Convergence towards higher leaf mass per area in dry and nutrient‐poor habitats has different consequences for leaf life span

We examined the variability in stable carbon isotope ratio (δ13C) in leaves of two deciduous broad-leaved species and two evergreen conifer species along an altitudinal gradient in central Japan. The δ13C of the two deciduous species decreased with altitude, except near the upper distribution limit. The two evergreen species, however, showed no clear altitudinal trends for δ13C. The δ13C of the two deciduous species was positively correlated with leaf mass per area (LMA), indicating that the altitudinal variation in δ13C was controlled by LMA. Leaf nitrogen per mass (as a proxy of assimilation capacity, Nmass) was negatively correlated with LMA for the two deciduous species, while it was not correlated with LMA for the two evergreen species. Leaf life span of the two deciduous species decreased with altitude, whereas that of the two evergreen species increased. Thus, the two deciduous species had shorter-lived thinner leaves with higher Nmass at higher altitudes, and the two evergreen species had longer-lived leaves. These changes contribute to the positive carbon balance at higher altitudes. Therefore, the different changes in δ13C with altitude between the deciduous and evergreen species are ascribed to the different altitudinal changes in the leaf traits for carbon balance.

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A weak relationship between crown architectural and leaf traits in saplings of eight tropical rain-forest species in Indonesia

Journal of Tropical Ecology ◽

10.1017/s0266467408005178 ◽

2008 ◽

Vol 24 (4) ◽

pp. 425-432 ◽

Cited By ~ 4

Author(s):

Koichi Takahashi ◽

Yumi Mikami

Keyword(s):

Life Span ◽

Rain Forest ◽

Tropical Rain Forest ◽

Leaf Size ◽

Leaf Traits ◽

Height Growth ◽

Leaf Life Span ◽

Degree Of Branching ◽

Leaf Mass ◽

Assimilation Capacity

AbstractThere are two trade-offs at the levels of leaves and crowns, i.e. assimilation capacity per leaf mass is greater for shorter-lived leaves, and unbranched species grow faster in height by allocating carbon more to trunk than to leaves and branches compared with highly branched species. The hypotheses were tested that the degree of branching (LTB) correlates with leaf traits and that height growth rate is negatively correlated with the degree of branching and leaf life span (LLS) by examining saplings of five canopy and subcanopy species, two shrub species and one invasive subshrub species (Clidemia hirta) in a tropical rain forest, West Java, Indonesia. Of the eight species, the most and least branched species wereCastanopsis acuminatissimaandMacaranga semiglobosa, respectively. Leaf traits examined were leaf size, LLS, leaf mass per area (LMA), leaf nitrogen concentration per mass (Nmass) and per area. LLS tended to be positively correlated with LMA, and negatively correlated withNmass. Leaf size was negatively correlated withLTB, but the other leaf traits were not correlated withLTB. The height growth of the eight species was low, irrespective ofLTBand LLS, for understorey individuals. The height growth of gap individuals was negatively correlated with LLS for the eight species, and also negatively withLTBfor the seven species other than one subshrub species. Thus, the degree of branching was correlated with leaf size only among the five leaf traits, and both leaf life span and the degree of branching affected the height growth of gap individuals, except for the subshrub species.

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Nitrogen availability, leaf life span and nitrogen conservation mechanisms in leaves of tropical trees

Scientia Agricola ◽

10.1590/s0103-90162009000600014 ◽

2009 ◽

Vol 66 (6) ◽

pp. 812-818 ◽

Cited By ~ 1

Author(s):

Guilherme Nascimento Corte ◽

Patrícia Macchiaverni ◽

Inácio Maria Dal Fabbro ◽

Claudia Regina Baptista Haddad

Keyword(s):

Life Span ◽

Nitrogen Availability ◽

Leaf Mass Per Area ◽

Leaf Life Span ◽

Evergreen Species ◽

Resorption Proficiency ◽

Nitrogen Resorption ◽

Nitrogen Conservation ◽

Use Efficiency ◽

Efficient Mechanisms

Evergreen species of temperate regions are dominant in low-nutrient soils. This feature is attributed to more efficient mechanisms of nutrient economy. Nevertheless, the cashew (Anacardium occidentale- Anacardiaceae), a deciduous species, is native to regions in Brazil with sandy soil, whilst the annatto (Bixa orellana- Bixaceae), classified as an evergreen species native to tropical America, grows spontaneously in regions with more humid soils. Evergreens contain robust leaves that can resist adverse conditions for longer. The physical aspects of the leaves and mechanisms of nutrient economy between the two species were compared, in order to verify whether the deciduous species had more efficient mechanisms that might explain its occurrence in regions of low soil fertility. The mechanisms of nitrogen economy were also compared for the two species at available concentrations of this nutrient. The following were analysed: (i) leaf life span, (ii) physical leaf characteristics (leaf mass per area, and rupture strain), (iii) nitrogenous compounds (nitrogen, chlorophyll, and protein), (iv) nitrogen conservation mechanisms (nitrogen resorption efficiency, resorption proficiency, and use efficiency), and (v) nitrogen conservation mechanisms under different availability of this mineral. The higher values of leaf mass per area and leaf rupture strain found in A. occidentale were related to its longer leaf life span. A. occidentale showed lower concentrations of nitrogen and protein in the leaves than B. orellana. Under lower nitrogen availability, A. occidentale had higher nitrogen resorption proficiency, nitrogen use efficiency and leaf life span than B. orellana. These characteristics may contribute to the adaptation of this species to sandy soils with low nitrogen content.

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