scholarly journals Constant gardeners: Endozoochory promotes repeated seedling recruitment in clonal plants

Ecosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
Author(s):  
Alberto García‐Rodríguez ◽  
Nuria Selva
1996 ◽  
Vol 74 (9) ◽  
pp. 1369-1374 ◽  
Author(s):  
Ove Eriksson ◽  
Heléne Fröborg

Two experiments were performed to analyse seedling recruitment in Vaccinium myrtillus, Vaccinium vitis-idaea, Vaccinium uliginosum, and Vaccinium oxycoccos. The purpose was to examine the probability of recruitment at "windows of opportunity," i.e., spatially or temporally unpredictable conditions in which seedling recruitment is possible within stands of established conspecific adults. Seedling emergence in all four investigated species depended on a combination of seed and microsite (disturbance) availability. In V. myrtillus, which was studied in more detail than the other species, emergence and survivorship were similar on non wood substrate and on decaying wood, but seedling growth was favored on the latter substrate. An experiment along an environmental gradient with all four species showed that recruitment required approximately similar conditions even though the adults of the species exhibited a clear zonation along the gradient. For all species except V. oxycoccos, recruitment was confined to only a part of the adults' range. Vaccinium species are generally good seed dispersers and have a high fecundity but usually lack developed seed banks. This behavior is interpreted as a response to occurring windows of opportunity for recruitment, i.e., small disturbances with high moisture and organic soil content. Recruitment at windows of opportunity is suggested as one distinct pattern of recruitment among clonal plants, along with previously suggested repeated and initial seedling recruitment patterns, and some implications of this distinction are briefly discussed. Keywords: clonal plants, genets, life histories, population dynamics, seedling establishment, Vaccinium.


2014 ◽  
Vol 67 (4) ◽  
pp. 87-98 ◽  
Author(s):  
Kinga Kostrakiewicz-Gierałt

<p>In majority of plant communities with a closed canopy, the disturbances created by abiotic factors and biotic agents contribute to origin of an area free of existing vegetation and considered as safe sites for seedling recruitment. Although the gaps are characterized by several features, the size is proposed to be the most important characteristic. The investigations of recruitment of clonal taxa in different–sized gaps were conducted in the years 2011–2012 in <em>Molinietum caeruleae</em> meadows representing various successional stages and dominated by different species. Patch ES, representing early-successional stage, was dominated by small meadow species, Patch MS, representing mid-successional stage, was prevailed by tall-growing macroforbs, while Patch LS representing late-successional stage was overgrown by macroforbs and willows. In the successive sites the mean height of plant canopy, as well as the period of spring inundation increased gradually.</p><p>The total number of species and seedlings decreased from the Patch ES, through the Patch MS, to the Patch LS. Almost all plants presenting positive correlation between seedling number and gap area created hypogeogenous stems with substantial lateral growth and considerable number of short-lived daughter ramets allowing the fast colonization of neighbourhood. The majority of species showing negative relationship formed epigeogenous stems with slight lateral growth, as well as low number of long-lived ramets contributing to slow colonization of area.</p><p>In light of performed studies, it might be concluded, that making disturbance in continuous plant canopy and litter might be very effective way of conservation of <em>Molinietum caeruleae</em> meadows. The creation of different-sized gaps seems to be especially valuable due to the maintenance of heterogeneity of clonal species, which is particularly important in advanced successional stages.</p>


2017 ◽  
Vol 70 ◽  
pp. 160-164 ◽  
Author(s):  
G.W. Bourdôt ◽  
S. Jackman ◽  
D.J. Saville

Flupropanate (sodium 2,2,3,3 tetrafluoropropanate), a slow-acting lipid bio- synthesis-inhibiting herbicide, was recently registered in New Zealand as Taskforce (745 g/L flupropanate as the sodium salt) for the selective and long-term control of Nassella trichotoma (nassella tussock) in pastures. In five dose-response experiments in permanent hill pastures in Canterbury, conducted between 2012 and 2016, we measured the efficacy of the herbicide against established plants of N. trichotoma and its residual activity against recruiting seedlings. Mortality, as an average across the five sites, was 93% 1.5 years after applying 1.49 kg flupropanate/ha (the label-recommended rate), and 100% at 2.98 kg/ha. This indicates that an application rate higher than the label rate will be necessary for complete control of a N. trichotoma infestation. The presence of 1,000 and 6,250 visible seedlings of N. trichotoma/ha in the autumn 3.2 and 2.1 years after applying 1.49 kg flupropanate/ha (at a Greta Valley and Scargill site respectively) indicates that the herbicide’s soil residues had decayed within 12 months to a concentration lower than necessary to kill the germinating seedlings of N. trichotoma.


