scholarly journals The Role of Reproductive Phenology, Seedling Emergence and Establishment of Perennial Salix gordejevii in Active Sand Dune Fields

2007 ◽  
Vol 99 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Q. Yan ◽  
Z. Liu ◽  
J. Ma ◽  
D. Jiang
Keyword(s):  
Sand Dune ◽  
Seedling Emergence ◽  
Reproductive Phenology ◽  
Salix Gordejevii

The role of waterlogging and sand accretion in modulating the morphology of the dune slack plant Scirpus americanus

1990 ◽  
Vol 68 (8) ◽  
pp. 1780-1787 ◽  
Author(s):  
Denise M. Seliskar
Keyword(s):  
Sand Dune ◽  
Plant Morphology ◽  
Common Garden ◽  
Stem Growth ◽  
Reciprocal Transplant ◽  
Dune Slack ◽  
Coastal Sand Dune ◽  
Scirpus Americanus ◽  
Common Garden Experiments

Scirpus americanus Pers., a major dune slack plant in coastal sand dune ecosystems, differs in height along transects ranging between the lowest and highest elevational areas of slacks located along the coast of Delaware, U.S.A. Using reciprocal transplant and common garden experiments, results suggest that environmental factors rather than hereditary traits are more important in accounting for the differences in plant morphology expressed in the field. Dune slack plants are exposed to stresses of waterlogging and sand accretion in their natural environment. In controlled greenhouse experiments waterlogging was shown to inhibit stem growth and cause an increase in aerenchymatous tissue, whereas periodic sand deposition caused an increase in the plant height of Scirpus.

scholarly journals Potential Role of Sequential Glufosinate and Foramsulfuron Applications for Management of Fescues (Festucaspp.) in Wild Blueberry

2017 ◽  
Vol 31 (1) ◽  
pp. 100-110 ◽  
Author(s):  
Scott N. White ◽  
Shanthanu Krishna Kumar
Keyword(s):  
Field Study ◽  
Seed Production ◽  
Potential Role ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Early Spring ◽  
Seedling Mortality ◽  
Wild Blueberry

Sheep and hair fescue are perennial, tuft forming grasses that spread by seed and form dense sods in wild blueberry fields. These sods compete with the crop for resources and hinder harvest. Field and greenhouse studies were conducted in 2015 to evaluate 1) the effect of sequential glufosinate and foramsulfuron applications on suppression of fescues in the greenhouse and field, and 2) efficacy of glufosinate and foramsulfuron on fescue seedlings when applied at 2, 4, 6, and 8 wk after seedling emergence in the greenhouse. Glufosinate applications at 750 and 1,005 g ai ha−1followed by foramsulfuron application at 35 g ai ha−1reduced fescue leaf number and biomass relative to foramsulfuron application alone in the greenhouse. In the field study, fescue flowering tuft density, tuft inflorescence height, seed production, and seed viability were reduced by foramsulfuron alone, but there was a trend towards lower seed production and tuft height when fescues were treated with glufosinate at 1,005 g ha−1followed by foramsulfuron. Foramsulfuron caused low seedling mortality at all application timings evaluated, but glufosinate caused >90% mortality in seedlings when applied at 2, 4, 6, or 8 wk after seedling emergence. Our results suggest that sequential applications of these herbicides are less effective under field conditions relative to results obtained in the greenhouse, though burndown glufosinate applications may have a role in reducing fescue seedling recruitment. Additional research should be conducted to determine the effect of early spring and autumn glufosinate applications on fescue seedling recruitment and suppression of established fescue tufts with subsequent foramsulfuron applications.

scholarly journals The Role of Population Origin and Microenvironment in Seedling Emergence and Early Survival in Mediterranean Maritime Pine (Pinus pinaster Aiton)

PLoS ONE ◽  
2014 ◽  
Vol 9 (10) ◽  
pp. e109132 ◽  
Author(s):  
Natalia Vizcaíno-Palomar ◽  
Bárbara Revuelta-Eugercios ◽  
Miguel A. Zavala ◽  
Ricardo Alía ◽  
Santiago C. González-Martínez
Keyword(s):  
Pinus Pinaster ◽  
Seedling Emergence ◽  
Maritime Pine ◽  
Population Origin ◽  
Early Survival

scholarly journals Seed Rain, Soil Seed Bank, and Seedling Emergence Indicate Limited Potential for Self-Recovery in a Highly Disturbed, Tropical, Mixed Deciduous Forest

