Variations with altitude in reproductive traits and resource allocation of three Tibetan species of Ranunculaceae

2006 ◽  
Vol 54 (7) ◽  
pp. 691 ◽  
Author(s):  
Zhao Zhigang ◽  
Du Guozhen ◽  
Zhou Xianhui ◽  
Wang Mantang ◽  
Ren Qingji
Keyword(s):  
Resource Allocation ◽  
High Altitude ◽  
Seed Size ◽  
Nutrient Availability ◽  
Reproductive Traits ◽  
Plant Size ◽  
The Self ◽  
Allocation Pattern ◽  
Carpel Number ◽  
Female Investment

We investigated the adaptive response of alpine plants to elevational gradients by examining reproductive traits and resource allocation of three species of Ranunculaceae with contrasting mating systems in alpine and subalpine populations on the eastern QinhaiTibetan Plateu. The results showed that (i) at alpine sites, the self-incompatible Trollius ranunculoides Hemsley tended to become limited by pollination rather than by nutrient availability, although the self-compatible Anemone rivularis var. flore-minore Maxim. Fl. Tang. and A. obtusiloba D.Don. seemed not to be limited by pollen availability; (ii) influences on the reproduction of these three species induced by high altitude were seen in different reproductive characters, and the influences were, to some extent, dependent on the plant. Female investment in the self-compatible A. rivularis and A. obtusiloba was influenced by altitude and plant size; with a much lower carpel number per flower and larger mean seed size in A. rivularis, and a much higher carpel number per flower and smaller mean seed size in A. obtusiloba, at a higher altitude. Floral investment in the self-incompatible T. ranunculoides was also influenced by altitude and plant size, with a smaller single-flower size and larger seed at the higher altitude. Results also showed that (iii) reproductive allocation to flowering and fruiting did not always decrease with altitude as predicted. This may be due to higher nutrient availability in soil at alpine sites. (iv) Although self-pollination may be an assurance mechanism alleviating pollination limitation, changes in allocation pattern, (i.e. the male-biased floral sexual allocation in A. rivularis and the higher allocation to attractive structure in A. obtusiloba) seem to promote pollinator visits at the high altitude.

scholarly journals Effects of fragmentation on plant adaptation to urban environments

2017 ◽  
Vol 372 (1712) ◽  
pp. 20160038 ◽  
Author(s):  
Jonathan Dubois ◽  
Pierre-Olivier Cheptou
Keyword(s):  
Reproductive Traits ◽  
Urban Ecosystems ◽  
Terrestrial Ecosystems ◽  
Plant Size ◽  
Urban Environments ◽  
Trait Variation ◽  
Fragmented Habitats ◽  
Dispersal Traits ◽  
Neutral Markers

Urban ecosystems are relatively recent and heavily human-altered terrestrial ecosystems with a surprisingly high diversity of animals, plants and other organisms. Urban habitats are also strongly fragmented and subject to higher temperatures, providing a compelling model for studying adaptation to global change. Crepis sancta (Asteraceae), an annual Mediterranean wasteland weed, occupies fragmented urban environments as well as certain unfragmented landscapes in southern France. We tested for shifts in dispersal, reproductive traits and size across a rural–urban gradient to learn whether and how selection may be driving changes in life history in urban and fragmented habitats. We specifically compared the structure of quantitative genetic variation and of neutral markers (microsatellites) between urban and rural and between fragmented and unfragmented habitats. We showed that fragmentation provides a better descriptor of trait variation than urbanization per se for dispersal traits. Fragmentation also affected reproductive traits and plant size though one rural population did conform to this scheme. Our study shows the role of fragmentation for dispersal traits shift in urban environments and a more complex pattern for other traits. We discuss the role of pollinator scarcity and an inhospitable matrix as drivers of adaptation. This article is part of the themed issue ‘Human influences on evolution, and the ecological and societal consequences’.

scholarly journals Sexual Dimorphism in the Chemical Composition of Male and Female in the Dioecious Tree, Juniperus communis L., Growing under Different Nutritional Conditions

