02206nas a2200169   4500008004100000245010900041210006900150490000800219520163100227100001701858700001701875700001901892700001401911700001701925700002001942856007401962       2011                        eng d00aWoody plant proliferation in North American drylands: A synthesis of impacts on ecosystem carbon balance0 aWoody plant proliferation in North American drylands A synthesis0 v1163 a<p>[1] Changes in the magnitude and direction of ecosystem carbon (C) balance accompanying woody plant encroachment are among the largest contributors to the uncertainty in the North American C budget. In this synthesis we identify the important species contributing to woody encroachment, summarize our current knowledge of aboveground and belowground C storage change with woody encroachment, and evaluate the range of human and natural disturbance factors that alter the course of C gains and losses within ecosystems experiencing woody encroachment. Available data indicate that relative to the historic vegetation, aboveground net primary production (ANPP) decreases with woody plant encroachment in arid regions (mean annual precipitation (MAP) &lt; 336 mm), but increases in semiarid and subhumid regions (on the order of 0.7 g C m&minus;2 yr&minus;1 per mm of MAP over 336 mm). Soil organic carbon response to woody plant encroachment ranged from losses of 6200 g C m&minus;2 to gains of 2700 g C m&minus;2 with an average accumulation of 385 g C m&minus;2 across all studies and did not appear to be closely coupled to ANPP. Taken together, in the absence of disturbance, woody encroachment appears to result in a net ecosystem C gain across most species and ecoregions. However, disturbance associated with wildfire, land management practices, and drought may quickly and significantly offset these gains and should be explicitly factored into regional-scale C balance estimates. Our findings may be used to better constrain future estimates of woody plant encroachment influences on the North American C budget.</p>1 aBarger, N.N.1 aArcher, S.R.1 aCampbell, J.L.1 aHuang, C.1 aMorton, J.A.1 aKnapp, Alan, K.  uhttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010JG00150601892nas a2200241   4500008004100000245013500041210006900176300001300245490000700258520110800265100002001373700001901393700002401412700001701436700002101453700001601474700001701490700001601507700001701523700001601540700001701556856007701573       2008                        eng d00aShrub encroachment in North American grasslands: Shifts in growth form dominance rapidly alters control of ecosystem carbon inputs0 aShrub encroachment in North American grasslands Shifts in growth  a615 -6230 v143 a<p>Shrub encroachment into grass-dominated biomes is occurring globally due to a variety of anthropogenic activities, but the consequences for carbon (C) inputs, storage and cycling remain unclear. We studied eight North American graminoid-dominated ecosystems invaded by shrubs, from arctic tundra to Atlantic coastal dunes, to quantify patterns and controls of C inputs via aboveground net primary production (ANPP). Across a fourfold range in mean annual precipitation (MAP), a key regulator of ecosystem C input at the continental scale, shrub invasion decreased ANPP in xeric sites, but dramatically increased ANPP (&gt;1000 g m&minus;2) at high MAP, where shrub patches maintained extraordinarily high leaf area. Concurrently, the relationship between MAP and ANPP shifted from being nonlinear in grasslands to linear in shrublands. Thus, relatively abrupt (&lt;50 years) shifts in growth form dominance, without changes in resource quantity, can fundamentally alter continental-scale pattern of C inputs and their control by MAP in ways that exceed the direct effects of climate change alone.</p>1 aKnapp, Alan, K.1 aBriggs, J., M.1 aCollins, Scott., L.1 aArcher, S.R.1 aBret-Harte, M.S.1 aEwers, B.E.1 aPeters, D.P.1 aYoung, D.R.1 aShaver, G.R.1 aPendall, E.1 aCleary, M.B.  uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2486.2007.01512.x01561nas a2200193   4500008004100000245007400041210006900115300001300184520093700197100001801134700001801152700001701170700001801187700001901205700001601224700001701240700001501257856009501272       1996                        eng d00aNew technologies for remote sensing of ecosystem change in rangelands0 aNew technologies for remote sensing of ecosystem change in range  a139 -1423 aThe collective area of rangelands, 40-50% of the global land surface, presents significant logistical challenges for obtaining ecological data for large, heterogeneous areas quickly, cheaply and with a significant level of accuracy. The use of remote sensing for rangeland monitoring and scaling up from plot to region is reviewed. A major challenge in remote sensing applications lies with assessing ecosystem function from spectral measurements of ecosystem structure. New methods which may assist in the identification and tracking of rangeland response to management practices at the regional scale and provide information on vegetation structure at the continental scale are described. On-going attempts to develop a coupled remote sensing rangeland ecosystem modelling approach for monitoring structure and quantifying energy flow and nutrient cycling are described and examples using Konza Prairie, Kansas, USA data are given1 aWessman, C.A.1 aSchimel, D.S.1 aArcher, S.R.1 aBateson, C.A.1 aBraswell, B.H.1 aOjima, D.S.1 aParton, W.J.1 aWest, N.E.  uhttp://knz.lternet.edu/content/new-technologies-remote-sensing-ecosystem-change-rangelands