Stem orientation is related to growth rate, leaf dimensions, and the deciduous habit in temperate forest saplings

2001 ◽  
Vol 79 (11) ◽  
pp. 1282-1291 ◽  
Author(s):  
David A King
Keyword(s):  
Growth Rate ◽  
Leaf Size ◽  
Morphological Plasticity ◽  
Tree Architecture ◽  
Extension Rate ◽  
Deciduous Species ◽  
Evergreen Species ◽  
Leaf Habit ◽  
Central Stem ◽  
Leaf Dimensions

The orientation of the central stem is a key component of tree architecture. Stem orientation was related to extension rate in saplings growing in light conditions ranging from forest understories to large openings in 11 deciduous angiosperms, 1 evergreen angiosperm, and 2 evergreen conifers in the Appalachian Mountains of the southeastern United States. Most of the deciduous species showed pronounced differences between arced, dorsiventrally symmetric forms in slow-growing, shaded saplings and erect, radially symmetric forms in fast growing, sunlit saplings. In contrast, the evergreen species showed little or no shift in stem orientation in relation to growth rate and tended to be more erect in shade than the deciduous species. Evergreen saplings studied at other sites were also more erect in shade than the deciduous species studied here. Within the deciduous species, the degree of arcing in shade declined with increasing leaf size and petiole length. These results, involving two congeneric pairs, suggest that stem orientation is related more to leaf dimensions and leaf habit than to taxonomic classification per se. The positioning of a single cohort of nonoverlapping leaves in shaded deciduous saplings may increase the efficiency of light interception in arced forms, as compared with evergreen saplings, where new leaves must be positioned in relation to older leaf cohorts.Key words: tree architecture, growth rate, stem orientation, morphological plasticity.

Relating leaf photosynthetic rate to whole-plant growth: drought and shade effects on seedlings of four Quercus species

2008 ◽  
Vol 35 (8) ◽  
pp. 725 ◽  
Author(s):  
José L. Quero ◽  
Rafael Villar ◽  
Teodoro Marañón ◽  
Regino Zamora ◽  
Dolores Vega ◽  
...  
Keyword(s):  
Growth Rate ◽  
Photosynthetic Rate ◽  
Seed Mass ◽  
Response Curves ◽  
Drought Treatment ◽  
Evergreen Species ◽  
Leaf Habit ◽  
Wide Range ◽  
Quercus Species ◽  
Absolute Growth

Understanding the impacts of combined resource supplies on seedlings is critical to enable prediction of establishment growth, and forest dynamics. We investigated the effects of irradiance and water treatments on absolute growth, and relative growth rate (RGR) and its components, for seedlings of four Quercus species differing in leaf habit and with a wide variation in seed mass. Plants were grown for 6.5 months at three levels of irradiance (100, 27, and 3% daylight), and treated during the last 2.5 months with two watering treatments (frequent watering v. suspended watering). Both shade and drought reduced seedling growth rates, with a significant interaction: under full irradiance the drought treatment had a stronger impact on RGR and final biomass than under deep shade. For three species, seed mass was positively related to absolute growth, with stronger correlations at lower irradiance. The evergreen species grew faster than the deciduous species, though leaf habit accounted for a minor part of the interspecific variation in absolute growth. Seedling biomass was determined positively either by RGR or seed mass; RGR was positively linked with net assimilation rate (NAR) and leaf mass fraction (LMF), and seed mass was negatively linked with RGR and LMF, but positively linked with NAR. Seedling RGR was not correlated with light-saturated net photosynthetic rate, but was strongly correlated with the net carbon balance estimated, from photosynthetic light-response curves, considering daily variation in irradiance. These findings suggest an approach to applying short-term physiological measurements to predict the RGR and absolute growth rate of seedlings in a wide range of combinations of irradiance and water supplies.

Phenology explains different storage remobilization in two congeneric temperate tree species with contrasting leaf habit

2021 ◽  
Author(s):  
Sidonie Löiez ◽  
Frida I Piper
Keyword(s):  
Shoot Growth ◽  
Shoot Elongation ◽  
Nutrient Concentrations ◽  
Soluble Carbohydrates ◽  
High Temporal Resolution ◽  
Nutrient Storage ◽  
Deciduous Species ◽  
Evergreen Species ◽  
Spring Phenology ◽  
Leaf Habit

