scholarly journals Factors Affecting Germination and Establishment Success of an Endemic Cactus of the Chihuahuan Desert

2021 ◽  
Author(s):  
Eder Ortiz Martínez ◽  
Jordan Golubov ◽  
Maria C. Mandujano ◽  
Gabriel Arroyo Cosultchi
Keyword(s):  
Seed Germination ◽  
Seed Bank ◽  
Seedling Recruitment ◽  
Chihuahuan Desert ◽  
Seedling Survival ◽  
Life Cycles ◽  
Exclusion Experiment ◽  
Factors Affecting ◽  
Nurse Plants ◽  
Predator Exclusion

Abstract Seeds and seedlings are the most critical stages of cacti life cycles. From the thousands of seeds produced in a reproductive season, only a small fraction successfully germinate, the rest are lost to predation, go dormant and remain viable in the seed bank or lose viability. These early stages often depend on facilitation by nurse plants for germination and seedling recruitment. We aim to prescribe actions for the conservation of Cephalocereus polylophus by improving recruitment in the population. The viability of seeds with different storage times was evaluated as an indicator of their potential to form a short-term seed bank. Through the analysis of seed germination and seedling survival under the canopy of two nurse plant species and open areas, we assessed the importance of facilitation for recruitment. A predator exclusion experiment evaluated the intensity of herbivory on seeds and seedlings of different ages. Seeds had germination rates above 90\% under laboratory conditions, even after two years of storage. Seed germination was only registered under one of the two nurses and after two years, up to 4 % of the seedlings planted under both nurse plants survived and protection against herbivores increased seedlings survival. Considering that facilitation and age are crucial for seedling survival of C. polylophus, future conservation programs should include the protection of plant communities and the introduction of seedlings instead of seeds.

scholarly journals Factors affecting germination and establishment success of an endemic cactus of the Chihuahuan Desert

2020 ◽  
Author(s):  
Eder Ortiz-Martínez ◽  
Jordan Golubov ◽  
María C. Mandujano ◽  
Gabriel Arroyo-Cosultchi
Keyword(s):  
Seed Germination ◽  
Seed Bank ◽  
Developmental Stages ◽  
Seedling Recruitment ◽  
Chihuahuan Desert ◽  
Exclusion Experiment ◽  
Factors Affecting ◽  
Nurse Plants ◽  
Predator Exclusion ◽  
Storage Times

AbstractSeed and seedling are the most critical stages of cacti life cycle. From the thousands of seeds produced in a reproductive season, only a small fraction gets to germinate, the rest gets lost due to predation or gets potentially buried in the seed bank. These early stages depend on facilitation by nurse plants for germination and seedling recruitment. In this paper, we aim to describe some aspects of the recruitment of Cephalocereus polylophus. We tested the viability of seeds with different storage times as an indicator of their potential to form a short-term seed bank. Through the analysis of seed germination and seedlings survival under the canopy of two nurse plant species and open areas, we aimed to assess the importance of facilitation for recruitment. A predator exclusion experiment was used to evaluate the intensity of herbivory on seeds and seedlings of different developmental stages. Seeds had germination rates above 90%, even after two years of storage. Seed germination was only registered under one of the two nurses. After two years, up to 19% of the seedlings planted under both nurse plants survived. Protection against herbivores increased survival chances from 30 to 52 % for all age-group seedlings. Considering that facilitation is a crucial interaction for C. polylophus, future conservation programs should include the protection of plant communities.

Ecological Studies of the Endangered Rutidosis Leptorrhynchoides .I. Seed Production, Soil Seed Bank Dynamics, Population Density and Their Effects on Recruitment

1995 ◽  
Vol 43 (1) ◽  
pp. 1 ◽  
Author(s):  
JW Morgan
Keyword(s):  
Population Density ◽  
Seed Production ◽  
Seed Bank ◽  
Seedling Recruitment ◽  
Fire Regime ◽  
Seedling Survival ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Bank Dynamics ◽  
The Impact

The seasonal dynamics of the soil seed bank of Rutidosis leptorrhynchoides F.Muell. were studied by the seedling emergence technique. Seed longevity in soil was quantified in a seed burial and retrieval experiment. The importance of annual seed production to recruitment was also determined over a 2-year-period, as was the impact of conspecific neighbour density on seed production per inflorescence. Rutidosis leptorrhynchoides appears to form a transient seed bank with little capacity to store germinable seeds in the soil from year to year. No seedlings were observed in soil sampled after the autumn germination pulse and no viable seed was present in the soil within 16 weeks of burial. The rate of seed loss was similar when seed was buried under all intact grassland canopy and in 0.25m2 canopy gaps. It appears that most seeds simply rot in moist soil or are predated by soil invertebrates. Seedling recruitment was at least 15 times greater in plots where natural seed input occurred than where it was curtailed. Less than 10% of seed shed resulted in seedling emergence. It is suggested that recruitment in the large populations studied was limited by germination rather than by microsite availability for seedling survival. Population density had an impact on seed production with sparsely distributed individuals producing fewer seeds per inflorescence than plants from denser colonies, although there was much variation. Sparse plants produced significantly fewer seeds per inflorescence than hand crosspollinated heads suggesting reduced pollinator efficacy in these colonies relative to larger colonies where there was no such difference. Rutidosis leptorrhynchoides is dependent on the maintenance of the standing population for recruitment. Any factors that influence flowering and subsequent seed production will limit the ability of the species to regenerate. Over sufficient time, this could lead to the localised extinction of the species and may explain why R. leptorrhynchoides has failed to reappear in remnants where a suitable fire regime has been re-implemented after a period of management unfavourable to the survival, flowering and regeneration of this species.

