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排序方式: 共有221条查询结果,搜索用时 78 毫秒
1.
Robert Manuel L. Juárez-Gómez Juan Chaires-Pacheco Mariana Peña-Ramírez Yuri J. 《New Forests》2020,51(2):335-347
New Forests - Spanish red cedar, Cedrela odorata L. (Meliaceae), is a valuable timber tree in tropical American forests. Existing demand for elite individuals endangers the conservation of... 相似文献
2.
Tomo’omi Kumagai Koichiro Kuraji Hironori Noguchi Yuri Tanaka Katsunori Tanaka Masakazu Suzuki 《Journal of Forest Research》2001,6(4):257-264
Environmental factors, such as global solar radiation, wind speed, air temperature, humidity, and CO2 concentration, were measured above and within the canopy of a tropical rainforest in Lambir Hills National Park, Sarawak,
Malaysia. Few data concerning the environment of this forest have been reported. Intensive observations were carried out in
1998, 1999, and 2000 with the following results: (1) The fraction of global solar radiation reaching the upper layer of the
canopy varied with global solar radiation above the canopy. Even though the global solar radiation above the canopy fluctuated,
the fraction of that reaching the lower canopy and the ground was constantly approximately 5%. (2) The fraction of wind speed
reaching each layer of the canopy increased with wind speed above the canopy. Little wind was usually present at the lower
canopy. (3) The daytime air temperature at the canopy top was higher than that near the ground. The maximum difference between
the air temperature at the canopy top and that at the ground was about 5°C, and the diurnal temperature ranges at the canopy
top and those at the ground were about 8°C and about 5°C, respectively. The highest daytime water vapor pressure occurred
within the canopy and particularly near the ground. Vertical gradients of water vapor pressure during the day were steep,
probably because of high transpiration. (4) In the 1998 observation the minimum and the maximum CO2 concentrations were 360 ppm in the day and 450 ppm at night, while in the 2000 observation the minimum and the maximum CO2 concentrations were 350 ppm in the day and 540 ppm at night. The higher CO2 concentration in the daytime and the lower concentration at night observed during the 1998 observation period were probably
due to reduced photosynthesis and soil respiration caused by exceptional dry conditions during the observation period. 相似文献
3.
Natalia Kirichenko Julie Flament Yuri Baranchikov Jean-Claude Grégoire 《European Journal of Forest Research》2011,130(6):1067-1074
The Siberian moth, Dendrolimus sibiricus, Tschtv. is the most harmful defoliator of coniferous forests in North Asia. The pest has already spread over the Urals and
continues moving westwards. Recently, it has been recommended for quarantine in member countries by European and Mediterranean
Plant Protection Organization (EPPO). The performances of the pest on coniferous species planted in Europe were assessed on
a range of potted trees corresponding to the spectrum of economically important conifers in the EU: European larch Larix decidua, Norway spruce Picea abies, Scots pine Pinus sylvestris, European black pine Pinus nigra, and the North American species: Douglas fir Pseudotsuga menziesii and grand fir Abies grandis. Larvae showed a potential to survive and complete the development on all these host tree species. Favorable hosts were grand
fir, European larch, and Douglas fir that allowed higher survival, better larval development, and as a result, yielded heavier
pupae and adult moths with higher longevity. Black pine was a poor host but, however, could still support larval and pupal
development. Norway spruce and Scots pine had an intermediate behavior. If accidentally introduced to Europe, the Siberian
moth may become especially damaging in forest stands predominated by European larch and by the North American firs. Norway
spruce and especially the two-needle pines will be less prone to intensive defoliation by this species. The fact that the
pest may damage the range of economically important coniferous species should be taken into account in the pest risk assessment
for Europe and also for North America where the Siberian moth occurrence is considered likely. 相似文献
4.
Joseph Otterman Avihu Ginzburg George Ohring Yuri Mekler 《Water, air, and soil pollution》1974,3(1):53-61
Israel is a participant in the Earth Resources Technology Satellite Program (ERTS). The imagery of Israel and vicinity taken by the Multi Spectral Scanner of the ERTS-1 Satellite has been the subject of analysis in a multidisciplinary research program. The objectives of the program are mapping of agricultural crops, mainly wheat and orange groves, mapping of natural vegetation, and studies for Israeli hydrology, arid regions research, geology, and oceanography. Cases of water, air, and soil pollution have been observed in the imagery on several dates, and are reported in this paper. These are: oil slicks in the Gulf of Suez and possibly near Haifa; smoke plumes, extending over some 100 km in a nearly straight line along the Gulf of Suez, and soil pollution caused by copper mine effluents in the Arava Valley in Israel. The images of these cases of pollution are presented and ‘space signatures’, i.e., the radiometric spectral characteristics of these cases of pollution as seen from space are also given. 相似文献
5.