2020 ◽  
Vol 21 (21) ◽  
pp. 8094
Author(s):  
Mariola Rabska ◽  
Emilia Pers-Kamczyc ◽  
Roma Żytkowiak ◽  
Dawid Adamczyk ◽  
Grzegorz Iszkuło
Keyword(s):  
Resource Allocation ◽  
Nutrient Availability ◽  
C:N Ratio ◽  
Annual Life Cycle ◽  
Soil Fertilization ◽  
Intensive Phase ◽  
Juniperus Communis ◽  
Availability Analysis ◽  
Nutritional Conditions ◽  
Cone Development

We hypothesized that female and male individuals of the dioecious tree species, Juniperus communis, exhibit different strategies of resource allocation when growing under stress conditions. To test this hypothesis, we performed a two-year pot experiment on plants exposed to different levels of nutrient availability. Analysis of the plants revealed a higher concentration of carbohydrates, carbon, and phenolic compounds in needles of female plants, indicating that females allocate more resources to storage and defense than males. This difference was independent of nutrient availability. Differences in carbohydrates levels between the sexes were most often significant in June, during the most intensive phase of vegetative growth in both sexes, but could also be attributed to female resources investment in cone development. A higher level of nitrogen and other macroelements was observed in males than in females, which may have been connected to the accumulation of resources (nitrogen) for pollen grain production in males or greater allocation of these elements to seeds and cones in females. The interaction between sex and soil fertilization for the C:N ratio may also indicate sex-specific patterns of resource allocation and utilization, which is impacted by their availability during specific periods of J. communis annual life cycle.

Simultaneous effects of reintroduction strategy and seed size on the initial development of two tropical tree species in an abandoned eucalyptus plantation

2020 ◽  
Vol 68 (6) ◽  
pp. 439
Author(s):  
Julie Christine Scaloppi ◽  
Andréa Lúcia Teixeira de Souza
Keyword(s):  
Seed Size ◽  
Tree Species ◽  
Survival Rates ◽  
Plant Size ◽  
Plant Performance ◽  
Initial Development ◽  
Eucalyptus Plantation ◽  
Hymenaea Courbaril ◽  
Stem Size ◽  
Direct Sowing

Seedling planting is the most common strategy used to reintroduce tropical native tree species; however, direct sowing has simplicity and operational ease advantages. Functional traits such as seed size and growth rates have been shown to be relevant for better plant performance. We evaluated the effects of intraspecific variation in seed size and the reintroduction strategy simultaneously on the development of Hymenaea courbaril (L.) and Enterolobium timbouva (Mart.) introduced in an abandoned eucalyptus plantation over 462 days. Plants from small, medium and large seeds were reintroduced by planting seedlings and direct seeding. Both species achieved high rates of emergence and survival was high in the two reintroduction strategies. Seed size was not related to emergence and mean time to emergence for either species. The survival of both species was higher than 74% in the field, and seed size had little effect on survival rates. In general, H. courbaril plants introduced by direct sowing had higher growth, and seed size correlated positively with stem size. In contrast, the growth of E. timbouva plants introduced by seedling planting was higher than in plants introduced by direct sowing regardless of seed size. The light requirements of this species seem higher than for H. courbaril. Our results suggest the feasibility of reintroducing species by direct sowing in eucalyptus understory, but since plant growth varies between species, there may be a balance between the advantage of the initial plant size provided by planting seedlings and the advantage of a better root development provided by direct sowing.

Responses of the lichen Xanthoria parietina (L.) Th. Fr. to varying thallus nitrogen concentrations

2005 ◽  
Vol 37 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Gisela GAIO-OLIVEIRA ◽  
Lena DAHLMAN ◽  
Kristin PALMQVIST ◽  
Cristina MÁGUAS
Keyword(s):  
Resource Allocation ◽  
Dry Weight ◽  
Specific Weight ◽  
Allocation Pattern ◽  
Total N ◽  
Green Algal ◽  
N Concentration ◽  
N Assimilation ◽  
Xanthoria Parietina ◽  
Nitrogen Concentrations

