Saproxylic species from different taxonomic groups often occur only on certain types of deadwood with specific qualitative characteristics. The various types of deadwood are very dynamic elements of ...forest ecosystems, associated with many site and stand features, as well as with the type of forest management. Using a pool of 29,098 sample plots spread across Poland, we analyzed 30 different deadwood types defined on the basis of three characteristics: position (standing, lying), degree of decomposition, and size. Statistical hurdle models were used to assess changes in the volume of individual deadwood types based on a broad range of independent variables. Depending on the type of management, terrain, site fertility, stand volume, tree density, and stand age, the models revealed substantial differences in the volume of different deadwood types, ranging from 0 to approx. 4 m3 ha−1. It was found that the volume of most deadwood types (except for a few, mostly with diameters under 15 cm) increases with stand age or stand volume. In managed forests at all stages of stand development there is a deficiency of thick deadwood. Both standing and lying deadwood at different decay stages is available continuously, irrespective of the values of individual independent variables, but considerable differences exist. While most lying deadwood exhibits higher levels of decomposition, in standing deadwood the proportions of different decay stages are strongly associated with tree diameter at breast height. The developed models make it possible to predict the volume of individual deadwood types for a broad range of independent variables. The current work presents several examples, with the results showing extremely complex relationships between deadwood diversity and site and stand features at every stage of forest development, with continuous changes in the volume and proportions of different deadwood types. In general, at the landscape level Polish forests contain both standing and lying deadwood at all decay stages in more or less equal proportions. However, in forest management one should pay special attention to the dimensions of retained deadwood. The absence of thick deadwood is particularly conspicuous in lowland managed forests.
•The total deadwood volume consists of many deadwood types with very different characteristics.•Statistical models based on stand features describe the diversity of dead wood with high accuracy.•The diversity of the deadwood changes with the age of the stand, the method of management and habitat conditions.•Some types of deadwood are not found in all forests, especially thick deadwood is completely removed.•Management of deadwood resources should be largely based on its diversity.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•We synthesize the measurement and dynamics of dead wood carbon and decomposition.•Many protocols exist for inventorying standing dead trees and downed woody debris.•Research needs are presented to ...promote the accurate quantification of dead wood.•Issues presented here are hindered by unknowns of future global change scenarios.
The amount and dynamics of forest dead wood (both standing and downed) has been quantified by a variety of approaches throughout the forest science and ecology literature. Differences in the sampling and quantification of dead wood can lead to differences in our understanding of forests and their role in the sequestration and emissions of CO2, as well as in developing appropriate strategies for achieving dead wood-related objectives, including biodiversity protection, and procurement of forest bioenergy feedstocks. A thorough understanding of the various methods available for quantifying dead wood stores and decomposition is critical for comparing studies and drawing valid conclusions. General assessments of forest dead wood are conducted by numerous countries as a part of their national forest inventories, while detailed experiments that employ field-based and modeling methods to understand woody debris patterns and processes have greatly advanced our understanding of dead wood dynamics. We review methods for quantifying dead wood in forest ecosystems, with an emphasis on biomass and carbon attributes. These methods encompass various sampling protocols for inventorying standing dead trees and downed woody debris, and an assortment of approaches for forecasting wood decomposition through time. Recent research has provided insight on dead wood attributes related to biomass and carbon content, through the use of structural reduction factors and robust modeling approaches, both of which have improved our understanding of dead wood dynamics. Our review, while emphasizing temperate forests, identifies key research needs and knowledge which at present impede our ability to accurately characterize dead wood populations. In sum, we synthesize the current literature on the measurement and dynamics of forest dead wood carbon stores and decomposition as a baseline for researchers and natural resource managers concerned about forest dead wood patterns and processes.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•We monitored 2744 retention trees individually for 20 years after timber harvests.•Retention tree mortality was high initially, but low after 4 years.•Retention level and prescribed burning affected ...the availability of deadwood.•Higher retention level promotes the volume and diversity of deadwood.•Low retention levels impose a trade-off between deadwood volume and continuity.
