Post-fire Seedling Recruitment in Coastal Heathland in Relation to Regeneration Strategy and Habitat

1998 ◽  
Vol 46 (1) ◽  
pp. 75 ◽  
Author(s):  
Andrew S. Benwell
Keyword(s):  
Growth Rate ◽  
Shoot Growth ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Regeneration Strategy ◽  
Seedling Density ◽  
Fire Response ◽  
Ecotypic Variation ◽  
North Eastern ◽  
Shoot Growth Rate

Post-fire seedling recruitment was studied at six heathland sites near Evans Head, north-eastern NSW, in a range of habitats from dry to wet sand-heath. Species fire responses were recorded and seedling density, seedling survival and seedling shoot-growth rate were monitored for 3 years. There were marked differences in total seedling density and survivorship in different habitats, caused by several possible factors. Obligate seeders and facultative resprouters were found to have overlapping yet broadly distinctive patterns of seedling recruitment behaviour. Facultative resprouters as a group had significantly lower levels of seedling density and survival than obligate seeders. Six species exhibited ecotypic variation in mode of regeneration, five accompanied by marked changes in seedling density. Patterns of seedling recruitment behaviour in relation to fire response and habitat were consistent with the theory that resprouting is a stress-tolerant regeneration strategy and that for a given species regeneration strategy is linked with habitat quality.

Shoot Growth Rate of Soybean as Affected by Drought Stress 1

1987 ◽  
Vol 79 (4) ◽  
pp. 598-607 ◽  
Author(s):  
Gerrit Hoogenboom ◽  
Curt M. Peterson ◽  
M. G. Huck
Keyword(s):  
Growth Rate ◽  
Drought Stress ◽  
Shoot Growth ◽  
Shoot Growth Rate

scholarly journals Shoot Growth Rate and Density Affect Bud Necrosis of `Riesling' Grapevines

1995 ◽  
Vol 120 (6) ◽  
pp. 989-996 ◽  
Author(s):  
Tony K. Wolf ◽  
M. Kay Warren
Keyword(s):  
Growth Rate ◽  
Positive Relationship ◽  
Shoot Growth ◽  
Growth Retardant ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Dormant Bud ◽  
High Incidence ◽  
Shoot Growth Rate ◽  
Growing Conditions

Examination of `Riesling' grape (Vitis vinifera L.) in Virginia suggested that a high incidence of bud necrosis (BN) in some vineyards was associated with canopy shade and rapid shoot growth. BN appeared to originate as an abortion and dehydration of the primary, and occasionally secondary, buds of the developing dormant bud. BN frequency was lowest among the basal four nodes of a given shoot or cane, and increased in frequency through node 20. Experiments were conducted in 1991 and 1992 to evaluate the specific involvement of shoot growth rate and canopy shade on `Riesling' BN. Shoot growth rate (SGR), measured in a 17-day period around bloom, had a significant, positive relationship with BN in one of two vineyards. BN was positively associated with cane diameter and average internode length. Applying the growth retardant paclobutrazol significantly reduced SGR and BN incidence up to 80% among nodes 6 to 15 in two separate vineyards. Artificial shade (64% or 92% reduction in photosynthetic photon flux), suspended over vine canopies in the 3-week period before véraison, did not affect BN. Shoots of canopies that had been thinned before bloom to 10 shoots/m of canopy expressed slightly lower BN levels than shoots sampled from canopies that had been thinned to 20 shoots per meter. `Riesling' BN appeared more influenced by shoot vigor than shade under Virginia growing conditions. Chemical name β-[(4-chlorophenyl)methyl]-α-(1,1-dimethyl-ethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).

scholarly journals Irrigation Frequency Affects Zoysiagrass Rooting and Plant Water Status

HortScience ◽  
1996 ◽  
Vol 31 (2) ◽  
pp. 234-237 ◽  
Author(s):  
Y.L. Qian ◽  
J.D. Fry
Keyword(s):  
Growth Rate ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Shoot Growth ◽  
Leaf Water ◽  
Water Volume ◽  
Leaf Rolling ◽  
Irrigation Frequency ◽  
Dry Down ◽  
Shoot Growth Rate

