The Eucalypt Forest Grassland/Grassy Woodland Boundary in Central Tasmania

1992 ◽  
Vol 40 (2) ◽  
pp. 123 ◽  
Author(s):  
RJ Fensham ◽  
JB Kirkpatrick
Keyword(s):  
Seedling Establishment ◽  
Suppressive Effect ◽  
Root Competition ◽  
Detectable Effect ◽  
Tree Seedlings ◽  
Herbicide Application ◽  
Eucalypt Forest ◽  
High Elevations ◽  
Planted Tree ◽  
Primary Agent

Downslope boundaries of forest with grassland and grassy woodland occur over a wide altitudinal range in central Tasmania. Three sites were selected for study of the causes of these boundaries at low, medium and high elevations. The open vegetation was generally associated with moister and less rocky soils and more subdued topography than the adjacent forest. Frost incidence and intensity, soil moisture and waterlogging varied markedly among the three open areas. Planted tree seedlings survived 4 years in the open at all sites, and seedlings established in the open both naturally, and after sowing, where grass competition was reduced by herbicide application, digging or root competition from adult eucalypts. Grazing had no detectable effect on seedling establishment. A pot experiment demonstrated a suppressive effect of native grass swards on both seedling establishment and growth, this effect being largely independent of available moisture and nutrients. While frost, waterlogging, fire and drought may play a role in inhibiting eucalypt establishment and increasing eucalypt mortality at some or all of the sites, the dense grass swards found in all the open areas are considered to be the most likely primary agent of tree exclusion.

The Role of Fallen Logs in the Regeneration of Tree Species in Tasmanian Mixed Forest

1999 ◽  
Vol 47 (5) ◽  
pp. 745 ◽  
Author(s):  
J. B. Kirkpatrick ◽  
H. J. A. McKenny
Keyword(s):  
Bulk Density ◽  
Tree Species ◽  
Substrate Surface ◽  
Mixed Forest ◽  
Canopy Cover ◽  
Root Competition ◽  
Tree Seedlings ◽  
Establishment Success ◽  
Moss Cover ◽  
Litter Cover

This study was designed to determine whether fallen logs were a more favourable habitat for tree species establishment than soil in moist eucalypt forest in Tasmania, whether establishment success on logs varied between two forests in contrasting environments, and whether surface and substrate qualities and light conditions were associated with establishment success. Data on tree and shrub species densities and heights by species, moss cover, litter cover, Blechnum wattsii cover, canopy cover, bulk density of the substrate, and substrate surface pH, nitrogen content and phosphorus content were obtained from paired soil and log quadrats. Tree seedlings were found to be significantly more abundant on fallen logs than on adjacent ground at both sites, with the differences being greater at the moister Tahune site than at Mount Field. At Tahune, logs significantly differed from adjacent soil in canopy cover, litter cover, moss cover Blechnum wattsii cover, pH and slope. At Mount Field, there were significant differences between logs and soil in litter cover, moss cover, pH, bulk density and nitrogen. Litter cover may be critical in explaining the superior establishment of trees on logs rather than soil in Tasmanian mixed forest, although the possible impacts of variations in bioturbation and root competition require further research.

scholarly journals Evaluation of Four Herbicides and Tillage for Weed Control on 1-0 Planted Tree Seedlings

2002 ◽  
Vol 19 (3) ◽  
pp. 101-105 ◽  
Author(s):  
John R. Seifert ◽  
Keith Woeste
Keyword(s):  
Weed Control ◽  
Height Growth ◽  
Post Treatment ◽  
Tree Seedlings ◽  
Single Treatment ◽  
Bare Ground ◽  
Conifer Species ◽  
Herbicide Treatments ◽  
The Mean ◽  
Planted Tree

Abstract Azafenidin, sulfometuron, pendimethalin, and simazine were applied alone and in combination to 1-0 seedlings of nine hardwood and one conifer species. Percent bare ground at 30, 60, and 90 days, diameter and height growth of the seedlings were determined for 16 herbicide treatments, tillage and a control. Azafenidin applications alone and in combination with sulfometuron resulted in about 85% bare ground 90 days post-treatment. There were significant differences for diameter, height growth, and volume among the treatments for every species. No single treatment ranked best for all species, but comparison of the mean ranks of the treatments for all species indicated that azafenidin and pendimethalin resulted in the most growth. Azafenidin-treated seedlings also had the greatest volume at the end of the season.

