Vegetative reproduction as a stabilizing feature of the population dynamics of Yucca glauca

Oecologia ◽  
1986 ◽  
Vol 69 (3) ◽  
pp. 380-387 ◽  
Author(s):  
R. W. Kingsolver
Keyword(s):  
Population Dynamics ◽  
Vegetative Reproduction

The role of seed reproduction in the dynamics of established populations of Hieracium floribundum and a comparison with that of vegetative reproduction

1975 ◽  
Vol 53 (24) ◽  
pp. 3022-3031 ◽  
Author(s):  
A. G. Thomas ◽  
H. M. Dale
Keyword(s):  
Population Dynamics ◽  
Seedling Establishment ◽  
Vegetative Reproduction ◽  
Soil Surface ◽  
Growing Season ◽  
Population Based ◽  
Early Spring ◽  
Viable Seed ◽  
Density Patch

In the crowded parts of patches of Hieracium floribundum Wimm. and Grab., which were established for at least a decade in an ungrazed pasture, 7–10% of the population (3700 individuals/m2) flowered. Of the plants that flowered, 94% were alive a year later, but only 5% of these flowered. Abortion of flower heads was common; one half of all those which were initiated in early June had aborted by flowering time in early July. Freshly dispersed seed had a viability of 57%, which was reduced to 17% a year later, after its storage close to the soil surface. Less than 6% of the viable seed was innately dormant. Dry, laboratory-stored seed retained its viability for the year but was slower to germinate than soil-stored seed. In field conditions, germination was temperature inhibited during most of the growing season. Maximum daytime microsite temperatures of less than 32 °C, which is necessary for germination, were found to occur only in early spring and late fall. Successful seedling establishment accounts for 1% of the individuals in a crowded population. Based on the maximum sexual reproduction from plants in crowded populations, a seed has a probability of 1 in 20 000 of becoming an established seedling. A model of population dynamics in a high-density patch traces the fate of seedling establishment, surviving adults, and stolon-derived rosettes for a single year.

scholarly journals The dynamics of Listera ovata populations on mineral islands in the Biebrza National Park

2014 ◽  
Vol 71 (3) ◽  
pp. 243-251 ◽  
Author(s):  
Emilia Brzosko
Keyword(s):  
Population Dynamics ◽  
National Park ◽  
Vegetative Reproduction ◽  
Leaf Size ◽  
The Other ◽  
Costs Of Reproduction ◽  
Isolated Populations ◽  
Other Hand ◽  
Population Sizes

Observations of two isolated populations of <em>Listera ovata</em> (Oparzelisko and Zabudnik) were conducted for 7 years in the Biebrza National Park. The studied populations differed in size, proportion of flowering individuals and effectiveness of reproduction. High number of juvenile individuals in OPA population was noted under conditions more favourable for germination (gaps in vegetation and higher moisture of soil). On the other hand, vegetative reproduction is important in the dynamics of ZAB population. The natural fruiting rate of <em>L. ovata</em> is relatively high (up to 90%) and does not seem to be pollinator limited. Some costs of reproduction especially in terms of leaf size were observed. The dormancy is important in the population dynamics. In some years even one third of the population may be dormant. <em>L. ovata</em> produces enough seeds and offspring to maintain or even increase population sizes. These facts, connected with the longevity of individuals,indicate that populations of <em>L. ovata</em> in the Biebrza National Park are not threatened with extinction in the nearest future.

Persistence of giants: population dynamics of the limpet Scutellastra laticostata on rocky shores in Western Australia

2020 ◽  
Vol 646 ◽  
pp. 79-92
Author(s):  
RE Scheibling ◽  
R Black
Keyword(s):  
Population Dynamics ◽  
Western Australia ◽  
Size Structure ◽  
Survival Rates ◽  
Maximum Size ◽  
High Rate ◽  
Adult Survival ◽  
Rocky Shores ◽  
Adult Size ◽  
Decadal Time Scale

Population dynamics and life history traits of the ‘giant’ limpet Scutellastra laticostata on intertidal limestone platforms at Rottnest Island, Western Australia, were recorded by interannual (January/February) monitoring of limpet density and size structure, and relocation of marked individuals, at 3 locations over periods of 13-16 yr between 1993 and 2020. Limpet densities ranged from 4 to 9 ind. m-2 on wave-swept seaward margins of platforms at 2 locations and on a rocky notch at the landward margin of the platform at a third. Juvenile recruits (25-55 mm shell length) were present each year, usually at low densities (<1 m-2), but localized pulses of recruitment occurred in some years. Annual survival rates of marked limpets varied among sites and cohorts, ranging from 0.42 yr-1 at the notch to 0.79 and 0.87 yr-1 on the platforms. A mass mortality of limpets on the platforms occurred in 2003, likely mediated by thermal stress during daytime low tides, coincident with high air temperatures and calm seas. Juveniles grew rapidly to adult size within 2 yr. Asymptotic size (L∞, von Bertalanffy growth model) ranged from 89 to 97 mm, and maximum size from 100 to 113 mm, on platforms. Growth rate and maximum size were lower on the notch. Our empirical observations and simulation models suggest that these populations are relatively stable on a decadal time scale. The frequency and magnitude of recruitment pulses and high rate of adult survival provide considerable inertia, enabling persistence of these populations in the face of sporadic climatic extremes.

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