| dc.description.abstract | To understand the pattern of adaptive variation of jack pine in north
central Ontario better, short-term provenance tests were established. Seed
was collected from 64 sites to the east and west of Lake Nipigon and
grown in three common garden tests, including a greenhouse trial at
Lakehead University, a farm field trial at Lakehead University, and a field
trial near Raith. Eight growth variables were measured (two annual
heights from the greenhouse trial and three annual heights from each of
the field trials), fourteen phenological variables were determined
(elongation initiation and cessation dates, elongation duration and needle
flush date at each trial; and foliage purpling at the greenhouse and
Lakehead University field trials), and survival at the Raith trial was
examined. Variation expressed among seed sources was significant for all
growth variables and many phenological variables. Multiple regressions
were run for 18 of the 23 variables against climatic variables interpolated
using geographic information systems techniques from weather data of 56
weather stations, as well as spatial, soil, and vegetative variables which
described the environment at seed origin resulting in coefficients of
determination as high as 0.57. Principal components analysis (PCA) was
used to summarize the variables examined, with 33 and 21 per cent of the
variation accounted for by the first and second component respectively.
Multiple regressions were run on the factor scores produced from PCA
against the variables describing environment at seed origin. These
regression models had coefficients of determination of 0.323 and 0.429
for the first and second factor scores respectively. The pattern of
variation in this portion of the range as displayed in the mapping of the
predicted factor scores was clinal with numerous irregularities. July and
average annual temperatures, heating degree days, frost dates, and soil and
vegetation variables were included in the predictive models. The contrast
displayed in height performance between seedlings from the southwestern
portion of the range and those from the north shore of Lake Superior
reflects trends seen in a previous study of cone and needle characteristics. | |