Peter J. Steer Colleen H. M. Tashiro William D. Mcillveen Ray E. Clement 《Water, air, and soil pollution》1995,82(3-4):659-674
In early February 1990, vandals set fire to a used tire storage facility near Hagersville, Ontario, Canada, During the fire, the Ontario Ministry of Environment and Energy (MOEE) monitored the site and surrounding impact zone for numerous organic contaminants. Samples of air, soil, vegetation, runoff water, and oily residue were collected and analyzed for polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF). Air samples produced complex incineration patterns with a large number of isomers detected. Total toxicity equivalents (TEQ) at 1 km downwind of the fire were an order of magnitude higher than those at 3 km downwind. Soil samples collected during the fire did not show elevated PCDD or PCDF concentrations, however, low concentrations were detected in vegetation collected at 100 m and 200 m from the site. PCDD and PCDF concentrations in the foliage decreased with time but were still detectable for at least 200 days after the fire started. As the tires burned, water used to extinguish the fire caused runoff of oil and oily water. Unique patterns of PCDDs and PCDFs were detected in these samples. 相似文献
6.
Tetsuya Suzuki Jun Itakura Masumi Watanabe Mari Ohta Yuri Sato Yuko Yamaya 《Journal of agricultural and food chemistry》2002,50(1):230-234
Electrolyzed anodic NaCl solutions [EW+], prepared by the electrolysis of 0.1% NaCl, have been shown to instantly inactivate most pathogens that cause food-borne disease. Elimination of food-borne pathogens does not necessarily guarantee food safety because enterotoxins produced by pathogens may remain active. We have tested whether EW+ can inactivate Staphylococcal enterotoxin A (SEA), one of the major enterotoxins responsible for food poisoning. Fixed quantities of SEA were mixed with increasing molar ratios of EW+, and SEA was evaluated by reversed-phase passive latex agglutination (RPLA) test, immunoassay, native polyacrylamide gel electrophoresis (PAGE), and amino acid analysis after 30 min incubations. Exposure of 70 ng, or 2.6 pmol, of SEA in 25 microL of PBS to a 10-fold volume of EW+, or ca. 64.6 x 10(3)-fold molar excess of HOCl in EW+, caused a loss of immuno-reactivity between SEA and a specific anti-SEA antibody. Native PAGE indicated that EW+ caused fragmentation of SEA, and amino acid analysis indicated a loss in amino acid content, in particular Met, Tyr, Ile, Asn, and Asp. Staphylococcal enterotoxin-A excreted into culture broth was also inactivated by exposure to an excess molar ratio of EW+. Thus, EW+ may be a useful management tool to ensure food hygiene by food processing industries. 相似文献
7.
Khrimian A Klun JA Hijji Y Baranchikov YN Pet'ko VM Mastro VC Kramer MH 《Journal of agricultural and food chemistry》2002,50(22):6366-6370
Efficient syntheses of (Z,E)-5,7-dodecadienol, a pheromone component of the Siberian moth, Dendrolimus superans sibiricus, and (E,Z)-10,12-hexadecadienol, a pheromone component of various Lepidoptera pheromones, were accomplished by cis reduction of the corresponding enynols with activated zinc. The most energetic reagent was zinc galvanized with copper and silver (Zn/Cu/Ag) that achieved rapid and high-yield reduction in methanol-water. The stereoselectivity of semi-hydrogenation was > or =98%. A process whereby zinc dust was continuously activated throughout the reduction with an acid was also satisfactory (95-98% cis). Field evaluation of the 1:1 mixture of (Z,E)-5,7-dodecadienol and (Z,E)-5,7-dodecadienal with the Siberian moth in Russia showed that the rubber septa pretreated with compound and stored at -80 degrees C were as effective as freshly treated septa. Moth responses to septa aged in open air indicated that lure effectiveness declined significantly after 2 weeks of aging. Thus, if rubber septa are used as pheromone dispensers in Siberian moth traps monitoring, they should be replaced biweekly with fresh septa for optimal trap effectiveness. 相似文献
8.
