Forestry ecological footprint in China during 1973–2003

The ecological footprint （EF） model has received much attention as an assessment indicator for sustainable development in recent years. Firstly, the temporal changes of domestic timber production, imports and exports in China were analyzed from 1973 to 2003, the analysis results showed an apparent fluctuation in timber production during 1973-1995 but a decreasing trend during 1995-2002, an increasing trend in timber imports since 1995 especially after the implementation of the Natural Forest Protection Project （NFPP）, an decreasing trend year by year in timber exports since 1995. Secondly, this paper presented a time series analysis of actual forest area demand in the sustainable yield and production approach in China from 1973 to 2003, which includes both import and export forest area demand. The results showed the actual forest area demand simulated from the sustainable yield approach was slightly higher than that from the production approach during 1978-1988 and a little lower during 1989-2003; however, the actual forest area demands simulated by these two model approaches were larger than calculations that expressed in conventional forest EF. Meanwhile, the results indicated the forestry development in China during 1978-1988 was unsustainable due to overexploitation of forest stocking volumes, and China＇s forestry moved toward sustainable development since 1989 because forest resources are exploited at lower rates than they are regenerated. However, compared to forestry developed countries, the forestry development capacity in China is still lower. Finally, based on the model results we analyzed the relationships between forestry EF and the key policies, including trade policy, economic policy and forest conservation programs. In addition, several suggestions about reducing forestry EF and enhancing sustainable forestry development in China are given.

Effects of salinity on egg and fecal pellet production, development and survival, adult sex ratio and total life span in the calanoid copepod, A cartia tonsa:a laboratory study

The ef fects of salinity on the copepod, A cartia tonsa in terms of daily egg production rate(EPR), hatching success, fecal pellet production rate(FPR), naupliar development time and survival, sex ratio, and total life span were determined in laboratory conditions through three experiments. In experiment 1, EPR, hatching success, and FPR of individual females were monitored at salinities of 13, 20, 35 and 45 during short-periods(seven consecutive days). Results show EPR was aff ected by salinity with the highest outputs recorded at 20 and 35, respectively, which were considerably higher than those at 13 and 45. Mean FPR was also higher in 35 and 20. In experiment 2, the same parameters were evaluated over total life span of females(long-term study). The best EPR and FPR were observed in 35, which was statistically higher than at 13 and 20. In experiment 3, survival rates of early nauplii until adult stage were lowest at a salinity of 13. The development time increased with increasing of salinity. Female percentage clearly decreased with increasing salinity. Higher female percentages(56.7% and 52.2%, respectively) were signifi cantly observed at two salinities of 13 and 20 compared to that at 35(25%). Total longevity of females was not af fected by salinity increment. Based on our results, for mass culture we recommend that a salinity of 35 be adopted due to higher reproductive performances, better feeding, and faster development of A. tonsa.

Design of a Foot-End Three-Axis Force Sensing Module for Gecko-Like Robot

The problems of attachment failure and detachment impact within gecko-like robots’ locomotion control are considered in this paper. A real-time foot-end force intelligent sensing module with integrated sensing and structure is developed to help the robot get the foot-end force information in time and realize stable locomotion in an uncertain environment. Firstly,a structure/sensing integrated elastomer based on a Maltese cross/cantilever beam structure is completed by designing and finite element analysis. Secondly,a real-time data acquisition and transmission system is designed to obtain the foot-end reaction force which is miniaturized and distributed. Thirdly,based on this system,a force sensor calibration platform is built to complete the calibration,decoupling,and performance testing of the sensing module. Finally,the experiment of single-leg attachment performance is carried out. The results indicate that the three-axis sensing module can detect robot’s weight,measure the reaction force with high precision and provide real-time force from robot’s foot end.

十足 实足

1．虽久疏战场，但拼劲实足，有竞争才有动力。——摘自某报《夺冠路上大步迈》一文2．给自己实足的动力，为理想而奋斗!

Color change in a marine isopod is adaptive in reducing predation

Although background matching is a common form of camouflage across a wide diversity of animals, there has been surprisingly little experimental work testing the fitness consequences of this camouflage strategy, especially in marine ecosystems. In this study, we tested whether color camouflage enhances survival of the intertidal marine isopod Pentidotea （Idotea） wosnesenskii, quantified patterns of camouflage in different algal habitats, and examined how algal diet affected color change and growth using laboratory assays. In the field, isopods collected from two differently colored algal habitats （the brown alga Fucus distichus and the red alga Odonthaliafloccosa） matched the color of their respective algal habitats, and also differed significantly in body size： smaller red isopods were found on red algae, while larger brown isopods were found on brown algae. Predation ex- periments demonstrated these color differences had fitness benefits： brown isopods that matched their brown algae habitats sur- vived at higher rates than red unmatched isopods. Surprisingly, despite the propensity of isopods to match their algal habitats, algal diet had no effect on color change in color change experiments. Instead, isopods in all treatments turned browner, matching the color of the algal habitat that many isopods are found on as adults. In summary, our data supported our hypothesis that back- ground matching serves an adaptive function in reducing predation, with important evolutionary implications for explaining the wide variation in color change mechanisms in idoteid isopods [Current Zoology 61 （4）： 739-748, 2015].