The responses of the nitrophytic green algal lichen Xanthoria parietina to varying nitrogen (N) concentrations were investigated by collecting 67 X. parietina thalli from clay roof tiles from 13 sites in Portugal with different exposures to N. Concentrations of total N, chlorophyll a (a marker for the photobiont), ergosterol (a marker for the mycobiont), and thallus specific weight (TSW; thallus dry weight in relation to surface area) were quantified for each thallus to see how biont investments were related to thallus N concentrations. Thallus N ranged from 11 to 43 mg g−1 DW revealing a wider N concentration range in this lichen compared to other green algal lichen species. Both chlorophyll a and ergosterol concentrations increased with increasing thallus N, with a steeper increase of the photobiont marker. TSW was similar in all thalli without any significant effect of thallus N concentration, suggesting that thallus developmental patterns are similar in low and high thallus N concentrations. The relatively higher resource allocation to the photobiont in relation to the mycobiont with increasing thallus N concentrations is an indication of the capacity of X. parietina to meet the C demands associated with N assimilation. This result is also in agreement with the inter-specific resource allocation pattern for green algal lichens across the same N concentration range.

Differences in disturbance type and nutrient availability favour different functional traits across three co-occurring montane wetland systems in eastern Australia

2016 ◽  
Vol 64 (6) ◽  
pp. 526 ◽  
Author(s):  
John T. Hunter
Keyword(s):  
Life History ◽  
Seed Size ◽  
Functional Traits ◽  
Nutrient Availability ◽  
Vascular Plant ◽  
Fruit Size ◽  
Functional Trait ◽  
Freshwater Wetland ◽  
Disturbance Regime ◽  
Eastern Australia

Three co-occurring temperate montane non-riparian freshwater wetland communities of the New England Batholith of eastern Australia were chosen to test differences in resource allocation to select functional traits. Each of the wetlands was tested against inferred gradients of nutrient availability, fire and disturbance frequency. Collated functional trait data on 563 native vascular plant taxa known to occur in bogs, fens and lagoons were used against a centrally weighted means redundancy analysis. Traits included life form, plant height, leaf area, fruit size, seed size, mono- or polycarpy, storage organs, fruit type, vegetative spread and geographic range size. Where disturbances were moderate to low in frequency and habitats persistent, tolerance and in-situ permanence traits were favoured. With high nutrient availability and a low disturbance regime polycarpic species with large leaves that allow for larger fruit development were more common. Under low nutrient availability and a moderate disturbance regime, persistence was shifted to a longer lived polycarpic life history that includes woody taxa with increased seed size and a greater diversity of fruit types. In frequently inundated habitats, with shifting windows of available habitats, avoidance was the best strategy. Here persistence shifts to long-lived soil stored diaspores and a monocarpic life history with rapid vegetative growth to capture above ground spatial resource within temporary habitats.

Effect of seed weight on height growth of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) seedlings in a nursery

1985 ◽  
Vol 15 (6) ◽  
pp. 1109-1115 ◽  
Author(s):  
Frank C. Sorensen ◽  
Robert K. Campbell
Keyword(s):  
Seed Size ◽  
Seed Weight ◽  
Germination Rate ◽  
Plant Size ◽  
Height Growth ◽  
Douglas Fir ◽  
Genetic Makeup ◽  
Practical Implications ◽  
Filled Seeds

Different mean seed weights were produced within each of 10 young Douglas-fir trees by leaving some developing cones unbagged and enclosing others in Kraft paper bags for two different durations. On the average, 10 days in the bag increased filled-seed weight by about 1%. Unbagged cones and cones from the 117-day bagging duration were wind pollinated. Seeds from these cones were, therefore, of comparable genetic makeup and were used in further nursery growth tests. To eliminate the effect of germination rate or time, samples of filled seeds from each treatment on each parent tree were sown as germinant seedlings on one date. Cotyledon number was counted and 1st-year epicotyl lengths and 2nd-year total heights were measured on all seedlings. Seedling volumes were estimated by assuming diameters were proportional to heights. On the average, bagging cones for 117 days increased seed weight by 10.7%, 1st-year epicotyl length by 9.1%, and 2-year total height by 4.0%. All differences were statistically significant. Results were compared with other reports of the relations between seed weight and growth and reasons for inconsistencies were discussed. Size differences were projected to later ages with a growth model and practical implications of long-term seed effects on plant size, of increasing seed size through cultural techniques, and of grading seed lots by size were considered.

