a significant correlation between the microbial community data and four environmental variables (Na+, DOC, water table depth, and DIN), reflecting continentality, hydrology, and nitrogen deposition gradients. Carbon dioxide enrichment modified the structure of microbial communities, but total microbial biomass was unaffected. The biomass of heterotrophic bacteria increased by 48%, and the biomass of testate amoebae decreased by 13%. These results contrast with the absence of overall effect on methane production or on the vegetation, but are in line with an increased below-ground vascular plant biomass at the same sites. We interpret the increase in bacterial biomass as a response to a CO2-induced enhancement of Sphagnum exudation. The causes for the decrease of testate amoebae are unclear but could indicate a top-down rather than a bottom-up control on their density.     

Restoration Ecology of Lowland Tropical Peatlands in Southeast Asia: Current Knowledge and Future Research Directions

Studies of restoration ecology are well established for northern peatlands, but at an early stage for tropical peatlands. Extensive peatland areas in Southeast Asia have been degraded through deforestation, drainage and fire, leading to on- and off-site environmental and socio-economic impacts of local to global significance. To address these problems, landscape-scale restoration measures are urgently required. This paper reviews and illustrates, using information from on-going trials in Kalimantan, Indonesia, the current state of knowledge pertaining to (i) land-cover dynamics of degraded peatlands, (ii) vegetation rehabilitation, (iii) restoration of hydrology, (iv) rehabilitation of carbon sequestration and storage, and (v) promotion of sustainable livelihoods for local communities. For a 4500 km² study site in Central Kalimantan, Indonesia, we show a 78% reduction in forest cover between 1973 and 2003 and demonstrate that fire, exacerbated by drainage, is the principal driver of land-use change. Progressive vegetation succession follows infrequent, low-intensity fires, but repeated and high-intensity fires result in retrogressive succession towards non-forest communities. Re-wetting the peat is an important key to vegetation restoration and protection of remaining peat carbon stocks. The effectiveness of hydrological restoration is discussed and likely impacts on greenhouse gas emissions evaluated. Initial results indicate that raised water levels have limited short-term impact on reducing CO₂ emissions, but could be critical in reducing fire risk. We conclude that successful restoration of degraded peatlands must be grounded in scientific knowledge, relevant to socio-economic circumstances, and should not proceed without the consent and co-operation of local communities.     

Towards sustainable management of Indonesian tropical peatlands

Large areas of Indonesian peatlands have been converted for agricultural and plantation forest purposes. This requires draining with associated CO₂ emissions and fire risks. In order to identify alternative management regimes for peatlands, it is important to understand the sustainability of different peatland uses as well as the economic benefits peatlands supply under different land uses. This study explores the key sustainability issues in Indonesian peatlands, the ecosystem services supplied by peatlands, and potential responses to promote more sustainable peatland use. A literature review and spatial analysis were conducted. Based on predominantly government data, we estimate the amount of Indonesian peatlands that has been converted between 2000 and 2014. We quantify increases in oil palm and plantation forest crop production in this period, and we analyse key sustainability issues, i.e. peat fires and smoke-haze, soil subsidence and flood risk, CO₂ emissions, loss of habitat (in protected areas), and social conflicts that influence sustainability of Indonesian peatlands management. Among others we show that CO₂ emissions from peatlands in Indonesia can be estimated at between 350 and 400 million ton CO₂ per year, and that encroachment of oil palm and plantation forestry (acacia, rubber) has taken place on 28% of protected areas. However, as we examine, the uncertainties involved are substantial. Based on our findings, we distil several implications for the management of the peatlands.     

