Tree shoot elongation in northern Wisconsin and relationships with temperature and precipitation

1976 ◽  
Vol 6 (4) ◽  
pp. 487-498
Author(s):  
Richard R. Buech

The relative amount of shoot elongation in the upper crowns of mature trees was studied in a forest community near Rhinelander, Wisconsin. Curves of the percentage of total elongation for the 1970 through 1973 growing seasons were similar to those previously reported for younger trees, but the elongation periods were generally shorter. Quercusrubra had the shortest period of elongation, followed by Acersaccharum. Tiliaamericana, Acerrubrum, Betulapapyrifera, Populustremuloides, and Abiesbalsamea in order of increasing duration. Comparisons were also made of the elongation patterns among species and years. Expected dates for the attainment of 10% elongation based on heat sums and year-day were compared with the observed dates. For all species except A. balsamea and A. saccharum, the comparison demonstrated the use of heat sums in predicting initial elongation.


2001 ◽  
Vol 31 (8) ◽  
pp. 1444-1455 ◽  
Author(s):  
Isabelle Chuine ◽  
Sally N Aitken ◽  
Cheng C Ying

Periodicity of shoot elongation in seedlings of Pinus contorta Dougl. ex Loud. was assessed during one growing season in two extremely different environments (Cowichan Lake, and Red Rock, British Columbia) for 109 provenances sampled range wide. Analysis of variance of total elongation and growth parameters showed significant differences among geographic regions and among provenances within each region. Our study also revealed tremendous genotype-by-environment interaction for growth and phenological traits. The response of growth to temperature of each provenance was assessed from their growth curve using an original methodology. The estimated temperature threshold of the provenance growth responses (i.e., the temperature for which the response reaches half of its maximum) varied between 4.1 and 6.5°C among regions. Threshold temperatures showed less variation than total elongation, and only the northern provenances showed thresholds significantly different from the other regions. Our results show that, across highly contrasting environments, relationship between phenology and growth may not be as important as the relationship between growth and number of internode priomordia. This tempers the results of studies, carried out in one or few similar environments, that have shown that phenological differences were important in determining total height growth in lodgepole pine.



1981 ◽  
Vol 11 (4) ◽  
pp. 789-795 ◽  
Author(s):  
S. Thompson

When seedlings of a single seed source of Scots pine (Pinussylvestris L.) were raised for 26 weeks in a naturally lit, heated greenhouse, two types of shoot morphology were observed. Type 1 was that normally found in 1-year-old seedlings. Type 2 had a shoot morphology similar to that of seedlings raised outdoors for two growing seasons. When compared with type 1 plants, type 2 plants had an earlier start to shoot elongation, set their buds earlier, and stopped shoot elongation sooner. After one growing season, type 2 plants were shorter, had fewer stem units for shoot elongation in the second season, but carried a greater foliage biomass than 1-year-old type plants. After two seasons they remained shorter. Thus, plant rearing practices which result in the production of seedlings with this type of shoot morphology arc undesirable.The relationship between early "budsct," shoot morphology, and plant height suggests that the proportion of seedlings with a 2-year-old shoot morphology after one growing season in a heated greenhouse may be used as an early test for height growth potential in seed origins and possibly in progenies of north temperate pine species.



1987 ◽  
Vol 65 (3) ◽  
pp. 466-475 ◽  
Author(s):  
Alastair D. Macdonald ◽  
D. H. Mothersill

Reproductive buds and developing inflorescences were collected weekly from mature trees during three successive growing seasons in northwestern Ontario. Material was prepared to show all stages of inflorescence and flower development and meiosis. Male inflorescence induction, involving the long-shoot bud apex and one or two proximal axillary apices, occurred in early May, before bud burst. Female induction involved the short-shoot bud apex and occurred in late June – early July. Both male and female partial inflorescences resembled a simple dichasium. The male flower consisted of usually two stamens and two or three tepals variably arranged. Meiosis occurred in late July – early August. Each female flower consisted of two stigmas, two connate tepals that were not noticeable at maturity, and a parietal placenta bearing two unitegmic ovules. Meiosis occurred in mid-June, after pollination in mid-May. It is concluded that developmental data do not help elucidate whether the inferior portion of the gynoecial wall is cauline or appendicular and whether the placenta is derived from axial or carpellary tissue. It is suggested that the trigger(s) evoking male and female inflorescence induction may be different and that the metabolic prerequisites for induction and early development would be supplied by winter-stored material for male development and by current metabolic processes for female development.