Deadwood is essential for species diversity in forests. Forest management has led to the shortage of deadwood in managed forests and, consequently, to the decline of biodiversity. Prescribed burning and tree retention during harvests may promote deadwood formation, but the long-term effectiveness of these methods is not known. We examined patterns of tree mortality and deadwood dynamics following tree retention and prescribed burning in Finnish boreal forests in a large-scale replicated field experiment with two factors: retention level (10 or 50 m3/ha) and burning (burned or unburned). We monitored 2744 trees individually for 20 years. Deadwood input was initially high after the treatments, since nearly all retention trees on the burned sites and about one third of the trees on the unburned sites died within four years. For the rest of the monitoring period, deadwood input was much lower since the mortality rate of retention trees decreased to a level similar to the background mortality rate. After 20 years from the treatments, deadwood volume varied from about 40 m3/ha on the burned sites with 50 m3/ha retention to about 5 m3/ha on the unburned sites with 10 m3/ha retention. Prescribed burning altered deadwood composition e.g. via the complete mortality of fire-susceptible tree species. Still, deadwood diversity was mainly affected by retention level. Lastly, prescribed burning generated high numbers of snags, which fell rather quickly, with an estimated maximal longevity of 49 years. We conclude that the combination of a high retention level and prescribed burning produces high volumes of diverse deadwood, and thereby has the potential to support the conservation of deadwood-associated biodiversity in managed forests. However, the stand-scale continuity of deadwood throughout the forestry rotation period is still uncertain. The application of management methods should be adjusted at the landscape level to ensure the continuity of deadwood habitats.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•The C and N dynamics are regulated mainly by tree species identity.•Wood density loss and cellulose and lignin degradation are related to the N dynamics.•Bark fragmentation partly controls the C and ...N amounts dynamics at the log level.•In boreal forests, downed logs contribute significantly to long-term C and N cycles.
Quantifying forest carbon (C) and nitrogen (N) turnover rates requires better understanding of the mechanisms of decomposition of coarse woody debris (CWD). We examined the dynamics of bulk density, C, N, cellulose and lignin in downed logs, taking into account initial interspecific trait differences in bark and wood, in a 66-year-long decomposition chronosequence in an old-growth mixed boreal forest.
Wood and bark density decreased with increasing decay class and time since tree death. The C concentration per mass did not change or slightly decreased. Nitrogen increased in wood faster than in bark. In aspen wood, it increased two times more intensively than in wood of conifers. The C/N ratio and the cellulose content decreased, whereas the lignin content increased, decreased or remained stable in wood depending on tree species and calculation basis. Spruce wood was characterized by the greatest cellulose degradation rates. The N availability positively influenced wood bulk density loss and cellulose degradation in wood of all tree species, as well as the C loss in conifer bark.
The total C amount in bark and wood of individual downed logs decreased. The total N amount decreased in bark and increased in wood with different rates depending on tree species identity.
The results indicate the importance of accounting for the CWD tissue tree species specific traits in decomposition studies. In old-growth boreal forests, downed logs contribute significantly to long-term C and N sequestration.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Deadwood is an important element of forest ecosystems that affects many of its components, including the soil environment. Our research is an attempt to determine the role of decaying wood in shaping ...the properties of forest soils in mountain ecosystems. The aim of our research was to present the influence of beech deadwood on physicochemical properties and microbiological diversity of soils. The research was carried out in the Baba Góra Massif at its northern exposure. The research plots were established in the altitude gradient at 600, 800 and 1000 m above sea level. On each plot, samples were taken from decaying wood, from the soil directly under the decaying log, and a soil sample 1 m from the log as a control. We determined the basic properties of the samples, that is pH, C and N concentration and lignin content. The enzymatic activity and additionally, the taxonomic composition of soil bacterial and fungal communities was determined in the collected samples. Our research indicates the important role of decaying beech wood in shaping the properties of forest soils. We noted a positive effect of decaying wood on the properties of the tested soils. Soils affected by deadwood were characterized by significantly higher pH, C and N concentrations compared to control soils, regardless of their location in the altitude gradient. Additionally, we found that soils affected by decaying wood are characterized by a different composition of microorganisms regardless of their location in the altitude gradient. In control soil the fungal and bacterial alpha diversity were lowest compared with the deadwood and soil under the influence of deadwood. Our results may have practical applications in the management of forest ecosystems. The presented results indicate the possibility of leaving deadwood in order to improve its basic physicochemical properties and increase microbial diversity.
Display omitted
•Decaying wood affects pH, C and N content in soils.•Enzymatic activity is a good measure of changes occurring in soil under deadwood.•Soils affected by deadwood are characterized by different microorganism composition.•Decaying wood effect is more visible at the lower positions of the altitude gradient.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Dead wood (DW) provides critical habitat for thousands of species in forests, but its amount, quality and diversity have been heavily reduced by forestry. Therefore, interventions aiming to increase ...DW might be necessary to support its associated biodiversity, even in protected forests, which may be former production forests. Our aim was to synthesize the current state of knowledge drawn from replicated experimental studies into solid quantitative evidence of the effects of DW manipulation on forest biodiversity, with a focus on protected forests.
