White-naped crane (Grus vipio) is a globally threatened spe- cies. It is very important to analyze its nest site selection in circum- stances where there are multiple disturbances, and also helpful to accu- mulate valuable information about this threatened species and supply scientific suggestions for conservation and management. We studied nest site selection and the effects of environmental variables on nesting habits of white-naped crane at Zhalong National Nature Reserve, Qiqihar City, Heilongiiang, China, during March-May of 2002-2008. White-naped crane responded and adapted to changes in the quality of the spatial environments of landscape and microhabitat under multiple environ- mental disturbances. Nest site selection included two scales and two choices, namely the choice of nest site habitat type within the macro-habitat scale and nest site micro-habitat selection within the mi- cro-habitat scale. Nest sites were recorded only in reed marshes. The choice of nest site micro-habitat included three basic elements and six factors, namely incubation element (nest parameters factor, incubation temperature factor and incubation humidity factor), safety element (pro- tection factor and concealment factor), and food element (water factor). Water, remnant reed clusters, and fire were major resource management challenges during the breeding period for the white-naped crane in this Reserve. 相似文献
There is a growing body of literature showing that physical activity and nature have a positive effect on people's health and well-being. Additionally literature indicates that there may even be a synergic benefit from being physically active whilst simultaneously being directly exposed to nature. This insight is used in recovery programmes for work related stress and mental health care settings. However, as primary care is usually people's first point of contact with the health care system, the greatest benefits for people's health can probably be obtained in primary health care settings. The aim of the present study is therefore to investigate to what extent general practitioners advise patients on physical activity and whether they refer to the additional health benefits of physical activity in a natural environment.
A secondary analysis was performed on a random sample of 2784 video-taped patient consultations of 100 general practitioners in The Netherlands. Many characteristics of these consultations were known on the basis of earlier analyses: diagnosis, age and sex of patient and whether or not the issue of physical activity had been brought up by either patient or doctor. First, we investigated to what extent and with which health problems advice was given concerning physical activity. Second, from these consultations, a stratified sample of 100 consultations was observed in order to investigate whether an advice was given by the general practitioner concerning the additional benefits of nature. In 26% of all consultations advice on physical activity was given by the general practitioner. Physical activity was mentioned more often in cases of vague complaints than in cases with a clear cut diagnosis. As could have been expected, physical activity was mentioned relatively frequently in cases of musculoskeletal complaints and complaints of the nervous system. The additional benefits of physical activity in natural environments was not mentioned during any of the consultations.
In conclusion, general practitioners regularly give advice on physical activity. However, they fail to mention that physical activity in nature areas might have additional health benefits. Given the fact that medical treatment is increasingly evidence based, we think the evidence for the health benefits of physical activity in nature needs to be stronger. Results from such research could eventually find their way into the guidelines of the general practitioners. 相似文献
Forest disturbance and recovery are critical ecosystem processes,but the temporal patterns of disturbance have not been studied in subtropical China.Using a tree-ring analysis approach,we studied post-logging above-ground(ABG)biomass recovery dynamics over a 26-year period in four plots with different degrees of logging disturbance.Before logging,the ABG biomass ranged from 291 to 309 t ha-1.Soon after logging,the plots in primary forest,secondary forest,mixed forest and singlespecies forest had lost 33,91,90 and 100%of their initial ABG biomass,respectively.Twenty-six years after logging,the plots had regained 147,62,80 and 92%of their original ABG biomass,respectively.Over the 26 years following logging,the mean CAI(Current annual increment)were 10.1,5.5,6.4 and 10.8 t ha^-1 a^-1 and the average MAI(Mean annual increment)8.7,2.5,5.6 and 7.8 t ha^-1 a^-1 for the four forest types,respectively.The results indicate that subtropical forests subjected to moderate logging or disturbances do not require intensive management and single-species plantings can rapidly restore the above-ground biomass to levels prior to heavy logging. 相似文献