Advanced Stages Of Decay Research Articles

How do environmental conditions affect the deadwood decomposition of European beech (Fagus sylvatica L.)?

European beech is one of the most important European trees, not only because of its expected role in the face of climate change, but also as a frequent species in forest reserves, national parks and the NATURA 2000 network. For such areas, naturalness and biodiversity conservation are significant issues, in which the presence of deadwood plays an important role. To manage deadwood in forests, one needs to know how the residence time of coarse woody debris is influenced by the environment. In this study, we analysed a dataset of 4260 logs from beech-dominated primeval and natural forest reserves in three climatically different regions (cold-dry, warm-dry and warm-humid region), working with a time series of more than 40years (1972–2015). With the help of Bayesian Survival Trajectory Analysis, we examined differences between residence times in the three regions and in three DBH classes. In addition, we analysed qualitative characteristics of fallen logs – the mortality mode and the position of logs during decomposition – and calculated their total decomposition time and time to reach an advanced decay stage. The analyses confirmed the significant impact of macroclimate on residence time. In the cold-dry region the diameter classes 10–24cm (small-sized logs) and 25–54cm (medium-sized logs) had the longest residence time (38and48years, respectively). In the warm-dry region with a favourable composition of fungal communities, the diameter class 55+ cm (large-sized logs) logs had the shortest residence time (43years). The rates of decomposition of beech logs in contact with the ground or suspended logs were significantly different in all three regions, with logs lying on the ground decomposing 9–15years sooner. These results can be used in retention forestry. If the continuity of the deadwood environment is to be preserved, it is necessary to ensure a “supply” of dead stems (offering differing habitats) at least once every 24–35years. During this period, 50% of logs decay completely and the other 50% of logs progress to an advanced decay stage.

Carbon and nitrogen stocks in dead wood of tropical lowland forests as dependent on wood decay stages and land-use intensity

Rapid transformation of natural forests into other land-use systems in the lowlands of Sumatra, Indonesia, strongly reduces total aboveground biomass and affects nutrient cycling. However, the consequences of this conversion for C and N stocks of dead wood remains poorly understood particularly in natural forests and jungle rubber. This study examined the differences in dead wood abundance, and C, N and lignin concentrations of three decay stages of dead wood as well as the stocks of these chemical components stored in dead wood. Standing and fallen dead wood was determined as coarse woody debris with diameter ≥ 10 cm and classified into three decay stages of wood. Mass of dead wood was estimated using allometric equation. Total C and N stocks in dead wood in the natural forests (4.5 t C ha -1 , 0.05 t N ha -1 , respectively) were three times higher than those in the jungle rubber (1.5 t C ha -1 , 0.02 t N ha -1 , respectively). The stocks of C and N at early and advanced wood decay stages in the natural forests were also higher than those in the jungle rubber. The decay stages showed pronounced differences in concentrations of chemical components. With advancing stage of wood decay, N concentration increased and C/N ratio decreased, while concentrations of C and lignin were variable. The distribution of dead wood mass and stocks of C, and lignin were found to be higher in the early decay than those in the advanced decay stage. Higher input of dead wood in natural forests indicated a higher importance of dead wood decay in natural forests than in jungle rubber systems. Thus, replacing natural forests with jungle rubber strongly reduces total C and N stocks which might have a marked negative effect on the ecosystems' nutrient turnover and cyle.

Foraging Behaviour in Magellanic Woodpeckers Is Consistent with a Multi-Scale Assessment of Tree Quality.

