The effects of burning cycles and pine basal area levels were assessed on natural pine regeneration and hardwood development in uneven-aged stands of loblolly andshortleafpines (Pinw taeda L. and P. echinata Mill.). The treatments included an unburned control and prescribed winter burrs at 3-, 6-, and 9-yr intervals. Basal area treatments were 9, 14, 18, and 23 m2 ha-’ for the merchantable-pine...

Quadrats are standard sampling units of relatively small, uniformly defined areas that divide a habitat of interest into subregions of equal size. They are used in ecography for 2-dimensional sampling of plants, slowmoving animals, and (more recently) microorganisms to (i) estimate population sizes when it is not feasible to measure their abundance in entirety, (ii) define the patterns of their...

relationships between soil factors and vegetation types in playa of damghan was investigated. six vegetationtypes including artemisia.sieberi, arundo. sp, artemisia.sieberi-peganum.harmala, alhagi.cammelerom,artemisia.sieberi-petropyron.sp, tamarix.passerinoides-halocnemum strobilaceum. one bare land was recognized inthe study area and the research was conducted within mentioned types. canopy p...

Emergencies resulting in large-scale displacement often lead to populations resettling in areas where basic health services and sanitation are unavailable. To plan relief-related activities quickly, rapid population size estimates are needed. The currently recommended Quadrat method estimates total population by extrapolating the average population size living in square blocks of known area to ...

A version of the Rao-Blackwell theorem is shown to apply to most, but not all, stereological sampling designs. Estimators based on random test grids typically have larger variance than quadrat estimators; random s-dimensional samples are worse than random r-dimensional samples for s < r. Furthermore, the standard stereological ratio estimators of diierent dimensions are canonically related to e...

In this paper we calculate the values of eight pattern detection indices, using different quadrat sizes where individuals of angico above 1.5 m were located, in order to examine their statistical behaviour with increasing sample size. It was concluded that the best index is the standardized Morisita index (Ip) which is completely independent of sample size.