Sex-allocation plasticity in hermaphrodites of sexually dimorphic Fragaria virginiana (Rosaceae)

Botany ◽  
2010 ◽  
Vol 88 (3) ◽  
pp. 231-240 ◽  
Author(s):  
Eric J. Bishop ◽  
Rachel B. Spigler ◽  
Tia-Lynn Ashman
Keyword(s):  
Sex Allocation ◽  
Seed Set ◽  
Reproductive Traits ◽  
Plant Size ◽  
Sexually Dimorphic ◽  
Flower Number ◽  
Fragaria Virginiana ◽  
Ovule Number ◽  
Indirect Consequence ◽  
Resource Gradient

Sex-allocation plasticity is thought to play an important role in the evolution of separate sexes in plants. Accordingly, much attention has been paid to environmentally induced variation in fruit and seed production in sexually dimorphic species, but we know little about whether this variation arises as a direct response to environmental variation or is instead an indirect consequence of changes in plant size. In this study, we characterize sex-allocation plasticity across a resource gradient for several reproductive traits in hermaphrodites of gyno(sub)dioecious Fragaria virginiana Duch. We find significant plasticity, on average, for flower number, proportion fruit set, ovule number, proportion seed set, and runner number in response to resource variation. Plasticity of most traits examined tended to be at least partially independent of variation in plant size, suggesting that it is not simply an indirect consequence of plant allometry. Moreover, we find genetic variation for plasticity of key reproductive traits. Comparisons of relative plasticities among traits reveal that F. virginiana hermaphrodites are more likely to adjust female investment via changes in fruit and seed set than ovule number, and most likely to adjust male investment via flower number rather than anther number or pollen per anther, although there is genotypic variation for plasticity in pollen per anther. Evidence of within-population variation can logically be extended to suggest that variation in hermaphrodite sex-expression seen among natural populations of F. virginiana may be due, at least in part, to sex-allocation plasticity.

Resource Allocation and Seed Size Selection in Perennial Plants under Pollen Limitation

2017 ◽  
Vol 190 (3) ◽  
pp. 430-441 ◽  
Author(s):  
Qiaoqiao Huang ◽  
Martin Burd ◽  
Zhiwei Fan
Keyword(s):  
Resource Allocation ◽  
Seed Size ◽  
Pollen Limitation ◽  
Perennial Plants ◽  
Size Selection

Seed size effects and competitive ability in Thlaspi arvense L. (Brassicaceae)

Botany ◽  
2008 ◽  
Vol 86 (3) ◽  
pp. 259-267 ◽  
Author(s):  
David J. Susko ◽  
Paul B. Cavers
Keyword(s):  
Soil Fertility ◽  
Seed Size ◽  
Intraspecific Competition ◽  
Competitive Ability ◽  
Plant Biomass ◽  
Seed Mass ◽  
Soil Nutrient ◽  
Plant Size ◽  
Thlaspi Arvense ◽  
High Nutrient

We examined the effects of seed size on plant size and competitive ability of Thlaspi arvense L. grown with and without intraspecific competition under contrasting soil fertility regimes. For solitary plants from each of four half-sibship families, seed mass was positively correlated with percentage germination, cotyledon size, and plant biomass after 15 d of growth, but differences in plant biomass largely disappeared at later dates. Small and large seeds of a single maternal family were sown in uniform or mixed arrangements of seed size classes (small:large; 100%:0%; 75%:25%; 50%:50%; 25%:75%; 0%:100%) at each of two densities (8 or 16 seeds·pot–1) under low and high soil nutrient regimes. In mixtures at low density under low soil fertility, plants from small seeds had significantly lower relative yields than expected. At high density, under either low or high nutrient conditions, plants from large seeds had significantly greater relative yields than expected. Hence, under most conditions, size inequalities between plants from seeds of different size resulted in a relative competitive advantage for plants from large seeds. The duration and extent of differences in plant size arising from T. arvense seeds of contrasting size depends on maternal genetic differences, intensity of intraspecific competition, and soil fertility.

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