Theoretical models predict that animals should make foraging decisions after assessing the quality of available habitat, but most models fail to consider the spatio-temporal scales at which animals perceive habitat availability. We tested three foraging strategies that explain how Magellanic woodpeckers (Campephilus magellanicus) assess the relative quality of trees: 1) Woodpeckers with local knowledge select trees based on the available trees in the immediate vicinity. 2) Woodpeckers lacking local knowledge select trees based on their availability at previously visited locations. 3) Woodpeckers using information from long-term memory select trees based on knowledge about trees available within the entire landscape. We observed foraging woodpeckers and used a Brownian Bridge Movement Model to identify trees available to woodpeckers along foraging routes. Woodpeckers selected trees with a later decay stage than available trees. Selection models indicated that preferences of Magellanic woodpeckers were based on clusters of trees near the most recently visited trees, thus suggesting that woodpeckers use visual cues from neighboring trees. In a second analysis, Cox’s proportional hazards models showed that woodpeckers used information consolidated across broader spatial scales to adjust tree residence times. Specifically, woodpeckers spent more time at trees with larger diameters and in a more advanced stage of decay than trees available along their routes. These results suggest that Magellanic woodpeckers make foraging decisions based on the relative quality of trees that they perceive and memorize information at different spatio-temporal scales.

Volatile Organic Compounds of Decaying Piglet Cadavers Perceived by Nicrophorus vespilloides.

In the necrophagous burying beetle Nicrophorus vespilloides (Coleoptera: Silphidae), cadaver preference appears to depend on cadaver size and on the maturity of the beetle. We previously showed that newly emerged females with immature ovaries prefer later stages of decomposition of large cadavers. Our present aim is the determination of specific chemical compounds involved in the discrimination of cadaveric odor bouquets and the recognition of specific stages of decomposition. We used headspace samples of maggot-infested piglet cadavers at various decomposition stages and performed gas chromatography coupled with electroantennography (GC-EAD) to record 45 EAD-active compounds. Using GC coupled with mass spectrometry, we identified 13 of the EAD-active compounds. The headspace of the fresh decomposition stage was characterized mainly by high relative amounts of trimethylpyrazine. High relative amounts of dimethyl trisulfide were characteristic of bloated, post-bloating, and advanced decay stages. The advanced decay and dry remains stages were dominated by high relative amounts of phenol. Statistically, this compound had the highest impact on discrimination between the fresh decomposition stage, which is important for mature burying beetles for reproduction, and the advanced decay stage, which is nutritionally more attractive for newly emerged beetles. Phenol might, therefore, function as a key substance for newly emerged female burying beetles, so that they can locate suitable cadavers for feeding to maturation.

Erratum: A pyrosequencing insight into sprawling bacterial diversity and community dynamics in decaying deadwood logs of Fagus sylvatica and Picea abies.

Deadwood is an important biodiversity hotspot in forest ecosystems. While saproxylic insects and wood-inhabiting fungi have been studied extensively, little is known about deadwood-inhabiting bacteria. The study we present is among the first to compare bacterial diversity and community structure of deadwood under field conditions. We therefore compared deadwood logs of two temperate forest tree species Fagussylvatica and Piceaabies using 16S rDNA pyrosequencing to identify changes in bacterial diversity and community structure at different stages of decay in forest plots under different management regimes. Alphaproteobacteria, Acidobacteria and Actinobacteria were the dominant taxonomic groups in both tree species. There were no differences in bacterial OTU richness between deadwood of Fagussylvatica and Piceaabies. Bacteria from the order Rhizobiales became more abundant during the intermediate and advanced stages of decay, accounting for up to 25% of the entire bacterial community in such logs. The most dominant OTU was taxonomically assigned to the genus Methylovirgula, which was recently described in an experiment of Fagussylvatica woodblocks. Besides tree species we were able to demonstrate that deadwood physico-chemical properties, in particular remaining mass, relative wood moisture, pH, and C/N ratio serve as drivers of community composition of deadwood-inhabiting bacteria.

A checklist of beetles (Insecta, Coleoptera) on pig carcasses in the suburban area of southwestern China: A preliminary study and its forensic relevance

Examining the succession pattern of carrion insects on vertebrate carcasses is widely accepted as an effective method to estimate the postmortem interval (PMI) of decayed bodies. Investigation of the community of sarcosaprophagous insects, especially flies and beetles, is the foundation of the succession pattern study. This study aimed to investigate the sarcosaprophagous beetles succession on animal carcasses in the suburban area of southwestern China and to establish a basic catalog for forensic application. The present study was conducted in 2013 in a mountain in Chongqing municipality with modified Schoenly traps. Carcasses of miniature pig were used to simulate human bodies. For most carcasses, five decomposition stages were observed. A total of 2108 adult coleopterans belonging to at least 61 species and 18 families were collected in the study, and most of the specimens occurred at the advanced decay stage. Omosita colon (Linnaeus, 1758), Necrodes nigricornis (Harold, 1875), Necrobia ruficollis (Fabricius, 1775) and Neosilusa ceylonica (Kraatz, 1857) were the dominant species.

