scholarly journals Utilization of lightflecks by seedlings of five dominant tree species of different subtropical forest successional stages under low-light growth conditions

2012 ◽  
Vol 32 (5) ◽  
pp. 545-553 ◽  
Author(s):  
Q. Zhang ◽  
Y. J. Chen ◽  
L. Y. Song ◽  
N. Liu ◽  
L. L. Sun ◽  
...  
Keyword(s):  
Tree Species ◽  
Growth Conditions ◽  
Subtropical Forest ◽  
Low Light ◽  
Successional Stages

Light-dependent seedling survival and growth of four tree species in Costa Rican second-growth rain forests

2005 ◽  
Vol 21 (4) ◽  
pp. 383-395 ◽  
Author(s):  
Silvia Iriarte Vivar Balderrama ◽  
Robin L. Chazdon
Keyword(s):  
Tree Species ◽  
Seedling Survival ◽  
Light Availability ◽  
Light Transmittance ◽  
Growth Responses ◽  
Low Light ◽  
Growth Increments ◽  
Light Gradient ◽  
Second Growth ◽  
Survival And Growth

The dependence of tree seedling survival and growth on light availability was evaluated over 15 mo in three second-growth, wet forest stands (15–18 y old) in north-eastern Costa Rica. Seedlings of four canopy tree species (Dipteryx panamensis, Hyeronima alchorneoides, Virola koschnyi and Vochysia guatemalensis) were planted into four canopy treatments in three replicated stands and in a pasture site, spanning a nearly complete gradient of light availability. Survival and growth of all species increased in response to increasing light availability, but species differed in survival in shaded microsites (6–20% light transmittance) and in growth increments per light increase. Hyeronima showed the highest mortality at low light levels and the highest relative height growth increase per light increase. In contrast, Virola showed high survival at low and moderate light, but showed the lowest leaf area and above-ground biomass per light increase among all species. Dipteryx and Vochysia maintained relatively high rates of survival and growth across the entire light gradient. Hyeronima and Virola showed trade-offs between growth and survival responses to light, unlike Dipteryx and Vochysia. Differences among species in seedling survival at low light may be determined by a variety of physiological and morphological traits that may or may not be mechanistically linked to growth responses.

Development of System for High Quality Wood Grain Design

2011 ◽  
Author(s):  
Takuya Mori ◽  
Satoshi Shibasaki ◽  
Hideki Aoyama
Keyword(s):  
Computer Graphics ◽  
Tree Growth ◽  
Wood Surface ◽  
Environmental Conditions ◽  
Tree Species ◽  
Growth Conditions ◽  
High Quality ◽  
New Approach ◽  
Conventional Methods ◽  
Wood Grain

Various approaches for generating woodgrain patterns using computer graphics have been proposed so far. However, it is difficult to reproduce real woodgrain patterns using such conventional methods. In this paper, a new approach for generating woodgrain patterns is proposed. Virtual trees are generated by simulating tree growth in consideration of environmental conditions. Moreover, fine tree tissues and reflection properties at the wood surface are modeled. By applying these modeled factors, more diverse and accurate woodgrain patterns can be generated. With this approach, various types of virtual trees can be obtained by changing growth conditions such as period and location of growth or form of tissue in trees without the need to reset complicated parameters of each tree species. After this, the virtual trees can be cut at arbitrary areas, thus allowing a variety of woodgrain patterns to be generated by easy parameter setup.

scholarly journals Tree species co-occurrence patterns change across grains: insights from a subtropical forest

Ecosphere ◽  
2018 ◽  
Vol 9 (5) ◽  
pp. e02213 ◽  
Author(s):  
Avi Bar-Massada ◽  
Qingsong Yang ◽  
Guochun Shen ◽  
Xihua Wang
Keyword(s):  
Tree Species ◽  
Subtropical Forest ◽  
Occurrence Patterns

Scientific Results of the BRYOTROP Expeditioni to Zaire and Rwanda 1. The ecology of epiphytic bryophytes on Mt. Kahuzi (Zaire)

1994 ◽  
Vol 9 (1) ◽  
pp. 137-152 ◽  
Author(s):  
Jan-Peter Frahm
Keyword(s):  
Life Form ◽  
Growth Conditions ◽  
Sudden Increase ◽  
Low Light ◽  
Ph Measurements ◽  
Tropical Mountains ◽  
Host Trees ◽  
The Mean ◽  
Scientific Results ◽  
Forest Line

Along a transect from 900 m to 3300m elevation, various ecological parameters concerning epiphytic bryophytes have been studiesd. The most characteristic life form between 900 and 2300 m elevation is the dendroid, which is interpreted as an adaptation to better gas exchange under the unfavourable conditions (low light, high air humidity) of the rain forest. Above 2500 m, cushions are the predominant lif form. The cushion are 2-5 cm high but can reach 50 cm at the forest line. In spectacular cases, moss balls are formed up to 1 m in diameter. PH measurements of the bark of host trees revealed values between 4.1 and 6.2, which is in accordance with result from South America and SE-Asia. The bryophyte cover on soil is very low (<5%) below 2700 m but raises to 90% in the subalpine ericaceous belt, but not in the subalpine Senecio-belt. The percentage cover of bryophytes on bark increases from 5 to 80% in the transect with increasing elevation, and the light intensity increases from <1% to 50%. The mean annual temerature decreases continously from 20.6°C at 900 m elevation to 2.5° at 4500 m elevation. This allows a comparison of the growth conditions of bryohyte species occurring disjunct in the oceanic parts of the temperate regions and the tropical mountains. The phytomass of epiphytic bryophytes per m² and per ha increases synchronously in the transect. There is a sudden increase from 8-44 kg/ha in 900-1300 m to 100-600 kg/ha in elevationis between 1900 and 2900 m. Maximum values of 6 tonnes/ha are found at the forest line , being 750 time higher than the lowest value in the lower part of the transect. The water storing capacity of epiphytic bryophytes is 20-60 1/h at elevations between 900 and 1300 m, 130-2000 1/ha between 1900 and 2900 m and 18000 1/ha at the forest line. The latter is 18% of the estimated rainfall.

The effect of forest successional stage on seed removal of tropical rain forest tree species

2002 ◽  
Vol 18 (2) ◽  
pp. 261-274 ◽  
Author(s):  
Marielos Peña-Claros ◽  
Henneleen De Boo
Keyword(s):  
Tree Species ◽  
Removal Rate ◽  
Forest Tree ◽  
Primary Forest ◽  
Secondary Forests ◽  
Seed Removal ◽  
Successional Stage ◽  
Successional Stages ◽  
Agricultural Areas ◽  
Number Of Seeds

Seed removal was evaluated at the macro- and micro-habitat level in areas differing in successional stage in the Bolivian Amazon. The successional stages consisted of secondary forests of 2, 10 and 20 years old and primary forest. Seeds of nine tree species were artificially dispersed and the number of seeds removed was evaluated over 7 weeks. Several stand characteristics were measured at the sites where seeds were dispersed. Seed removal at the end of the experiment varied from 50 to 100% depending on the species, and from 74 to 90% depending on successional stage. In general, the removal rate decreased with an increase in age of successional stage. The seed removal rate was related to liana density and not to litter thickness. Different microhabitat characteristics explained the seed removal rate of four species but microhabitat characteristics did not explain the decrease in seed removal rate with an increase in forest age. The results support the idea that post-dispersal seed removal reduces the number of seeds available for germination, consequently playing an important role in the regeneration of abandoned agricultural areas.

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