Aboveground Conditions Research Articles

Variations in cuticular hydrocarbons of Calliphora vicina (Diptera: Calliphoridae) empty puparia: Insights for estimating late postmortem intervals.

Necrophagous flies, particularly blowflies, serve as vital indicators in forensic entomology and ecological studies, contributing to minimum postmortem interval estimations and environmental monitoring. The study investigates variations in the predominant cuticular hydrocarbons (CHCs) viz. n-C25, n-C27, n-C28, and n-C29 of empty puparia of Calliphora vicina Robineau-Desvoidy, 1830, (Diptera: Calliphoridae) across diverse environmental conditions, including burial, above-ground and indoor settings, over 90 days. Notable trends include a significant decrease in n-C25 concentrations in buried and above-ground conditions over time, while n-C27 concentrations decline in buried and above-ground conditions but remain stable indoors. Burial conditions show significant declines in n-C27 and n-C29 concentrations over time, indicating environmental influences. Conversely, above-ground conditions exhibit uniform declines in all hydrocarbons. Indoor conditions remain relatively stable, with weak correlations between weathering time and CHC concentrations. Additionally, machine learning techniques, specifically Extreme Gradient Boosting (XGBoost), are employed for age estimation of empty puparia, yielding accurate predictions across different outdoor and indoor conditions. These findings highlight the subtle responses of CHC profiles to environmental stimuli, underscoring the importance of considering environmental factors in forensic entomology and ecological research. The study advances the understanding of insect remnant degradation processes and their forensic implications. Furthermore, integrating machine learning with entomological expertise offers standardized methodologies for age determination, enhancing the reliability of entomological evidence in legal contexts and paving the way for future research and development.

Soil nitrogen fertilization reduces relative leaf nitrogen allocation to photosynthesis.

The connection between soil nitrogen availability, leaf nitrogen, and photosynthetic capacity is not perfectly understood. Because these three components tend to be positively related over large spatial scales, some posit that soil nitrogen positively drives leaf nitrogen, which positively drives photosynthetic capacity. Alternatively, others posit that photosynthetic capacity is primarily driven by aboveground conditions. Here, we examined the physiological responses of a non nitrogen-fixing plant (Gossypium hirsutum) and a nitrogen-fixing plant (Glycine max) in a fully factorial combination of light by soil nitrogen availability to help reconcile these competing hypotheses. Soil nitrogen stimulated leaf nitrogen in both species, but the relative proportion of leaf nitrogen used for photosynthetic processes was reduced under elevated soil nitrogen in all light availability treatments due to greater increases in leaf nitrogen content than chlorophyll and leaf biochemical process rates. Leaf nitrogen content and biochemical process rates in G. hirsutum were more responsive to changes in soil nitrogen than G. max, likely due to strong G. max investments in root nodulation under low soil nitrogen. Nonetheless, whole plant growth was significantly enhanced by increased soil nitrogen in both species. Light availability consistently increased relative leaf nitrogen allocation to leaf photosynthesis and whole plant growth, a pattern that was similar between species. These results suggest that the leaf nitrogen-photosynthesis relationship varies under different soil nitrogen levels and that these species preferentially allocated more nitrogen to plant growth and non-photosynthetic leaf processes, rather than photosynthesis, as soil nitrogen increased.

Restoring the iconic Ulmus americana to urban landscapes: Early tree growth responds to aboveground conditions

