Winter Daytime Warming and Shift in Summer Monsoon Increase Plant Cover and Net CO2 Uptake in a Central Tibetan Alpine Steppe Ecosystem

Over the past decades, human-induced climate change has led to a widespread wetting and warming of the Tibetan Plateau (TP), affecting both ecosystems and the carbon cycling therein. Whether the previously observed climate changes stimulate carbon uptake via enhanced photosynthesis or carbon loss via enhanced soil respiration remains unclear. Here we present 14 years of observations of carbon fluxes, meteorological variables and remotely sensed plant cover estimations from a central Tibetan alpine steppe ecosystem at Nam Co, the third largest lake on the TP. Using modified Mann-Kendall trend tests, we found a significant increasing daily net carbon uptake of 0.5 g C m−2 decade−1, which can be explained by a widespread greening at the southern shore of lake Nam Co. The Plateau-wide changes in temperature and precipitation are locally expressed as an increasing diurnal temperature range during winter, higher water availability during spring, higher cloud cover during early summer and less water availability during late summer. While these changes differ over the course of the year, they tend to stimulate plant growth more than microbial respiration, leading to an increased carbon uptake during all seasons. This study indicates that during the 14 years study period, a higher amplitude in winter temperatures and an earlier summer monsoon promote carbon uptake in a central Tibetan alpine steppe ecosystem

Seasonal Variations in Vegetation Indices derived from in situ Type Vegetation Monitoring System at typical landcovers in Japan : From the Observation Results in PGLIERC and Lake Biwa Project

研究概要:本研究では光学センサー搭載衛星データの検証及び地表面フラックスとの対応関係を調べるために簡易式の地上設置型植生モニタリングシステムを日本を代表する土地被覆上(草地,水田,アカマツ林,落葉広葉樹)に設置し,それぞれの土地被覆から得られる植生指標の季節変化について示した.その結果,以下の知見が得られた;1.草原系(草地・水田)では各植生の季節変化特性を良好にモニターすることが可能である,2.森林系(アカマツ林・落葉広葉樹)ではセンサーとキャノピーの距離が近すぎるため,思うような結果を得ることが出来なかった.3.ただし全般としては各土地被覆特性を示す連続したデータを取得することができ,システムの妥当性を示すことができた

The downward spiral of mental disorders and educational attainment: a systematic review on early school leaving.

BACKGROUND: Most psychiatric disorders present symptom patterns that cause severe impairment on the emotional, cognitive and social level. Thus, adolescents who suffer from a mental disorder risk finding themselves in a downward spiral caused by the reciprocal association of psychological symptoms and negative school experiences that may culminate in early school leaving. In addition to previous collective work that mainly focused on school refusing behaviour among children and was presented as an expert's opinion, the following systematic review fills the knowledge gap by providing a structured overview of the bidirectional association between mental health and secondary school dropout based on a sound methodology and with a particular focus on mediating factors. METHODS: Four electronic databases were searched from January 1990 until June 2014. Selected references were assessed for study details, main results, mediating factors and methodological limitations. Standardized risk of bias assessment was conducted. RESULTS: Mood and anxiety disorders seemed to have a less consequential direct effect on early school leaving than substance use and disruptive behaviour disorders. The association between externalizing disorders and educational attainment was even stronger when the disorder occurred early in life. On the other hand, internalizing disorders were reported to develop as a consequence of school dropout. Only few studies had addressed gender differences, with discrepant results. Socio-economic background, academic achievement and family support were identified as significant mediating factors of the association between mental disorders and subsequent educational attainment. CONCLUSIONS: Findings suggested a strong association between mental health and education, in both directions. However, most studies focused on mediating factors that could not be targeted by intervention programs