Comparison of macroinvertebrate assemblages in a stream before and after fine sedimentation by deer‐induced forest floor degradation

2021 ◽  
Author(s):  
Hikaru Nakagawa
Keyword(s):  
Forest Floor ◽  
Macroinvertebrate Assemblages ◽  
Before And After

scholarly journals Survival of Neonectria fuckeliana in woody material

2008 ◽  
Vol 61 ◽  
pp. 390-390
Author(s):  
A.J.M. Hopkins ◽  
M.A. Dick ◽  
I.G. Simpson
Keyword(s):  
New Zealand ◽  
Pinus Radiata ◽  
Forest Floor ◽  
Woody Debris ◽  
The Third ◽  
Significant Difference ◽  
Pathogen Survival ◽  
Before And After ◽  
Growth Loss ◽  
Neonectria Fuckeliana

In southern New Zealand Neonectria fuckeliana is associated with a stem flute canker of Pinus radiata which can result in severe stem malformation and growth loss This research consisting of three distinct experiments aimed to determine pathogen survival in processed and unprocessed wood and woody debris In the first experiment the survival of the pathogen in living trees was examined by sampling trees infected with N fuckeliana in 6 different years In the second experiment the survival of the pathogen in woody debris was examined using 36 infected logs in a range of sizeclasses The logs were left on the forest floor in shaded and unshaded conditions and sampled for N fuckeliana after 4 and 9 months The third experiment examined the survival of the pathogen in processed wood Boards cut from infected trees were tested in six standard timber drying treatments Boards were sampled before and after drying to determine the presence of living N fuckeliana Neonectria fuckeliana was successfully isolated from trees at all infection times tested The fungus was also successfully isolated from 81 of logs after 9 months on the forest floor There was no significant difference between shaded and unshaded treatments Neonectria fuckeliana was not found in any boards following kilndrying but was successfully isolated from 69 of infected boards subjected to the two standard airdrying treatments for 9 weeks

scholarly journals Impact of the Disturbances for Forest Grazing on Flora Composition in a Natural Forest

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 872
Author(s):  
Gyuil Han ◽  
Eunju Cheong ◽  
Wangeun Park ◽  
Sechang Kim
Keyword(s):  
Plant Species ◽  
Forest Floor ◽  
Vascular Plant ◽  
Rare Plants ◽  
Cool Temperature ◽  
Survey Period ◽  
Conservation Area ◽  
Forest Grazing ◽  
Before And After ◽  
Ground Condition

Daegwallyeong is a mountain pass at an altitude of 832 m, which has been designated a conservation area because of its essential role in Korea’s forest ecosystem. Simultaneously, this area is considered a suitable place for forest grazing due to the cool temperature during the summer. Some areas have been converted to grassland for livestock feeding, and the scale has continued increasing. Although livestock in a forest area is more ecofriendly than industrialized facilities, it could impact the native ecosystem, especially in terms of the flora and vegetation. We investigated the changes in flora and vegetation of Daegwallyeong before and after the grassland formation. The total number of vascular plant species changed throughout the survey period. It was decreased by thinning and forest floor removal in 2015. However, it bounced back to the original number in 2016, even after grazing. However, there was a dramatic decrease after the second forest floor removal and 3 months of grazing in 2017. The number of flora slightly increased after the fallow of grazing in 2019, but it did not fully recover. Although the number of flora seemed back to normal, the composition of the flora in 2019 was significantly changed from the forest without disturbance in 2014. First, there was the invasion of naturalized plants such as Taraxacum officinale and Barbarea vularis, as well as ecosystem-disturbing flora such as Carex callitrichos var. nana and Rumex acetosa. Second, the coverage of those species expanded after thinning and grazing. Most importantly, we lost five valuable rare species, Anemone koraiensis, Viola diamantiaca, Chionanthus retusus, Scopolia japonica, and Streptopus ovalis, from the area. Additionally, the ground condition of the area was severely damaged, and plants no longer grow in some areas. The survey and analysis of plants in this study showed the adverse effects of forest grazing practices on rare plants in Daegwallyeong. Forest grazing practices should be carefully conducted to preserve vulnerable plant species and a healthy ecosystem.

