Positive and negative interactions between environmental conditions affecting Cercocarpus ledifolius seedling survival

Oecologia ◽  
2001 ◽  
Vol 129 (4) ◽  
pp. 543-550 ◽  
Author(s):  
Inés Ibáñez ◽  
Eugene W. Schupp
Keyword(s):  
Environmental Conditions ◽  
Seedling Survival ◽  
Cercocarpus Ledifolius ◽  
Negative Interactions

FOREST REGENERATION QUALITY ASSESSMENT BY ASTA SYSTEM

2018 ◽  
Author(s):  
Karlis DUMINS ◽  
Toms STALS ◽  
Dagnija LAZDINA
Keyword(s):  
Survival Rate ◽  
Environmental Conditions ◽  
Forest Regeneration ◽  
Forest Type ◽  
Growth Parameters ◽  
Seedling Survival ◽  
Monitoring Methods ◽  
Annual Increment ◽  
Soil Preparation ◽  
Micro Topography

In Latvia one third of the total forest area is regenerated by planting tree seedlings and therefore it is important to choose the appropriate soil preparation method and the right type of regeneration material for each forest type. Usually the success of afforestation is evaluated by how high is the average seedling survival rate and growth parameters like height, annual increment, diameter at breast height while the location of the seedling is disregarded. This may be of great importance since in such stands the environmental conditions typically are not entirely homogenous. Micro topography differences impact seedling growth, because it modifies water regime, temperature, micronutrient availability, sun radiation and other factors. Therefore, aim of this work is to improve monitoring methods and determine the most efficient soil preparation and seedling preparation combination to improve the quality of forest regeneration. That could be done using ASTA documentation system originally developed to show seedling and mound location and density in planting area during mechanic planting. But it also allows to link the precise location of the seedling and growing conditions with its growing rate and survival and therefore it is easier to exclude seedlings that are affected by other factors than those that you are interested in, so you can gain more representative results. This also could be used in forest management. When using ASTA system it is also possible to display how different tree disease are distributed in the stand, if they have spread eventually or localized only in some parts of the stand, also it can be used for browsing and other tree damage monitoring in the stand. In conclusion: in harsh environmental conditions on unprepared forest soil and soil prepared in furrows made by disc trench larger seedlings show better survival rate. Survival of seedlings is significantly impacted by micro topography, whereas mounded micro sites equalize local environmental conditions that reduce impact of micro topography.

Postfire environmental conditions influence the spatial pattern of regeneration for Pinus ponderosa

2005 ◽  
Vol 35 (1) ◽  
pp. 37-47 ◽  
Author(s):  
V H Bonnet ◽  
A W Schoettle ◽  
W D Shepperd
Keyword(s):  
Pinus Ponderosa ◽  
Environmental Conditions ◽  
Ponderosa Pine ◽  
Seedling Survival ◽  
Mineral Soil ◽  
Safe Sites ◽  
Burned Areas ◽  
Seed Availability ◽  
Pine Regeneration ◽  
Ground Conditions

Regeneration of ponderosa pine after fire depends on the patterns of seed availability and the environmental conditions that define safe sites for seedling establishment. A transect approach was applied in 2002 to determine the spatial distribution of regeneration from unburned to burned areas within the landscape impacted by the Jasper Fire of 2000 in the Black Hills of South Dakota (USA). Canopy conditions alone, reflecting seed availability, at the stand level were not correlated with regeneration success. However, canopy conditions in combination with ground conditions explained patterns of regeneration success at the plot level (2 m × 6 m scale), and ground conditions explained these patterns at the quadrat level (0.2 m × 0.2 m scale). Only at the finer level of the quadrat could environmental factors explain seedling survival. Safe sites were characterized, in part, by the presence of scorched needle litter on blackened mineral soil. Areas with high understory cover restricted regeneration in the undisturbed forest and reduced seedling survival in the burned areas. The description of environmental conditions that favor and discourage ponderosa pine regeneration success will improve our understanding of how environmental heterogeneity within burned areas will contribute to the future forested landscape.