Germination and development of sown mahogany (Swietenia macrophylla King) in secondary tropical dry forest habitats in Costa Rica

1996 ◽  
Vol 12 (2) ◽  
pp. 275-289 ◽  
Author(s):  
Karin Gerhardt
Keyword(s):  
Costa Rica ◽  
Seedling Establishment ◽  
Rainy Season ◽  
Deciduous Forest ◽  
Secondary Forest ◽  
Dry Forest ◽  
Root Competition ◽  
Evergreen Forest ◽  
Swietenia Macrophylla ◽  
Seedling Mortality

ABSTRACTEffects of irradiance, root competition and water availability on germination and seedling establishment of Swietenia macrophylla King were investigated in tropical secondary dry forests in the Guanacaste Conservation Area, Costa Rica. The fate of seeds sown in the beginning and the middle of the rainy season was studied in abandoned pasture, and in deciduous and semi-evergreen secondary forest. In the pasture, experimental treatments were mown and unmown grass. In the forest sites, thinning to increase light and trenching to reduce root competition were combined in a factorial design. Effects of moisture availability on germination were tested by supplementing natural rainfall in the initial rainy month. Germination at the beginning of the rainy season was not influenced by the supplementary water and was higher in the semi-evergreen forest than in the deciduous forest and pasture. In the forests, germination was little affected by irradiance or root competition. More seeds germinated in unmown than in mown pasture during the initial rains, but were not influenced by mowing when sown in the peak of the rainy season. Seedling mortality was low (>10%) during the initial months, but increased greatly in the dry season. Seedlings germinating early in the rainy season had a higher survival than those germinating later. The relatively slight effects of the different treatments and habitats on seedling establishment suggest that this species is rather insensitive to the large microsite variation in secondary vegetation.

Effects of root competition and soils on seedling establishment at the ecotone between an arid grassland and succulent shrubland in South Africa

2013 ◽  
Vol 25 (2) ◽  
pp. 402-410 ◽  
Author(s):  
Ndafuda N. Shiponeni ◽  
Peter J. Carrick ◽  
Nicky Allsopp ◽  
M. Timm Hoffman
Keyword(s):  
South Africa ◽  
Seedling Establishment ◽  
Root Competition

Factors affecting growth and distribution of kauri (Agathis australis Salisb.) II. Effect of light intensity on seedling growth

1959 ◽  
Vol 7 (3) ◽  
pp. 268 ◽  
Author(s):  
RL Bieleski
Keyword(s):  
Light Intensity ◽  
Seedling Growth ◽  
Seedling Establishment ◽  
Dry Weight ◽  
Forest Tree ◽  
Stem Length ◽  
Tree Seedlings ◽  
Seedling Mortality ◽  
Seedling Morphology ◽  
Effect Of Light

The effect of various light intensities on the growth of kauri seedlings is described. Daylight was screened to the required level with lath screens. There was no significant effect of light on seedling mortality in the light intensity range 0.40–0.02 full daylight. Seedling morphology was affected by light intensity, the ratios stem dry weight/root dry weight, stem length/root length, and fresh weight / dry weight increasing significantly with decreasing light intensity. Seedling growth was a linear function of log (light intensity), the growth rates and assimilation rates being similar to those for other forest tree seedlings. The compensation point was at 0.009 full daylight, close to the low light intensity limit to seedling establishment in the field but low compared with those of other tree seedlings. There was no high light intensity limit to seedling growth, such as that shown for seedling establishment in the field. The apparent discrepancy is discussed.

scholarly journals Effects of grass clearing and soil tilling on establishment of planted tree seedlings in tropical riparian pastures

New Forests ◽  
2015 ◽  
Vol 46 (4) ◽  
pp. 507-525 ◽  
Author(s):  
Paula Meli ◽  
José María Rey Benayas ◽  
Miguel Martínez Ramos ◽  
Julia Carabias
Keyword(s):  
Tree Seedlings ◽  
Planted Tree

Influence of a common palm, Oenocarpus mapora, on seedling establishment in a tropical moist forest in Panama

2004 ◽  
Vol 20 (4) ◽  
pp. 429-438 ◽  
Author(s):  
Krista Farris-Lopez ◽  
Julie S. Denslow ◽  
Barry Moser ◽  
Heather Passmore
Keyword(s):  
Leaf Litter ◽  
Seedling Establishment ◽  
Light Availability ◽  
Biomass Accumulation ◽  
Transplant Experiment ◽  
Tree Seedlings ◽  
Lowland Forest ◽  
Advance Regeneration ◽  
Litter Depth ◽  
Moist Forest