Native trees provide a range of benefits, from supporting native wildlife to climate regulation, and many urban natural resource managers prioritize native tree planting and restoration. Ulmus americana (American elm) was once widely planted in American cities but has been decimated by Dutch elm disease (DED; Ophiostoma ulmi). Our study evaluated U. americana establishment and growth across urban landscapes. We planted ramets from three DED-tolerant U. americana genotypes (RV16, RV474, and Sunfield) along an urbanization gradient in Newark, DE and Philadelphia, PA, and assessed physiological and morphological responses. We analyzed how U. americana clone growth, chlorophyll fluorescence, and foliar chemistry relate to impervious surface area, ozone (O3) concentrations, and soil characteristics. The one-year post planting mortality rate was low (4%) demonstrating these elms can withstand urban environmental conditions when provided ample water supply and protection from deer. As expected, the elms differed in growth rate, chlorophyll fluorescence, and foliar chemistry between the cities. Elms planted in Philadelphia had greater photosynthetic capacity in July (Fv/Fm = 0.76) and September (Fv/Fm = 0.75), while Newark elms had greater photosynthetic capacity in August (Fv/Fm = 0.78). Depleted foliar δ13C signatures in Philadelphia suggest elms are experiencing greater fossil-fuel derived atmospheric CO2 than in Newark, possibly contributing to the greater growth rates observed in Philadelphia compared to Newark. Enriched foliar δ15N and greater foliar %N in Philadelphia clones suggest they are experiencing greater N deposition from NOx-derived sources compared to Newark clones. Clones growing in Philadelphia had greater foliar nutrient concentrations despite growing in soils with greater heavy metal concentrations. These foliar-soil chemistry patterns suggest that clones growing in Philadelphia respond positively to urban environmental conditions in a large city, whereas clones growing in Newark may be experiencing N limitation in the first year of growth after planting.

The Assembly of Tropical Dry Forest Tree Communities in Anthropogenic Landscapes: The Role of Chemical Defenses.

The effect of anthropogenic disturbance on plant community traits and tradeoffs remains poorly explored in tropical forests. In this study, we aimed to identify tradeoffs between defense and other plant functions related to growth processes in order to detect potential aboveground and edaphic environmental conditions modulating traits variation on plant communities, and to find potential assembly rules underlying species coexistence in secondary (SEF) and old-growth forests (OGF). We measured the foliar content of defense phytochemicals and leaf traits related to fundamental functions on 77 species found in SEF and OGF sites in the Jalisco dry forest ecoregion, Mexico, and we explored (1) the trait-trait and trait-habitat associations, (2) the intra and interspecies trait variation, and (3) the traits-environment associations. We found that phytochemical content was associated with high leaf density and leaf fresh mass, resulting in leaves resistant to drought and high radiation, with chemical and physical defenses against herbivore/pathogen attack. The phytochemicals and chlorophyll concentrations were negatively related, matching the predictions of the Protein Competition Model. The phylogenetic signal in functional traits, suggests that abundant clades share the ability to resist the harsh biotic and abiotic conditions and face similar tradeoffs between productive and defensive functions. Environmental filters could modulate the enhanced expression of defensive phytochemicals in SEF, while, in OGFs, we found a stronger filtering effect driving community assembly. This could allow for the coexistence of different defensive strategies in OGFs, where a greater species richness could dilute the prevalence of pathogens/herbivores. Consequently, anthropogenic disturbance could alter TDF ecosystem properties/services and functioning.

Understanding how an amphicarpic species with a mixed mating system responds to fire: a population genetic approach.

Amphicarpic plants produce both above-ground and below-ground seeds. Because below-ground seeds are protected in the soil and may maintain viability when above-ground conditions are stressful, they were proposed as an adaptation to recolonize a site after disturbance. However, whether below-ground seeds are the main colonizers after a disturbance remains unknown. Our goal was to understand whether recolonization by an amphicarpic species after fire was accomplished primarily through germination of seeds produced above-ground or below-ground. We investigated Polygala lewtonii, an amphicarpic, perennial species endemic to fire-prone Florida sandhill and scrub, where fire kills plants but subsequently increases recruitment and population sizes. Polygala lewtonii produces three flower types: above-ground chasmogamous flowers and above-ground and below-ground cleistogamous flowers, with previous research demonstrating chasmogamous flowers produce a much greater proportion of seeds than cleistogamous flowers. We quantified outcrossing in seeds produced by chasmogamous flowers to determine whether it differed from the 100 % self-fertilized below-ground seeds. Approximately 25 % of seeds from chasmogamous flowers showed evidence of cross-pollination. Assuming that chasmogamous flowers produce the majority of the above-ground seeds, as was shown previously, this indicates it is possible to differentiate between germination by above-ground versus below-ground seeds in post-fire colonization. We next compared genetic diversity, admixture, inbreeding and population genetic structure pre- and post-fire. If fire promoted germination of chasmogamous seeds, heterozygosity and admixture would increase, and genetic structure and inbreeding would decrease. Instead, inbreeding and genetic structure increased and admixture decreased, suggesting that the below-ground selfed seeds (with limited dispersal ability) increased their contribution to the population after fire, possibly because fire reduced above-ground seed viability. Additionally, new alleles not found previously in range-wide analyses emerged from the seed bank post-fire. These results suggest that amphicarpy is a powerful adaptation to preserve genetic variation, maintain adaptive potential and promote rapid post-fire colonization.