Cynthia Yuri Ogawa Katsuyuki Hamasaki Shigeki Dan Shuichi Kitada 《Fisheries Science》2011,77(6):915-927
The fishery biology of mud crabs Scylla spp. was examined using baited traps and gill nets from September 2001 to August 2005 at Iriomote Island, Japan. To elucidate
the growth of the crabs, artificially produced S. serrata juveniles were released and recaptured at the study site. The sizes at which 50% of females and males of S. serrata reached sexual maturity (SM50) were estimated as an external carapace width (ECW) based on the morphology of the abdomen and the chela respectively. Two
species, S. serrata and S. olivacea, were identified in the area with S. serrata being the dominant species (>95% of the catch). Changes in the mean ECW and the results of the release and recapture experiments
suggested that the recruitment of young crabs to the fishery occurred from December/January to April/May. The SM50 of females and males occurred at 132.4 and 150.7 mm ECW respectively. The body size composition of S. serrata revealed that immature crabs comprised approximately 40 and 65% of the catch for females and males respectively. To maintain
a sustainable fishery for S. serrata, a minimum landing size based on the SM50 estimates should be implemented as a fishing regulation. 相似文献
9.
Md. Shaheed Reza Nanami Mizusawa Ayaka Kumano Chiharu Oikawa Daisuke Ouchi Atsushi Kobiyama Yuichiro Yamada Yuri Ikeda Daisuke Ikeda Kazuho Ikeo Shigeru Sato Takehiko Ogata Toshiaki Kudo Mitsuru Jimbo Ko Yasumoto Kazutoshi Yoshitake Shugo Watabe 《Fisheries Science》2018,84(3):563-577
In an effort to determine genus- or species-level taxonomic profiles and diversity of bacterial consortia in the Tama River around urban Tokyo, next-generation sequencing technology targeting a 16S ribosomal RNA (rRNA) gene amplicon was employed. Metagenomic analysis performed by an Ion Personal Genome Machine after sequentially filtering samples through 5-, 0.8- and 0.2-μm filters yielded 1.48 Gb of 16S sequences (average 2.38 M reads/sample). The results indicated that half of the bacterial sequences belonged to Proteobacteria, followed by Bacteroidetes, Actinobacteria and Cyanobacteria. Flavobacterium (Bacteroidetes), possibly including a potential fish pathogen, was the most numerous genera in the Tama River metagenome, and accounted for?~?16% of assigned 16S reads, followed by Mycobacterium. Other dominant bacterial genera including Zoogloea, Sediminibacterium, Hyphomicrobium, Sphingopyxis, Thiothrix and Lysobacter, were thought to be associated with waste water and sludge. MiSeq metagenomic analysis revealed that environmental factors, particularly water temperature, influenced the bacterial composition throughout the year, with a strong negative correlation observed for Proteobacteria and a positive correlation for Bacteroidetes. In terms of bacterial genera, Flavobacterium was positively correlated with temperature, while Polaromonas, Pseudomonas and Bradyrhizobium were negatively correlated with this, suggesting dynamic change in the free-living bacterial population throughout the year and versatile adaptation strategies in relation to environmental factors. 相似文献
10.
Ikue Murata Sigefumi Saruki Katsuyoshi Kubota Sachiko Inoue Naoaki Tashiro Tsutomu Enoki Yasuhiro Utsumi Susumu Inoue 《Journal of Forest Research》2009,14(5):296-301
Effects of sika deer (Cervus nippon) and dwarf bamboo (“sasa;” Sasamorpha borealis) on seedling emergence and survival were investigated in cool-temperate mixed forests in the Kyushu mountain range, Japan.
We compared the effects of sika deer between two sites with different sika deer densities. One site (no-sasa forest) has sparse
cover of S. borealis and a high density of sika deer, and the other site (sasa forest) has dense cover of S. borealis with a low density of sika deer. In the no-sasa forest, more seedlings emerged and the survival rate of the seedlings was
higher compared with the sasa forest. Compared with the sasa forest, the canopy in the no-sasa forest was more open, the organic
layer was shallower and drier, the mean daily soil temperature was higher, and soil temperature fluctuated more widely. Those
environmental parameters did not differ between unfenced and fenced plots. The comparison between the sasa and no-sasa forests
suggested that removal of S. borealis by sika deer had an indirect positive effect on seedling emergence and survival. However, the fenced-plot experiments indicated
that sika deer inhibited seedling emergence and survival. These contradictory conclusions could result from the much larger
negative effects of S. borealis on seedling emergence and survival compared with the effects of sika deer browsing. 相似文献