We conducted a full systematic review of effects of DW manipulation on forest biodiversity in boreal and temperate regions. We included three intervention types: creation of DW from live trees at the site, addition of DW from outside the site and prescribed burning. Outcomes included abundance and species richness of saproxylic insects, ground insects, wood‐inhabiting fungi, lichens, reptiles and cavity‐nesting birds. In total, we included 91 studies, 37 of which were used in meta‐analyses.
Although meta‐analysis outcomes were heterogeneous, they showed that increasing the amount of DW (“DW enrichment”) has positive effects on the abundance and richness of saproxylic insects and fungi. The positive effect on saproxylic pest insect abundance tended to be less than that on saproxylic insects in general. No significant effects were found for ground insects or cavity‐nesting birds.
Although reviewed studies were mainly short term, our results support that management that increases DW amounts has the potential to increase the abundance of DW‐dependent species and, in most cases, also their species richness. Studies of burning showed positive effects on the abundance of saproxylic insects similar to those of other interventions, even though burning on average resulted in a smaller enrichment of DW amounts.
Policy implications. The findings of the review suggest that manipulating dead wood (DW) can be an effective part of conservation management to support biodiversity in protected areas. The findings also indicate that the diversity of DW types is important, a mix of DW qualities should be favoured. Burning seems to be an effective method to increase biodiversity but to benefit cavity‐nesting birds, snag losses need to be minimized.
Sammanfattning
Död ved utgör ett viktigt habitat för tusentals skogslevande arter men mängden, kvaliteteten och dess diversitet har kraftigt minskat på grund av skogsbruket. Aktiva åtgärder som ökar mängden död ved kan därför bli nödvändigt för att förbättra situationen för arter kopplade till död ved. Dessa åtgärder kan även bli aktuella i skyddade skogar, varav många områden utgörs av skogar som har en historik av mänsklig påverkan. Vårt syfte med denna studie var att kvantitativt sammanfatta befintlig kunskap som handlar om död ved‐manipulation och dess inverkan på biodiversitet med huvudfokus på skyddade skogar.
Vi har genomfört en komplett systematisk översiktssammanfattning om effekterna av död ved‐manipulation på biodoversiteten i tempererade och boreala skogar. Vi inkluderade tre typer av aktiva åtgärder: skapande eller adderande av död ved samt naturvårdsbränning. Vi inkluderade effekterna på förekomst och artmångfald av vedlevande insekter, marklevande insekter, vedlevande svampar, lavar, reptiler och hålhäckande fåglar. Vi hittade relevanta 91 studier och 37 av dessa användes i en meta‐analys.
Resultaten från meta‐analysen visade på att en ökning av död ved hade en tydlig positiv effekt på både förekomst och artmångfald av vedlevande insekter och svampar. Förekomsten av vedlevande insekter som klassades som skadegörare ökade också men inte i samma utsträckning som vedlevande insekter totalt sett. Vi hittade ingen signifikant effekt på marklevande insekter eller hålhäckande fåglar.
I de flesta studier som ingick i vår studie hade det gått endast en kort tid efter den aktiva åtgärden men resultaten visar ändå på att skötsel som ökar mängden död ved har potential att öka förekomst, samt i de flesta fall, även artförekomst, av arter kopplade till död ved. Även studierna som inkluderade naturvårdsbränning ökade förekomst av vedlevande insekter, trots att mängden död ved denna skötselmetod resulterade i var ungefär hälften jämfört med de övriga åtgärderna.
Riktlinjer för praktiker: Denna studie visade på att åtgärder som ökar mängden död ved kan vara en effektiv naturvårdande skötselåtgärd som ökar biodiversiteten i skyddade skogar. Resultaten indikerar även att diversiteten av den döda veden är viktig och att en mix av kvalité bör gynnas. Naturvårdsbränning verkar vara en effektiv metod för att gynna biodiversitet men för att gynna hålhäckande fåglar bör torrakor skyddas.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
•We studied several key drivers of earthworm abundance and composition in wood logs.•Earthworms are also deadwood worms: their communities in logs are abundant and diverse.•Tree species, decay stage, ...forest and soil type affect earthworm communities in logs.•Deadwood resources contribute to earthworm diversity in forests.•Forest management leaving deadwood after logging contributes to earthworm diversity.
