科學(xué)家發(fā)現(xiàn),，吹向山地的沙漠塵埃可能改變植物對調(diào)控其生命周期的氣候信號的響應(yīng),。山地的塵埃水平自從19世紀(jì)以來一直在增加,，這在很大程度上是由于人類在沙漠的活動增加。
Heidi Steltzer及其同事模擬了塵埃對科羅拉多州落基山上的實(shí)驗(yàn)區(qū)域融雪的影響,，從而測量塵埃對高山植物的生命周期的影響,。在正常條件下，融雪的時機(jī)向山地植物發(fā)出了開始生長和開花的信號,。然而,，沙漠塵埃吸收了干凈的雪本來能夠反射的熱量，因此增加了來自太陽光的熱效應(yīng)并導(dǎo)致了雪更早融化,。這種提前融雪可能導(dǎo)致植物推遲它們的年度生長周期,，直到空氣溫度變暖。這組作者預(yù)測說,，塵埃的增加量可能讓高山凍原的植物變綠和開花時間同步,，而且有可能通過改變傳粉者和野生動物可以獲取的資源從而改變物種相互作用以及營養(yǎng)循環(huán)。這組作者說,，他們的結(jié)果顯示,，人類改變沙漠與山地的植物生命周期有聯(lián)系。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS June 29, 2009, doi: 10.1073/pnas.0900758106
Biological consequences of earlier snowmelt from desert dust deposition in alpine landscapes
Heidi Steltzera,1, Chris Landryb, Thomas H. Painterc, Justin Andersond and Edward Ayresa
Dust deposition to mountain snow cover, which has increased since the late 19th century, accelerates the rate of snowmelt by increasing the solar radiation absorbed by the snowpack. Snowmelt occurs earlier, but is decoupled from seasonal warming. Climate warming advances the timing of snowmelt and early season phenological events (e.g., the onset of greening and flowering); however, earlier snowmelt without warmer temperatures may have a different effect on phenology. Here, we report the results of a set of snowmelt manipulations in which radiation-absorbing fabric and the addition and removal of dust from the surface of the snowpack advanced or delayed snowmelt in the alpine tundra. These changes in the timing of snowmelt were superimposed on a system where the timing of snowmelt varies with topography and has been affected by increased dust loading. At the community level, phenology exhibited a threshold response to the timing of snowmelt. Greening and flowering were delayed before seasonal warming, after which there was a linear relationship between the date of snowmelt and the timing of phenological events. Consequently, the effects of earlier snowmelt on phenology differed in relation to topography, which resulted in increasing synchronicity in phenology across the alpine landscape with increasingly earlier snowmelt. The consequences of earlier snowmelt from increased dust deposition differ from climate warming and include delayed phenology, leading to synchronized growth and flowering across the landscape and the opportunity for altered species interactions, landscape-scale gene flow via pollination, and nutrient cycling.
