Stem Sprouts Research Articles

Resprouting Control of Ailanthus altissima by Means of Cut and Stump Covering: Experimental Evidence for a Promising Technique

Ailanthus altissima is an invasive tree threatening the biodiversity in natural and disturbed habitats of temperate regions, primarily because of its high resprouting vigor. To test the effect of light exclusion on stem and root sprouting, black covers were applied on the cut stumps of 3-year-old saplings grown in pots. The treatments were as follows: SL, stumps exposed to light; SH, only stumps covered; SPH, the entire pot covered; C, intact control plants. The covers were removed when the root sprouts appeared. The emergence of stem and root sprouts was checked weekly, and their number and biomass were determined at the growth peak (cut I and III) and the end (cut II and IV) of two seasons after cutting. Stem sprouts were produced only in the first growth season in SL and SH and never in SPH and the controls. The number and biomass of the root sprouts were the highest in SH at cut I and in SL in the following cuts. In SH, the sprouting ceased completely after cut I, suggesting a rapid consumption of root reserves, while in SL and SPH, repeated cutting progressively reduced the sprouting vigor. We concluded that covering the stems after cutting is a promising technique to control ailanthus resprouting without the use of herbicides.

Distribution of genetic variation in five coppice growth traits among natural populations of seven North American willow (Salix) species

Genetic variation and population structure in biomass yield and coppice growth traits were assessed in seven native North American willow species (Salix amygdaloides (AMY), Salix bebbiana (BEB), Salix discolor (DIS), Salix eriocephala (ERI), Salix humilis (HUM), Salix interior (INT), and Salix nigra (NIG)) established together in common-garden field tests on two sites. Differences in biomass yield, coppice stem number, and average single-stem mass were significant at the site, species, population, and genotype (clonal) levels. There were also species × site interactions. Analyses of variance components for these traits showed that only 3%–5% of the total variation in these traits was due to site differences, whereas genetic variation at the species, population, and genotype levels accounted for approximately 10%–39%, 5%–13%, and 12%–23%, respectively. Populations were a significant source of variation in some willow species (e.g., AMY, DIS, ERI, and INT) but not in other species. Tree willows were less prolific in stem sprout production than shrub willows, and ERI coppices produced by far the highest number of stem sprouts per coppice. This multispecies investigation demonstrated strong species and clonal differences, but variation among populations within a species, although significant, was relatively small, indicating that major growth and yield gains can be made through proper species selection and clonal selection within local populations.

Allometric relationships from coppice structure of seven North American willow (Salix) species

Biomass yield and component coppice growth traits were assessed in up to 20 clones from seven native North American willow species, Salix amygdaloides (SAM), Salix bebbiana (BEB), Salix discolor (DIS), S eriocephala (ERI), Salix humilis (HUM), Salix interior (INT), and Salix nigra (NIG), established together in a clonally replicated common-garden field test. Aboveground mass, coppice stem number, stem length, and stem basal diameter measurements on up to 20 of the largest stems from 2-yr-old coppiced plants showed that ERI had the greatest aboveground mass, followed by INT, and then a close grouping of BEB, DIS, and HUM; the “tree” willows, AMY and NIG, had the lowest yields. The tree willows were not as prolific in coppice stem sprout production as were the shrub willows. The greatest number of stem sprouts was produced by ERI, with one coppice producing 67 2-yr-old stem sprouts, and ERI also showed an atypical, non-negative relationship between stem size and stem number; whereas the other six willows showed a varying but expected negative relationship between coppice stem size and stem number. Species differences in allometric relationships highlight the need to develop species-specific models for more accurate non-destructive biomass yield estimation.

Phenotypic Plasticity in Response to Short Term Nutrient Availability in Cylindropuntia fulgida (Cactaceae)

Abstract Individuals of the cactus Cylindropuntia fulgida, are adapted to long periods of environmental stress with ephemeral periods of resource abundance (e.g., seasonal rains and subsequent nutrient mineralization) which requires this slow-growing cactus to act quickly to acquire nutrients. A short-term phenotypic response to varying levels of a fertilizer pulse was investigated in this species. Phenotypic plasticity could be a mechanism whereby this plant can modify its phenotype to allow for high resource intake during ephemeral nutrient pulses. The phenotype of a clone grown across fertilizer treatments was described for several morphological growth characteristics: root biomass, shoot length growth, weight increase, and number of new stem sprouts. Root concentrations of carbon (C) and nitrogen (N) were used to measure plasticity in nitrogen uptake capacity and allocation. Significant differences between clones were found in all response variables except root biomass, when each response variable was...

