鼎湖山马尾松径向生长动态与气候因子的关系

Dendroclimatology method was used to study the relationship between ring index of Pinus massoniana and three climate factors in Dinghushan, South China. The ring indices were negatively correlated with the average temperature in June, August and September, and positively correlated with the average temperature of March, whereas no statistically significant correlation was found with monthly precipitation, showing that high summer temperature could limit the radial growth of the species. Meanwhile, tree ring indices showed a strong positive correlation with the relative humidity of April, June, August, September, October and November, and also with the average humidity of the whole year, indicating that atmospheric moisture could not fully satisfy the growth of Pinus massoniana despite of abundant rainfall. The possible impact of climate change on the growth of Pinus massoniana was discussed accordingly.

Soil physicochemical properties and vegetation structure along an elevation gradient and implications for the response of alpine plant development to climate change on the northern slopes of the Qilian Mountains

Elevation is one of key factors to affect changes in the environment, particularly changes in conditions of light, water and heat. Studying the soil physicochemical properties and vegetation structure along an elevation gradient is important for understanding the responses of alpine plants andtheir growing environment to climate change. In this study, we studied plant coverage, plant height, species richness, soil water-holding capacity, soil organic carbon(SOC) and total nitrogen(N) on the northern slopes of the Qilian Mountains at elevations from2124 to 3665 m. The following conclusions were drawn:(1) With the increase of elevation, plant coverage and species richness first increased and then decreased, with the maximum values being at 3177 m.Plant height was significantly and negatively correlated with elevation(r=–0.97, P<0.01), and the ratio of decrease with elevation was 0.82 cm·100 m-1.(2) Both soil water-holding capacity and soil porosity increased on the northern slopes of the Qilian Mountains with the increase of elevation. The soil saturated water content at the 0-40 cm depth first increased and then stabilized with a further increase of elevation, and the average ratio of increase was2.44 mm·100 m-1. With the increase of elevation, the average bulk density at the 0-40 cm depth first decreased and then stabilized at 0.89 g/cm3.(3) With the increase of elevation, the average SOC content at the 0-40 cm depths first increased and then decreased,and the average total N content at the 0-40 cm depth first increased and then stabilized. The correlation between average SOC content and average total N content reached significant level. According to the results of this study, the distribution of plants showed a mono-peak curve with increasing elevation on the northern slopes of the Qilian Mountains. The limiting factor for plant growth at the high elevation areas was not soil physicochemical properties, and therefore,global warming will likely facilitate the development of plant at high elevation areas in the Qilian Mountains.

Time-Series Modeling and Prediction of Global Monthly Absolute Temperature for Environmental Decision Making

A generalized, structural, time series modeling framework was developed to analyze the monthly records of absolute surface temperature, one of the most important environmental parameters, using a deterministicstochastic combined （DSC） approach. Although the development of the framework was based on the characterization of the variation patterns of a global dataset, the methodology could be applied to any monthly absolute temperature record. Deterministic processes were used to characterize the variation patterns of the global trend and the cyclic oscillations of the temperature signal, involving polynomial functions and the Fourier method, respectively, while stochastic processes were employed to account for any remaining patterns in the temperature signal, involving seasonal autoregressive integrated moving average （SARIMA） models. A prediction of the monthly global surface temperature during the second decade of the 21st century using the DSC model shows that the global temperature will likely continue to rise at twice the average rate of the past 150 years. The evaluation of prediction accuracy shows that DSC models perform systematically well against selected models of other authors, suggesting that DSC models, when coupled with other ecoenvironmental models, can be used as a supplemental tool for short-term （10-year） environmental planning and decision making.

Perceptions of Climate Change in Puerto Rico before and after Hurricane Maria

This article analyzes the perceptions of Puerto Rican citizens of global climate change (GCC) before and after an extreme weather event, specifically Hurricane Maria (HM). The purpose of the current article is to evaluate Puerto Ricans’ perceptions of the impact of extreme meteorological phenomena and of GCC before and after HM. This tropical cyclone entered the island as a category IV hurricane on September 17, 2017, causing enormous destruction, loss of life, and economic damage. In this study, two data samples were collected before and after HM struck Puerto Rico (PR) (the second sample was collected approximately six months after the hurricane). Surveyed citizens with general knowledge of GCC increased from 43% to 62%, which the researchers consider a small increase, considering the severe destruction caused by HM. This study also found that Puerto Ricans trust non-profit institutions and the scientific community more than state authorities. Furthermore, 85% of citizens believe that public policies on GCC should be directed by the state (federal, state, and municipal governments);this did not change after HM. In addition, this study found that the poor response of the federal and state governments to the destruction caused by HM increased citizens’ trust in the scientific community.