Abstract The dependence of trees on carbon and nutrient storage is critical to predicting the forest vulnerability under climate change, but whether evergreen and deciduous species differ in their use and allocation of stored resources during spring phenology is unclear. Using a high temporal resolution, we evaluated the role of spring phenology and shoot growth as determinants of the carbon and nutrient storage dynamics in contrasting leaf habits. We recorded the phenology and shoot elongation and determined the concentrations of total non-structural carbohydrates (NSC), starch, soluble carbohydrates (SC), nitrogen (N) and phosphorus (P) in buds, expanding shoots and previously formed shoots of two sympatric Nothofagus species with contrasting leaf habit. Species reached similar shoot lengths, though shoot expansion started 35 days earlier and lasted c. 40 days more in the deciduous species. Thus, while the deciduous species had a relatively constant shoot growth rate, the evergreen species experienced a conspicuous growth peak for c. 20 days. In the evergreen species, the greatest decreases in NSC concentrations of previously formed shoots and leaves coincided with the maximum shoot expansion rate and fruit filling, with minimums of 63% and 65% relative to values at bud dormancy, respectively. In contrast, minimum NSC concentrations of the previously formed shoots of the deciduous species were only 73% and occurred prior to the initiation of shoot expansion. Bud N and P concentrations increased during budbreak, while previously formed shoots generally did not decrease their nutrient concentrations. Late spring phenology and overlapping of phenophases contributed to the greater dependence on storage of proximal tissues in the studied evergreen compared to deciduous species, suggesting that phenology is a key determinant of the contrasting patterns of storage use in evergreen and deciduous species.

scholarly journals Two maize cultivars of contrasting leaf size show different leaf elongation rates with identical patterns of extension dynamics and coordination

AoB Plants ◽  
2021 ◽  
Author(s):  
Tiphaine Vidal ◽  
Hafssa Aissaoui ◽  
Sabrina Rehali ◽  
Bruno Andrieu
Keyword(s):  
Genotypic Variation ◽  
Leaf Size ◽  
High Rate ◽  
Time Interval ◽  
Extension Rate ◽  
Leaf Production ◽  
Maize Cultivars ◽  
Plant Environment ◽  
The Difference ◽  
Leaf Extension

Abstract Simulating leaf development from initiation to maturity opens new possibilities to model plant–environment interactions and the plasticity of plant architecture. This study analyses the dynamics of leaf production and extension along a maize (Zea mays) shoot to assess important modelling choices. Maize plants from two cultivars originating from the same inbred line, yet differing in the length of mature leaves were used in this study. We characterised the dynamics of the blade and sheath lengths of all phytomers by dissecting plants every 2–3 days. We analysed how differences in leaf size were built up and we examined the coordination between the emergence of organs and phases of their extension. Leaf extension rates were higher in the cultivar with longer leaves than in the cultivar with shorter leaves; no differences were found in other aspects. We found that (i) first post-embryonic leaves were initiated at a markedly higher rate than upper leaves; (ii) below ear position, sheaths were initiated at a time intermediate between tip emergence and appearance, while above the ear position, sheaths were initiated at a high rate, such that the time interval between the blade and sheath initiations decreased for these leaves; and (iii) ear position also marked a change in the correlation in size between successive phytomers with little correlation of size between upper and lower leaves. Our results identified leaf extension rate as the reason for the difference in size between the two cultivars. The two cultivars shared the same pattern for the timing of initiation events, which was more complex than previously thought. The differences described here may explain some inaccuracies reported in functional-structural plant models. We speculate that genotypic variation in behaviour for leaf and sheath initiation exists, which has been little documented in former studies.

Differential impact of liana colonization on the leaf functional traits of co-occurring deciduous and evergreen trees

2021 ◽  
Author(s):  
vivek pandi ◽  
Kanda Naveen Babu
Keyword(s):  
Functional Traits ◽  
Tree Species ◽  
Dry Matter Content ◽  
Differential Impact ◽  
Deciduous Species ◽  
Evergreen Species ◽  
Leaf Functional Traits ◽  
Leaf Trait ◽  
Host Trees ◽  
Significant Difference