Performance of Thermally Modified Spruce Timber in Outdoor Above-Ground Conditions: Checking, Dynamic Stiffness and Static Bending Properties

Previous studies have shown that thermally modified wood (TMW) performs well in outdoor, above-ground conditions in terms of resistance to wood-decaying fungi. Yet, little is known about the development of defects such as checks and the corresponding mechanical properties of TMW in this condition. This experiment focused on the effect of 30 months outdoor above-ground exposure (weathering) on the degree of checking, dynamic stiffness and static bending properties of thermally modified timber (TMT) of Norway spruce. Two board pairs per log were cut from 190 logs; one board of each pair was thermally modified and the other used as control. Then, 90 board pairs were exposed to the weather in south Sweden. Surface checking and axial stiffness were monitored at six-month intervals by using digital photography and non-destructive tests (time-of-flight and resonance method) to monitor changes in the material upon weathering. Finally, all boards were tested destructively in a 4-point static bending test following EN 408 standard. Results showed that weathering had no significance influence on static bending properties of TMT even though the degree of checking was considerably higher in TMT than unmodified timber after weathering. In particular, checks along growth rings were deeper, longer and more common in TMT after weathering, especially on the pith side of boards. The maximum depth of these checks did not depend on board orientation (i.e., which side was exposed) and exceeded limits given in strength grading standards for 7% of the modified boards included. Axial dynamic stiffness determined at 6-month intervals was less influenced by fluctuations in moisture content for TMT compared to unmodified timber, but did not confirm the increase in the degree of checking of TMT. The presence of checks from weathering did influence failure modes in TMT; horizontal shear failure became more frequent and some boards failed in compression.

Recent researches on durability assessment of wood products used in above-ground conditions

Recent researches on durability assessment of wood products used in above-ground conditions

Exploring hbox {CE}nu hbox {NS} with NUCLEUS at the Chooz nuclear power plant

Coherent elastic neutrino–nucleus scattering (hbox {CE}nu hbox {NS}) offers a unique way to study neutrino properties and to search for new physics beyond the Standard Model. Nuclear reactors are promising sources to explore this process at low energies since they deliver large fluxes of anti-neutrinos with typical energies of a few MeV. In this paper, a new-generation experiment to study hbox {CE}nu hbox {NS} is described. The NUCLEUS experiment will use cryogenic detectors which feature an unprecedentedly low-energy threshold and a time response fast enough to be operated under above-ground conditions. Both sensitivity to low-energy nuclear recoils and a high event rate tolerance are stringent requirements to measuring hbox {CE}nu hbox {NS} of reactor anti-neutrinos. A new experimental site, the Very-Near-Site (VNS), at the Chooz nuclear power plant in France is described. The VNS is located between the two 4.25 hbox {GW}_{mathrm {th}} reactor cores and matches the requirements of NUCLEUS. First results of on-site measurements of neutron and muon backgrounds, the expected dominant background contributions, are given. In this paper a preliminary experimental set-up with dedicated active and passive background reduction techniques and first background estimations are presented. Furthermore, the feasibility to operate the detectors in coincidence with an active muon veto at shallow overburden is studied. The paper concludes with a sensitivity study pointing out the physics potential of NUCLEUS at the Chooz nuclear power plant.