Ecophysiological adjustment of two Sphagnum species in response to anthropogenic nitrogen deposition

Here, it was investigated whether Sphagnum species have adjusted their nitrogen (N) uptake in response to the anthropogenic N deposition that has drastically altered N-limited ecosystems, including peatlands, worldwide. A lawn species, Sphagnum balticum, and a hummock species, Sphagnum fuscum, were collected from three peatlands along a gradient of N deposition (2, 8 and 12 kg N ha(-1) yr(-1)). The mosses were subjected to solutions containing a mixture of four N forms. In each solution one of these N forms was labeled with (15)N (namely (15)NH(+)(4), (15)NO(-)(3) and the amino acids [(15)N]alanine (Ala) and [(15)N]glutamic acid (Glu)). It was found that for both species most of the N taken up was from , followed by Ala, Glu, and very small amounts from NO(-)(3). At the highest N deposition site N uptake was reduced, but this did not prevent N accumulation as free amino acids in the Sphagnum tissues. The reduced N uptake may have been genetically selected for under the relatively short period with elevated N exposure from anthropogenic sources, or may have been the result of plasticity in the Sphagnum physiological response. The negligible Sphagnum NO(-)(3) uptake may make any NO(-)(3) deposited readily available to co-occurring vascular plants.     

Farmers’ Perspectives on Vital Soil-related Ecosystem Services in Intensive Swidden Farming Systems in the Peruvian Amazon

A growing dilemma is how to conserve Amazonian forest while allowing local people to secure their livelihoods. Small-scale swidden farming in Amazonia is entirely dependent on the continued provision of ecosystem services (ES) that generate the conditions for agriculture. This study identified soil-related ES needed for, and enhanced by, productive swidden systems from the farmer’s perspective. Workshops in six farming communities in northeastern Peru discussed various land uses, swidden systems that continue to be productive, and swidden systems on degraded land. The participating farmers noted changes in their production systems and described the ES (or lack thereof) in terms of soil quality, crop production quantity and quality, burning practices, forest regeneration, and farming skill. The central elements described in farmers’ own strategies for managing soil-related ES were fallow management for biomass production and crop diversity, factors identified as central to future ES management work in established agricultural areas in Amazonia.     

Is woody bioenergy carbon neutral? A comparative assessment of emissions from consumption of woody bioenergy and fossil fuel

Under the current accounting systems, emissions produced when biomass is burnt for energy are accounted as zero, resulting in what is referred to as the ‘carbon neutrality’ assumption. However, if current harvest levels are increased to produce more bioenergy, carbon that would have been stored in the biosphere might be instead released in the atmosphere. This study utilizes a comparative approach that considers emissions under alternative energy supply options. This approach shows that the emission benefits of bioenergy compared to use of fossil fuel are time‐dependent. It emerges that the assumption that bioenergy always results in zero greenhouse gas (GHG) emissions compared to use of fossil fuels can be misleading, particularly in the context of short‐to‐medium term goals. While it is clear that all sources of woody bioenergy from sustainably managed forests will produce emission reductions in the long term, different woody biomass sources have various impacts in the short‐medium term. The study shows that the use of forest residues that are easily decomposable can produce GHG benefits compared to use of fossil fuels from the beginning of their use and that biomass from dedicated plantations established on marginal land can be carbon neutral from the beginning of its use. However, the risk of short‐to‐medium term negative impacts is high when additional fellings are extracted to produce bioenergy and the proportion of felled biomass used for bioenergy is low, or when land with high C stocks is converted to low productivity bioenergy plantations. The method used in the study provides an instrument to identify the time‐dependent pattern of emission reductions for alternative bioenergy sources. In this way, decision makers can evaluate which bioenergy options are most beneficial for meeting short‐term GHG emission reduction goals and which ones are more appropriate for medium to longer term objectives.     

Net land‐atmosphere flows of biogenic carbon related to bioenergy: towards an understanding of systemic feedbacks

The notion that biomass combustion is carbon neutral vis‐a‐vis the atmosphere because carbon released during biomass combustion is absorbed during plant regrowth is inherent in the greenhouse gas accounting rules in many regulations and conventions. But this ‘carbon neutrality’ assumption of bioenergy is an oversimplification that can result in major flaws in emission accounting; it may even result in policies that increase, instead of reduce, overall greenhouse gas emissions. This commentary discusses the systemic feedbacks and ecosystem succession/land‐use history issues ignored by the carbon neutrality assumption. Based on recent literature, three cases are elaborated which show that the C balance of bioenergy may range from highly beneficial to strongly detrimental, depending on the plants grown, the land used (including its land‐use history) as well as the fossil energy replaced. The article concludes by proposing the concept of GHG cost curves of bioenergy as a means for optimizing the climate benefits of bioenergy policies.     