Assessing adaptation planning strategies of interconnected infrastructure under sealevel rise by economic analysis

This study assesses the commonly adopted adaptation planning strategies of infrastructures in Northwest Florida(USA)based on economic analysis under different objective years.Specifically,the economic analysis considers both direct and indirect impacts of sea level rise by deploying the interdependence of infrastructures.We demonstrate the difference and significance of considering indirect economic impacts in the process of cost-benefit analysis under sea level rise.Based on the results,we recommend that the most effective strategy is partial protection of land use plus inundated transportation network upgrade,even though the total shoreline protection can make more benefits.Furthermore,we compare the performance of objective planning year from two criteria:total benefits and cost-effectiveness.The result indicates that the year 2080 could be the most economical if it is set as the objective year for the long-term infrastructure planning.The result also highlights that the economic analysis of infrastructure should be conducted over time since the total costs are distributed over many years.It is not to say that the farther the year is,the more effectiveness the strategy would be,although the total benefits would be greater.

Interdecadal Variability of the East Asian Winter Monsoon and Its Possible Links to Global Climate Change

This paper presents a concise summary of the studies on interdecadal variability of the East Asian winter monsoon （EAWM） from three main perspectives. （1） The EAWM has been significantly affected by global climate change. Winter temperature in China has experienced three stages of variations from the beginning of the 1950s： a cold period （from the beginning of the 1950s to the early or mid 1980s）, a warm period （from the early or mid 1980s to the early 2000s）, and a hiatus period in recent 10 years （starting from 1998）. The strength of the EAWM has also varied in three stages： a stronger winter monsoon period （1950 to 1986/87）, a weaker period （1986/87 to 2004/05）, and a strengthening period （from 2005）. （2） Corresponding to the interdecadal variations of the EAWM, the East Asian atmospheric circulation, winter temperature of China, and the occurrence of cold waves over China have all exhibited coherent interdecadal variability. The upper-level zonal circulation was stronger, the mid-tropospheric trough over East Asia was deeper with stronger downdrafts behind the trough, and the Siberian high was stronger during the cold period than during the warm period. （3） The interdecadal variations of the EAWM seem closely related to major modes of variability in the atmospheric circulation and the Pacific sea surface temperature. When the Northern Hemisphere annular mode/Arctic Oscillation and the Pacific decadal oscillation were in negative （positive） phase, the EAWM was stronger （weaker）, leading to colder （warmer） temperatures in China. In addition, the negative （positive） phase of the Atlantic multi decadal oscillation coincided with relatively cold （warm） temperatures and stronger （weaker） EAWMs. It is thus inferred that the interdecadal variations in the ocean may be one of the most important natural factors influencing long-term variability in the EAWM, although global warming may have also played a significant role in weakening the EAWM.

Monitoring variations of inland lakes in the arid region of Central Asia

Inland lakes are the major surface water resource in the arid regions of Central Asia. Therefore, the surface area changes in inland lakes have been a sensitive indicator of climate changes and human activ- ities, and have often been the focus of ecological and environmental research. This study aimed to monitor the changes in surface area of nine major lakes over a 32-year period. The water body was extracted from MSS images from the mid-1970s, TM images from the early 1990s, ETM ＋ images in the late 1990s, and TM images in 2007. The results indicated that the total surface area of these nine lakes had decreased over time to 50.38% of the area, from 91402.06km^2 in 1975 to 46049.23 km^2 in 2007. As the surface area of lakes in the western part of Central Asia was larger than that in the eastern part, the shrinking trend of lake area was more significant in the west than in the east. There was a varied reduction of closed lakes in flat regions. The most substantial decrease was in the surface area of closed lakes in flat regions. Most significantly, the area of the Aral Sea was reduced by 75.7% from its original area in 1975. The area of alpine lakes remained relatively stable; the change in surface area was less than 0.7% during the period 1975-2007. The area change in opened lakes with outlets was notably different from the other two types. The area of Zaysan had increased sharply by 5.85%, and that of Bosten had decreased by 9.1%. Sasykkol had hardly any changes in this period. Due to global climate wanning, vapor transfer to the south via westerly winds had been blocked, resulting in a decrease of much-needed precipitation in the western parts of Turkmenistan, Uzbekistan, and Kazakhstan between 1970 and 2000. The decrease in precipitation and the increase in water consumption for agricultural irrigation resulted in the decrease of fiver runoff. Consequently, thearea of inland lakes in Central Asia shrank over the past 32 years.