Nitrogen cycling responses to simulated emerald ash borer infestation in Fraxinus nigra-dominated wetlands

Understanding short- and long-term responses of forest nutrient cycling to disturbance is vital to predicting future forest function. Mortality of ash trees (Fraxinus spp.) due to emerald ash borer [EAB, Agrilus planipennis (Coleoptera: Buprestidae)] invasion is likely to alter ecosystem processes within infested stands throughout North America. In particular, the loss of Fraxinus nigra (black ash) from F. nigra-dominated swamps may significantly impact the biogeochemical cycles within these ecologically important wetlands. A multiyear manipulative study of nine F. nigra-dominated wetlands in Michigan, USA was undertaken to investigate the potential response of above- and belowground biogeochemical processes to EAB. Short- and long-term changes to site conditions following infestation were emulated by respectively girdling or felling F. nigra saplings and overstory trees. Following disturbance, a short-term reduction in demand for soil nitrogen (N) by dominant canopy species was hypothesized to result in increased soil N availability and a subsequent increase in N uptake by retained species. Though reduced total N return via litterfall indicated decreased demand, this resulted in minimal impacts to soil N availability following treatment. Additionally, increased N uptake by co-dominant Acer rubrum (red maple) and Betula alleghaniensis (yellow birch) was not observed; these combined responses may be attributable to increased immobilization of N by soil microbes. In the 3 years following treatment, the response of foliar characteristics of residual stems—including decreased N concentrations and increased leaf mass per area—appeared to be driven primarily by aboveground conditions and a change from shade- to sun-acclimated leaves. While increased microbial immobilization of N may reduce long-term changes in site fertility, these responses may also limit the potential for short-term positive growth responses of extant woody vegetation. In the longer term, replacing N-rich F. nigra leaf litter with that of A. rubrum and B. alleghaniensis, which have lower N content, is likely to have important feedback effects on soil processes.

Grapevine Leaf Application of Steinernema yirgalemense to Control Planococcus ficus in Semi-field Conditions

The vine mealybug, Planococcus ficus Signoret (Hemiptera: Pseudococcidae), is a key insect pest of South African grapevine. The ability of mealybugs to avoid or resist the action of chemical pesticides has led to the investigation of alternative control methods, such as the application of entomopathogenic nematodes (EPNs). However, EPN application faces challenges, due to the maladaptation of EPN species to aboveground conditions. In this study, the ability of adjuvants to improve the control of P. ficus in grapevine using an indigenous nematode species, Steinernema yirgalemense, was investigated. A trial was performed to assess EPN survival on grapevine foliage, when applied in the morning (high humidity / low temperature) compared with in the afternoon (high temperature / low humidity). In a semi-field trial, the combination of adjuvants Zeba® and Nu-Film-P® resulted in 66% control of P. ficus after 48 h, compared to the use of Zeba® alone (43%), and EPNs alone (28%). Additionally, lower concentrations of EPNs showed predictably lower mortality rates of P. ficus. Significantly, higher EPN survival was recorded at each time interval in the morning, compared with the corresponding interval in the afternoon. This study demonstrates the ability of S. yirgalemense, when applied with adjuvants and at an appropriate time of day, to control P. ficus on grapevine, under semi-field conditions.

Soil amendments effects on radiocesium translocation in forest soils

We conducted an experiment to investigate the potential of phytoremediation by soil amendments in a forest area. To desorb radiocesium (137Cs) from variable charges in the soil, ammonium sulfate (NH4+) and elemental sulfur (S) (which decrease soil pH) were applied to forest soil collected from contaminated area at a rate of 40 and 80 g/m2, respectively. A control condition with no soil treatment was also considered. We defined four groups of aboveground conditions: planted with Quercus serrata, planted with Houttuynia cordata, covered with rice straw as litter, and unplanted/uncovered (control). Cultivation was performed in a greenhouse with a regular water supply for four months. Following elemental sulfur treatment, soil pH values were significantly lower than pH values following ammonium sulfate treatment and no treatment. During cultivation, several plant species germinated from natural seeds. No clear differences in aboveground tissue 137Cs concentrations in planted Q. serrata and H. cordata were observed among the treatments. However, aboveground tissue 137Cs concentration values in the germinated plants following elemental sulfur treatment were higher than the values following the ammonium sulfate treatment and no treatment. Although biomass values for Q. serrata, H. cordata, and germinated plants following elemental sulfur treatment tended to be low, the total 137Cs activities in the aboveground tissue of germinated plants were higher than those following ammonium sulfate treatment and no treatment in rice straw and unplanted conditions. Although no significant differences were observed, 137Cs concentrations in rice straw following ammonium sulfate and elemental sulfur treatments tended to be higher than those in the control case. The results of this study indicate that elemental sulfur lowers the soil pH for a relatively long period and facilitates 137Cs translocation to newly emerged and settled plants or litter, but affects plant growth in large concentrations and/or anaerobic conditions. Combining elemental sulfur application with forest management practices, such as mowing and thinning, could be a suitable method of decontamination of the forest environment.

