wood debris
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2022 ◽  
Vol 5 (1) ◽  
Author(s):  
CHONG DONG ◽  
GONG-LE SHI ◽  
ZI-XI WANG ◽  
DI-YING HUANG

Well-preserved coprolites (fossil faecal pellets) were found from lignite seams of the Lower Cretaceous Huolinhe Formation at the Huolinhe Basin in eastern Inner Mongolia, Northeast China. These coprolites provide a combination of following features: oval to cylindrical shaped with six longitudinal ridges, hexagonal to elliptical cross-sections, and one blunt end and the other pointed end. According to these distinct features and their size range, the producers of these coprolites are attributed to termites. Termites were estimated to have originated in the earliest Cretaceous with an evolutionary radiation in the Early Cretaceous. The presence of wood debris in the coprolites indicate that the Early Cretaceous termites from the Huolinhe Basin had wood-feeding habits; and anatomical features displaying on the wood debris further suggest their feeding preference was coniferous wood. Besides, the results of a k-means clustering analysis performed for these coprolites indicate that three clusters with different proportion were present, suggesting the division of labor in termites’ sociality existed as early as the Early Cretaceous.


Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3283
Author(s):  
Norio Harada ◽  
Kana Nakatani ◽  
Ichiro Kimura ◽  
Yoshifumi Satofuka ◽  
Takahisa Mizuyama

Improvements in sediment retarding basin design are required to mitigate flood damage caused by bed load and wood debris outflow in lower river reaches. We used a scaled sediment retarding basin model to optimize our basin design, with the goal of improving sediment and wood debris transport and capture. Changes to the structural dimensions and elements of the sediment retarding basin were assessed under experimental debris flow conditions. The results obtained from the experiments and simulations were in good agreement regarding sediment flow and containment. The proposed one-dimensional model is useful for showing the effects of flow conditions within a sediment retarding basin on sediment transport.


2021 ◽  
Vol 60 (2) ◽  
pp. 337-349
Author(s):  
Panaghiotis TSOPELAS ◽  
Nikoleta SOULIOTI ◽  
Michael J. WINGFIIELD ◽  
Irene BARNES ◽  
Seonju MARINCOWITZ ◽  
...  

Ceratocystis ficicola causes vascular wilt of fig trees in Japan, invading root systems and the main stems eventually leading to tree death. In surveys from 2018 to 2020 in fig orchards in Greece, this fungus was detected in two separated regions. The fungus was consistently isolated from infected wood and from rhizosphere soil. The isolates were identified based on multi-locus phylogenetic analyses of rpb2, bt1 and tef1 gene regions and detailed morphological characteristics, including comparisons with an ex-type isolate of C. ficicola from Japan. The pathogenicity of Greek isolates was proven on Ficus carica and F. benjamina plants. Ceratocystis ficicola is a soil-borne pathogen, and the occurrence of vascular wilt outbreaks suggest that the pathogen spreads within and between orchards with infested soil and wood debris during ploughing. The pathogen is also spreading in Greece with infected propagation material. This is the first detailed report of C. ficicola outside Japan, and there is concern over potential spread of the pathogen to other Mediterranean countries, where approx. 70% of the world fig production occurs.


Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2118
Author(s):  
Simone Pagliara ◽  
Deep Roy ◽  
Michele Palermo

Structures like blunt-nosed chevrons, log deflectors and double-winged log frames help in modifying the flow regime in the channel by concentrating the flow and increasing navigability. Moreover, they create scour pools in the downstream stilling basin, which can be used either as fish refuge or as an in-stream storage site for previously dredged material. In this respect, the use of wood debris in the channel in the form of wood bundles has gained attention for the ability of these structures to integrate into the surrounding fluvial habitat and to divert the flow partially towards the central part of the channel when placed in curves. Considering the absence of studies dealing with wood bundles as a restoration structure, the aim of this paper is to analyse the scour mechanism and equilibrium scour morphology of wood bundles in straight and curved channels. In doing so, a wide range of hydraulic conditions, structure positions and configurations were tested. Thereafter, dimensional analysis was carried out to derive useful empirical relationships to predict the maximum scour depth and length as well as the maximum dune height based on a novel, equivalent Froude number, which accounts for the effects of channel curvature and structure position. Moreover, the various resulting scour morphology types were classified, and conditions of their existence were determined depending on the abovementioned Froude number and other key hydraulic parameters.


2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Praveen Kumar Nagadesi ◽  
Venkatesh Rampilla

Wood inhabiting fungi that grow specifically on leaf litter, wood debris, humus rich soil of forest helps in biodegradation and increase soil fertility. The fruiting bodies of fungi were collected from partially dead forest trees, fallen wooden logs, leaf litter and decomposing humus rich soil of Kondapalli forest area, Central Eastern Ghats of India. Detailed macroscopic and microscopic study of collected fungal samples revealed the occurrence of wood inhabiting fungi belonging to 7 genera and 9 species; i.e. Geastrum triplex Jungh., Marasmius siccus (Schweinitz) Fries, M. fulvoferrugineus Gilliam, M. oreades (Bolt.: Fries) Fries Epicr. Lactarius piperatus (L.) Pers., Flammulina velutipes (Curtis) Singer, Artomyces microsporus (Qiu X. Wu & R. H. Petersen) Lickey, Hymenochaetopsis rigidula (Berk. & M. A. Curtis) S. H. He & Jiao Yang and Bjerkandera adusta (Willd: Fr.) Karst. For the first time, A. microsporus (Qiu X. Wu & R. H. Petersen) Lickey and H. rigidula (Berk. & M. A. Curtis) S. H. He & Jiao Yang., were reported from India. M. fulvoferrugineus Gilliam was reported second time from India. The wood inhabiting fungi were new records to Kondapalli forest area, Central Eastern Ghats of India.


