02791nas a2200337 4500008004100000022001400041245013400055210006900189260001600258300001400274490000800288520170200296653002901998653004202027653004902069653002202118653003102140100001602171700002802187700002402215700002002239700001602259700001802275700001502293700001402308700001702322700001702339700001702356700001402373856006602387 2015 eng d a0029-854900aGlobal environmental change and the nature of aboveground net primary productivity responses: insights from long-term experiments0 aGlobal environmental change and the nature of aboveground net pr cJan-04-2015 a935 - 9470 v1773 a
Many global change drivers chronically alter resource availability in terrestrial ecosystems. Such resource alterations are known to affect aboveground net primary production (ANPP) in the short term; however, it is unknown if patterns of response change through time. We examined the magnitude, direction, and pattern of ANPP responses to a wide range of global change drivers by compiling 73 datasets from long-term (>5 years) experiments that varied by ecosystem type, length of manipulation, and the type of manipulation. Chronic resource alterations resulted in a significant change in ANPP irrespective of ecosystem type, the length of the experiment, and the resource manipulated. However, the pattern of ecosystem response over time varied with ecosystem type and manipulation length. Continuous directional responses were the most common pattern observed in herbaceous-dominated ecosystems. Continuous directional responses also were frequently observed in longer-term experiments (>11 years) and were, in some cases, accompanied by large shifts in community composition. In contrast, stepped responses were common in forests and other ecosystems (salt marshes and dry valleys) and with nutrient manipulations. Our results suggest that the response of ANPP to chronic resource manipulations can be quite variable; however, responses persist once they occur, as few transient responses were observed. Shifts in plant community composition over time could be important determinants of patterns of terrestrial ecosystem sensitivity, but comparative, long-term studies are required to understand how and why ecosystems differ in their sensitivity to chronic resource alterations.
10aAboveground productivity10aHierarchical response framework (HRF)10aLong-Term Ecological Research (LTER) Network10aNutrient addition10aPrecipitation manipulation1 aSmith, M.D.1 aLa Pierre, Kimberly, J.1 aCollins, Scott., L.1 aKnapp, Alan, K.1 aGross, K.L.1 aBarrett, J.E.1 aFrey, S.D.1 aGough, L.1 aMiller, R.J.1 aMorris, J.T.1 aRustad, L.E.1 aYarie, J. uhttps://link.springer.com/article/10.1007%2Fs00442-015-3230-9