2021 ◽  
Vol 14 (1) ◽  
pp. 3-8
Author(s):  
Philip W. Tipping ◽  
Melissa R. Martin ◽  
Jeremiah R. Foley ◽  
Ryan M. Pierce ◽  
Lyn A. Gettys

AbstractThe potential of Melaleuca quinquenervia (Cav.) S.T. Blake to reinvade cleared areas was evaluated over a 13-yr period that included two wildfires and the introduction of biological control agents. The first wildfire occurred in 1998 and was followed by a mean of 591.5 recruited seedlings m−2. Recruits from that fire were cleared 7 yr later in July 2005 for a second experiment to evaluate seedling recruitment into cleared areas. Seed rain, seedling recruitment and mortality, and sapling growth rates were measured in four plots located around individual large reproductive trees. A second natural wildfire in 2007 burned through those plots, leading to increases in seed rain followed by a pulse in recruitment of 21.04 seedlings m−2, 96.5% fewer than after the 1998 fire. Recruits in half of the plots around each tree were then treated with regular applications of an insecticide to restrict herbivory by biological control agents, while herbivory was not restricted in the other half. There was no difference in seedling mortality between treatments 1,083 d post-fire (2007) with 96.6% seedling mortality in the unrestricted herbivory treatment and 89.4% mortality in the restricted herbivory treatment. Recruits subjected to the restricted herbivory treatment grew taller than those in the unrestricted herbivory treatment, 101.3 cm versus 37.4 cm. Many of the recruits were attacked by the biological control agents, which slowed their growth. Although solitary M. quinquenervia trees retain some capacity to reinvade areas under specific circumstances, there was a downward trend in their overall invasiveness at this site, with progressively smaller recruitment cohorts due to biological control agents. Land managers should prioritize removing large reproductive trees over treating recently recruited populations, which can be left for many years for the biological control agents to suppress before any additional treatment would be needed.


2021 ◽  
Vol 492 ◽  
pp. 119219
Author(s):  
Yuan-Yuan Li ◽  
Yu-Pei Liu ◽  
Jun Gong ◽  
Shen-Hou Fan ◽  
Guo-Chun Shen ◽  
...  

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 185
Author(s):  
Adrian S. Monthony ◽  
Serena R. Page ◽  
Mohsen Hesami ◽  
Andrew Maxwell P. Jones

The recent legalization of Cannabis sativa L. in many regions has revealed a need for effective propagation and biotechnologies for the species. Micropropagation affords researchers and producers methods to rapidly propagate insect-/disease-/virus-free clonal plants and store germplasm and forms the basis for other biotechnologies. Despite this need, research in the area is limited due to the long history of prohibitions and restrictions. Existing literature has multiple limitations: many publications use hemp as a proxy for drug-type Cannabis when it is well established that there is significant genotype specificity; studies using drug-type cultivars are predominantly optimized using a single cultivar; most protocols have not been replicated by independent groups, and some attempts demonstrate a lack of reproducibility across genotypes. Due to culture decline and other problems, the multiplication phase of micropropagation (Stage 2) has not been fully developed in many reports. This review will provide a brief background on the history and botany of Cannabis as well as a comprehensive and critical summary of Cannabis tissue culture. Special attention will be paid to current challenges faced by researchers, the limitations of existing Cannabis micropropagation studies, and recent developments and future directions of Cannabis tissue culture technologies.


Alpine Botany ◽  
2021 ◽  
Author(s):  
Vera Margreiter ◽  
Janette Walde ◽  
Brigitta Erschbamer

AbstractSeed germination and seedling recruitment are key processes in the life cycle of plants. They enable populations to grow, migrate, or persist. Both processes are under environmental control and influenced by site conditions and plant–plant interactions. Here, we present the results of a seed-sowing experiment performed along an elevation gradient (2000–2900 m a.s.l.) in the European eastern Alps. We monitored the germination of seeds and seedling recruitment for 2 years. Three effects were investigated: effects of sites and home sites (seed origin), effects of gaps, and plant–plant interactions. Seeds of eight species originating from two home sites were transplanted to four sites (home site and ± in elevation). Seed sowing was performed in experimentally created gaps. These gap types (‘gap + roots’, ‘neighbor + roots’, and ‘no-comp’) provided different plant–plant interactions and competition intensities. We observed decreasing germination with increasing elevation, independent of the species home sites. Competition-released gaps favored recruitment, pointing out the important role of belowground competition and soil components in recruitment. In gaps with one neighboring species, neutral plant–plant interactions occurred (with one exception). However, considering the relative vegetation cover of each experimental site, high vegetation cover resulted in positive effects on recruitment at higher sites and neutral effects at lower sites. All tested species showed intraspecific variability when responding to the experimental conditions. We discuss our findings considering novel site and climatic conditions.


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