Intraspecific Variation in Leaf Life Span for the Semi-evergreen Liana Akebia trifoliata is Caused by Both Seasonal and Aseasonal Factors in a Temperate Forest
1
조회
0
다운로드
1
인용
0
참고문헌
키워드
초록
We investigated the leaf demography of a temperate woody liana, Akebia trifoliata, in a temperate forest in Japan. Akebia is semi-evergreen: some leaves are shed before winter, while others remain through the winter. Previous studies of semi-evergreen species found that variation in leaf life span was caused by variation in the timing of leaf emergence. Leaves that appeared just before winter over-wintered, while leaves appearing earlier were shed. However, it is unclear whether leaves of the same cohort (i.e., leaves that appear at the same time within a single site) show variation in life span under the effect of strong seasonality. To separate variation in life span among the leaves in each cohort from variation among cohorts, we propose a new method - the single leaf diagram, which shows the emergence and death of each leaf. Using single leaf diagrams, our study revealed that Akebia leaves within a cohort showed substantial variation in life span, with some over-wintering and some not. In addition, leaves on small ramets in the understory showed great variation in life span, while leaves on large ramets, which typically reach higher positions in the forest canopy, have shorter lives. As a result, small ramets were semi-evergreen, whereas large ramets were deciduous. The longer lives of leaves on small ramets can be interpreted as a shade-adaptive strategy in understory plants.
Abstract
We investigated the leaf demography of a temperate woody liana, Akebia trifoliata, in a temperate forest in Japan. Akebia is semi-evergreen: some leaves are shed before winter, while others remain through the winter. Previous studies of semi-evergreen species found that variation in leaf life span was caused by variation in the timing of leaf emergence. Leaves that appeared just before winter over-wintered, while leaves appearing earlier were shed. However, it is unclear whether leaves of the same cohort (i.e., leaves that appear at the same time within a single site) show variation in life span under the effect of strong seasonality. To separate variation in life span among the leaves in each cohort from variation among cohorts, we propose a new method - the single leaf diagram, which shows the emergence and death of each leaf. Using single leaf diagrams, our study revealed that Akebia leaves within a cohort showed substantial variation in life span, with some over-wintering and some not. In addition, leaves on small ramets in the understory showed great variation in life span, while leaves on large ramets, which typically reach higher positions in the forest canopy, have shorter lives. As a result, small ramets were semi-evergreen, whereas large ramets were deciduous. The longer lives of leaves on small ramets can be interpreted as a shade-adaptive strategy in understory plants.
참고문헌 (29)
- Ackerly DD, "Leaf dynamics, self-shading and carbon gain in seedlings of a tropical pioneer tree", Oecologia, 101, pp.289~298 (1995)
- Chabot BF, "The ecology of leaf life spans", Ann Rev Ecol Syst, 13, pp.229~259 (1982)
- Franklin O, "Leaf senescence and resorption as mechanisms of maximizing photosynthetic production during canopy development at N limitation", Funct Ecol, 16, pp.727~733 (2002)
- Hikosaka K, "A model of dynamics of leaves and nitrogen in a plant canopy: An integration of canopy photosynthesis, leaf life span, and nitrogen use efficiency", Am Nat, 162, pp.149~164 (2003)
- Hikosaka K, "Leaf canopy as a dynamic system: ecophysiology and optimality in leaf turnover", Ann Bot, 95, pp.521~533 (2005)
- Jurik TW, "Leaf dynamics and profitability in wild strawberries", Oecologia, 69, pp.296~304 (1986)
- Karst AL, "Are correlations among foliar traits in ferns consistent with those in the seed plants?", New Phytol, 173, pp.306~312 (2007)
- Kikuzawa K, "Leaf survival of woody plants in deciduous broadleaved forests. 1. Tall trees", Can J Bot, 61, pp.2133~2139 (1983)
- Kikuzawa K, "Leaf survival of woody plants in deciduous broadleaved forests. 2. Small trees and shrubs", Can J Bot, 62, pp.2551~2556 (1984)
- Kikuzawa K, "Leaf survivals of tree species in deciduous broadleaved forests", Pl Sp Biol, 3, pp.67~76 (1988)
- Kikuzawa K, "A cost-benefit analysis of leaf habit and leaf longevity of trees and their geographical pattern", Am Nat, 138, pp.1250~1263 (1991)
- Kikuzawa K, "Significance of leaf longevity in plants", Pl Sp Biol, 14, pp.39~45 (1999)
- Kikuzawa K, "Toward synthesis of relationships among leaf longevity, instantaneous photosynthetic rate, lifetime leaf carbon gain, and the gross primary production of forests", Am Nat, 168, pp.373~383 (2006)
- Kume A, "Adaptation of stomatal response of Camellia rusticana to a heavy snowfall environment: Winter drought and net photosynthesis", Ecol Res, 11, pp.207~216 (1996)
- Kyparissis A, "Leaf demography and photosynthesis as affected by the environment in the drought semi-deciduous Mediterranean shrub Phlomis fruticosa L", Acta Oecologica, 18, pp.543~555 (1997)
- Noda H, "Morphological and physiological acclimation responses to contrasting light and water regimes in Primula sieboldii", Ecol Res, 19, pp.331~340 (2004)
- Ohwi J, "New Flora of Japan, Revised (in Japanese)", pp.724~725 (1992), Shibundo
- Oikawa S, "Leaf lifespan and lifetime carbon balance of individual leaves in a stand of an annual herb, Xanthium canadense", New Phytol, 172, pp.104~116 (2006)
- Oikawa S, "Does leaf shedding increase the whole-plant carbon gain despite some nitrogen being lost with shedding?", New Phytol, 178, pp.617~624 (2008)
- Oikawa S, "Cost-benefit relationships in leaves emerging at different times in a deciduous fern Pteridium aquilinum", Can J Bot, 82, pp.521~527 (2004)
- Poorter L, "Are species adapted to their regeneration niche, adult niche, or both?", Am Nat, 169, pp.433~442 (2007)
- Reich PB, "Generality of leaf trait relationships: a test across six biomes", Ecology, 80, pp.1955~1969 (1999)
- Reich PB, "Leaf demography and phenology in Amazonian rain forest: a census of 40,000 leaves of 23 tree species", Ecol Monogr, 74, pp.3~23 (2004)
- Sakai A, "Adaptation of plants to deposited snow", Low Temp Sci Ser B, 34, pp.47~76 (1976)
- Seiwa K, "Ontogenetic changes in leaf phenology of Ulmus davidiana var. japonica, a deciduous broad-leaved tree", Tree Physiol, 19, pp.793~797 (1999)
- Seiwa K, "Phenology of tree seedlings in relation to seed size", Can J Bot, 69, pp.532~538 (1991)
- Vincent G, "Leaf life span plasticity in tropical seedlings grown under contrasting light regimes", Ann Bot, 97, pp.245~255 (2006)
- Wright IJ, "The worldwide leaf economics spectrum", Nature, 428, pp.821~827 (2004)
- Yagi T, "Patterns in size-related variations in current-year shoot structure in eight deciduous tree species", J Plant Res, 112, pp.343~352 (1999)