Abstract The present study was carried out to analyse the leaf functional traits of co-occurring evergreen and deciduous tree species in a tropical dry scrub forest. This study also intended to check whether the species with contrasting leaf habits differ in their leaf trait plasticity, responding to the canopy-infestation by lianas. A total of 12 leaf functional traits were studied for eight tree species with contrasting leaf habits (evergreen and deciduous) and liana-colonization status (Liana+ and Liana−). In the liana-free environment (L−), evergreen trees had significantly higher specific leaf mass (LMA) and leaf dry matter content (LDMC) than the deciduous species. Whereas, the deciduous trees had higher specific leaf area (SLA) and mass-based leaf nitrogen concentration (Nmass). The leaf trait-pair relationship in the present study agreed to the well-established global trait-pair relationships (SLA Vs Nmass, Lth Vs SLA, Nmass Vs Lth, Nmass Vs LDMC, LDMC Vs SLA). There was no significant difference between L+ and L− individuals in any leaf functional traits studied in the deciduous species. However, evergreen species showed marked differences in the total chlorophyll content (Chlt), chlorophyll b (Chlb), SLA, and LMA between L+ and L− individuals of the same species. Deciduous species with the acquisitive strategy can have a competitive advantage over evergreen species in the exposed environment (L−) whereas, evergreen species with shade-tolerant properties were better acclimated to the shaded environments (L+). The result revealed the patterns of convergence and divergence in some of the leaf functional traits between evergreen and deciduous species. The results also showed the differential impact of liana colonization on the host trees with contrasting leaf habits. Therefore, liana colonization can significantly impact the C-fixation strategies of the host trees by altering their light environment. Further, the magnitude of such impact may vary among species of different leaf habits. The increased proliferation of lianas in the tropical forest canopies may pose a severe threat to the whole forest carbon assimilation rates.

Architectural differences in saplings of temperate versus tropical angiosperms; consequences of the deciduous habit?

2005 ◽  
Vol 83 (11) ◽  
pp. 1391-1401 ◽  
Author(s):  
David A. King
Keyword(s):  
High Frequency ◽  
Plant Architecture ◽  
Tropical Species ◽  
Deciduous Species ◽  
Evergreen Species ◽  
Crown Shape ◽  
Temperate Deciduous ◽  
Lower Height ◽  
Filtering Effect ◽  
Overstory Trees

The architecture of saplings of temperate deciduous species of the southeastern United States was compared with that of tropical evergreen species of Central America, Borneo, and northeastern Australia. The deciduous species were more planar in the understory than were the tropical species, because of (i) more planar leaf displays within branches, (ii) a high frequency of arching, plagiotropic main stems (associated with greater plasticity in crown symmetry in relation to light), and (iii) a lower height of first branching. The deciduous species also had more planar branches than did subtropical and temperate evergreen angiosperms. This greater planarity in temperate deciduous understories may be associated with the simultaneous positioning of most leaves during a single flush in the spring. In contrast, saplings in tropical understories typically bear multiple leaf cohorts and position new leaves at the peripheries of existing leaf displays. These results and those of other studies suggest that there are adaptive links between plant architecture and phenology. Other factors, such as latitudinal variation in sun angles, may influence crown shape in overstory trees, but did not seem to be involved here, possibly because the filtering effect of the canopy results in smaller latitudinal shifts in understory illumination angles during the growing season. Thus, by favouring the deciduous habit, the cold winters and warm, humid summers of the eastern deciduous biome of North America appear to have had a notable influence on sapling architecture.

scholarly journals Susceptibility of Viburnum Species and Cultivars to Phytophthora ramorum

2010 ◽  
Vol 28 (4) ◽  
pp. 197-202 ◽  
Author(s):  
Timothy L. Widmer
Keyword(s):  
Leaf Area ◽  
Phytophthora Ramorum ◽  
Necrotic Area ◽  
Deciduous Species ◽  
Evergreen Species ◽  
Whole Plants

Abstract Phytophthora ramorum causes ramorum blight on Viburnum species, which are commonly grown as ornamentals. This study evaluated 24 different species or cultivars for susceptibility to P. ramorum. Whole plants were inoculated with an NA1 isolate of P. ramorum and placed in dew chambers at 20C (68F). After 5 days, the percentage of necrotic leaves for each plant and the percentage of necrotic area for each leaf were calculated. The percentage of necrotic leaves per plant ranged from 96.1% (V. tinus) to 7.9% (V. opulus ‘Notcutt’) and the percentage of necrotic leaf area ranged from 73.0% (V. × carlcephalum ‘Cayuga’) to 2.4% (V. trilobum ‘Wentworth’). In addition, six species or cultivars were evaluated for their susceptibility to a EU1 isolate of P. ramorum. The isolate had a significant effect on three of the six species or cultivars tested, although one isolate did not always yield the greatest necrosis. Evergreen species and cultivars had a higher percentage of necrotic leaves and higher percentage of necrotic leaf area than semi-evergreen or deciduous species and cultivars. All Viburnum species and cultivars showed some degree of susceptibility to P ramorum.

scholarly journals Phenology and water relations of eight woody species in the Coronation Garden of Kirtipur, central Nepal

1970 ◽  
Vol 4 (6) ◽  
pp. 49-56
Author(s):  
Bharat B Shrestha ◽  
Yadav Uprety ◽  
Keshav Nepal ◽  
Sandhya Tripathi ◽  
Pramod K Jha
Keyword(s):  
Woody Species ◽  
Dry Season ◽  
Elastic Tissue ◽  
Deciduous Species ◽  
Evergreen Species ◽  
Central Nepal ◽  
Relative Water ◽  
Bauhinia Variegata ◽  
Celtis Australis ◽  
Woodfordia Fruticosa