The legal and commercial determinants of unconventional gas production in East Asia

The US “shale gas revolution” has triggered a worldwide search for unconventional gas in different forms on other continents. Asia’s growing demand for energy and need to switch from coal to natural gas has made governments in this region determined to exploit these newly accessible resources, inspired by the US experience. However, in addition to geological differences, the above-ground conditions in Asian countries are quite different from those in the USA. The papers in this Special Issue analyse the investment frameworks and the consequent outlook for unconventional gas production in China, Indonesia and Vietnam. Our paper sets the context for these accounts by identifying some relevant insights from the experience of the USA and summarises some of the key conclusions from the later papers. A number of common themes emerge from the case studies, for example: the limited capacity of government, the role of the national oil companies and other interested economic actors, complex approval procedures, poor coordination between different government agencies and between different levels of government, access to land, and inadequate infrastructure, as well as the inappropriate nature of the prevailing laws, regulations and contracts designed for the extraction of conventional hydrocarbons. Despite these commonalities, the specific nature of each potential constraint and their relative importance varies between each country and even across an individual country. One challenge arising from the nature of unconventional gas extraction that is common to all countries is the need for effective engagement with society.

Nutrient accumulation in aboveground biomass of planted tropical trees: a meta-analysis

Efficient nutrient use is essential for biomass production by tropical trees growing in infertile soils. Accumulation of nitrogen (N) and phosphorus (P) in the aboveground biomass of four groups of tree stands [Acacia, Eucalyptus, N2-fixing trees excluding Acacia, and other non-N2-fixing broadleaved (ONNFB) trees] were investigated using meta-analyses of a range of biomass data to test the hypothesis that fast-growing Acacia and Eucalyptus trees accumulate fewer nutrients. Data for 83 tropical tree stands were selected from the literature. Standardized major axis regressions were applied between the log10-transformed biomass and N or P accumulation. Nutrient use efficiency was compared with aboveground biomass and topsoil conditions. The slope of the regression between aboveground biomass and N accumulation for Eucalyptus was significantly smaller than the slopes for the N2-fixing trees (excluding Acacia) and the ONNFB trees. N use efficiency of Eucalyptus increased with biomass more than that of N2-fixing trees (excluding Acacia) and the ONNFB trees, because their stems and twigs tended to accumulate less N than in the other groups as biomass increased. The regressions between aboveground biomass and P accumulation had a common slope, and the intercepts of Acacia and Eucalyptus were significantly lower than that of ONNFB trees. P use efficiency of Acacia was consistently higher than that of the ONNFB trees. P use efficiency is more affected by other factors like soil conditions than is N use efficiency, and the differences in the tree groups significantly affect the use efficiency of both nutrients. These results explained some aspects of the general suitability of Acacia and Eucalyptus species for tropical plantations on infertile soils.

