Responses of West African Forest Tree Seedlings to Irradiance and Soil Fertility

Veenendaal, E.M.; Swaine,; Lecha, R.T.; Walsh, M. F.; Abebrese, I. K.; Owusu‐Afriyie, Kennedy

doi:10.2307/2389943

Cited by 138 publications

(141 citation statements)

References 32 publications

Supporting

Mentioning

123

Contrasting

Unclassified

Order By: Relevance

“…The seedling growth and allocation patterns oí Alseis are also similar to those of pioneer species grown under a range of light conditions (e.g., Popma and Bongers 1988, Osunkoya et al 1994, Veenendaal et al 1996, Poorter 1999). In our pot experiment in which seedlings Barone (1996).…”

Section: Discussion Alseis Regeneration Requirementsmentioning

confidence: 67%

The Unusual Life History of Alseis blackiana: A Shade-Persistent Pioneer Tree?

Dalling¹,

Winter²,

Nason³

et al. 2001

Ecology

View full text Add to dashboard Cite

Abstract. Classifications of tree species into regeneration guilds or functional groups are often based on a limited number of life history characteristics indicative of requirements for early establishment, with the assumption that these traits are correlated with growth requirements of larger individuals. We tested the validity of this assumption for Alseis blackiana, a common canopy tree in central Panama, by examining its seed germination, seedling growth, and sapling distribution, growth, and mortality. We found that the early life history of Alseis is characteristic of pioneer species: the seed germination rate was much higher in forest gaps than in the forest understory, small seedlings were absent from the understory, and seedlings showed strong plastic responses to variation in light. Seedling relative growth rate, leaf area production rate, and maximum carbon assimilation rates of Alseis are much more similar to those of the pioneer tree Miconia argéntea than to those of the non-pioneer tree Tetragastris panamensis. However, in contrast to Miconia, established seedlings oí Alseis are capable of remarkable persistence in the understory; in a 1-ha plot on Barro Colorado Island, the mortality rate for 722 saplings <1 cm dbh was <4% per year between 1986 and 1998. We suspect that shade tolerance in Alseis is achieved by both physiological and morphological adaptations, e.g., efficient light interception by thin, nonoverlapping leaves, tolerance to litterfall damage, and a high resprouting capacity. These results show that existing functional group classifications do not account for the full range of seedling trait combinations found in tropical trees and indicate that a gap requirement for seedling establishment need not limit the abundance of adult individuals in a stand.

show abstract

Section: Discussion Alseis Regeneration Requirementsmentioning

confidence: 67%

The Unusual Life History of Alseis blackiana: A Shade-Persistent Pioneer Tree?

Dalling¹,

Winter²,

Nason³

et al. 2001

Ecology

View full text Add to dashboard Cite

show abstract

“…With a few exceptions (e.g., Popma and Bongers 1988, Osunkoya et al 1994, and Veenendaal et al 1996, these studies only include two or three species, one from each different light environment. Patterns of plastic responses to the light environment based on a few species, each representing a contrasting ecological strategy, should be interpreted with caution.…”

Section: Discussionmentioning

confidence: 99%

Plastic Phenotypic Response to Light of 16 Congeneric Shrubs from a Panamanian Rainforest

