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Arid and semi-arid ecosystems of the southwestern US are undergoing changes in vegetation composition and are predicted to experience shifts in climate. To understand implications of these current and predicted changes, we conducted a precipitation manipulation experiment on the Santa Rita Experimental Range in southeastern Arizona. The objectives of our study were to determine how soil surface and seasonal timing of rainfall events mediate the dynamics of leaf-level photosynthesis and plant water status of a native and non-native grass species in response to precipitation pulse events. We followed a simulated precipitation event (pulse) that occurred prior to the onset of the North American monsoon (in June) and...
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The dataset is comprised of leafing and flowering data collected across the continental United States from 1956 to 2014 for purple common lilac ( Syringa vulgaris), a cloned lilac cultivar (S. x chinensis ‘Red Rothomagensis’) and two cloned honeysuckle cultivars ( Lonicera tartarica ‘Arnold Red’ and L. korolkowii ‘Zabeli’). Applications of this rich legacy dataset range from detecting regional weather patterns to understanding the impacts of global climate change on the onset of spring at the national scale. While minor changes in methods have occurred over time, and some documentation is lacking, the dataset has proven robust in combination with climatic data for detecting spatio-temporal changes in the onset...
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Scientists gathered at a workshop in Cambridge, Mass., last June to identify opportunities and challenges associated with integrating multiscale, multiplatform streams of data to produce higher-level phenological data products (e.g., models) and applications at a variety of spatial and temporal resolutions.
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Climate change and invasions by non-native organisms are two factors of global change likely to alter the structure and function of arid and semi-arid ecosystems. We conducted a large-scale field experiment to determine how changes in amount of summer precipitation and invasions by an African grass (Eragrostis lehmanniana) may interact with soil texture to affect community and ecosystem processes in temperate grasslands and savannas of southern Arizona, USA. In particular, we investigated the response of soil moisture at several soil depths within seventy-two 2.7 m2 plots under six 9 m×18 m rainout shelters to a 3-fold difference in irrigation between February and November 2002, as well as to a single large pulse...
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