The relative ability of fungi from Sphagnum fuscum to decompose selected carbon substrates

Nine species from a suite of 55 microfungi isolated from living and decomposing Sphagnum fuscum were selected for studies of in vitro decomposition of tannic acid, cellulose, and starch. In vitro decomposition of S. fuscum plants and spruce wood chips was also examined. Oidiodendron maius and Oidiodendron scytaloides degraded tannic acid, giving a positive reaction for polyphenol oxidases. Most taxa degraded cellulose and starch via the synthesis of cellulases and amylase, respectively. Mass losses of spruce wood chips generally exceeded those of S. fuscum. A basidiomycete, similar to Bjerkandera adusta, caused the greatest mass losses in spruce wood chips (10.2%), while O. scytaloides caused the smallest mass losses (3.4%) after 8 weeks. For S. fuscum, Sordaria fimicola caused the greatest (5.1%) and Mucor hiemalis the smallest (0.1%) mass losses after 8 weeks. Filamentous microfungi have considerable potential to decompose a variety of carbon substrates of bryophilous residues in peatlands.     

Mercury methylation in Sphagnum moss mats and its association with sulfate-reducing bacteria in an acidic Adirondack forest lake wetland

Processes leading to the bioaccumulation of methylmercury (MeHg) in northern wetlands are largely unknown. We have studied various ecological niches within a remote, acidic forested lake ecosystem in the southwestern Adirondacks, NY, to discover that mats comprised of Sphagnum moss were a hot spot for mercury (Hg) and MeHg accumulation (190.5 and 18.6 ng g?1 dw, respectively). Furthermore, significantly higher potential methylation rates were measured in Sphagnum mats as compared with other sites within Sunday Lake's ecosystem. Although MPN estimates showed a low biomass of sulfate-reducing bacteria (SRB), 2.8 × 10? cells mL?1 in mat samples, evidence consisting of (1) a twofold stimulation of potential methylation by the addition of sulfate, (2) a significant decrease in Hg methylation in the presence of the sulfate reduction inhibitor molybdate, and (3) presence of dsrAB-like genes in mat DNA extracts, suggested that SRB were involved in Hg methylation. Sequencing of dsrB genes indicated that novel SRB, incomplete oxidizers including Desulfobulbus spp. and Desulfovibrio spp., and syntrophs dominated the sulfate-reducing guild in the Sphagnum moss mat. Sphagnum, a bryophyte dominating boreal peatlands, and its associated microbial communities appear to play an important role in the production and accumulation of MeHg in high-latitude ecosystems.     

Reforestation: A potential approach to mitigate excess atmospheric CH4 build‐up

Summary Methane (CH₄) is a very dangerous greenhouse gas, and its atmospheric concentration is rising due to natural and anthropogenic disturbances. Anthropogenic disturbances such as forest clearing, land‐use changes and farming practices all result in considerable increases in N inputs and alterations in soil properties, including the CH₄ sink potential of the soil. Forest soils contribute to the consumption of CH₄ due to the presence of methanotrophic bacteria. It is proposed that the restoration of degraded forest ecosystems or unused degraded land may significantly contribute to the recovery of methanotrophic activity in the soil and thereby the soil CH₄ sink potential.     