Author(s):  
Guohai Jia ◽  
Guoshuai Tian ◽  
Zicheng Gao ◽  
Dan Huang ◽  
Wei Li ◽  
...  

Abstract Cyclone venturi dryer is suitable for drying materials with large particle size and wide distribution. The working process of cyclone venturi dryer is a very complicated three-dimensional and turbulent motion, so it is difficult to be studied theoretically and experimentally. In order to study the internal flow characteristics of the biomass particle cyclone venturi dryer, the computational fluid dynamics (CFD) software was used to simulate the gas-solid two-phase flow field inside the cyclone venturi dryer. The continuous phase adopts the Realizable k-ε turbulence model and the particle phase is discrete. The effects of different injection volume on the pressure, velocity, and temperature fields inside a cyclone venturi dryer were analyzed. The results showed that the maximum pressure drop and velocity change inside the dryer were at the venturi pipe. The wet material of the cyclone venturi dryer was inhaled into the venturi contraction tube by the negative pressure formed after the highspeed airflow was ejected, thus the mixture was completed in the venturi throat. The wood debris material was mixed with the high-speed hot gas flow in the venturi throat and then sprayed into the diffusion pipe. In the diffusion pipe of venturi, the heat and mass transfer process of wet wood debris and heat flow in venturi diffusion tube was completed. It is in good agreement with the simulation results. This study can provide a reference for the optimization design of the related cyclone venturi dryer structure.


Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 401
Author(s):  
Kashif Khan ◽  
Tran Thi Tuyen ◽  
Lixin Chen ◽  
Wen Biao Duan ◽  
Anwaar Hussain ◽  
...  

Coarse wood debris (CWD) plays a critical role in forest productivity, nutrient cycling, decomposition, and carbon sequestration, and shapes the carbon pool in the forest ecosystem. However, the elemental composition of CWD varies among different forest types and decay classes for the same dominant tree species (Pinus koraiensis, PK). We compared CWD elemental composition across different forest types (Picea koraiensis-Abies nephrolepis-Pinus koraiensis forest (PAPF), Betula costata-Pinus koraiensis forest (BPF), Tilia amurensis-Pinus koraiensis forest (TPF)), considering four classes of wood decay. Results showed that N, P, Mg, Mn, Na, Zn, S, Al, and Fe concentrations almost totally increased with decay level for all three forest types, except for K in all three forest types and B in Picea koraiensis-Abies nephrolepis-Pinus koraiensis forest (PAPF). Similarly, maximum concentrations of N, P, B, Mg, K, C, Zn, and Mn of CWD were observed in Betula costata-Pinus koraiensis forest (BPF) under varying decay classes, but their maximum concentrations of Fe and S were found in Picea koraiensis-Abies nephrolepis-Pinus koraiensis forest (PAPF) and Tilia amurensis-Pinus koraiensis forest(TPF), respectively. Only C content did not significantly differ in decay classes across all three forest types. The C:N ratio decreased significantly with increasing decay levels across all forest types. The decay rates were significantly related to N concentration and C:N ratio in decay classes across all forest types. These results suggest that C and N concentration are the key factors affecting its decomposition. The variation in nutrient concentrations observed here underscores the complexity of nutrients stored in wood debris in forested ecosystems.


2021 ◽  
Vol 67 (No. 2) ◽  
pp. 51-65
Author(s):  
Ivan Mihál ◽  
Eva Luptáková ◽  
Martin Pavlík

Wood-inhabiting macromycete (WIM) communities in the ecosystem of uneven-aged spruce stands growing on former agricultural land were investigated in relation to the supply of wood substrate, degree of wood rot, and selected climatic and ecological conditions. Altogether, 58 WIM species were detected at research plots during 2016–2018. The abundance of fruiting bodies and WIM species richness increased from the youngest to the oldest forest stands. The highest numbers of fruiting body abundance were recorded for Gymnopus perforans (11 756), Hypholoma fasciculare (2 971), Coprinellus disseminatus (326), Exidia pithya (318) and Panellus mitis (147). The influence of stand age on WIM abundance was highly significant (P < 0.001), WIM abundance was not affected by precipitation (P > 0.05). The relationships between abundance and air temperature (P < 0.001), species richness and precipitation (P < 0.001), species richness and air temperature (P < 0.001) were highly significant. The most frequent damage to trees was caused by insects and forest animals (81%), which resulted in a high occurrence of resin secretion (70%). The total volume of coarse wood debris (CWD) and the decay rate were not statistically dependent. We confirmed the occurrence of Heterobasidion annosum s.s., H. abietinum s.s., H. parviporum s.s., Armillaria ostoyae s.s. and A. cepistipes s.s. by use of molecular genetic analyses.


Author(s):  
David Cottrell ◽  
Gavin Glore

A dynamic revetment was constructed at North Cove, Washington, USA in December 2018 along a historically eroding 2-km shoreline reach of coastal barrier at the northern entrance to Willapa Bay. The revetment is composed of poorly sorted angular quarry rock ranging in size from pea gravel to small boulders as well as large wood debris and structures, a dune ridge, and native vegetation integrated with the revetment. The design, aim, and maintenance of the dynamic revetment is to simulate the functions of naturally forming cobble berms along composite beaches in the U.S. Pacific Northwest. The dynamic revetment continues to be adaptively constructed over time, enabling the testing of innovative design approaches and concepts that are rarely possible to do at full-scale in the field. The project provides a unique opportunity to explore nature-based engineering principles and design features.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/5w18tEjEePg


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