1995 ◽  
Vol 13 (4) ◽  
pp. 178-181 ◽  
Author(s):  
Daniel M. Lauderdale ◽  
Charles H. Gilliam ◽  
Donald J. Eakes ◽  
Gary J Keever ◽  
Arthur H. Chappelka

Abstract Effects of red maple transplant size [3.8 cm (1.5 in, small) and 7.6 cm (3.0 in, large) trunk diameter] on growth were evaluated at park and residential planting sites in Mobile, AL, during 1993 and 1994. Gas exchange and leaf water potential of transplants were monitored. Small trees had greater shoot elongation than large trees during both growing seasons. In 1994, small trees had greater height increases than large trees. Trunk diameter increases of small transplants were twice those of large transplants in 1994. Photosynthesis, leaf conductance, transpiration, and water use efficiency were higher for small transplants than large transplants on every observation date. In August 1993, pre-dawn and daily leaf water potentials were higher (less negative) for small trees than for large trees.



2018 ◽  
Vol 13 (1) ◽  
pp. 113-123 ◽  
Author(s):  
Vijyeta Manral ◽  
Kirtika Padalia ◽  
Himani Karki

Plant diversity is essential for human survival and economic well-being and also for the ecosystem function and stability. The total number of accessible seedlings and saplings in a forest community indicates the regeneration status/potential of a species or a forest. In this study, composition, diversity and population structure of three different forests (Banj oak, Chir-pine and Mixed oak-pine) was assessed around Nainital town of Uttarakhand state. Species richness and diversity were maximum in Banj-oak forest (9 species and 1.970, respectively) and minimum in Chir-pine forest (4 species and 0.634, respectively). The total tree density ranged from 1670 (Chir pine forest) to 1830 ind.ha-1 (Mixed oak pine forest) and the total basal area ranged from 87.22 (Mixed oak pine forest) to 208.37 m2ha-1 (Banj oak forest). Population structure revealed dominancy of mature trees and less number of seedlings evidently indicated the poor regeneration across the forests type. Viability of seeds, disturbances brought by frequent fire incidence, erosion of soil and water, uncontrolled grazing by animals, lopping/cuttings of under canopy plant species by villagers for fuel and fodder are the possible causes of the poor regeneration of the forests.



Forests ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 774 ◽  
Author(s):  
Haonan Zhang ◽  
Jianhui Xue

Bamboo has invaded native forests worldwide, and its aggressive spread by rhizomes facilitates patch expansion and the eventual replacement of adjacent forests. However, fine-scale studies of the spatial pattern and competitive relationships of bamboo in native forests are still lacking. We obtained data from nine plots in a native south subtropical rainforest in Guizhou Province, northwest China. Pair-correlation functions indicated that competition caused by bamboo expansion has not led to large-scale regular spatial distributions in bamboo forest and negative density-related dependence mechanisms regulating the spatial pattern of the native forest community. Marked correlation functions indicated small bamboo in clusters form colony patches that grow around the larger mature trees, resulting in patch expansion in the native forest community. Mark variogram functions identified significant positive spatial autocorrelation of moso bamboo caused by interactions with similar-sized trees within colony patches. This study showed that moso bamboo has colonized and expanded within the native forest community. Compared to the native forest species, the strategy of patch expansion and equal tree sizes in colony patches of moso bamboo could prevent regular distribution trend and size-asymmetric competition between nearby bamboo for the asymmetric and limited sources (i.e., light) in the forest, enhancing the persistence of moso bamboo in the native forest in our study stand located in a south subtropical rainforest in a river valley.