Delayed tree mortality in the Atchafalaya Basin of southern Louisiana following Hurricane Andrew

Hurricanes can damage trees in forested wetlands, and the potential for mortality related to these storms exists due to the effects of tree damage over time. In August 1992, Hurricane Andrew passed through the forested wetlands of southern Louisiana with winds in excess of 225 kph. Although more than 78% of the basal area was destroyed in some areas, most trees greater than 2.5 cm dbh were alive and resprouting prolifically the following year (98.8%). Survival of most tree species was similarly high two years after the hurricane, but mortality rates of some species increased dramatically. For example, Populus heterophylla (swamp cottonwood) mortality increased from 7.8 to 59.2% (n = 76) and Salix interior (sandbar willow) mortality increased from 4.5 to 57.1% (n = 21). Stem sprouts on many up-rooted hardwood trees of other species were still alive in 1998, 6 years after the hurricane. Due to the understory tree species composition, regeneration, and high levels of resprouting, there was little change in species composition or perhaps a slight shift toward more shade and flood tolerant species six years following the hurricane event. Triadica sebifera (Chinese tallow) was found on some of the sites heavily disturbed by Hurricane Andrew, and may proliferate at the expense of native tree species.

Contributions of root and stump sprouts to natural regeneration of a logged tropical dry forest in Bolivia

A major impediment to the sustainable management of tropical dry forests in Bolivia is the scarcity of natural regeneration of commercial timber tree species. Where regeneration is present, true seedlings of many species are outnumbered by vegetative sprouts from roots, broken stems, and the stumps of felled trees. This study evaluates the importance of resprouts promoted by logging operations for the regeneration of commercially important canopy tree species. The objectives of the study were: (1) to characterize stump and root sprouting behaviors of canopy tree species harvested for timber; (2) to quantify the effect of logging on relative abundances and growth rates of stump sprouts, root sprouts, and true seedlings; (3) to relate the species-specific probabilities of stump sprouting to stump diameter and stump height; and (4) to explore how sprouting varies with the ecological requirements of canopy tree species. The study was carried out 1–5 years after logging of a privately owned land in a Bolivian tropical dry forest. Twenty-seven of the 31 species monitored resprouted at least occasionally, among which Centrolobium microchaete (Leguminosae-Fabaceae) and Zeyheria tuberculosa (Bignoniaceae) were the most frequent stump sprouters, and Acosmium cardenasii (Leguminosae-Fabaceae) and C. microchaete were the most frequent root sprouters. In all species the number of sprouts declined with increasing stump diameter and stump height. The probability of stump resprouting differed among species but did not vary consistently with stump diameter, except in Z. tuberculosa in which it declined. Approximately 45% of juveniles <2 m tall of canopy tree species originated from root or stem sprouts. Light-demanding species tended to regenerate more from seeds and root sprouts than from stumps. Seedling densities were higher in microsites opened by logging, while root and stem sprouts were equally common across microsites. Given their abundance and the fact that root and stem sprouts at least initially grew faster than true seedlings, we conclude that vegetative regeneration in this tropical dry forest is an important mode of post-logging regeneration especially for species that regenerate poorly from seed. Resprout management should be considered as a potentially effective strategy for the procurement of regeneration following logging, especially for species that do not readily recruit from seed.

Colonization and Sporulation of Phytophthora infestans on Volunteer Potatoes Under Western Washington Conditions

Growth, sporulation, and survival of Phytophthora infestans on volunteer potato tubers, was investigated under temperatures representative of winter (4°C, 7°C, and 10°C) and spring (13°C, 16°C, 19°C) soil conditions in western Washington. Inoculated tubers stored at 10°C for 8 days had a significantly (P < 0.05) higher percentage of disease symptoms on tuber surfaces and a higher number of lenticels and eyes with P. infestans sporulation compared to those stored at 4°C or 7°C. Sporulation of P. infestans on cut tuber surfaces was observed following 3-week storage at the three winter soil temperatures. After 12-week storage, tubers inoculated with a US-8 isolate had a significantly higher percentage of late blight on cut surfaces than those inoculated with a US-11 isolate (70% versus 50%, respectively). For spring soil temperature studies, tubers inoculated with the US-8 isolate and held at 19°C had a significantly higher number of lenticels per tuber with P. infestans sporulation than tubers held at 13°C or 16°C. Sporulation of P. infestans on tuber surfaces was detected on infected tubers buried 5-cm deep in potting medium at all tested winter and spring temperatures for 3- or 6-day periods, respectively. The site or depth of tuber inoculation with P. infestans did not influence tuber-to-sprout infection events and whether apical end or stem sprouts become infected. Tubers with late blight that survive the winter in western Washington and support sporulation of P. infestans via lenticels and eyes may enable the transmission of P. infestans from infected tissues to sprouts of volunteer plants. However, the impact of these events on primary inoculum production by P. infestans in the region is probably limited by the mild, winter conditions favoring tuber break-down in soil.