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1391
Author(s):  
Anussara Chalermsri ◽  
La-aw Ampornpan ◽  
Witoon Purahong
Keyword(s):  
Mortality Rate ◽  
Seed Bank ◽  
Tree Species ◽  
Deciduous Forest ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Rain ◽  
Reproductive Phenology ◽  
Mixed Deciduous Forest ◽  
Standing Vegetation

Human activity negatively affects the sustainability of forest ecosystems globally. Disturbed forests may or may not recover by themselves in a certain period of time. However, it is still unclear as to what parameters can be used to reasonably predict the potential for self-recovery of human-disturbed forests. Here, we combined seed rain, soil seed bank, and seed emergence experiments to evaluate the potential for self-recovery of a highly disturbed, tropical, mixed deciduous forest in northeastern Thailand. Our results show a limited potential for self-recovery of this forest due to low seedling input and storage and an extremely high mortality rate during the drought period. There were 15 tree species of seedlings present during the regeneration period in comparison with a total number of 56 tree species in current standing vegetation. During the dry season, only four tree seedling species survived, and the highest mortality rate reached 83.87%. We also found that the correspondence between the combined number of species and composition of plant communities obtained from seed rain, soil seed bank, and seedling emergence experiments and the standing vegetation was poor. We clearly show the temporal dynamics of the seed rain and seedling communities, which are driven by different plant reproductive phenology and dispersal mechanisms, and drought coupled with mortality. We conclude that this highly disturbed forest needs a management plan and could not recover by itself in a short period of time. We recommend the use of external seed and seedling supplies and the maintenance of soil water content (i.e., shading) during periods of drought in order to help increase seedling abundances and species richness, and to reduce the mortality rate.

Adaptations of plants to burial in coastal sand dunes

1998 ◽  
Vol 76 (5) ◽  
pp. 713-738 ◽  
Author(s):  
M A Maun
Keyword(s):  
Sand Dune ◽  
Sand Dunes ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Threshold Level ◽  
Coastal Sand Dune ◽  
Bare Area ◽  
Plant Vigour ◽  
Storage Organs ◽  
Coastal Sand

One of the most obvious features on the foredunes and strands of coasts and lakes is recurrent burial in sand. Burial levels vary in different coastal sand dune systems and influence the physical and biotic microenvironment of the plant and soil. Foredune plants along coasts possess numerous adaptations to withstand burial. Studies show that below a certain threshold level of burial, the growth of all foredune plant species is stimulated probably because of multiple factors, namely improved soil resources, increase in soil volume, reactive plant growth, and enhanced mycorrhizal activity. However, as the level of burial increases, the positive response starts to decline until it becomes a negative value. For example, burial may reduce seed germination, seedling emergence, survival, and growth of seedlings and adult plants. At the community level, burial acts as a filter and selectively eliminates susceptible species, reduces the relative abundance of less tolerant species, and increases the abundance of tolerant and sand-dependent species. However, if sand deposition continues unabated, even the sand-dependent species are eliminated and a bare area is created. The emergence of a plant from a burial deposit primarily depends on the energy reserves in its storage organs and the speed, depth, and frequency of burial. Upon burial the plants shift resources from the belowground to the aboveground parts. Different plants show varied morphological responses to sand accretion. For example, the culms of grasses emerge by an increase in the number of nodes per culm and the elongation of internodes. Similarly, the emergent trunks and woody branches of tolerant trees and shrubs produce new buds and suckers at a higher level on the stem. In response to burial, the coastal sand dune species produce shootborne roots close to the new soil surface probably because of decreased oxygen levels.Key words: sand accretion, adaptations to burial, zonation of vegetation, burial of seeds, plant vigour, impact on communities, modes of emergence.

The role of cotyledons in growth and development of woody angiosperms

1974 ◽  
Vol 52 (1) ◽  
pp. 239-245 ◽  
Author(s):  
P. E. Marshall ◽  
T. T. Kozlowski
Keyword(s):  
Light Intensity ◽  
Seedling Emergence ◽  
Robinia Pseudoacacia ◽  
Dry Weight ◽  
Weight Increase ◽  
Betula Alleghaniensis ◽  
Ulmus Americana ◽  
Weight Increment ◽  
Stems And Leaves