First Record Of Meroplius Fukuharai (Iwasa 1984) (Diptera: Sepsidae) On Romanian Territory

Abstract The present study represents the first report on the presence of Meroplius fukuharai (Diptera: Sepsidae) in Romania. The research area was located in Bucharest. Meroplius fukuharai was recorded during an experiment for investigating necrophagous insect species dynamics. Adult specimens were sampled during the summer (August 2013) from swine carcasses at the beginning of the advanced decay stage. The species had a sporadic occurrence, only four male specimens being sampled and identified both morphologically and genetically during the four-month survey. The recorded environmental parameters during the sampling period showed an air temperature of 28-33°C and a relative humidity of 53-57%. This report on the presence of M. fukuharai in Romania leads to the expansion of its known distribution range in the South Eastern part of Europe.

Anatomical changes in the cell-wall structure of Leucaena leucocephala (Lam.) de Wit as caused by the decay fungi Trametes versicolor and Trametes hirsuta

The structural changes in the cell wall and delignification pattern caused by Trametes versicolor and Trametes hirsuta in the sap wood of Leucaena leucocephala were examined by light and confocal laser scanning microscopy. The in vitro decay test was conducted for 12 weeks. Both species of Trametes used in this study caused anatomical characteristics specific to simultaneous white rot. Formation of boreholes, erosion troughs, erosion channels with U-shaped notches in tangential sections and thinning of cell walls were evident in the wood inoculated with each of the fungal species. Cell separation due to removal of middle lamellae occurred at the early stages of infection (30 d) with T. versicolor. In contrast, middle lamellae remained intact in wood inoculated with T. hirsuta and showed cell separation due to degradation of the outer layer of the secondary wall and degradation of the middle lamellae observed only in severely decayed wood at late stages. Confocal microscopy revealed the delignification pattern particularly from cell corners and vessel walls at an advanced stage of decay, indicating strong ligninolytic activity of both species in the sapwood of L. leucocephala.

Deadwood residence time in alluvial hardwood temperate forests – A key aspect of biodiversity conservation

There are hundreds of scientific papers dealing with the issues of biodiversity and extinction debt in temperate forests, both of which are partly related to the absence of deadwood. Some studies have derived habitat thresholds for deadwood (according to species, size, spatial distribution) as baselines for management recommendations. But a majority of studies have one important knowledge gap – how long does it take for deadwood to decompose? To derive the residence time of deadwood, we used a 40-year time series of 4 censuses in European lowland hardwood temperate forests. The deadwood residence of 2252 logs of 5 main tree species was calculated using Bayesian Survival Trajectory Analysis. Pedunculate oak (Quercus robur) had the longest residence time, with the largest logs decomposing for an average of 62years. Next was narrow-leaved ash (Fraxinus angustifolia) with a residence time of about 42years. Field maple (Acer campestre) and hornbeam (Carpinus betulus) had a similar residence time – with the largest logs averaging 37–39years. Elm (Ulmus sp.) had the fastest decomposition of large-sized logs – estimated at 24years. Generally, small-sized logs of all investigated species decomposed quickly. Conversely, large-sized logs of hornbeam and ash decomposed as quickly as their intermediate-sized logs. Large-sized logs of elm decayed even faster than intermediate-sized logs. An analysis of the position of field maple logs during decomposition showed that those decomposing in the air or in water decomposed slower than logs “on the ground”, with a half-life of 40years (compared to 28years on the ground) and a residence time of 54years (44years on the ground). Our results suggest that the management of deadwood should focus on (i) leaving the largest logs, which took the longest time to reach advanced decay stages, and (ii) a diversified approach regarding the individual residence time of different tree species.

