Growth and Population Dynamics of Espeletia (Compositae) in the Venezuelan Andes

Smith, Alan P.

doi:10.5479/si.0081024x.48

Cited by 47 publications

(21 citation statements)

References 10 publications

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“…The species studied here showed light responses similar to those documented for species adapted to sun and shaded environments (Boardman 1977;Grime 1979;Bazzaz and Pickett 1980;BjoÈ rkman 1981;Smith 1981;Mooney et al 1978Mooney et al , 1983Augspurger 1984;Oberbauer and Strain 1985;Walters and Field 1987;Sims and Pearcy 1989;Denslow et al 1990;SaÂ nchez-Coronado et al 1990;Lambers and Poorter 1992;RincoÂ n and Huante 1993;Kitajima 1994). In general, fast-growing species adapted to high light intensity showed higher biomass production, RGR, SLA, rate of photosynthesis per unit of leaf area, and stomatal conductance than species adapted to low light.…”

Section: Contrasting Light Responsessupporting

confidence: 50%

Responses to light changes in tropical deciduous woody seedlings with contrasting growth rates

Huante

Rincón

1997

Oecologia

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We evaluated the responses in growth, biomass allocation, photosynthesis and stomatal conductance, to changes in light in woody seedlings from the tropical deciduous forest in Mexico, which shows a highly seasonal rain pattern. We studied ten species, which differed by 30-fold in relative growth rate (RGR). We analyzed plant growth in two contrasting light levels during 52 days and two transfers: from high to low (HL) and from low to high (LH) light intensity, and the respective controls in high (HH) and low (LL) light for another 52 days. The photosynthetic capacity (A ) and stomatal conductance were measured at the day of the transfer between light conditions and at the end of the experiment. Species with high RGR showed the largest changes in RGR in response to contrasting light conditions (HH/LL ratio), and species with low RGR showed low responses. The fast-growing species were the most plastic, followed by species with intermediate growth rates, with the slow-growing species being the least plastic. Fast-growing species achieved higher maximum photosynthetic capacities (A) and stomatal conductance and higher response to light than slow-growing species. Species with high RGR showed a low RGR HH/LH ratio, suggesting a large response of L plants when transfered to H. The RGR of the species were associated with species specific leaf area and with the response in the leaf area, net assimilation rate and leaf weight ratio, suggesting the importance of the leaf area produced and the leaf characteristics rather than root:shoot ratio in determining RGR. Considering that seed germination is expected at the beginning of the rainy period, seedlings of most of the species will experience high-light conditions during its early growth. There are large annual variations in the time required for canopy closure (35-75 days). The influence of these variations may have different effect on the species studied. Species with intermediate growth rate and intermediate response to light changes were less affected by light reduction than fast-growing species. The intermediate-RGR species Caesalpiniaeriostachys is the most abundant and widely distributed species, perhaps this could be in part due to its ability to acclimate to both light increases and decreases. The fast-growing species studied here can be found in open sites in the forest and in areas cleared for pasture growth. These fast-growing species eventually reach the canopy, although this may require several canopy openings during their lives, which implies juvenile shade tolerance. In the tropical deciduous forest juvenile pioneer trees also benefit from the temporary high light available caused by the dry period during the rainy season. The slow-growing species Celaenodendronmexicanum forms small patches of monospecific forest; the adult trees are not completely deciduous, and they retain their old leaves for a long time period before shedding. Thus seedlings of this species may receive lower levels of light, in agreement with its shade tolerance and its lower response to ...

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Section: Contrasting Light Responsessupporting

confidence: 50%

Responses to light changes in tropical deciduous woody seedlings with contrasting growth rates

Huante

Rincón

1997

Oecologia

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“…E. timotensis in Venezuela has its lowest frequency of individuals in the smallest size class (Monasterio 1979), as do other Andean giant rosettes (Smith 1981;Perez 1992a), suggesting irregular and infrequent establishment. The giant Afro-alpine rosette Lobelia telekii has a population structure where all size (and age) classes are equally represented (Young & Peacock 1992).…”

Section: Discussionmentioning

confidence: 99%

Microsite requirements, population structure and growth of the cushion plant Azorella compacta in the tropical Chilean Andes

Kleier

Rundel²

2004

Austral Ecology

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In the altiplano of northern Chile, we investigated the microsite habitats, adult population structure and growth rates over 14 months for the giant cushion plant Azorella compacta . The majority of plants (52.0%) were found growing downslope of large (>50 cm diameter) boulders and on north-facing rocky slopes with a slope angle greater than 10 Њ inclination (44.4%). Size was used as a surrogate for age. The youngest size class was most common; remaining size classes were roughly equal in frequency; but very large cushions were scarce. Growth rates were expressed as height, diameter and perimeter over a 14-month period. Height increased an average of 1.40 cm, perimeter increased an average of 10.28 cm and diameters actually decreased 2.30 cm, although this was not a significant difference. Using perimeter averages based on mean plant size, we estimated a radial growth rate of 1.70 cm per 14 months. Trenches 4 cm wide were cut over the length of five plants, and these trenches were nearly repaired after 1 year, indicating that growth is overall and not just on the perimeter of the plant. These findings indicate that although Azorella compacta populations may be recovering from past exploitation, future monitoring is still necessary to ensure viable populations.

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“…Size-or stage-specific life tables are often used in demography and have two main advantages over agespecific life tables. First, in many long-lived organisms the ages of individuals are not known and can only be inferred from size and documented transition times (Lord 1959, Laws 1966, Inouye and Taylor 1980, Smith 1981, Young 1984. Second, size is a better predictor offate than is age for several short-lived herbs (Werner 1975, Werner and Caswell 1977, Gross 1981.…”

Section: Introductionmentioning

confidence: 99%

Lobelia telekii Herbivory, Mortality, and Size at Reproduction: Variation with Growth Rate

Young¹

1985

Ecology

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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. This content downloaded from 128.235.251.160 on Mon, Abstract. Size-specific life tables are often used in plant and animal demography when age-specific tables cannot be assembled or are less predictive. However, age x stage interactions may confuse the interpretation of size-specific life tables. I demonstrate here several age x stage interactions in the demography of Lobelia telekii, a long-lived semelparous rosette plant on Mount Kenya. Analysis of 4 yr of demographic data indicated that slower growing plants were more subject to herbivory, more likely to die, and tended to flower at a smaller size, than faster growing plants in the same population. If overlooked, these effects would cause overestimation of both plant age and the variance in generation time, when such estimates are based on size-specific life tables. Because these patterns parallel largescale temporal and spatial trends in L. telekii demography related to soil moisture availability, I suggest that slow-growing plants occupied less favorable microsites than fast-growing plants.

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Growth and Population Dynamics of Espeletia (Compositae) in the Venezuelan Andes

Cited by 47 publications

References 10 publications

Responses to light changes in tropical deciduous woody seedlings with contrasting growth rates

Responses to light changes in tropical deciduous woody seedlings with contrasting growth rates

Microsite requirements, population structure and growth of the cushion plant Azorella compacta in the tropical Chilean Andes

Lobelia telekii Herbivory, Mortality, and Size at Reproduction: Variation with Growth Rate

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