The role of photosynthetically active cotyledons in the growth of young woody angiosperm seedlings was studied over a 35-day period under controlled environmental conditions. Two experiments were performed. In the first, cotyledons of Robinia pseudoacacia, Ulmus americana, and Ailanthus altissima were removed or covered at 7, 14, or 21 days after seedling emergence. In the second experiment, seedlings of Robinia pseudoacacia, Betula alleghaniensis, and Acer saccharum were grown over a range of light intensities. Removing or covering Robinia cotyledons of seedlings of any age resulted in lower dry weights of roots and stems than in controls. Removing or covering cotyledons of only 7-day-old Robinia seedlings retarded dry weight increase of foliage. Robinia seedling heights were unaffected by cotyledon covering or removal. Covering Ulmus americana cotyledons had no significant effect on dry weight increment of stems or foliage or on seedling height. Removal of Ulmus cotyledons from 7-day-old seedlings inhibited dry weight increase of roots, stems, and leaves and inhibited height growth. Removal of Ailanthus cotyledons inhibited dry weight increment of roots, stems, and leaves more than did covering of cotyledons. Species varied greatly in cotyledon development and response to light intensity. Cotyledon size was affected by light intensity in Robinia, but not in Betula or Acer. Responses of cotyledons to light intensity differed from those of foliage leaves. Cotyledon photosynthesis appeared to have a very important role in seedling growth in Robinia and Ailanthus and a less important role in Ulmus.

Apical Thickening of Epicarp is Responsible for Embryo Protection in Acorns of Quercus Variabilis

2010 ◽  
Vol 56 (2) ◽  
pp. 153-164 ◽  
Author(s):  
Xianfeng Yi ◽  
Yueqin Yang
Keyword(s):  
Seedling Emergence ◽  
Survival Rates ◽  
Close Correlation ◽  
Middle Part ◽  
Seedling Emergence And Survival ◽  
Defensive Mechanism ◽  
Oviposition Sites ◽  
Evolutionary Role ◽  
Weevil Infestation

The present study explored the evolutionary role of epicarp thickness ofQ. variabilisacorns as a defensive mechanism against weevil infestation. Our results, based on two years' study, suggested that length and fresh mass of insect-damaged acorns were not different from those of intact ones, but width did differ. About 2, 18, and 79% of oviposition sites are distributed at the apical end, middle part, and basal end of acorns, respectively. About 5, 49, and 55% of eggs or larvae are infested at the apical end, middle part, and basal end, respectively. Similarly, about 10, 43, and 45% of emergence holes are found at the apical end, middle part, and basal end. Epicarp thickness varied among the three parts of acorns and was significantly negatively correlated with the appearance percentage of oviposition sites, infestation sites, and emergence sites, respectively. However, secondary metabolites and nutrition reserve showed no close correlation with the appearance percentage of oviposition sites, infestation sites, and emergence sites. Acorns with emergence holes at the apical end exhibited significantly lower seedling emergence and survival rates. Therefore, variation in epicarp thickness in individual acorns may be responsible for the weevil's preference for oviposition, infestation, and emergence, and acts as an alternative and important strategy protecting acorn embryos from pre-dispersal larval damage.

Effects of burial of seeds and seedlings from different seed sizes on the emergence and growth of Strophostyles helvola

1996 ◽  
Vol 74 (8) ◽  
pp. 1322-1330 ◽  
Author(s):  
Mary Yanful ◽  
M. A. Maun
Keyword(s):  
Lake Erie ◽  
Sandy Beach ◽  
Seedling Emergence ◽  
Seed Mass ◽  
Large Mass ◽  
Burial Depth ◽  
Different Depths ◽  
Mass Burial ◽  
Provincial Park

Field and greenhouse studies were conducted to examine the role of seed mass in (i) the emergence of seedlings of Strophostyles helvola (L.) Ell. from different depths of burial in sand and (ii) the ability of seedlings originating from seeds of different seed mass (weight per seed) to re-emerge from sand deposits. Seeds were sorted into four different seed mass classes (small, < 55 mg; medium, 55–65 mg; large, 65–75 mg; and extra large, > 75 mg) and sown at different depths ranging from 2 to 24 cm in sand on a sandy beach at Port Burwell Provincial Park along Lake Erie. Seeds of large mass class (65–75 mg) sown at 18 cm depth produced the largest plants. Under greenhouse conditions, all S. helvola seedlings buried to 100 and 125% of their height survived the treatment, but survival declined to 66% when they were buried to 150% of their height. Stimulation in growth was observed only when the seedlings were buried to 50 and 75% of their height. Seedlings originating from large seed masses took fewer days to re-emerge from different burial depths than seedlings from small seeds. However, the interaction term between seed mass and burial depth for the re-emergence of seedlings was not significant. Keywords: seed mass, burial of seeds, burial of seedlings, Strophostyles helvola, seedling emergence.

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