To determine the cause of the severe drought that hit five provinces (autonomous regions, municipalities) of Southwest China in 2010, the ecological water demand (EWD) of regional vegetation was explored. The key scientific question was whether the plantation of Eucalyptus and Hevea trees in this area could have led to the breaking of the regional EWD balance, thereby causing a regional drought. Therefore, major research progress and trends related to EWD of vegetation, such as characterization of vegetation water consumption from transpiration and eco-hydrological effects, were explored. Theories, methods, and practices regarding EWD of vegetation, and the correlation between regional vegetation types and droughts were evaluated. Finally, suggestions were made for specific scientific research on temporal and spatial evolution of typical artificial vegetation in Southwest China and on the relationship between EWD from regional vegetation and droughts. Thus, future research should include the following three aspects: (i) historical evolution and distribution pattern of regional artificial vegetation; (ii) water consumption from transpiration, water saving for drought prevention, and water and soil conservation of regional artificial vegetation; and (iii) the relationship between EWD of regional artificial vegetation and regional droughts. The proposed research focus is expected to provide a scientific basis for identifying the causes of regional droughts and the reasonable allocation of water resources. In addition, it will be of great importance in guiding restoration and reconstruction of regional artificial vegetation.

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The build‐up of topsoil phosphorus (P) through excess fertilizer application can increase P losses in run‐off leading to negative impacts on aquatic ecosystems. To better understand the risk of P losses, the fractions of soil P in four aggregate size classes were quantified for two vegetable production sites (<10 and >25 yrs) and a conservation buffer site (8 yrs) in southwestern China. Sequential extraction methods of inorganic P (Pi) and organic P (Po) were carried out on samples from Nitisol and Gleysol soils from 0 to 5 cm and 5 to 10 cm depths. On average, soil Pi concentrations exceeded Po concentrations threefold, primarily in the bioavailable Pi fractions (labile Pi, loosely bound Pi and non‐occluded Pi). Soil Po fractions and bioavailable Pi fractions were significantly greater under the >25 yrs field than in the <10 yrs field. The conversion of fields under vegetable production to forested buffer substantially decreased the levels of the bioavailable Pi and labile Po in the Gleysol after 8 yrs. Soil macro‐aggregates (>0.25 mm) had greater concentrations of bioavailable Pi fractions and of labile and moderately labile Po than did micro‐aggregates and silt and clay size components. Although more P was stored in recalcitrant P forms, a larger percentage of all P fractions was found in macro‐aggregates in these soils. Small active P‐enriched aggregates potentially intensify export of P from the vegetable soils by run‐off, and therefore, management practices must be optimized to enhance agricultural P efficiencies.

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