Soil bacterial community structure in five tropical forests in Malaysia and one temperate forest in Japan revealed by pyrosequencing analyses of 16S rRNA gene sequence variation

Bacterial community structure was investigated in five tropical rainforests in Sarawak, Malaysia and one temperate forest in Kyoto, Japan. A hierarchical sampling approach was employed, in which soil samples were collected from five sampling-sites within each forest. Pyrosequencing was performed to analyze a total of 493,790 16S rRNA amplicons. Despite differences in aboveground conditions, the composition of bacterial groups was similar across all sampling-sites and forests, with Acidobacteria, Proteobacteria, Verrucomicrobia, Planctomycetes and Bacteroidetes accounting for 90% of all Phyla detected. At higher taxonomic levels, the same taxa were predominant, although there was significant heterogeneity in relative abundance of specific taxa across sampling-sites within one forest or across different forests. In all forests, the level of bacterial diversity, estimated using the Chao1 index, was on the order of 1,000, suggesting that tropical rainforests did not necessarily have a large soil bacterial diversity. The average number of reads per species (OTUs) per sampling-site was 8.0, and more than 40-50% of species were singletons, indicating that most bacterial species occurred infrequently and that few bacterial species achieved high predominance. Approximately 30% of species were specific to one sampling-site within a forest, and 40-60% of species were uniquely detected in one of the six forests studied here. Only 0.2% of species were detected in all forests, while on average 32.1% of species were detected in all sampling-sites within a forest. The results suggested that bacterial communities adapted to specific micro- and macro-environments, but macro-environmental diversity made a larger contribution to total bacterial diversity in forest soil.

Biological Decay and Termite Resistance of Post-Treated Wood-Based Composites under Protected Above-Ground Conditions: A Preliminary Study after 36 Months of Exposure

Five kinds of commercially available wood-based composites (softwood plywood, hardwood plywood, medium density fiberboard, oriented strand board, and particle board, hereinafter abbreviated as SWP, HWP, MDF, OSB, and PB, respectively) post-treated with alkaline copper quat (ACQ) and copper azole (CA) were exposed to decay and subterranean termite activity under protected above-ground conditions in a southern Japan field test site for three years. Variables examined included comparisons of untreated and treated wood-based composites, preservative type, and retention levels. Both biological attacks developed with time. Termite damage started earlier, and the severity of attack was higher than decay fungi. Untreated MDF and PB were highly resistant to field conditions during the 36 months. Untreated OSB, HWP, and SWP were the least resistant composite types. ACQ and CA treatments significantly improved the durability of the wood-based composites resulting in 64.4%, 47.9%, and 22.5% higher termite ratings when compared to their untreated controls for OSB, HWP, and SWP, respectively. Preservative types and increased retentions did not significantly affect the decay and termite ratings. These results suggest that ACQ and CA post-treatments at exterior protected and unprotected (K3) and double K3 retention levels significantly improved durability of wood-based composites tested but failed to provide full protection.

Durability of thermally modified Norway spruce and Scots pine in above-ground conditions

One of the main objectives of thermal modification is to increase the biological durability of wood. In this study the fungal resistance of Norway spruce and Scots pine, thermally modified at 195°C and 210°C, was studied with a lap-joint field test. Untreated pine and spruce and pine impregnated with tributyl tin oxide (TBTO) and copper, chromium and arsenic (CCA) were selected as reference materials. The evaluations were carried out after 1, 2 and 9 years of exposure. After 1 and 2 years of exposure mainly discoloration was detected. Only the untreated pine was slightly affected by decay fungi. There were significant differences in the decay ratings of untreated and thermally modified wood materials after 9 years in the field. While the untreated wood materials were severely attacked by decay fungi or reached failure rating, only small areas of incipient decay were detected in the thermally modified samples. Thermally modified pine was slightly more decayed than thermally modified spruce. The only wood material without any signs of decay was CCA-treated pine, since some of the TBTO-treated pine samples were also moderately attacked by fungal decay. The results of the lap-joint test had a good correlation with mass losses in a laboratory test with brown-rot fungi.

