Meadow Invasion from High-Elevation Spruce-Fir Forest in South-Central New Mexico

Abstract

Stands of corkbark fir-Englemann spruce were sampled on Buck Moun tion 3,282 m) within the White Mountains of south-central New Mexico. A time series of aerial This content downloaded from 132.235.26.35 on Mon, 24 Jul 2017 15:08:03 UTC All use subject to http://about.jstor.org/terms

Hydrological Control of Greenhouse Gas Fluxes in a Sierra Nevada Subalpine Meadow

“…For example, recreational packstock use and livestock grazing, which are common in Sierra Nevada meadows, can compact soil (i.e., less gas diffusivity and waterfilled pore space), increase coverage of bare ground, and alter C and N inputs to soil (Kosco and Bartolome, 1981;McClaran, 1989;Cole et al, 2004), perhaps creating a more heterogeneous pattern of GHG emission with more hotspots. Furthermore, shifts in meadow plant community composition associated with climate change, exotic species, and conifer encroachment could impact C and N inputs, microclimate (Dyer and Moffett, 1999;Haugo and Halpern, 2007;Debinski et al, 2010;Zald et al, 2012), and thus GHG fluxes. Amidst all these changes, hydrological gradients in montane meadows can serve as the context for spatial upscaling and an improved understanding of the underlying mechanisms of GHG emissions.…”

Historical Meadow Dynamics in Southwest British Columbia: a Multidisciplinary Analysis

“…Sometimes we consider only ecological explanations for historical ecosystem dynamics, and may consider only a single driving factor. Studying the historical dynamics of meadows in this way has resulted in different studies of the same meadow ascribing different primary processes (Dyer and Moffett 1999). In this paper, we present the results http://www.consecol.org/vol7/iss3/art5 of a multidisciplinary collaboration to examine the human, ecological, and physical processes responsible for the historical and current state of a meadow in southwestern British Columbia, Canada.…”

“…If humans were igniting the fires that maintained the meadow, we would expect to find evidence of human use of the meadow and a change in the fire regime of the meadow around the time when aboriginally set fires were restricted. (Vale 1981, Agee and Smith 1984, Butler 1986, Taylor 1990, Dyer and Moffett 1999. Since the mid-1970s, spring temperature has increased across the Northern Hemisphere, resulting in a decrease in spring snow cover across North America, including the upper Skagit Valley (Karl et al 1993, Cayan et al 2001).…”

“…For example, some meadows in western North America were historically maintained within forested landscapes by a combination of fire (Arno and Gruell 1986, Magee and Antos 1992, Hadley 1999, Tveten and Fonda 1999, domestic livestock grazing (Vale 1981), or substrate (Hadley 1999). Other meadows, particularly subalpine meadows, were maintained by climate or by interactions between climate and fire (Vale 1981, Agee and Smith 1984, Butler 1986, Taylor 1990, Dyer and Moffett 1999. Many meadows are currently threatened because of recent changes in these processes.…”

Recent advance of forest–grassland ecotones in southwestern Yukon

“…This compensated for uncertainty in the number of years to coring height, or estimates of rings to missing pith (Dyer and Moffett 1999), but was also advantageous in the climate relationship analysis (see below) as climatic variables can influence successful establishment of trees in the years before, and after, establishment (Suarez and Kitzberger 2010). Separate pooled distributions were developed for spruce and aspen in Kluane and Aishihik, as well for the three topographic positions.…”