Valladares

Wright

Lasso

et al. 2000

Ecology

272

369

View full text Add to dashboard Cite

Abstract. The comparative phenotypic plasticity of 16 species of tropical rainforest shrubs (genus Psychotria, Rubiaceae) was investigated by growing plants in three light environments on Barro Colorado Island (BCI, Panama). The three light environments gave daily photon flux densities (PPFD) similar to the natural light gradient from shaded forest understory to small and large canopy gaps. Six of the species are principally found in gaps or forest edge environments, whereas the other ten species are principally found in shaded understories. Interactions between light treatment and species resulted in unpredictable mean phenotypic expression across light treatments. Shoot relative growth rates (RGR) were similar for understory and gap species in the low light treatment. Gap species had significantly greater shoot RGR in the intermediate light treatment than in the high light treatment. Mean plasticity was significantly lower for morphological variables when compared to physiological variables, while variation in plasticity was significantly greater for structural variables. Significant differences between gap and understory species were found in the plasticity of six out of the seven variables. The mean phenotypic plasticity of the seven variables was significantly greater for gap than for understory species. The high plasticity of gap species was consistent with the hypothesis that specialization in a more favorable environment increases plasticity. The species exhibited a wide range of leaf longevities, from four to 29 months, with gap species having, on average, shorter leaf lifespan than understory species. Mean phenotypic plasticity decreased with increasing leaf longevity. Selection for greater plasticity may be stronger in the gap species because gaps exhibit a relatively predictable decrease in PPFD for which plasticity could be adaptive. While we have found a significant correlation between phenotypic plasticity and habitat affiliation, phylogeny (subgenus ascription) was not correlated with plasticity or with plant performance in any given PPFD treatment, reinforcing the hypothesis that phenotypic plasticity has evolved through natural selection in this diverse genus.

show abstract

“…Corresponding decreases in both the temperature and rates of evapotranspiration result in improved moisture regimes (see Clough, 1979;Golden, 1979). In addition, experimental studies of seedling growth also demonstrate that topographic gradients in soil fertility can cause differences in growth of individual species (Gunatilleke et al, 1996;Veenendaal et al, 1996). Therefore, the role of topographic gradients in determining spatial variation in stand-level growth rates can be difficult to discern and interpret.…”

Section: Discussionmentioning

confidence: 99%

Diameter growth performance varies with species functional-group and habitat characteristics in subtropical rainforests

Kariuki

Rolfe

Smith³

et al. 2006

Forest Ecology and Management

View full text Add to dashboard Cite

We examined tree diameter growth in 20 plots subjected to various disturbance intensities (natural, low, moderate and intensive logging) in a bid to understand the general tree growth responses in relation to habitat characteristics in subtropical rainforests of north-eastern New South Wales, Australia. Species-specific regeneration strategy, maximum size and level of shade tolerance were used to classify species into 5 groups; emergent and shade tolerant main canopy (group 1), shade tolerant mid canopy (2), shade tolerant understoreys (3), moderate shade tolerant (4), and shade intolerant (5) tree species. Data series for trees ≥ 10 cm diameter at 1.3 m above the ground level (dbh) providing observations spanning over 36-years were used in multilevel regression analyses. The results showed that spatial and temporal effects in tree growth at the stand-level are a combination of the differences between species functional-group compositions and environmental gradients. High growth responses were observed in the shade intolerant species while increasing level of shade tolerance and decreasing maximum size decreased trees growth rates. Tree growth increased with altitude on a large scale across regions, and with disturbance intensity on a small scale at the plot (stand) level. Increase in northness (south through flat to north facing sites) increased growth in species group 1 for trees < 67 cm dbh, but beyond this dbh threshold the opposite was true. These showed that saplings of species group 1 may require increased illumination to reach the forest canopy, but once in the canopy, low soil water availability may be limiting to tree growth in the north facing sites. Decrease in northness was associated with increased growth in species group 2 indicating that reduced illumination and improved soil moisture in the south facing sites were conducive for maximum growth in this species group. Maximum growth potential in species group 4 and 5 increased with decrease in eastness, suggesting that the increased afternoon solar radiation and temperature were conducive for high growth rates in these species. Although topographic gradient may determine the spatial and temporal variations in tree growth where growth appeared to increase from the crest down the slope into the creek, its effects on soil fertility and water availability, and interactions between these and other factors may make it difficult to discern clear growth patterns.

show abstract

Responses of West African Forest Tree Seedlings to Irradiance and Soil Fertility

Cited by 138 publications

References 32 publications

The Unusual Life History of Alseis blackiana: A Shade-Persistent Pioneer Tree?

The Unusual Life History of Alseis blackiana: A Shade-Persistent Pioneer Tree?

Plastic Phenotypic Response to Light of 16 Congeneric Shrubs from a Panamanian Rainforest

Diameter growth performance varies with species functional-group and habitat characteristics in subtropical rainforests

Contact Info

Product

Resources

About