Site preparation burning to improve southern Appalachian pine–hardwood stands: aboveground biomass, forest floor mass, and nitrogen and carbon pools

1993 ◽  
Vol 23 (10) ◽  
pp. 2255-2262 ◽  
Author(s):  
James M. Vose ◽  
Wayne T. Swank
Keyword(s):  
Forest Floor ◽  
Early Summer ◽  
Carbon Pools ◽  
Southern Appalachians ◽  
N Availability ◽  
Size Distributions ◽  
N Losses ◽  
Southern Appalachian ◽  
Before And After ◽  
Early Fall

On three sites in the southern Appalachians, stands characterized by sparse overstories and dense Kalmialatifolia L. shrub layers were felled in early summer and burned in early fall. Amounts of aboveground vegetation and forest floor mass, nitrogen (N), and carbon (C) were measured before and after treatment by sampling wood, foliage, herbs, grasses, and forest floor (Oi and Oe + Oa layers). Burning decreased woody mass by 48 to 60% across the three sites. The most intense burn reduced mass from 180 to 70 Mg•ha−1, and N and C losses were 300 kg•ha−1 and 52 Mg•ha−1, respectively. Significant losses of mass, N, and C occurred in the Oi layer, but not in the Oe + Oa layer. Foliage, herbs, and grasses were totally consumed by the fires. Total aboveground N losses across sites ranged from 193 to 480 kg•ha−1. These losses may be significant because N availability is low on these sites. Variations in patterns of mass, N, and C consumption were related to differences in amounts, types, size distributions, and moisture contents of fuels.

Changes in forest floor bryophyte (moss and liverwort) communities 4 years after forest harvest

2003 ◽  
Vol 81 (7) ◽  
pp. 714-731 ◽  
Author(s):  
Nicole J Fenton ◽  
Katherine A Frego ◽  
Mary R Sims
Keyword(s):  
Forest Floor ◽  
Community Change ◽  
Managed Forest ◽  
Forest Harvest ◽  
Potential Threat ◽  
Before And After ◽  
Canopy Removal ◽  
Forest Floor Disturbance ◽  
Managed Landscapes ◽  
Harvest Techniques

Forest harvest presents a potential threat to forest floor bryophyte communities primarily through alteration of the microclimate and disturbance of substrates on the forest floor. Management, including harvest, applied at the landscape scale creates patches of disturbance of differing severities at the spatial scale experienced by bryophytes. Presumably, bryophyte diversity in managed landscapes is best conserved by forest harvest techniques that minimize community change, thereby allowing disturbed communities to reassemble to approach predisturbance composition. We monitored bryophyte community reassembly by sampling quadrats established in a 54-ha management block of Acadian forest in New Brunswick, before and after harvest. Quadrats were either in unharvested areas, or experienced a range of disturbance severities from removal of some or all canopy, to forest floor disturbance with complete canopy removal. Bryophyte communities showed compositional change over 4 years, even in areas that were not harvested. Although species richness was maintained or recovered 4 years after harvest, changes in species composition were significant in all disturbance classes with greatest change related to forest floor disturbance. In particular, liverworts were lost in areas with forest floor disturbance. We suggest that the simplest method to reduce immediate species loss, and presumably promote conservation of bryophyte communities within managed forest landscapes, is to utilize techniques that reduce the area of forest floor and associated substrates that are physically disrupted.Key words: bryophyte, community change, disturbance, forest harvest, monitoring.

scholarly journals Effects of sediment replenishment on riverbed environments and macroinvertebrate assemblages downstream of a dam

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Izumi Katano ◽  
Junjiro N. Negishi ◽  
Tomoko Minagawa ◽  
Hideyuki Doi ◽  
Yôichi Kawaguchi ◽  
...  
Keyword(s):  
Habitat Structure ◽  
Particle Sizes ◽  
Reference Sites ◽  
Macroinvertebrate Assemblages ◽  
Before And After ◽  
Management Techniques ◽  
Community Assemblages ◽  
Materials Used ◽  
Harmful Effects ◽  
Dammed River