A pyrosequencing insight into sprawling bacterial diversity and community dynamics in decaying deadwood logs of Fagus sylvatica and Picea abies.

Deadwood is an important biodiversity hotspot in forest ecosystems. While saproxylic insects and wood-inhabiting fungi have been studied extensively, little is known about deadwood-inhabiting bacteria. The study we present is among the first to compare bacterial diversity and community structure of deadwood under field conditions. We therefore compared deadwood logs of two temperate forest tree species Fagus sylvatica and Picea abies using 16S rDNA pyrosequencing to identify changes in bacterial diversity and community structure at different stages of decay in forest plots under different management regimes. Alphaproteobacteria, Acidobacteria and Actinobacteria were the dominant taxonomic groups in both tree species. There were no differences in bacterial OTU richness between deadwood of Fagus sylvatica and Picea abies. Bacteria from the order Rhizobiales became more abundant during the intermediate and advanced stages of decay, accounting for up to 25% of the entire bacterial community in such logs. The most dominant OTU was taxonomically assigned to the genus Methylovirgula, which was recently described in a woodblock experiment of Fagus sylvatica. Besides tree species we were able to demonstrate that deadwood physico-chemical properties, in particular remaining mass, relative wood moisture, pH, and C/N ratio serve as drivers of community composition of deadwood-inhabiting bacteria.

Histological and ultrastructural alterations in the Ailanthus excelsa wood cell walls by Bjerkandera adusta (Willd.) P. Karst

Ailanthus excelsa Roxb. requires less care than other species and thrives in arid and semi-arid regions. Therefore, it becomes an important choice for forestry programs. Young branches of these trees are frequently invaded by the fungus Bjerkandera adusta (Willd.) P. Karst. The main aims of this study were to characterize the wood decay pattern and evaluate the extent of damage caused by the fungus. Infected samples were studied using light microscopy, confocal laser scanning microscopy, transmission electron microscopy, and scanning electron microscopy. Wood of the dead branches became pale white and very soft. In vitro decayed wood showed extensive weight loss of wood blocks (68.6%) at the end of three months. In the xylem, fibres were the most severely affected cell types, whereas wall structure of the axial parenchyma remained virtually unaltered. Unlike axial parenchyma, walls of the ray cells formed several boreholes and finally collapsed in the advanced stage of decay. By contrast, the middle lamella of all the xylem elements remained intact even at the end of three months. In the early stages of infection, vessels appeared to be resistant to the fungal action but they also became eroded at the advanced stage. The degradation pattern showed anatomical characteristics of both the white-rot and soft-rot type of decay. Thinning of walls from the lumen side and appearance of U-notches resembles white-rot decay, while tunnels through the S2 layer of the fibre wall added the characteristics of the soft-rot decay pattern. Extensive weight loss of wood blocks following infection suggests B. adusta is an aggressive wood-degrading fungus.

The Massaria disease of plane trees:its wood decay mechanism

Branches of Platanus × hispanica with distinct symptoms of the Massaria disease were investigated by light and transmission electron microscopy and cellular UVmicrospectrophotometry. The samples collected in the city of Mannheim, Germany, were infected in vivo with the fungus Splanchnonema platani and showed various degrees of wood decay. The investigations were focused on the decay pattern of cell walls in the different cells, i.e., fibres, vessels as well as ray and axial parenchyma cells. The following results were obtained. Hyphae of the ascomycete fungus Splanchnonema platani penetrated from cell to cell through the pits and not through the cell wall middle lamella, by the formation of thin perforation hyphae. During this process, the 1–5 μm thick hyphae became narrower without attacking the wall around the pit canal. After penetration through a pit, the hyphae again enlarged to their original diameter. This is true for all pit pairs connecting the various cell types. Late decay stages did not show a decay of cell corner regions and middle lamellae of fibres as well as vessel and parenchyma cell walls. Phenolic deposits in parenchyma cells were still present in severely attacked xylem tissue. These features point to a low lignolytic capacity of the fungus. The frequently found microscopic decay pattern with the formation of oval or spherical cavities in the S2 layer of the secondary wall with an often structurally intact S3 layer is a characteristic of softrot decay. This classification is also supported by the remaining cell corner and middle lamella regions in advanced decay stages. As a consequence of this decay type, branches fracture in a brittle mode.

