Nanoindentation is an effective nondestructive method for small scale determination of mechanical properties of materials. However, indentation response of metallic materials is very sensitive to indenter tip roundness, size effects, loading rate, and so forth. This study will analyze the effect of indenter shape imperfections on hardness determination. For this purpose, experimental investigations and finite element simulations are carried out. At first, it is found that hardness values determined with Oliver and Pharr’s method are affected by errors caused by imperfect indenter tip: errors increase for imperfect indenters with larger tip radii. Afterwards, several commonly used methods accounting at different extents for tip radius variations are compared. However, most of those methods are found not to be accurate for shallow indentation. For this reason, a novel hardness determination method based on geometrical relations of the imperfect indenter tip is developed. Results show that the new approach is very effective even in the case of shallow indentation.

Severe ice-snows caused break of many trees and a lot of crown debris in south China in 2008. Stem damage and crown debris. In order to determine the water holding characteristics of the crown debris, the water holding rate and water absorption rates of crown debris and litter were studied in a Cunninghamia lanceolata stand suffering from ice-snow damage occurring from January to February, 2008. The order of water-holding capacity of the components was leaves > litter > branches> stemwood > stembark in each stage of immersing water. The maximum water holding capacities of stemwood, branch, leaves, stembark and litter were 6.75, 8.13, 10.9, 2.72 and 8.22 t•ha 1, respectively. Maximum water holding rates of stemwood, branch, leaves, stembark and litter were 2271, 2144, 3199, 2800 and 3018 g•kg 1, respectively. Water absorption rate of each component sharply decreased with increasing immersed time from 0.5 to 4 hours, and then slowly decreased. The logarithm equation predicted water-holding capacity and water holding rates of crown debris and litter quite well and the negative exponential equation predicted water absorption rate within an 8.5% error.

Seedlings of Michelia macclurei, Cinnamomum camphora and Rhodoleiachampionii were placed in open-top chambers (OTC) with two ozonic treatments including E40 (nature air, 40 ppb) and E150 (150 ppb) and two water treatments. Physiological indexes such as chlorophyll, soluble sugar, soluble protein, proline, MDA and SOD of three seedling types were evaluated. With increasing experimental time, chlorophyll content generally decreased or remained steady, soluble sugar content increased followed by a decrease and SOD activity increased for the three seedling types in ozone treatment, drought treatment or ozone-drought intercross treatment. Contents of soluble protein and proline increased for the three seedling types in ozone treatment and drought treatment. The MDA content increased for M. macclurei and C. camphora in ozone treatment and drought treatment and for R. championii in the three stress treatments. Principal component analysis indicated that the resistance abilities of ozone, drought or intercross stress for the three seedling types was C. camphora seedlings > M. macclurei seedlings > R. championii seedlings.

Climate change refers to man-made changes in our climate, which is caused by changes in temperature, precipitation, and CO2. There is a lot of data coming from all over the world indicating that phenology of garden plants and biodiversity are being impacted by climate change. In the context of climate change, landscape plants can enhance carbon sink function, improve plant design, and mitigate climate change and so on. To determine the impact of these changes on garden plants, scientists would need to strengthen the study of garden plants under global climate change, including different garden type responses to climate change, invaliding species phenology study, extreme weather impacts on landscape plant phenology, the dominant factor of affecting garden plants in different regions, interactions of multiple environmental factors on influence mechanism of garden plants.