AbstractRiverbeds downstream of dams are starved of sediment, impacting habitat structure and ecological function. Despite the implementation of sediment management techniques, there has been no evaluation of their conservational effectiveness; the impacts on high trophic level organisms remain unknown. This study examined the effects of sediment replenishment on riverbeds and macroinvertebrates in a dammed river before and after sediment replenishment. We evaluated the particle sizes of replenished sediments and the case material of a case-bearing caddisfly. We observed significant changes in macroinvertebrate assemblages before and after sediment replenishment, and between the upstream and tributary references and downstream of the dam. The percentages of Ephemeroptera, Plecoptera, and Trichoptera, and the number of inorganic case-bearing caddisflies downstream of the dam following sediment replenishment, were significantly higher than the upstream and tributary reference sites. The particle size of case materials used by case-bearing caddisfly corresponded to the size of the replenished sediment. Dissimilarity results after replenishment showed that assemblages downstream of the dam differed from upstream sites, although they were similar to the tributary sites. The dissimilarity between the tributary and downstream of the dam was the same as that between the upstream and tributary. Sediment replenishment was observed to reduce the harmful effects of the dam, and partly restore benefits such as increasing species diversity and altering community assemblages, similar to the effects of tributary inflows.

Deformation Replication

1970 ◽  
Vol 28 ◽  
pp. 280-281
Author(s):  
J. Temple Black
Keyword(s):  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Rake Face ◽  
Orthogonal Machining ◽  
Aluminum Chips ◽  
Before And After ◽  
Materials Used ◽  
Glass Knife ◽  
Very High

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.

The Clinical, Roentgenological and Morphological Effects of an Acute Exposure of Phosgene on the Lungs of Dogs

1971 ◽  
Vol 29 ◽  
pp. 236-237
Author(s):  
R. F. Bils ◽  
W. F. Diller ◽  
F. Huth
Keyword(s):  
Latent Period ◽  
Chemical Industry ◽  
Toxic Substance ◽  
Lung Edema ◽  
X Rays ◽  
Beagle Dogs ◽  
Male And Female ◽  
Morphological Alterations ◽  
Before And After ◽  
Electron Microscopes

Phosgene still plays an important role as a toxic substance in the chemical industry. Thiess (1968) recently reported observations on numerous cases of phosgene poisoning. A serious difficulty in the clinical handling of phosgene poisoning cases is a relatively long latent period, up to 12 hours, with no obvious signs of severity. At about 12 hours heavy lung edema appears suddenly, however changes can be seen in routine X-rays taken after only a few hours' exposure (Diller et al., 1969). This study was undertaken to correlate these early changes seen by the roengenologist with morphological alterations in the lungs seen in the'light and electron microscopes.Forty-two adult male and female Beagle dogs were selected for these exposure experiments. Treated animals were exposed to 94.5-107-5 ppm phosgene for 10 min. in a 15 m3 chamber. Roentgenograms were made of the thorax of each animal before and after exposure, up to 24 hrs.

Ultrastructure of Melanin Formation in Curvularia sp., Alternaria sp., and Drechslera Sorokiniana

1977 ◽  
Vol 35 ◽  
pp. 398-399
Author(s):  
M. H. Wheeler ◽  
W. J. Tolmsoff ◽  
A. A. Bell
Keyword(s):  
Potassium Phosphate ◽  
Thielaviopsis Basicola ◽  
Wild Type ◽  
Potassium Phosphate Buffer ◽  
Transmission Microscopy ◽  
Electron Transmission ◽  
Melanin Formation ◽  
Before And After ◽  
Alternaria Sp ◽  
Electron Transmission Microscopy

(+)-Scytalone [3,4-dihydro-3,6,8-trihydroxy-l-(2Hj-naphthalenone] and 1,8-di- hydroxynaphthalene (DHN) have been proposed as intermediates of melanin synthesis in the fungi Verticillium dahliae (1, 2, 3, 4) and Thielaviopsis basicola (4, 5). Scytalone is enzymatically dehydrated by V. dahliae to 1,3,8-trihydroxynaphthalene which is then reduced to (-)-vermelone [(-)-3,4- dihydro-3,8-dihydroxy-1(2H)-naphthalenone]. Vermelone is subsequently dehydrated to DHN which is enzymatically polymerized to melanin.Melanin formation in Curvularia sp., Alternaria sp., and Drechslera soro- kiniana was examined by light and electron-transmission microscopy. Wild-type isolates of each fungus were compared with albino mutants before and after treatment with 1 mM scytalone or 0.1 mM DHN in 50 mM potassium phosphate buffer, pH 7.0. Both chemicals were converted to dark pigments in the walls of hyphae and conidia of the albino mutants. The darkened cells were similar in appearance to corresponding cells of the wild types under the light microscope.

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