Beetle succession and diversity between clothed sun-exposed and shaded pig carrion in a tropical dry forest landscape in Southern Mexico

Over a 31-day period, the decomposition process, beetle diversity and succession on clothed pig (Sus scrofa L.) carcasses were studied in open (agricultural land) and shaded habitat (secondary forest) in Southern Mexico. The decomposition process was categorised into five stages: fresh, bloated, active decay, advanced decay and remains. Except for the bloated stage, the elapsed time for each decomposition stage was similar between open and shaded habitats, all carcasses reached an advanced decay stage in seven days, and the fifth stage (remains) was not recorded in any carcass during the time of this study. A total of 6344 beetles, belonging to 130 species and 21 families, were collected during the entire decomposition process, and abundances increased from fresh to advanced decay stages. Staphylinidae, Scarabaeidae and Histeridae were taxonomically and numerically dominant, accounting for 61% of the species richness and 87% of the total abundance. Similar numbers of species (87 and 88 species for open and shaded habitats, respectively), levels of diversity and proportions (open 49%; shaded 48%) of exclusive species were recorded at each habitat. There were significantly distinct beetle communities between habitats and for each stage of decomposition. An indicator species analysis (“IndVal”) identified six species associated to open habitats, 10 species to shaded habitats and eight species to advanced decay stages. In addition, 23 beetle species are cited for the first time in the forensic literature. These results showed that open and shaded habitats both provide suitable habitat conditions for the carrion beetle diversity with significant differences in community structure and identity of the species associated to each habitat. This research provides the first empirical evidence of beetle ecological succession and diversity on carrion in Mexican agro-pastoral landscapes.

Evaluation of Schizophyllum commune Fr. potential for biodegradation of lignin: A light microscopic analysis

Lignin biodegradation potential of Schizophyllum commune Fr. is studied by using sound wood blocks of Ailanthus excelsa, Azadirachta indica, Tectona grandis, Eucalyptus sp. and Leucaena leucocephala. Initially, in vitro wood decay test showed minor weight loss, but it became rapid after one month. After 120 days of incubation, weight loss was minimum in T. grandis (24.05%) whereas it was maximum in A. excelsa (34.44%). Treated test blocks were characterised by enlargement of pits on ray cell wall, formation of additional boreholes in rays, separation of fibres and cell wall thinning and formation of ‘U’-shape notches. Fungal hyphae moved through the xylem cell lumen, and intercellular spaces formed in response to separation of fibres. Hyphae traverse in adjacent cell through the cell wall pits or by making additional boreholes. In all the species studied, xylem fibres and parenchyma (axial and ray) cells were more susceptible while vessels were resistant to fungal attack. In advanced stage of decay, fibres and axial parenchyma lost their rigidity while vessel walls showed uneven thinning. In the tension wood, G-fibres remained unaffected initially but loosening and separation of gelatinous layer facilitated fungal action and showed similar pattern of cell wall deterioration. Among the wood of different species studied, Tectona was more resistant whereas Ailanthus was more susceptible to fungal attack.

Patterns of aquatic decay and disarticulation in juvenile Indo-Pacific crocodiles (Crocodylus porosus), and implications for the taphonomic interpretation of fossil crocodyliform material