scholarly journals Stand Development and Population Dynamics of Curlleaf Mountain Mahogany (Cercocarpus ledifolius Nutt.) Woodlands in Utah's Bear River Mountains

2011 ◽  
Vol 26 (4) ◽  
pp. 183-188 ◽  
Author(s):  
Seth A. Ex ◽  
R. Justin DeRose ◽  
James N. Long
Keyword(s):  
Population Dynamics ◽  
Seedling Survival ◽  
Basal Area ◽  
Stand Age ◽  
Stand Development ◽  
Mature Trees ◽  
Cercocarpus Ledifolius ◽  
Northern Utah ◽  
Structure Height ◽  
Age Structures

Abstract Curlleaf mountain mahogany (Cercocarpus ledifolius Nutt.) is a little-studied woodland tree that occurs in pure stands throughout the Intermountain West. Stand development and population dynamics of this species are poorly understood, despite their relevance to management. We describe here the development of stand age structures and population dynamics of mahogany woodlands in northern Utah using tree ages and measurements representing five structurally diverse stands. Establishment periods in all stands lasted decades, and regeneration continued intermittently in the absence of stand-replacing disturbance, eventually creating multiaged structure. Height, crown size, and basal area varied among older mahogany, which may reflect more intense intraspecific competition or increased likelihood of crown damage in older stands. Mahogany woodland managers face significant challenges. It is difficult to characterize historic stand conditions using current age structures because aging mature trees is generally unfeasible. Furthermore, there is little precedent for regenerating mahogany using silvicultural methods. Results suggest that the biggest risk in regenerating mahogany woodlands is low seedling survival, leading to the prolonged absence of mature trees. Consequently, multiaged methods that retain mature trees are recommended.

scholarly journals Seed local adaptation and seedling plasticity account for Gleditsia triacanthos tree invasion across biomes

2019 ◽  
Vol 124 (2) ◽  
pp. 307-318 ◽  
Author(s):  
Pedro M Tognetti ◽  
Noemí Mazia ◽  
Gonzalo Ibáñez
Keyword(s):  
Phenotypic Plasticity ◽  
Seed Germination ◽  
Water Potential ◽  
Local Adaptation ◽  
Tropical Forests ◽  
Environmental Conditions ◽  
Seedling Survival ◽  
Common Garden ◽  
Temperate Grasslands ◽  
Vegetation Removal

Abstract Background and Aims Phenotypic plasticity and local adaption can contribute to the success of invasive species. While the former is an environmentally induced trait, the latter involves a selection process to filter the best genotype for a location. We examined the evidence for phenotypic plasticity and local adaptation for seed and seedling traits of the invasive tree Gleditsia triacanthos, with three origins distributed along an approx. 10° latitude gradient across three biomes. Methods In sub-tropical forests, dry woodlands and secondary temperate grasslands in Argentina, we harvested seeds from clusters of neighbouring trees (i.e. families) distributed within 15–20 km in each origin (biome). We manipulated the environmental conditions relevant to each biome, assuming that propagule availability did not represent an ecological barrier. In growth chambers, we evaluated seed imbibition and seed germination under different light, temperature and water potential. In a 2 year common garden, we evaluated the impact of resident vegetation removal on seedling survival and growth. Key Results Mean time to complete seed imbibition differed among origins; seeds from temperate grasslands reached full imbibition before seeds from dry woodlands and sub-tropical forests. Germination was always >70 %, but was differentially affected by water potential, and light quantity (dark–light) and quality (red–far red) among origins, suggesting local adaptation. In the common garden, vegetation removal rather than origin negatively affected seedling survival and enhanced seedling growth. Vegetation removal increased basal diameter, leaves per plant and spine number, and reduced the height:basal diameter ratio. Conclusions We conclude that local adaptation in seed germination traits and plastic changes in seedling allometry (e.g. height:diameter) may allow this tree to respond over the short and long term to changes in environmental conditions, and to contribute to shape G. triacanthos as a successful woody invader. Overall, our study revealed how local adaptation and plasticity can explain different aspects of tree invasion capacity across biomes.