Soil feedback does not explain mowing effects on vegetation structure in a semi-natural grassland

Due to its ability to create aboveground conditions that favour plant diversity, mowing is often used to preserve the high conservation value of semi-natural species-rich grasslands. However, mowing can also affect belowground conditions. By decreasing plant carbon supply to soil, mowing can suppress the activity of soil decomposers, diminish plant nutrient availability and thus create a feedback on plant growth. In this study, we first documented the effects of three-year mowing on plant community structure in a species-rich grassland. We found that mowing decreased the total areal cover of woody plants and increased the total cover of leguminous forbs. At the species level, mowing further increased the cover of two non-leguminous forbs, Prunella vulgaris and Sagina procumbens. Mowing did not affect the species number, diversity or evenness of the plant community. To study whether any of these effects could be explained by mowing-induced changes in the soil, and particularly by reduced nutrient availability, we then collected soil from different treatment plots and monitored the growth of nine plant species in these soils in a greenhouse. Plant growth did not differ between soils collected from mowed and unmowed plots, suggesting that our mowing regimes did not impose such changes in soil decomposer activity and nutrient supply that would feedback on plant growth. Moreover, each of the nine species responded equally to the different nutrient availability in different parts of the grassland, which indicates that even if mowing had reduced plant nutrient supply, this would not have led to changes in plant community structure. It appears that those changes in aboveground vegetation that we recorded after three years of mowing were purely due to the aboveground effects, such as frequent cutting of woody plants and enhanced light availability for low-growing forbs.

Role of Soil Organisms in the Maintenance of Species‐Rich Seminatural Grasslands through Mowing

Abstract To preserve species‐rich grasslands, management practices such as mowing are often required. Mowing is known to promote aboveground conditions that help to maintain plant species richness, but whether belowground effects are important as well is not known. We hypothesized that if mowing decreases belowground carbon transfer by reducing root mass, this will reduce the abundance and activity of soil decomposers and lead to diminished nutrient availability in soil. In grasslands, this would provide a means to mitigate the negative effects of nitrogen enrichment on plant species richness. We established experimental plots on grassland with one‐third of plots growing untouched, one‐third mowed once a summer, and one‐third mowed twice a summer for three growing seasons. Root and soil attributes were measured at each plot 1 month after each mowing. Mowing decreased root mass but had few effects on belowground biota and soil NH4‐N, NO3‐N, and PO4‐P concentrations. Mowing did not affect root N concentrations. Our results show that despite reducing root mass, mowing may have few effects on those soil biota that control nutrient supply and, as a result, have no clear‐cut effects on nutrient availability in soil. This suggests that the effects of mowing on soil decomposers and soil nutrient availability may not provide an effective means to mitigate N enrichment and enhance plant species richness in grasslands in a timescale of a few years. Whether such effects could, however, be achieved with longer lasting mowing remains open.

Fine root biomass and morphology of Pinus densiflora under competitive stress by Chamaecyparis obtusa

The fine root (diameter ≤2.0 mm) biomass and morphology of Japanese red pines (Pinus densiflora) grown under different aboveground conditions (i.e., high and low competitive environments) were examined in a pine–cypress mixed forest. All P. densiflora subject trees were about 40 years old, and the aboveground condition (i.e., size) of red pines appeared to be influenced by the surrounding Japanese cypress (Chamaecyparis obtusa). Smaller P. densiflora exhibited lower fine root biomasses, shorter root lengths, and lower root tip densities, but longer specific root lengths and higher specific root tip densities relative to larger pines. These results suggest that P. densiflora may adjust the morphological traits of fine roots to the different conditions in biomass allocation to fine roots of individuals with different aboveground growth.

Early soft rot colonization of Scots sapwood pine in above-ground exposure

The early colonization of Scots pine ( Pinus sylvestris L.) sapwood exposed above ground (staple bed) was studied. Two different types of exposures were used, one in an open field and the other in a shaded field. Decay type and degree of degradation due to soft rot, and mass and strength loss of wood were correlated. Fungal species in Scots pine sapwood were identified by sequencing, using the fungal nuclear ribosomal DNA (nrDNA) after 24 months. The most abundant decay type found was soft rot, which also agreed with the mass loss (7–8%). Pine sapwood did not differ significantly between the two sites regarding the average mass loss during the time of exposure. The early colonization of wood by soft rot fungi together with mass loss indicates that this fungal type might be more common in above-ground conditions than recognized earlier.