Floristic composition and structure of a rainforest area 25yr after logging

In 1949 an area of undisturbed warm temperate rainforest (simple notophyll vine forest) in mid-north coastal New South Wales, Australia was studied in terms of both floristics and structure (Burges A. & Johnston R. D. J. Ecol. 41, 72-83, 1953). During 1955-56, the area in which the transect was located was logged. Over 90% of the upper closed canopy trees adjacent to the creek and on the lower slope and about 35% of canopy trees on the upper slope were removed. The area was reassessed in terms of floristics and structure in 1981. The greatest impact of logging in the study area was structural and largely confined to the flat adjacent to the creek and to the lower slope. With the exception of the remaining gaps covering 6% of the area, structural recovery time is estimated at 140-190 yr. In the gaps structural recovery may take up to 250 yr. All flowering plants, ferns and mosses previously recorded were present 25 yr after logging. The two alien plant species on the site are short lived intolerant species and gradually disappearing with canopy closure of the regenerating forest. The regeneration of the original tree species is healthy and vigorous with most regeneration resulting from the growth of advance regeneration present at the time of logging or the germination of new seedlings. Eleven per cent of the regeneration is attributable to coppicing. The importance of remnant canopy trees as a source of propagules for the trees and epiphytes is recognised. The larger openings are slower to recover as a result of lack of protection from frost. The stability of floristic composition of this area of warm temperate rainforest following heavy logging is demonstrated.     

A STATISTICAL TEST OF CONSENSUS OBTAINED FROM GENERALIZED PROCRUSTES ANALYSIS OF SENSORY DATA

Matrix matching techniques such as Generalized Procrustes Analysis (GPA) always produce a matrix of maximal agreement which can then be used to graphically represent samples in “consensus plots”. The degree to which the consensus plots produced by GPA on sensory data (such as that obtained from free choice profiling) actually give a picture of true consensus among panelists, as opposed to being merely artifacts of the analysis, has not been examined. Using a Monte Carlo approach, a statistical test is defined for qualifying this consensus. Examples of the application of the test to sensory profiling data of fruit flavors are given.