Origin and deposition sites influence seed germination and seedling survival of Manilkara zapota: implications for long-distance, animal-mediated seed dispersal

2011 ◽  
Vol 21 (4) ◽  
pp. 305-313 ◽  
Author(s):  
Georgina O'Farrill ◽  
Colin A. Chapman ◽  
Andrew Gonzalez
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Environmental Conditions ◽  
Field Experiments ◽  
Seedling Survival ◽  
Transplant Experiment ◽  
Long Distance ◽  
Plant Populations ◽  
Manilkara Zapota ◽  
Survival Probabilities

AbstractThe distribution and dynamics of plant populations depend on the recruitment of young individuals, which is influenced by seed production, animal seed dispersal, dispersal distance, and the deposition of seeds in favourable places for seed germination/establishment and seedling survival. In particular, seeds dispersed over long distances will likely encounter new environmental conditions that occur at large spatial scales, with seed and seedling survival influenced by the adaptation of plant populations to soil and climate conditions. In this paper, it is hypothesized that seed germination and seedling survival probabilities depend on seed origin and deposition sites. A reciprocal seed and seedling transplant experiment was carried out with zapote seeds (Manilkara zapota) to determine the effect of origin and deposition sites on seed germination and seedling survival over a year in the Greater Calakmul Region of Mexico. Two origin and two deposition sites were selected that show different soil moisture levels within the habitat of the Baird's tapir, a major seed disperser of M. zapota seeds. The results show that sites of origin and deposition influenced seed germination and seedling survival probabilities. This suggests that the displacement of seeds far from parent trees, while potentially reducing intraspecific competition, does not ensure their survival, and that seeds need to be deposited in microsites within their environmental tolerance for dispersal to be successful. Furthermore, this paper emphasizes the importance of field experiments to provide strong inference about the effects of environmental conditions on recruitment and distribution of plant species.

Vibration Isolator System for Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 182-183
Author(s):  
K. Ohi ◽  
M. Mizuno ◽  
T. Kasai ◽  
Y. Ohkura ◽  
K. Mizuno ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Magnetic Fields ◽  
Environmental Conditions ◽  
Vibration Isolator ◽  
Air Conditioners ◽  
Vibration Isolators ◽  
Large Size ◽  
Electron Microscopes

In recent years, with electron microscopes coming into wider use, their installation environments do not necessarily give their performance full play. Their environmental conditions include air-conditioners, magnetic fields, and vibrations. We report a jointly developed entirely new vibration isolator which is effective against the vibrations transmitted from the floor.Conventionally, large-sized vibration isolators which need the digging of a pit have been used. These vibration isolators, however, are large present problems of installation and maintenance because of their large-size.Thus, we intended to make a vibration isolator which1) eliminates the need for changing the installation room2) eliminates the need of maintenance and3) are compact in size and easily installable.

The influence of external conditions on sound pressure in the pistonphone at the infrasound frequency range

2020 ◽  
pp. 67-72
Author(s):  
A. V. Konkov ◽  
D. V. Golovin
Keyword(s):  
Environmental Conditions ◽  
Sound Pressure ◽  
Primary Method ◽  
Frequency Range ◽  
External Conditions ◽  
Numerical Estimations

The influence of environmental conditions on a sound pressure reproduced by the primary method in the measuring chambers of the Pistonphone in the frequency range from 1 mHz to 250 Hz is estimated. Numerical estimations of influence of environmental conditions on sound pressure in pistonphone measuring chambers are given and special requirements to system of maintenance of required external conditions are specified.

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