`Meyer' zoysiagrass (Zoysia japonica Steud.) was established on a silt loam soil in 27-cm-diameter × 92-cm-deep containers in a greenhouse to investigate the influence of irrigation frequency on turfgrass rooting and drought tolerance. Turf was irrigated daily or at the onset of leaf rolling with a water volume equal to the cumulative evapotranspiration of well-watered turf in small weighing lysimeters. After >90 days of irrigation treatments, a dry-down was imposed during which no additional water was applied for 55 days. A recovery period followed during which time turf was watered to maintain soil matric potential at greater than –30 kPa. Compared to turf irrigated daily, that watered at the onset of leaf rolling exhibited 1) 32% to 36% lower leaf water potential and 14% to 22% lower osmotic potential before the onset of drought; 2) 13% higher leaf water potential ≈40 days into dry-down; 3) more extensive rooting at 55- and 75-cm soil depths as indicated by 11% to 19% lower volumetric soil moisture content at the end of dry-down; 4) 25% to 40% lower shoot growth rate during irrigation and 13% to 33% higher shoot growth rate during dry-down; and 5) higher quality ratings during dry-down and recovery. Thus, deep, infrequent irrigation better prepares zoysiagrass for an oncoming drought than light, frequent irrigation.

scholarly journals Nutrient and secondary metabolite concentrations in a savanna are independently affected by large herbivores and shoot growth rate

Plant Ecology ◽  
2013 ◽  
Vol 215 (1) ◽  
pp. 73-82 ◽  
Author(s):  
Peter F. Scogings ◽  
Joakim Hjältén ◽  
Christina Skarpe ◽  
Dawood Hattas ◽  
Alpheus Zobolo ◽  
...  
Keyword(s):  
Growth Rate ◽  
Secondary Metabolite ◽  
Shoot Growth ◽  
Large Herbivores ◽  
Metabolite Concentrations ◽  
Shoot Growth Rate

Frugivory and the fate of dispersed and non-dispersed seeds of six African tree species

1996 ◽  
Vol 12 (4) ◽  
pp. 491-504 ◽  
Author(s):  
Colin A. Chapman ◽  
Lauren J. Chapman
Keyword(s):  
Tree Species ◽  
National Park ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Kibale National Park ◽  
Lower Probability ◽  
Foraging Activity ◽  
Seedling Density ◽  
Trade Off ◽  
The Relationship

ABSTRACTThe relationship between seedling recruitment (under and away from parent trees) and the behaviour of seed dispersers and predators, was explored in a three-year study in Kibale National Park, Uganda. On the basis of 1261 hours of observation, the foraging activity of the diurnal frugivores which fed on fruit from six tree species was quantified. The fate of dispersed and non-dispersed seeds and seedlings was examined experimentally. The findings suggest that a trade-off exists between factors that promote seedling growth in areas with high seedling density and factors that promote dispersal by frugivores. For example, dispersal ofMimusops bagshaweiincreases both seed and seedling survival; seeds placed away from adult conspecifics had a 8% lower probability of disappearing than seeds placed under adults and seedlings away from adults had a 30% greater probability of surviving than seedlings grown under adults. In contrast, forUvariopsis congensis, dispersed seeds had a 56% greater probability of disappearing than seeds directly under a parent tree, while the survival of dispersed and non-dispersed seedlings was similar. Non-dispersed seed and seedling disappearance were correlated with the percentage of the fruit crop removed from focal trees, suggesting that the ability to survive under an adult maybe related to other aspects of the tree's life history.

Early Root and Shoot Development of Nine Plant Species

Weed Science ◽  
1973 ◽  
Vol 21 (4) ◽  
pp. 289-291 ◽  
Author(s):  
L. L. Evetts ◽  
O. C. Burnside
Keyword(s):  
Growth Rate ◽  
Root Growth ◽  
Seed Weight ◽  
Shoot Growth ◽  
Root Weight ◽  
Weed Species ◽  
Emergence Rate ◽  
Shoot Growth Rate ◽  
Broadleaf Species ◽  
Root Growth Rate

The root growth rate index of velvetleaf (Abutilon theophrastiMedic.) was significantly greater than that of five other weed species. The root growth rate index of sorghum [Sorghum bicolor(L.) Moench ‘RS-626’] was found to be significantly higher than that of soybeans [Glycine max(L.) Merr. ‘Ford’]. Shoot growth rate indexes of three perennial broadleaf species studied were significantly lower than shoot growth rate indexes of six annual species. Root weights of perennial broadleaf species were not significantly different from root weights of velvetleaf and soybeans. Soybeans were found to have a significantly higher shoot to root ratio than seven weed species but not higher than sorghum. All other species had larger leaf weights and leaf areas than the three broadleaf perennials. While there were significant differences in leaf weights among six species, there were no significant differences in leaf area. Seed weight was not significantly correlated with emergence rate index and root weight but was correlated to all other factors studied. Emergence rate index was correlated with root growth rate index but not with shoot growth rate index.

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