We present the calibration of a fast and non-destructive method to estimate aboveground plant biomass measuring vegetation cover. We double-sampled vegetation cover and aboveground biomass in the Patagonian steppe using 150 plots for shrubs and 50 plots for grasses. We performed simple linear regressions between vegetation cover and biomass for the dominant species and life forms (shrubs: Mulin...

The expansion of C(3) shrubs into C(4)-dominated tallgrass prairies represents a fundamental shift in growth-form dominance accompanied by changes in resource acquisition and use. We assessed these changes by comparing the ecophysiological traits of the dominant C(4) grass Andropogon gerardii, with traits of three C(3) invasive shrub species, Cornus drummondii, Prunus americana, and Rhus glabra...

Nitrogen limits plant growth in almost all terrestrial ecosystems, even in low-precipitation ecosystems. Vegetation in arid ecosystems is usually composed of two dominant plant-functional types, grasses and shrubs, which have different rooting and water acquisition patterns. These plant-functional types may respond differently to N availability because they have different strategies to absorb a...

Pihlgren, A. 2007. Small-scale structures and grazing intensity in semi-natural pastures effects on plants and insects. Doctor’s dissertation. ISSN 1652-6880, ISBN 91-576-7312-1. Semi-natural grasslands characterized by nutrient poor soils are among the most species-rich habitats in Europe and they harbour many red-listed species. The area of semi-natural grasslands has decreased drastically du...

The pocosins, or broad-leaved evergreen shrub bogs, constitute one of the most distinctive plant communities of the southeastern coastal plain. They occupy flat, poorly-drained areas where the soil is frequently water-logged for long periods of time, but where surface water seldom stands to a depth of more than a few inches, and then only for comparatively short periods. The water relations of ...

We introduce shrubs in this paper in order to present a first approach to studying the structure of the Mandelbrot set. Primary, secondary ... and N -ary shrubs are analyzed. We have experimentally obtained formulae to calculate the periods of the hyperbolic components representatives of the structural branches, and the preperiods and periods of both the nodes -where structural branches emanate...

We investigate pattern avoidance in permutations satisfying some additional restrictions. These are naturally considered in terms of avoiding patterns in linear extensions of certain forestlike partially ordered sets, which we call binary shrub forests. In this context, we enumerate forests avoiding patterns of length three. In four of the five non-equivalent cases, we present explicit enumerat...

We used snow fences and small (1m) open-topped fiberglass chambers (OTCs) to study the effects of changes in winter snow cover and summer air temperatures on arctic tundra. In 1994, two 60m long, 2.8m high snow fences, one in moist and the other in dry tundra, were erected at Toolik Lake, Alaska. OTCs paired with unwarmed plots, were placed along each experimental snow gradient and in control a...