Signals controlling root suckering and adventitious shoot formation in aspen (Populus tremuloides)

We determined the effects of removal of leaves, stem axillary buds, or the entire shoot on root suckering (adventitious shoot formation by roots) and basal stem sprouts in 3- and 4-year-old potted seedlings of aspen (Populus tremuloides Michx.). The greatest number of root suckers (67.9 +/- 8.5 per plant) emerged after excision of the entire shoot. Defoliated and debudded stems were the major source of inhibitory agents for root suckering, although axillary buds and developing new leaves also exerted a significant inhibitory effect. Removal of mature leaves had only a minor effect on root suckering. Removal of a continuous band of bark (girdling) at the base of the stem consistently stimulated growth of adventitious shoots from the stem below the girdle and occasionally promoted root suckering. Exogenous application of indole-3-acetic acid to excised stumps inhibited root suckering and basal stem sprouting. Naphthylphthalamic acid (NPA), an auxin polar transport inhibitor, had no effect on root suckering or stem sprouting when it was applied to the bark of the basal stem. However, NPA significantly increased root suckering when it was applied to the exposed surface of xylem after girdling. These results suggest that polar transport of auxin in the xylem parenchyma is an important inhibitor of root suckering. On decapitated stems, vacuum extraction of xylem sap from the root system lowered the frequency of root suckering compared with decapitation alone, indicating that substance(s) originating in the root system also play a significant role in controlling root suckering.

Recruitment of lianas into logging gaps and the effects of pre-harvest climber cutting in a lowland forest in Cameroon

The abundance of lianas (woody vines) and the detrimental impact that they have on tropical rain forest trees is widely recognized. Lianas are particularly abundant in disturbed areas of the forest, such as logging gaps, and pre-harvest liana cutting has been widely recommended throughout the tropics to reduce the impact of lianas during and following tree harvest. The effectiveness of forest-wide liana cutting, however, is currently unresolved, particularly for reducing liana abundance in logging gaps. Furthermore, our understanding of the dynamics and rate of liana colonization in gaps is limited. We tested: (1) the speed at which lianas recruit into logging gaps and their dynamics afterwards; and (2) whether pre-harvest liana cutting actually reduces the abundance of lianas in post-harvest logging gaps. To test hypothesis 1, we compared liana recruitment in new, 1 and 6-year-old logging gaps. For hypothesis 2, we compared liana abundance and tree infestation by lianas in 1-year-old logging gaps in which all lianas had been cut 9 months prior to tree felling vs. 1-year old logging gaps in which lianas were not cut. Lianas recruited heavily into logging gaps within 1 year, mostly by means of stem sprouts, and many of these new stems were apparently able to persist for longer than 6 years. Lianas were significantly more abundant in the root/bole zone of gaps than in the canopy zone, mostly due to the vigorous regeneration of stem sprouts. Canopy openness was highest in gaps one year after logging, possibly due to the smothering effect of the lianas on developing trees. Although liana abundance increased significantly over the 6-year gap chronosequence, direct liana infestation of trees remained the same. Pre-logging liana cutting, however, significantly reduced the number of lianas and also the number of liana-infested trees in logging gaps. Consequently, liana cutting appears to be an effective method to reduce the abundance of lianas and thus minimize their detrimental effects on regenerating trees in logging gaps.

Stem Turnover in the Rhizomatous Scrub Oak, Quercus inopina, from South-central Florida

Abstract Average length of time between fires is thought to limit shrub height of some Florida scrubs which has been found to exceed 3 m within 30 to 40 y, a height at which these scrubs no longer support the Florida scrub jay (Aphelocoma coerulescens) and possibly other rare species endemic to this vegetation type. We hypothesize, however, that stem lifespan, rather than the average fire return interval, limits the height attained by Quercus inopina, a dominant shrub oak endemic to scrubs on the Lake Wales Ridge in south-central Florida. To determine stem longevity and height growth, the perimeters of 56 stem clusters at nodes on the rhizomes of Q. inopina were outlined with wire flags in four scrub stands at Archbold Biological Station in south-central Florida and all stems in each cluster tagged. Height growth and survival of 448 stems were followed for 9–10 y, along with that of any new stem sprouts appearing within the perimeters of the marked clusters during this time. Between 80 and 90% of the init...