High levels of skeletal articulation and completeness in fossil crocodyliforms are commonly attributed to rapid burial, with decreasing articulation and completeness thought to result from prolonged decay of soft tissue and the loss of skeletal connectivity during ‘bloat and float’. These interpretations are based largely on patterns of decay in modern mammalian and avian dinosaur carcasses. To address this issue, we assessed the decay of buried and unburied juvenile Crocodylus porosus carcasses in a controlled freshwater setting. The carcasses progressed through typical vertebrate decay stages (fresh, bloated, active decay, and advanced decay), reaching the final skeletal stage on average 55days after death. Unburied carcasses commenced floating five days post-mortem during the bloated stage, and one buried carcass only commenced floating 12days post-mortem. While floating, skeletal elements remained articulated within the still coherent dermis, except for thoracic ribs, ischia and pubic bones. The majority of disarticulation occurred at the sediment–water interface after the carcasses sank during the advanced decay stage, ~36days post-mortem. Based on these results we conclude that fossil crocodyliform specimens displaying high levels of articulation are not the result of prolonged subaerial and subaqueous decay in a low-energy, aqueous environment. Using extant juvenile C. porosus as a proxy for fossil crocodyliforms, rapid burial in an aquatic setting would have to occur prior to the carcass floating, and would also have to continually negate the positive buoyancy associated with bloating. Rapid burial does not have to be the only avenue to preservation of articulation, as other mechanisms such as physical barriers and internal physiological chemistry could prevent carcasses from floating and subsequently disarticulating upon sinking. The inference that a large proportion of skeletal elements could drift from floating carcasses in a low energy setting with minimal scavenging, thereby causing a loss of completeness, seems unlikely.

The significance of deadwood for total bryophyte, lichen, and vascular plant diversity in an old-growth spruce forest

Modern silviculture has led to a reduction in deadwood, especially that of large diameter, and thus the loss of an important habitat niche in most European forests. We analyzed the significance of deadwood for the total species diversity in three plant groups (bryophytes, lichens, and vascular plants) in one of Central Europe’s few remnants of unmanaged old-growth forest. The site is a montane forest of Picea abies on Mt. Brocken, Harz Mountains, Germany, which has not been managed for at least several centuries, undergoes natural forest dynamics, and thus harbors large amounts of standing and downed deadwood. Epiphyte vegetation of live trees and the ground vegetation were studied for comparison. We did not find any obligate deadwood species. Nevertheless, 84 % (70 species) of the total species were found on standing or downed deadwood. One-third of these species, or 28 % of the total species in the forest, were only sampled on deadwood, whereas the remaining species were also found on live trees and/or the ground. Bryophytes were the largest group of species on deadwood (47 % of the deadwood-inhabiting species), followed by lichens (37 %) and vascular plants (16 %). Large-diameter deadwood in an advanced stage of decay harbored more species than smaller fragments in the early stages of decay. Despite the lack of obligate deadwood colonizers, deadwood apparently plays a key role for forest plant diversity, mainly by providing an environment with low competition and thus facilitating the establishment of species.

Succession of saproxylic beetles associated with decomposition of boreal white spruce logs

We reared saproxylic beetles from 54 white spruce [Picea glauca (Moench) Voss] logs collected in northwestern Alberta, Canada. Logs represented six decay classes, ranging from freshly dead to well decayed. Beetle assemblages were indicated mainly by phloeophagous and predaceous species in early decay stages, although indicator species were mainly predaceous in later stages of decay. No indicator species were identified for intermediate decay stages. Larvae from rearings were disproportionately predaceous. Thus, movement of juveniles within and among coarse woody debris (CWD) substrates is likely an important aspect of the life history for these species. Beetle assemblages changed progressively with increasing stages of decomposition. Assemblages of adjacent decay classes were highly similar, although similarity decreased with increasing difference in decay classes. Therefore, the retention of all decay classes of white spruce downed CWD on post-harvest landscapes is necessary to conserve the associated saproxylic beetle fauna. Retention of CWD in advanced decay stages, which contains species not found in earlier decay classes, presents a particular challenge in forest management because of the long times required to develop CWD in the later stages of decomposition.