Phenological activities of eight woody species planted in Kirtipur (central Nepal) were examined, each for one dry season between September 2001 and June 2003. From Pressure Volume (P-V) analysis, we determined relative water content at zero turgor (RWCz), osmotic potential at zero turgor (Ψsz) and full turgor (Ψsf ), and bulk modulus of elasticity (ε) once a month through the course of dry season. Both evergreen species (Cotoneaster bacillaris Wall., Quercus lanata Sm., Ligustrum confusum Decne., Woodfordia fruticosa (L.) Kurz.) and deciduous species (Celtis australis Linn., Alnus nepalensis D.Don., Bauhinia variegata Linn. and Lagerstroemia indica Linn.) put out their new leaves during the dry summer when day length and temperature were increasing. Generally, bud break coincided with concentrated leaf fall during the dry summer and the leaf fall reduced total leaf area to its lowest value. The deciduous species were leafless for one to three months, followed by a prolonged period of leaf production and shoot elongation. Evergreen and deciduous species manifested distinct adaptive strategies to water deficit. Evergreens can reduce osmotic potential (Ψs) to its low value and maintain proper water potential (Ψ) gradient from soil to plant, which facilitates absorption of water during dry season. Elastic tissue in deciduous species is coupled with leaf shedding during the dry season; both factors may help maintain proper Ψs for new growth during dry period. One evergreen species (Woodfordia fruticosa) and three deciduous species (Celtis australis, Bauhinia variegata and Lagerstroemia indica) have inherently high dehydration tolerance due to their elastic tissue. During drought there has been osmotic adjustment in Quercus lanata, and elastic adjustment in Ligustrum confusum, Celtis australis and Lagerstroemia indica. Key words: Himalayas, Pressure Volume (P-V) curve, relative water content (RWC), osmotic adjustment, elastic adjustment Himalayan Journal of Sciences Vol.4(6) 2007 p.49-56

Habitat and leaf habit as determinants of growth, nutrient absorption, and nutrient use by Alaskan taiga forest species

1983 ◽  
Vol 13 (5) ◽  
pp. 818-826 ◽  
Author(s):  
F. Stuart Chapin III ◽  
Peter R. Tryon
Keyword(s):  
Seasonal Pattern ◽  
Nitrogen Concentration ◽  
Leaf Nitrogen ◽  
Leaf Biomass ◽  
Deciduous Species ◽  
Nitrogen And Phosphorus ◽  
Leaf Respiration ◽  
Phosphate Absorption ◽  
Leaf Habit ◽  
Root Nitrogen

Four evergreen and four deciduous trees and shrubs were sampled from habitats with differing soil temperature regimes in interior Alaskan forests to examine the relative importance of habitat and leaf habit in determining seasonal patterns of shoot growth, tissue nutrient concentration, respiration rate, and phosphate absorption rate. Leaf habit was the primary determinant of shoot growth, with deciduous species producing leaf area and leaf biomass earlier in the season than evergreens. Deciduous trees produced more biomass per shoot and per unit ground area than did evergreens. The seasonal pattern of leaf nitrogen and phosphorus concentration was correlated closely with patterns of leaf growth, declining through the growing season in deciduous species first as nutrient concentrations were diluted by increasing leaf biomass and later as nutrients were retranslocated from senescing leaves. In evergreens the seasonal decline in nutrient concentration was entirely due to dilution by increasing leaf biomass, and there was no evidence of autumn retranslocation from 1st-year leaves. In contrast to seasonal pattern, the magnitude of leaf phosphorus and root nitrogen and phosphorus concentrations was correlated more closely with habitat than with leaf habit, generally being lower in cold sites. Leaf respiration was highly correlated with leaf nitrogen concentration, so that the seasonal pattern of leaf respiration was determined primarily by leaf habit, whereas the magnitude of respiration was more closely correlated with habitat. Root respiration showed no consistent correlation with either habitat or leaf habit but was lower than leaf respiration, as would be expected from low root nitrogen concentration. Phosphate absorption rate was determined more strongly by habitat than by leaf habit, being lower in cold sites characterized by slow plant growth and consequently low annual nutrient requirement. Evergreen species were more effective at absorbing phosphate at low solution concentrations than were deciduous species. Phosphate absorption was less temperature sensitive than root respiration, so that roots of all species absorbed more phosphorus per unit of carbon respired at low root temperature.

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