1987 ◽  
Vol 17 (11) ◽  
pp. 1408-1415 ◽  
Author(s):  
Robert A. Cecich ◽  
Edmund O. Bauer

The time from emergence of an ovulate strobilus to collection of viable seeds can be reduced to as little as 9 months instead of the usual 16 months spread over two growing seasons. The procedure is called the "shortened reproductive cycle." Two-year-old jack pine (Pinusbanksiana Lamb.) seedlings, grown under accelerated growth conditions, were brought into a greenhouse in the fall, where the environment simulated natural photoperiod and temperature conditions encountered during a growing season, including the approach of fall and winter. Ovulate strobili that subsequently emerged were pollinated and "2nd-year" cones, derived from those strobili, were collected the following September. The yield of filled seeds per cone was low and germination success was variable. The seedlings derived from the shortened reproductive cycle appeared to be normal and produced their own ovulate strobili 14 months after germination. Exposure to the greenhouse environment stimulated pollen production but decreased production of ovulate strobili 1 year after transplanting to the nursery. Flowering during the shortened reproductive cycle procedure was further promoted with gibberellin A4/7 application at the end of terminal shoot elongation in the greenhouse during the winter. Ovulate strobili were observed 6 months later in the nursery.



1989 ◽  
Vol 6 (1) ◽  
pp. 31-33
Author(s):  
Chen H. Lee ◽  
Hans G. Schabel

Abstract A permanent test plantation consisting of a single provenance of Japanese larch and six provenances of European larch was established in central Wisconsin in the spring of 1982 by hand planting 2-0 stock grown from seed originating in Europe. A randomized complete block design with seven replications was used. Altogether 294 trees (6 trees/plot X *** plots/block x 7 replications) were installed in the test. After five growing seasons in the field, plantation survival was 98%. Nineteen percent of the trees had suffered bark damage by deer, and 22% had terminals clipped by grasshoppers. The damages were not related to seed source origin, and they were of short duration. The between-seedlot differences in annual shoot elongation were statistically significant in each of three consecutive growing seasons. Mean annual height growth for both exotic larches combined was 53 cm. Mean total height reached 3.73 m after seven growing seasons (two in the nursery, five in the plantation). Early growth potential of both larches was more than three times that of native red pine planted adjacent to the larch study site. Although the single Japanese larch provenance was slowest growing, sensitive to late frost, and possessed the lowest percentage of straight stems, it still outperformed red pine. European larch of Polish provenances, combining good growth with straightness characteristics, is recommended for general planting purposes on suitable sites in central Wisconsin. North. J. Appl. For. 6(1):31-33, March 1989.



1990 ◽  
Vol 20 (9) ◽  
pp. 1448-1452 ◽  
Author(s):  
Throstur Eysteinsson ◽  
Michael S. Greenwood

Flowering was promoted on potted, indoor, and field-grown 3-year-old juvenile and mature Larixlaricina (Du Roi) K. Koch grafts by foliar sprays of the plant-growth regulator gibberellin A4/7 and root pruning. Biweekly gibberellin A4/7 applications of three different durations, commencing at the start of long-shoot elongation, yielded similar increases in female flowering in the greenhouse; this effect was synergistically enhanced by root pruning. Male flowering was promoted by gibberellin A4/7 + root pruning in mature but not juvenile grafts. In the field, female flowering was also promoted by the gibberellin A4/7 treatment commencing at the start of shoot extension, but gibberellin A4/7 applications starting later were not effective. Grafted scions from mature trees responded significantly better to gibberellin A4/7 + root pruning than did seedling scions.



Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1143
Author(s):  
Jan Deutscher ◽  
Ondřej Hemr ◽  
Petr Kupec

In the last two decades, the effects of global climate change have caused a continuous drying out of temperate landscapes. One way in which drying out has manifested is as a visible decrease in the streamflow in the water recipients. This article aims to answer the questions of how severe this streamflow decrease is and what is its main cause. The article is based on the analysis of daily streamflow, temperature, and precipitation data during five years (1 November 2014 to 31 October 2019) in a spruce-dominated temperate upland catchment located in the Czech Republic. Streamflow values were modeled in the PERSiST hydrological model using precipitation and temperature values obtained from the observational E-OBS gridded dataset and calibrated against in situ measured discharge. Our modeling exercise results show that the trend of decreasing water amounts in forest streams was very significant in the five-year study period, as shown in the example of the experimental catchment Křtiny, where it reached over −65%. This trend is most likely caused by increasing temperature. An unexpected disproportion was found in the ratio of increasing temperature to decreasing discharge during the growing seasons, which can be simplified to an increasing trend in the mean daily temperature of +1% per season, effectively causing a decreasing trend in the discharge of −10% per season regardless of the increasing precipitation during the period.



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