Age determination of coarse woody debris with radiocarbon analysis and dendrochronological cross-dating

To study the decay of coarse woody debris (CWD) in forest ecosystems, it is necessary to determine the time elapsed since tree death, which is difficult at advanced decay stages. Here, we compare two methods for age determination of CWD logs, dendrochronological cross-dating and radiocarbon analysis of the outermost tree ring. The methods were compared using samples from logs of European beech, Norway spruce and Sessile oak decomposing in situ at three different forest sites. For dendrochronological cross-dating, we prepared wood discs with diameters of 10–80 cm. For radiocarbon analysis, cellulose was isolated from shavings of the outermost tree rings. There was an overall good agreement between time of death determined by the two methods with median difference of 1 year. The uncertainty of age determination by the radiocarbon approach did not increase with decreasing carbon density, despite incomplete separation of chitin from the extracted cellulose. Fungal chitin has the potential to alter the radiocarbon signature of tree rings as the carbon for chitin synthesis originates from different sources. Significant correlations between year of tree death and carbon density of wood were found for beech and spruce, but not for oak due to relatively small decreases in carbon density within 50–60 years. Total residence times of CWD were calculated from these correlations and revealed 24 years for beech and 62 years for spruce. The uncertainty of total residence times results mainly from huge natural variability in carbon density of CWD rather than uncertainty in the age determination. The results suggest that both methods are suitable for age determination of CWD.

Fast but ephemeral effects of ecological restoration on forest beetle community

Many protected areas have a long history of human intervention before being protected. In protected forests, the past land use has reduced the amount of natural structures, which are crucial substrates for thousands of species. We evaluate the short-term ecological effect of forest restoration (dead wood creation) on conifer-associated saproxylic (dead-wood dependent) beetles. More specifically, we analyze the effect of dead wood creation on the number of beetle species and individuals 1 and 5 years after restoration in spruce and pine forests, using a large-scale monitoring network over Finland. The number of saproxylic beetle species and individuals was larger at restored than at control plots both 1 and 5 years after restoration in both spruce and pine forests. Community composition in restored plots was different from control plots 1 year after restoration, but had returned towards the control plot composition 5 years after restoration, while control plots remained largely unchanged. Both in spruce and pine forests, there were more red-listed and rare saproxylic beetles in restored than in control plots 1 and 5 years after restoration. Our results indicate that restoration has an overall positive influence on saproxylic beetle diversity immediately after dead wood creation, but this effect is rather short-lived. Long term monitoring of restored dead wood is crucial in investigating successional pathways as well as biotic communities in advanced decay stages, and in fully evaluating the ecological effect of dead wood creation as a forest restoration measure.

Distinct Bacterial Communities Dominate Tropical and Temperate Zone Leaf Litter

Little is known of the bacterial community of tropical rainforest leaf litter and how it might differ from temperate forest leaf litter and from the soils underneath. We sampled leaf litter in a similarly advanced stage of decay, and for comparison, we also sampled the surface layer of soil, at three tropical forest sites in Malaysia and four temperate forest sites in South Korea. Illumina sequencing targeting partial bacterial 16S ribosomal ribonucleic acid (rRNA) gene revealed that the bacterial community composition of both temperate and tropical litter is quite distinct from the soils underneath. Litter in both temperate and tropical forest was dominated by Proteobacteria and Actinobacteria, while soil is dominated by Acidobacteria and, to a lesser extent, Proteobacteria. However, bacterial communities of temperate and tropical litter clustered separately from one another on an ordination. The soil bacterial community structures were also distinctive to each climatic zone, suggesting that there must be a climate-specific biogeographical pattern in bacterial community composition. The differences were also found in the level of diversity. The temperate litter has a higher operational taxonomic unit (OTU) diversity than the tropical litter, paralleling the trend in soil diversity. Overall, it is striking that the difference in community composition between the leaf litter and the soil a few centimeters underneath is about the same as that between leaf litter in tropical and temperate climates, thousands of kilometers apart. However, one substantial difference was that the leaf litter of two tropical forest sites, Meranti and Forest Research Institute Malaysia (FRIM), was overwhelmingly dominated by the single genus Burkholderia, at 37 and 23 % of reads, respectively. The 454 sequencing result showed that most Burkholderia species in tropical leaf litter belong to nonpathogenic "plant beneficial" lineages. The differences from the temperate zone in the bacterial community of tropical forest litter may be partly a product of its differing chemistry, although the unvarying climate might also play a role, as might interactions with other organisms such as fungi. The single genus Burkholderia may be seen as potentially playing a major role in decomposition and nutrient cycling in tropical forests, but apparently not in temperate forests.