China's bioenergy potential

Despite great enthusiasm about developing renewable energy in China, the country's bioenergy potential remains unclear. Traditional utilization of bioenergy through primarily household combustion of crop residue and fuelwood is still a predominant energy source for rural China. More efficient utilization of ～300 million tons of crop residues for bioelectricity generation could add a couple of percent of renewable energy to China's total energy production. With <9% of the world's arable land supporting ～20% of the world's population, China is already a net grain importer and has little extra farmland for producing a significantly additional amount of biofuels from first‐generation energy crops, such as maize, sugarcane, and soybean. Second‐generation energy crops hold the greatest potential for bioenergy development worldwide. Miscanthus, a native perennial C4 grass that produces high biomass across almost the entire climatic zone of China, is the most promising second‐generation energy crop to domesticate and cultivate. A reasonable near‐term goal is to produce 1 billion tons of Miscanthus biomass annually from ～100 million hectares of marginal and degraded land concentrated in northern and northwestern China. This can generate ～1458 TW h electricity and mitigate ～1.7 billion tons of CO₂ emission from power coal, which account for ～45% of China's electricity output and ～28% of CO₂ emission in 2007. Furthermore, growing perennial grasses on marginal and degraded land will contribute to the ongoing efforts in China to restore vast areas of land under serious threat of desertification. With this potential taken into account, bioenergy can play a major role in meeting China's rapidly growing energy demand while substantially reducing greenhouse gas emission.     

How litter quality affects mass loss and N loss from decomposing Sphagnum

Nitrogen (N) deposition may affect litter decomposition and may thus have an impact on the rate of carbon (C) sequestration in Sphagnum peatlands. We present results from four separate experiments aimed at delineating the effects of litter N-enrichment, Sphagnum species, stem part of Sphagnum , and place of incubation on decomposition rate and N release. We measured mass loss and N loss from litterbags incubated at 10-15 cm in the field for one year.
Mass loss was positively related to the N/C quotient of the litter, but depended strongly on the range in N/C quotients observed; only a distinct difference in N/C quotients affected mass loss. Although hummock species decayed at a slower rate than hollow species, the differences between the species became less pronounced for old stem parts and for N-enriched litter. Old stem parts decayed at a slower rate than young stem parts, except for S. papillosum . Neither position of incubation (low hummock or hollow), nor the inorganic N concentration of the incubation environment affected mass loss. N loss was mainly determined by, and positively related to, the N/C quotient of the litter; species and stem part had minor effects. Above a N/C quotient of about 0.015, net N loss was observed for all species.
We conclude that decomposition of Sphagnum is stimulated by N deposition. As the latter also affects litter N concentration and thus N release, we think that positive feedbacks through changing litter quality should be taken into account when modelling the effects of N deposition on Sphagnum peatlands and C sequestration in these systems.     

Nutrient limitations in an extant and drained poor fen: implications for restoration

In a species-rich poor fen (Caricetum nigrae) and a species-poor drained fen, the difference in nutrient limitation of the vegetation was assessed in a full-factorial fertilization experiment with N, P and K. The results were compared to the nutrient ratios of plant material and to chemical analysis of the topsoil. A rewetting experiment with intact sods was carried out in the glasshouse and the results are discussed in view of restoration prospects of drained and degraded peatlands. In the undrained poor fen the above-ground biomass yield was N-limited while the vegetation of the drained fen was K-limited. Experimental rewetting of intact turf samples, taken in the drained site, did not change the biomass yield or the type of nutrient limitation. It was concluded that mire systems which have been subjected to prolonged drainage are inclined to pronounced K-deficiency, probably due to washing out of potassium and harvesting the standing crop. This may hamper restoration projects in degraded peat areas where nature conservation tries to restore species-rich vegetation types with a high nature value.     

In vitro decomposition of Sphagnum by some microfungi resembles white rot of wood

The abilities of some ascomycetes (Myxotrichaceae) from a Sphagnum bog in Alberta to degrade cellulose, phenolics, and Sphagnum tissue were compared with those of two basidiomycetes. Most Myxotrichaceae degraded cellulose and tannic acid, and removed cell-wall components simultaneously from Sphagnum tissues, whereas the basidiomycetes degraded cellulose and insoluble phenolics, and preferentially removed the polyphenolic matrix from Sphagnum cell walls. Mass losses from Sphagnum varied from up to 50% for some ascomycetes to a maximum of 35% for the basidiomycetes. The decomposition of Sphagnum by the Myxotrichaceae was analogous to the white rot of wood and indicates that these fungi have the potential to cause significant mineralization of carbon in bogs.