Plants often modify microsite conditions important for seedling establishment. In tropical moist forest, advance regeneration in the form of shade-suppressed seedlings is a major component of regrowth in new gaps. Tree seedlings may be filtered by the composition and structure of the forest understorey. In a lowland forest in Central Panama, we examined light availability, litter accumulation and the seedling community (abundance, diversity and composition) under and away from the canopies of a common subcanopy, clonal palm, Oenocarpus mapora, and tested whether seedling abundance varies as a function of changes in understorey light conditions and leaf litter depth. We found evidence that leaf litter was five times deeper and light availability 27% lower under O. mapora canopy than where it was absent. The probability of finding a seedling in plots under O. mapora canopies was 33% lower than in plots without the palm. Plots under O. mapora canopies also had 49% fewer species of seedlings and those seedlings came from significantly larger seeds than seedlings in plots not under the palm. Overall, seedling density was positively correlated with light availability and negatively correlated with leaf litter depth. A transplant experiment confirmed that for at least one large-seeded species of dicot, seedlings are negatively affected by the reduction in light availability and increase in leaf litter. Under O. mapora, seedlings of Gustavia superba (Lecythidaceae) had lower survivorship and biomass accumulation than away from the palm. Thus, site conditions produced by large, clonal, multi-layered palms such as O. mapora may reduce establishment of small-seeded and shade-intolerant species, potentially affecting species composition in the understorey seedling pool.

scholarly journals Copper stress affect seed germination and seedling establishment of Schinus terebinthifolia Raddi

Hoehnea ◽  
2020 ◽  
Vol 47 ◽  
Author(s):  
Matheus Casarini Siqueira ◽  
Armando Reis Tavares ◽  
José Marcos Barbosa ◽  
Nelson Augusto dos Santos Junior
Keyword(s):  
Seed Germination ◽  
Seedling Establishment ◽  
Environmental Problem ◽  
Copper Stress ◽  
Control Treatment ◽  
Tree Seedlings ◽  
Excess Copper ◽  
Pepper Tree ◽  
Mean Germination Time ◽  
Brazilian Pepper

ABSTRACT Pollution by the discharge of copper in the environment due to anthropogenic, industrial, and automobile activities is an environmental problem. Copper is also widely used in different forms as fertilizers and fungicides. Here, we aimed to evaluate seed germination and the establishment of Schinus terebinthifolia Raddi, popularly known as ‘Brazilian pepper tree’ seedlings submitted to different concentrations of copper. Five treatments were used, with four replicates and 20 seeds per replicate, totaling 400 seeds. Cu (CuSO4.5H2O) was added to the substrate at doses of 0; 60; 760; 2,100 or 10,000 mg kg-1. The variables percentage, speed, and mean germination time, as well as establishment of seedlings, were analyzed. Cu doses of 2,100 or 10,000 mg kg-1 inhibited seedling formation. Cu concentration of 10,000 mg kg-1 reduced the final values of germination and speed germination to about one third of those obtained in the control treatment. Compared to germination, establishment of seedlings was more affected by excess copper for the S. terebinthifolia. The species tolerated doses up to 760 mg kg-1 copper during seedling establishment, which indicates that it is a candidate for environmental restoration programs for soils with known copper contamination.

Spatial variation in tree regeneration in the forest-tundra ecotone, Rocky Mountain National Park, Colorado

1995 ◽  
Vol 25 (8) ◽  
pp. 1326-1339 ◽  
Author(s):  
Peter J. Weisberg ◽  
William L. Baker
Keyword(s):  
Seedling Establishment ◽  
National Park ◽  
Rocky Mountain ◽  
Tree Regeneration ◽  
Rocky Mountain National Park ◽  
Tree Seedlings ◽  
Tree Seedling ◽  
Forest Tundra ◽  
The Past ◽  
Environmental Controls

Ecotone vegetation may be especially sensitive to climate change. In particular, the invasion of subalpine meadows by tree seedlings has been well documented. However, there has been no systematic analysis of tree regeneration across the environmental heterogeneity of the alpine forest–tundra ecotone (FTE). Also, the position of the FTE may be relictual from more favorable climates of the past and therefore unresponsive to changing climate. To assess the environmental controls on FTE tree regeneration, to determine whether the ecotone might be relictual, and to determine whether tree invasion of nonforested FTE areas is occurring, we measured tree regeneration in various environments within the FTE of Rocky Mountain National Park, Colorado. Generally, seedling establishment appears to be controlled by patterns of soil moisture. Little seedling establishment was observed in krummholz openings, except for high seedling densities in willow wetlands. Tree seedling invasion of tundra is rare. Therefore, the upper limits of the FTE in Rocky Mountain National Park may be relictual from more favorable climates of the past. Abundant seedling establishment in patch forest openings suggests that patch forest may be poised to change to closed forest.

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