Earthworms are ecosystem engineers associated with important soil functions. Despite the large amount of literature on earthworm ecology, relatively few studies have examined earthworms in deadwood or quantified their importance in this habitat. We investigated earthworm communities in decaying deadwood and disentangled how their community dynamics are influenced by variation in tree species, wood decomposition stage, and forest environment. Decaying logs (of standardised size) of ten common, temperate tree species were laid out to decay on the soil surface for four years. The experiment was carried out in the “tree cemetery” experiment LOGLIFE, in two contrasting temperate forests in the central Netherlands. The decaying logs yielded surprisingly rich earthworm populations, with on average 19 individuals per meter of log and in total belonging to 12 different species. Our findings highlighted that earthworm communities in deadwood in terms of composition and abundance were influenced by tree species, wood decomposition stage and forest type with different soil properties, as well as their interactions. After one and two years of decay, earthworm abundance was higher in the logs of Picea abies and relatively fast decomposing Populus spp. than in other trees, while this pattern changed after four years with higher earthworm abundance observed in the other tree species. Overall, Populus spp. supported the highest earthworm abundance, followed by Picea abies and Quercus robur. The earthworm community composition in the logs in the two forest sites had broadly similar dynamic trends of first becoming very dissimilar between one and two years, then relatively more similar from two to four years of decay, although the community composition differed between sites. The interacting influences of tree species, wood decay stage and forest environment on earthworm communities strongly suggest that diversity in deadwood resources contributes to earthworm diversity in forests. Thus, by mixing different tree species and logging gradually through the years, forest managers could enhance the diversity of this abundant and understudied component of deadwood invertebrate diversity. Further research should study the feedback loop between earthworm communities and decomposition of deadwood.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•Dead wood varies greatly in quality as dependent on tree species and decay stage.•Differences in dead wood quality contribute greatly to forest invertebrate diversity.•Total invertebrate richness ...depends on specific tree species-decay stage combinations.•These findings can be used to optimize invertebrate diversity in managed forests.
Dead wood availability and the variability in dead wood quality, i.e. tree species and decay stages, are often low in managed forests, which negatively affects biodiversity of invertebrate species. Leaving more (coarse) dead wood can increase invertebrate richness, but it remains unclear how many and which combinations of tree taxa and decay stages are required to optimize niche heterogeneity in managed forests. We investigated the diversity of the main arthropod groups associated with dead wood, i.e. millipedes, centipedes, isopods and beetles, through the first four years of decomposition of logs of twenty common temperate tree species placed in the “common garden” experiment LOGLIFE. We hypothesized that (1) invertebrate richness for combinations of a given number of tree species would be promoted by mixing both tree species and decay period and that (2) invertebrate richness increases up to a saturation point with more tree species at different decay stages added. We also hypothesized that (3) an increase in phylogenetic distance among the tree species in combinations would promote their overall invertebrate diversity. We found that the better combinations, in terms of invertebrate richness, after one and two years of decay, but not after four years, consisted of a mix of gymnosperms and angiosperms, indicating that variation in tree species is especially important during the initial decomposition period. The best combinations in terms of invertebrate richness consisted of at least one tree species from each decay period, indicating that also variation in the decay stage of the tree is important to promote invertebrate diversity. We observed that at least four wood types were required to approach the 95% saturation point for species richness. The third hypothesis, that dissimilarity in phylogenetic position could be a predictive tool for increasing invertebrate richness in combinations of tree species, was not supported by our results. Thus, in order to maintain diversity of dead wood invertebrates in forests we recommend not only to provide richness in tree species, but also to plant particular combinations of trees (preferably angiosperm-gymnosperm combinations) that differ in the invertebrate communities they typically host and to temporally spread the logging of trees. This way the logging residues cover different resources and habitats at each moment in time, which is likely to result in a large diversity of dead wood invertebrates.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Coarse woody debris (CWD) is a structural feature in forests throughout the United States that provides unique cover, runways, and microclimate for various wildlife species. While use and selection ...of CWD for rodent foraging, travel, and nesting, which can impact an individual’s fitness, has been demonstrated across numerous studies, the role of CWD presence and abundance in rodent population and community dynamics varies across studies. To better understand rodent and CWD relationships, we studied rodent populations across two periods of CWD manipulation in randomly assigned experimental treatments in South Carolina (Period I: March 1996–November 2000; removal of all snags and fallen logs, removal of fallen logs only, and Control, and Period II: January 2002–September 2006; downed woody debris addition, snag addition, and Control). Overall, we found minimal effects of experimental treatments on the rodent community composition and structure, and community level variation was mainly explained by cotton mouse (Peromyscus gossypinus) and southern flying squirrel (Glaucomys volans) captures. There were no experimental treatment effects on captures of cotton mice and southern flying squirrels, but we observed variation across seasons and years. Here our study shows that over the long-term, rodent population and community dynamics are not affected by experimental manipulations of CWD in our study area.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF