Vegetative spread is key to applied nucleation success in non‐native dominated grasslands

2020 ◽  
Author(s):  
Karen D. Holl ◽  
Josephine C. Lesage ◽  
Tianjiao Adams ◽  
Jack Rusk ◽  
Richard D. Schreiber ◽  
...  
Keyword(s):  
Vegetative Spread

scholarly journals Impact of weather on dynamics of plant functional groups in an abandoned limestone grassland

2011 ◽  
Vol 80 (4) ◽  
pp. 259-268 ◽  
Author(s):  
Zbigniew Dzwonko ◽  
Stefania Loster
Keyword(s):  
Functional Groups ◽  
Early Summer ◽  
Climatic Conditions ◽  
Plant Functional Groups ◽  
Permanent Plots ◽  
Plant Groups ◽  
Successional Species ◽  
Abandoned Grassland ◽  
Vegetative Spread ◽  
Natural Grassland

We examined to what extend the rate and direction of changes in unmanaged grassland depend on fluctuations in climatic conditions. Vegetation data from permanent plots in a semi-natural grassland in southern Poland collected over 12 years were used. Relations between weather variables, time, and the cover of 41 more frequent species and 14 plant functional groups were analysed. The greatest effect on the dynamics of species and functional groups had precipitation in spring and/or early summer, particularly in the current year. The majority of plant groups were significantly affected also by the temperature in spring and early summer in one of the three previous years. During 12 years, the cover of annuals and biennials, short plants, and plants with small leaves decreased, while the cover of taller plants, plants with larger leaves, and with vegetative spread increased. The analyses suggest that these successional changes were not directly associated with climatic conditions but were affected by them indirectly through interspecific competition. The fluctuations in climatic conditions, chiefly precipitation, had a significant effect on both the composition and the rate of changes in abandoned grassland. The increase in the cover of tall perennial species with broad leaves hindered succession towards woodland despite of the presence of woods in the closed vicinity. It can be expected that during drier periods colonisation of grassland by later successional species could be easier.

Isozyme diversity in large and isolated populations of Luma apiculata (Myrtaceae) in north-western Patagonia, Argentina

2005 ◽  
Vol 53 (8) ◽  
pp. 781 ◽  
Author(s):  
Mayra S. Caldiz ◽  
Andrea C. Premoli
Keyword(s):  
Genetic Variation ◽  
Isolated Populations ◽  
Isozyme Electrophoresis ◽  
Wahlund Effect ◽  
Rivers And Lakes ◽  
Large Populations ◽  
Vegetative Spread ◽  
Number Of Individuals ◽  
North Western ◽  
Isozyme Diversity

We evaluated the amount and distribution of genetic variation in large and small isolated populations of Luma apiculata (DC.) Burret (Myrtaceae) in north-western Patagonia. The hypothesis tested was that isolated smaller populations were more affected by drift and isolation than large stands. Higher genetic diversity was predicted in the latter. Fresh leaf material for isozyme electrophoresis was collected from 30 individuals in four isolated and two large and continuous stands (Quetrihue Peninsula and Punta Norte, Isla Victoria). Five subpopulations were sampled in both large stands, and in addition, three regeneration gaps in Punta Norte. Eleven loci were resolved; 91% were polymorphic in at least one population. Isolated and large populations had similar levels of genetic variation. Reduced observed heterozygosity and elevated inbreeding were measured in subpopulations and regeneration gaps within dense stands. Although small populations consist of a reduced number of individuals they are mostly coastal populations nearby rivers and lakes that may maintain considerable gene flow with other faraway populations counteracting the effects of drift. In addition to potential selfing, increased inbreeding within large populations and regeneration gaps may be due to an intra-population Wahlund effect from local seedling establishment and vegetative spread, resulting in clustered cohorts of similar genotypes.

scholarly journals Genetic Structure of Heterobasidion annosum in White Fir Mortality Centers in California

1999 ◽  
Vol 89 (7) ◽  
pp. 546-554 ◽  
Author(s):  
Matteo Garbelotto ◽  
Fields W. Cobb ◽  
T. D. Bruns ◽  
William J. Otrosina ◽  
Tina Popenuck ◽  
...  
Keyword(s):  
Heterobasidion Annosum ◽  
Mixed Conifer ◽  
Tree Diameter ◽  
Single Tree ◽  
White Fir ◽  
Standing Trees ◽  
Local Genotypes ◽  
Study Sites ◽  
Individual Trees ◽  
Vegetative Spread

The structure of Heterobasidion annosum populations was studied in 15 mixed-conifer sites in central and northern California. Study sites displayed mortality of white fir trees in enlarging discrete patches (mortality centers). At each site, fungal genotypes were defined by somatic compatibility tests. In two sites, further genetic and molecular analyses were performed on field genotypes and on homokaryons obtained by dedikaryotization of field heterokaryons. Isolates were found to be colonizing mostly the roots and the bole sapwood of white fir trees, and no significant infections of other tree species were observed. Each mortality center was characterized by the presence of several fungal genotypes, all belonging to the S intersterility group. Both homokaryotic and heterokaryotic strains were present in all sites. Multiple genotypes were retrieved in individual trees or stumps. Out of 228 fungal genotypes, 86% were found only within a single tree or stump, while 14% had spread to adjacent trees. The two largest genotypes had diameters of 9 and 10 m, and had colonized five and nine trees, stumps, or both, respectively. The maximum distance between two adjacent trees colonized by the same genotype was 6 m, and a highly significant correlation was found between tree diameter and distance of fungal “vegetative” spread. The largest clones were found in areas characterized by high tree and stump densities, and secondary spread of the fungus was more significant in denser stands. In most cases, original infection courts of existing genotypes could be traced to standing trees and not to stumps. The genetic analysis performed in two mortality centers revealed that most local genotypes had different mating alleles, and thus originated from unrelated basidiospores. In a few cases, the same mating allele was shared by two heterokaryons (n+n genome) or by a homokaryon (n genome) and a heterokaryon. Molecular analysis showed that nuclei bearing the same mating allele were identical, providing evidence that the two nuclei forming heterokaryons can act independently in the field and can be shared among isolates, presumably via di-mon mating or by separate matings of different portions of widespread homokaryons.

Ecology of a forest weed of Newfoundland: vegetative regeneration strategy of Kalmia angustifolia

1993 ◽  
Vol 71 (1) ◽  
pp. 161-166 ◽  
Author(s):  
A. U. Mallik
Keyword(s):  
Growing Season ◽  
Regeneration Strategy ◽  
Stem Base ◽  
Kalmia Angustifolia ◽  
Vegetative Regeneration ◽  
Large Numbers ◽  
Below Ground ◽  
Vegetative Spread ◽  
First Time ◽  
Ground Structures

The vegetative regeneration characteristics of Kalmia angustifolia were studied by examining the near ground and below-ground structures of the plant. Three methods of vegetative regeneration were observed in Kalmia: layering, stem-base sprouting, and rhizomatous growth, which make the plant more resilient than other ericaceous plants of similar stature following disturbance. Layering occurred only in tall old Kalmia of undisturbed habitats. Stem-base sprouting and rhizomatous growth were found to be the most common and most effective modes of vegetative regeneration. These methods were common in both disturbed and undisturbed habitats. Three types of rhizome systems, namely primary, secondary, and tertiary rhizomes, were identified and described for the first time in Kalmia. Secondary rhizomes were found to be the most effective organ for vegetative spread of the plant. Some secondary rhizomes may grow more than 1 m in one growing season. A 5-year-old Kalmia may produce, on average, 36 secondary rhizomes with a total length of 750 cm. Secondary rhizomes of Kalmia first grow horizontally, then come aboveground growing vertically and exhibiting apical dominance. Large numbers of dormant vegetative buds (three at each node) and adventitious roots are produced at the rhizome nodes. Transverse sections of current-year rhizome showed many trichomes. The cells of the pith are thick-walled and are characterized by large lysigenous cavities. The anatomy of axillary buds and leaf primordia of the aboveground stems of Kalmia were similar to buds and bud scales of the rhizome. Key words: Kalmia, disturbance, fire, regeneration strategy, rhizome, trichomes.

Belowground traits of herbaceous species in young coniferous forests of the Olympic Peninsula, Washington

1999 ◽  
Vol 77 (7) ◽  
pp. 936-943 ◽  
Author(s):  
Ann L Lezberg ◽  
Joseph A Antos ◽  
Charles B Halpern
Keyword(s):  
Belowground Biomass ◽  
Lateral Spread ◽  
Forest Understory ◽  
Coniferous Forests ◽  
Total Biomass ◽  
Herbaceous Species ◽  
Olympic Peninsula ◽  
Evergreen Species ◽  
Closed Canopy ◽  
Vegetative Spread

Variation in belowground traits of herbaceous species may influence their ability to persist and spread during and after the closed-canopy period of forest development. In 40- to 60-year-old closed-canopy, coniferous forests of the Olympic Peninsula, Washington, we excavated root and rhizome systems of 11 herbaceous species to compare morphology, vegetative spread, and proportion of biomass in belowground structures. All species were perennial and most were rhizomatous; four species were nonclonal. Of the seven clonal species, only two (Maianthemum dilatatum and Oxalis oregana) spread extensively (mean lateral spread >50 cm) by belowground perennating structures. The proportion of total biomass in belowground structures varied considerably among species (21-85%) and was higher for deciduous than for evergreen species. High variability in belowground traits suggests that multiple strategies may contribute to survival during closed-canopy conditions. For species with a high proportion of belowground biomass, we suggest that the ability to store resources or to acquire new resources through lateral spread may contribute to persistence in dense coniferous forests.Key words: biomass allocation, canopy closure, forest understory plants, rhizomes, root systems, succession.

scholarly journals Potential for high country pasture improvement from planting of rhizome fragments of spreading legumes

1992 ◽  
pp. 127-129
Author(s):  
D. Scott ◽  
C.R. Mason
Keyword(s):  
Vegetative Propagation ◽  
Seed Set ◽  
Fragment Size ◽  
Subsequent Growth ◽  
Coronilla Varia ◽  
Vegetative Spread

Three legumes, zigzag clover (TrijXium medium), Caucasian clover (T. ambiguum) and crown vetch (Coronilla varia) are notable for their extensive vegetative spread by underground rhizomes but slow initial establishment and low seed set. The possibility of vegetative propagation was considered. A 9-year trial showed the success of transplanting rhizome fragments of different sizes under different fertiliser regimes into hieracium-dominated fescue tussock grasslands. Initial survival and establishment was influenced by fragment size and fertiliser. Subsequent growth was similar for the three species and mainly influenced by fertiliser. Keywords high country, legumes, pasture improvement, rhizome fragments

Growth and vegetative spread of Schizachyrium scoparium var. littoralis (Poaceae) in sand dune microhabitats along a successional gradient

1999 ◽  
Vol 77 (2) ◽  
pp. 219-229
Author(s):  
Teresa Valverde ◽  
Irene Pisanty
Keyword(s):  
Phenotypic Plasticity ◽  
Clonal Growth ◽  
Sand Dune ◽  
Growth Form ◽  
The Other ◽  
Schizachyrium Scoparium ◽  
Growth Forms ◽  
La Mancha ◽  
Reciprocal Transplants ◽  
Vegetative Spread

The architecture resulting from the iteration of modules during plant growth affects resource capture. Phalanx and guerrilla growth forms have been described as ends of a continuum regarding the spacing of modules in plants. In this study we investigated the growth form of the perennial, tussock-forming grass Schizachyrium scoparium Michx. var. littoralis (Nash) Hitchc. in three dune microhabitats at El Morro de la Mancha, southeastern Mexico: a mobile, a semi-mobile, and a stabilized site. We followed the growth of 15 genets at each site for two consecutive years and found that daughter-tussock formation was more frequent in the stabilized than in the semi-mobile or the mobile sites. Individual tussocks had a higher number of tillers in the mobile site than in the other two. Tiller production occurred within parental tussocks in the mobile site and in the form of daughter tussocks in the stabilized site. Reciprocal transplants suggested that phenotypic plasticity was responsible for the differences observed. Fertilization enhanced tiller production within parental tussocks but did not affect daughter tussock formation. Clearing experiments resulted in enhanced tiller production within tussocks. In these experiments, daughter-tussock production did not occur directionally towards nutrient-rich microsites. It appears that S. scoparium tillers are spaced at longer distances when resources are scarce and intraclonal competition is severe.Key words: clonal growth, growth form, nutrient availability, phalanx-guerrilla continuum.

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