Abstract. Population size, reproductive timing and habitats, seasonal behaviors, and juvenile activity were assessed in a British Columbia population of the endangered Oregon forestsnail, Allogona townsendiana , over a period of 4 years. Adult snail population size ranged from seven to 47 snails in four × 24-m2 sampling sites. The mating period peaked in March and April; adults aggregated in clusters of eight to 14 snails before mating. Pairs of snails were observed to mate for 225 min or more in close proximity to coarse woody debris and stinging nettle, Urtica dioica. Nesting peaked in April–May and resulted in a mean clutch size of 34 eggs (SD=9). Hatching for two nests occurred at 63 and 64 d after oviposition. Within hours of hatching, juveniles began dispersing from the nest site; by 1 month most had disappeared. Snails tracked with harmonic radar became less active or aestivated from late July to early September and hibernated from early November to mid-March within leaf litter and soil. Preliminary measurements of growth rate indicate this species takes a minimum of 2 years to reach adulthood and has a typical life span of at least 5 years. 相似文献
1. 1. Experiments were carried out concerning the characteristics of wettedness revealed under constant average skin temperature using sitting-resting nude subjects. From the basic measurements of both environmental parameters and human physiological responses, the conclusions detailed below were proposed regarding the changes of wettedness under constant average skin temperature.
2. 2. There is positive correlation between the wettedness and environmental humidity, and negative correlation between the wettedness and air temperature.
3. 3. There is positive correlation between the evaporative heat loss from the skin surface and air temperature, and negative correlation between the evaporative heat loss and environmental humidity.
4. 4. There is negative correlation between the wettedness and evaporative heat loss.
5. 5. Wettedness is not constant but takes varying values, that is, corresponding to each average skin temperature both the maximum and the minimum wettedness values occur.
6. 6. Deriving from the items mentioned above, the theoretical locus of equal average skin temperature is not a straight line, but is a curved line plotted on the psychrometric chart.
Author Keywords: Wettedness; sweat rate; evaporative heat loss; equal average skin temperature line; psychrometric chart; ET*; thermal comfort 相似文献
Geographic information system-based analysis was used to derive comprehensive, consistent estimates of the potential area
of broadly defined, shallow-water, tropical and subtropical coral ecosystems within the territorial sea and exclusive economic
zone of the United States. A coral ecosystem is composed of habitats including unconsolidated sediment, mangrove, hermatypic
coral, colonized hardbottom, and submerged vegetation, and major structural zones like reef crest, lagoon, and fore reef.
This broad definition reflects the importance of both reef and non-reef habitats and structural zones in the function of these
ecosystems. Nautical charts, published by the National Oceanic and Atmospheric Administration’s Office of the Coast Survey,
provide a consistent source of 10-fathom (∼18 m) and 100-fathom (∼183 m) depth curve information. The 10-fathom or 100-fathom
depth curves are used as surrogates for the potential distribution and extent of shallow-water coral ecosystems in tropical
and subtropical U.S. waters. An estimated 36,813 sq·km area has been identified where coral ecosystems can potentially be
found in waters less than 10 fathoms (18 m) deep. In addition, an estimated 143,059 sq·km area has been identified where coral
ecosystems potentially can be found in U.S. waters at depths down to 100 fathoms (183 m). Results also indicate that previous
studies underestimated the extent of potential coral ecosystems for some locations in U.S. tropical and subtropical waters
by as much as 100% and that the regional distribution of coral ecosystems has been incorrectly reported. 相似文献