Response of Immature Trembling Aspen to Season and Height of Cut

Abstract Forest managers in Ontario have identified trembling aspen (Populus tremuloides Michx.) as the most significant competitor of our commercially important spruce and pine crop. Although herbicides can be used to effectively control aspen, the public of Ontario would prefer to have herbicide alternatives, such as motor-manual cutting, used on public lands. Cutting of aspen has not been very successful, and research is required to improve its effectiveness. Effects of season and height of cutting to control the regrowth of young trembling aspen were studied on four sites in Ontario,Canada, with each location providing a replicate for the trial. Aspen stems, averaging 1.5 to 3.2 m in height, were cut in fall (October 1993), winter (February/March 1994), and summer (June/July 1994) at 10, 25, 50, 75, or 100 cm above ground level. Density and height of new root suckers;number, point of origin, and growth of stem sprouts; and tissue mortality in cut stems were evaluated by analyses of variance with linear contrasts to determine the effects of cutting height, season of cutting, and their interactions. Two years of post-treatment data indicate that aspen regeneration may be reduced if manual cutting occurs in June/July, at a cutting height of 50 to 75 cm. This timing and cutting height provides maximum stem mortality with minimum number of sprouts per stem and minimum sucker regeneration. If aspen regeneration is the goal, cut in the fall at 25 cm for maximum regrowth. North. J. Appl. For. 16(2):108-114.

Ecological Roles of Stem Sprouts and Creeping Sprouts of Aucuba japonica Thunb.

The ecological roles of stem sprouts and creeping sprouts of Aucuba japonica Thunb. were investigated through comparisons of the population structure at individual and stem level between two sites with different disturbance histories. Age and size structure of individuals indicated fewer chances for establishment of new individuals in undisturbed population. Maintenance of population was achieved by stem replacement within a clump and vegetative propagation with creeping sprouts which adapted to the non-severe disturbances. Rapid recovery by vigorous sprouting and encouraged seedling recruitment were detected in the disturbed sites. Results of the stem level analysis suggested transformation of stem sprouts into creeping sprouts. The major role of stem sprouts shifted from the maintenance of individuals to recovery of individuals by a severe disturbance. These differentiation of ecological roles among stem types, and their flexible changes according to disturbance regimes were thought to be the reasons whyA. japonica can achieve both the rapid dominance in a disturbed stand and the stable population in a less disturbed stand.

Studies on the cultivation technique of enviromental conservation forests in heavy snowfall regions : The development of stem sprouts in Fagus crenata stands and the growth of Cyptomeria japonica seedling trees underplanted in the stands

Studies on the cultivation technique of enviromental conservation forests in heavy snowfall regions : The development of stem sprouts in Fagus crenata stands and the growth of Cyptomeria japonica seedling trees underplanted in the stands

The effect of fire severity level on postfire recovery of hazel and raspberry in east-central Alberta

A study of the effects of fire on the regrowth of beaked hazel (Corylus cornuta Marsh.) and wild red raspberry (Rubus strigosus Michx.) was carried out in Elk Island National Park, Alberta. Shrubs growing under an aspen stand were subjected to five levels of fire severity by artificially adjusting the fuel load on small plots within a larger prescribed fire. Effects studied included mortality, number of stem sprouts, height growth of sprouts, and number of leaves per sprout, all during the first growing season, and biomass after the second season. Generally, fire killed the shrub stems at all severity levels. Variation in fire severity had little significant effect on regrowth, except that lower levels seemed to favor higher numbers of hazel sprouts and increased raspberry height growth.

Stem form response to repeated pruning of young black walnut trees

Five-year-old walnut trees were pruned for 3 consecutive years to remove branches from 0, 20, 40, 60, or 80% of the total length of the main stem. Increasing the amount of branch removal caused greater height growth, more cylindrical stems, and more stem sprouts, with the most pronounced response to the 60 and 80% pruning treatments. The response may be related to the relatively slow growth of the trees, wide spacing in the plantation, and early initiation and annual repetition of the pruning treatments.

