@article {50123,
	title = {Scale and the isotopic reocrd of C<sub>4</sub> plants in pedogenic carbonate: from the biome to the rhizosphere},
	journal = {Ecology},
	volume = {90},
	number = {6},
	year = {2009},
	note = {//USDA,OTHER//LTER V//entered 07/13/2009; pdf available},
	month = {2009},
	pages = {1498-1511},
	abstract = {The 13C/12C ratio in pedogenic carbonate (i.e., CaCO3 formed in soil) is a significant tool for investigating C4 biomes of the past. However, the paleoecological meaningof d13C values in pedogenic carbonate can change with the scale at which one considers the data. We describe studies of modern soils, fossil soils, and vegetation change in the Chihuahuan Desert of North America and elsewhere that reveal four scales important for paleoecologic interpretations. (1) At the broadest scale, the biome scale (hundreds to millions of km2), an isotopic record interpreted as C3 vegetation replacing C4 grasslands may indicate invading C3 woody shrubs instead of expanding C3 forests (a common interpretation). (2) At the landscape scale (several tens of m2 to hundreds of km2), the accuracy of scaling up paleoclimatic interpretations to a regional level is affected by the landform containing the isotopic record. (3) At the soil-profile scale (cm2 to m2), soil profiles with multiple generations of carbonate mixed together have a lower-resolution paleoecologic record than soil profiles repeatedly buried. (4) At the rhizosphere scale (lm2 to cm2), carbonate formed on roots lack the 14{\textendash}17{\o} enrichment observed at broader scales, revealing different fractionation processes at different scales. A multi-scale approach in dealing with d13C in pedogenic carbonate will increase the accuracy of paleoecologic interpretations and understanding of soil{\textendash}geomorphic{\textendash}climatic interactions that affect boundaries between C4 and C3 vegetation.},
	keywords = {article, C3 vs C4 vegetation, carbon isotopes, Chihuahuan Desert, climate change, desertification, Jornada Experimental Range, journal, landscape ecology, pedogenic carbonate, peleoclimate, peleoecology, soil-geomorphic-clmatic interaction, southern New Mexico, USA},
	author = {Curtis H. Monger and David R. Cole and B. J. Buck and R. A. Gallegos}
}
@conference {50689,
	title = {Broad-scale landscape, soil, and wind influences on fine-scale dynamics},
	booktitle = {Sixth Symposium on the Natural Resources of the Chihuahuan Desert Region},
	year = {2004},
	month = {October 15, 2004},
	pages = {35},
	address = {Alpine, TX},
	abstract = {Desertification and other ecogeomorphic changes in the Chihuahuan Desert are connected to broad-scale landscape, soil, and wind drivers via fine-scale processes. Landscapes function as a driver by their lithic composition and topographic configuration. These impact water redistribution and wind movement across the landscape that influence soil patterns at the landscape scale. Strong winds in the Jornada Basin, for example, have decapitated sandy soils, formed erosional streets, pushed sand grains up the piedmont slope and over ridges into intermountain valleys where they have accumulated as thick, eolian deposits overlying bedrock. Fine-scale processes are influenced by these broad-scale drivers in several ways. Wind erosion, for instance, removes organic matter and coarsens soil texture, thereby lowering water-holding capacity, cation exchange capacity, and nutrient availability. Because such fine-scale processes exert important controls on plants, vegetation patterns at the landscape scale reflect patterns of the broad-scale drivers. Consequently, some ecogeomorphic conditions, such as black grama on sandy, eolian upland soils, are more prone to desertification than other conditions, like tobosa grass on silty, alluvial soils in run-in positions.},
	keywords = {broad-scale, Chihuahuan Desert, desertification, ecogeomorphic, fine-scale dynamics, landscape, soil, wind},
	author = {Curtis H. Monger and D. E. Gillette and Brandon T Bestelmeyer}
}
