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91.
Son Truong NGUYEN Masaharu MOTOKAWA Tatsuo OSHIDA Hideki ENDO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(2):187-198
Southeast Asia is a region of high biodiversity, containing species of plants and animals that are yet to be
discovered. In this region, bats of the subfamily Kerivoulinae are widespread and diverse with six species
recorded in Vietnam. However, the taxonomy of the Kerivoulinae in Asia is complicated. In our study, we used
diagnostic characters and multivariate analysis to determine morphological differences between the genera
Kerivoula and Phoniscus. We showed that the two genera are distinguishable
by the size of second upper incisors, the shape of skull, nasal sinus, canines, second upper and lower
premolars. In addition, the two genera can be osteometrically separated by measurements of the braincase
height, interorbital width and shape of anterior palatal emargination. Our data clearly revealed the
morphological variations in the skull shape of Kerivoula hardwickii in Vietnam. This suggests
a possible separation into three morphotypes, representing cryptic species supported by statistical
differences with wide variation in skull shape, size and teeth. These results demonstrated Kerivoula
hardwickii can be separated three subspecies, and the result will serve as the basis for the future
assessment and classification of this group in Southeast Asia. 相似文献
92.
To improve the productivity and wood quality of poplar plantations, effects of four planting spacing on canopy characteristics, biomass production and stem roundness in poplar plantations were evaluated over 8 years. Planting spacing influenced canopy characteristics of the plantations, and further affected the understory vegetation and plantation productivity. Understory vegetation biomass and Shannon-Wiener index were negatively correlated with leaf area index, but both diversity indexes and aboveground biomass of understory vegetation were higher in stands with a wider spacing. Tree diameter growth increased with increasing planting spacing, while the increment in plantations of square configurations (5?×?5 m and 6?×?6 m) was higher than those with rectangular configurations (3?×?8 m, 4.5?×?8 m). The highest poplar biomass production was achieved in the plantation with 5?×?5 m spacing at age 8. Moreover, poplar trees showed a tendency with better stem roundness in a square configuration. The results suggest that planting spacing not only affect canopy characteristics, understory vegetation and tree growth but also wood quality, and square configurations (5?×?5 m and 6?×?6 m) could be a better option for poplar plywood timber production at similar sites. 相似文献
93.
近年来,鱼类寄生虫病在呼和浩特市地区经常发生。为此,作者于１９９２年３～１０月对呼市郊区主要经济鱼类进行了调查,共得到１６种鱼类寄生虫,隶属于８纲、１２目、１２科、１２属。同时,对鱼类寄生虫的感染情况也进行了研究。 相似文献
94.
95.
Weed control in smallholder farming systems of sub-Saharan Africa is labour intensive or costly. Many researchers have therefore advocated for the use of cover crops in weed management as an affordable alternative for smallholders. Cover crops may be grown in rotations to suppress weeds and reduce the reliance on herbicides. The use of cover crops creates microenvironments that are either conducive or inhibitive to the emergence of certain weed species. A study, initiated in 2008 in contrasting soils at four different locations of Zimbabwe, investigated the effect of maize (Zea mays L.)-cover crop rotations on the emergence of weeds that showed dominance in those soils. Weed assessments were however, carried out from 2011 to 2014. The weed species Galinsoga parviflora Cav., Commelina benghalensis L., and Richardia scabra L. showed dominance in all four locations with weed densities as high as 500 plants m−2 being recorded for R. scabra L. in a sandy soil. Maize-cover crop rotations resulted in higher densities of Bidens pilosa compared with maize monocropping (control treatment) due to its high nitrogen (N) requirement to produce more seeds. On the other hand, the integration of cover crops such as pigeon pea [Cajanus cajan (L.) Millsp.] that had poor shading qualities, due to large gaps or spaces and slower initial growth, had limited effects on competitive weeds such as Cyperus esculentus L. which tend to dominate exhausted soils. The density of C. esculentus was 38% greater in maize–pigeon pea rotations compared with the control treatment. Variability between seasons and sites affected emergence of all weeds in the present study, which masked long-term trends. The results suggest that there is need to identify the germination and emergence requirements of specific weeds and select cover crops best suitable for their control. The study provides useful information for farmers and advisors on the best cover crops for control of certain problematic weeds in different soil types of Zimbabwe. 相似文献
96.
97.
主要防风固沙植物及其应用价值 总被引：3，自引：0，他引：3
张兵 《内蒙古林业调查设计》2012,35(5):62-65
文章综述了11种常见防风固沙植物种的特性,并阐述了其应用价值,以期为沙区防风固沙实际应用提供借鉴。 相似文献
98.
99.
通过引种造林,对J172柳等5个柳树良种进行了不同区域抗寒、抗风力对比试验,结果表明:J172柳、J194柳抗寒、抗风力强;J369柳和青冈柳次之;准葛尔柳根据其生长特性,在高寒阴湿地区抗性明显好于其它品系。 相似文献
100.
《水产资源保护:海洋与淡水生态系统》2018,28(2):296-304
- Although the economic value of wildlife historically has been attributed to its consumptive use, the global growth of ecotourism has expanded wildlife valuation to include non‐consumptive uses. In California, the critically endangered giant sea bass (Stereolepis gigas) is paradoxically both a flagship species in the recreational dive industry and regularly sold in California's commercial fisheries when incidentally caught. The differences in the economic value of S. gigas to these two key stakeholders – commercial fishers and recreational scuba divers – were explored.
- The average annual landing value of S. gigas was US$12 600, this value was determined using California commercial fishery landing receipt data. In contrast the estimated average value of S. gigas to recreational divers was US$2.3 million per year. The non‐consumptive use value was calculated by approximating the annual number of recreational charter boat divers and determining divers' willingness‐to‐pay for a S. gigas sighting.
- Stated landings volumes of S. gigas appear to represent a minimum annual extraction of 2% to 19% of the S. gigas population. Using self‐reported fishery catch location data, S. gigas bycatch hotspots were identified and used to inform suggestions for strategic spatial and temporal closures.
- Overall, these results highlight the value of giant sea bass beyond fisheries and underscore the importance of incorporating non‐consumptive values when developing harvest policies and marine management plans.