Elm as Deer Browse

Sprouts and tops of American elm (Ulmus americana) were preferred woody deer browse on the Allegheny National Forest in northwestern Pennsylvania. More than 90 percent of the succulent sprouts and two-thirds of the available twigs in the tops of trees felled in winter were utilized in the growing season after cutting. Elm was found to sprout vigorously from stumps, and from the boles of trees that were successfully hinged to the stumps. These results are in general contrast to reports in the literature on deer browse in which elm is listed as low in use. The white-tailed deer (Odocoileus virgianus) has the reputation of being a highly selective feeder, browsing heavily on some plants, nibbling lightly or not at all on others. This paper reports on heavy utilization of American elm twigs as browse in northwestern Pennsylvania during spring and summer. Observations of the use of elm by deer were made in the late summer of 1964 in a northern hardwood poletimber stand, 40 to 60 years old, on the Allegheny National Forest in northwestern Pennsylvania. About 12 acres had been thinned the previous winter in one of the blocks used to study a method for increasing deer-browse production in poletimber stands (Jordan et al. 1965). Before cutting, elm was common in the stand, comprising up to 10 percent of the stems. Associated species were sugar maple (Acer saccharum), black cherry (Prunus serotina), basswood (Tilia americana), white ash (Fraxinus americana), yellow birch (Betula alleghaniensis), hop-hornbeam (Ostrya virginiana), and blue beech ( Carpinus caroliniana). Slippery elm (Ulmus rubra), beech (Fagus grandifolia), quaking aspen (Populus tremuloides), black birch (Betula lenta), eastern hemlock (Tsuga canadensis), red maple (Acer rubrum), and striped maple (A. pensylvanicum) were less common, occurring mainly as isolated trees. Under the stand-improvement method used, all stems except selected future crop trees were cut to produce browse. Wellformed sugar maple, white ash, and black cherry were favored in the residual stand. In the late summer following cutting, a randomized sample of woody browse production and utilization yielded the following number of twigs per acre and percent of browsing by species: sugar maple 183,900, 6.4; yellow birch 52,900, 15.7; hophornbeam 28,800, 6.6; basswood 14,400, 59.0; white ash 11,000, 23.6; black cherry 8,700, 21.8; blue beech 6,800, 0.0; beech 1,700, 11.8; and striped maple 300, 0.0. In felling, an effort was made to hinge the stem to the stump so that the top would remain alive to produce browse in succeeding years. Thus browse was produced by both the stumps and tops, and in many instances along the bole of the tree. American elm was found to sprout vigorously from the stumps, and from the boles of trees that were successfully hinged. To determine the extent to which American elm was browsed, individual trees accessible to deer were selected, and all browsed and unbrowsed twigs 2 inches or more in length to 5 ft in height were recorded. The twigs were grouped into three categories: stump sprouts, stem sprouts, and tops.

INHIBITION OF GROWTH IN GUAYULE AS AFFECTED BY TOPPING AND DEFOLIATION

THE PRACTICE of pruning woody transplants at the time of transplanting is very old. Bailey (1939, p. 2818) states that all woody transplants should be cut back to at least one-half their height. The samne authority states (p. 1637) that the removal of all or part of the leaves of the evergreen forms of holly is essential for success in transplanting. It has usually been assumed that removal of a portion of the top and leaves is important solely as a means of reducing water loss. The leaves are assumed to transpire water to such an extent that the root systein is dehydrated and new root growth fails to occur. Controlled experiments with transplants of guayule (Parthenium argentatum Gray) show that a consideration of the water relations alone.of this plant is insufficient to account for all of the responses which result after transplanting occurs. Some of the findings are presented in the present paper. Lloyd (1911, p. 209) states that survival was enhanced when transplanted guayule was cut back to the root. His experiments, however, showed poor survival at best and the plants used were apparently native shrubs of larger size than the nursery stock which has been used since in field culture. Topping to approximately one-half (3 to 5 inches) the stem height has been used for some years for one or more of the following reasons: (1) resumption of growth was quicker and usually resulted in a higher survival percentage than when topped to a lesser degree;2 (2) to accommodate the planting machine, and (3) to facilitate disease control in the nursery beds during damp or foggy periods of weather. Untopped guayule plants, when transferred to the greenhouse in mid-winter (1942-43), failed to resume growth for several weeks. When these plants were clipped to remove about one-half the top, and in addition all the remaining leaves were removed, the plants showed both root and stem sprouts within the next five or six days.3 This experiment was designed for other purposes than to show the effect of topping and leaf removal. It did, however, indicate certain facts that had an important bearing on future topping studies. These plants had the majority of their roots removed when transplanted into the sand culture. Yet, there was no indication of wilting over this period of several weeks in the greenhouse. The leaves were continuously erect and turgid. In most of the later experiments this also was true. In some tests with highly succulent plants, wilting did occur. In all tests, some of the plants that failed to