Seed Germination and Seedling Recruitment Behavior of Winged Sea Lavender (Limonium lobatum) in Southern Australia

Weed Science ◽  
2018 ◽  
Vol 66 (4) ◽  
pp. 485-493 ◽  
Author(s):  
Samuel G. L. Kleemann ◽  
Gurjeet Gill
Keyword(s):  
Seed Germination ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Base Temperature ◽  
Weed Species ◽  
Factors Affecting ◽  
Weed Seeds ◽  
Sea Lavender ◽  
C 50

AbstractWinged sea lavender [Limonium lobatum(L.f. Chaz)] is emerging as a significant weed of field crops in southern Australia. Several environmental factors affecting germination and seedling recruitment were examined to provide a better understanding of the behavior of its seedbank. At maturity, weed seeds were dormant for a period of around 2 mo, but dormancy was easily broken with scarification or by pretreatment with 564 mM NaOCL for 30 min, which confirms the role of the seed coat in regulating seed germination. Exposure to light significantly increased germination. Seeds were able to germinate over a broad range of temperatures (5 to 30 C), with maximum germination (~92%) at temperatures between 10 and 30 C. At 20 to 25 C, 50% germination was reached within 1.3 to 2 d, and the predicted base temperature for germination of the two populations ranged from 1.4 to 3.9 C. The NaCl concentration required to inhibit germination by 50% was 230 mM, with some seeds capable of germination at salinity levels as high as 480 mM. These results indicated greater tolerance to salinity inL. lobatumthan many other Australian agricultural weed species previously investigated. Seedling emergence was the highest (51% to 57%) for seeds present on the soil surface and was significantly reduced by burial at 1 cm (≤11%) and 2 cm (≤2%), with no emergence at 5 cm. Under field conditions, seedling recruitment varied considerably among the three experimental sites. The level of seedling recruitment was negatively associated with rainfall received at the site, organic carbon (OC) level, and microbial biomass of the soil. Rapid decay of weed seeds in high-OC soils appears to be an important determinant of seedling recruitment in this species and could explain greater occurrence ofL. lobatumon soils with low OC and low microbial activity in low-rainfall areas of southern Australia. Furthermore, many such soils in southern Australia are affected by salinity, which would enableL. lobatumto be more competitive with crops and other weeds present at a site.

scholarly journals What are the demographic consequences of a seed bank stage for columnar cacti?

2020 ◽  
Author(s):  
Gabriel Arroyo-Cosultchi ◽  
María C. Mandujano ◽  
Roberto Salguero-Gómez ◽  
Armando J. Martínez ◽  
Jordan Golubov
Keyword(s):  
Population Dynamics ◽  
Plant Species ◽  
Seed Bank ◽  
Seedling Recruitment ◽  
Early Stage ◽  
Life Cycles ◽  
Vital Rates ◽  
Matrix Population Models ◽  
Columnar Cacti ◽  
Seed Bank Dynamics

AbstractThe dynamics of plants populations are often limited by the early stages in their life cycles. The question if the columnar cacti have or not a seed bank in predictable environments. Yet, information regarding seed bank dynamics and how these may influence the full life cycle of plant species is remarkably scarce or ignore. This lack of knowledge is mostly due to the challenges in quantifying seed vital rates. Studies of arid land plant species have historically been focused on the drivers of sporadic recruitment. However, little attention has been given to the demographic consequences of early developmental stages, including seed banks. Here, we evaluate the effects of seed bank survival and seedling recruitment vital rates on the population dynamics and viability of 12 columnar cacti species, recent evidence suggests that cacti seeds may remain viable for the short-term. We assess how changes in the vital rates of these processes, and the inclusion of a seed bank affect population growth rate (λ). We found that a seed bank in the examined matrix population models significantly increased λ as well as the vital rate elasticities of λ to growth and fecundity, whereas that of overall survival decreased. Our numerical simulations showed that seed survival had a larger effect on λ than seedling recruitment and establishment. We suggest that seed bank may explain the structure and population dynamics. Thus, we argue reconsider that this early stage in demographic models will generate more informed decisions on the conservation and management of columnar cacti.

Seed-bank dynamics of Eleocharis: can spatial and temporal variability explain habitat segregation?

2004 ◽  
Vol 52 (1) ◽  
pp. 119 ◽  
Author(s):  
Dorothy M. Bell ◽  
Peter J. Clarke
Keyword(s):  
Life History ◽  
Seed Bank ◽  
Temporal Variability ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Soil Seed Bank ◽  
Decay Rates ◽  
Habitat Partitioning ◽  
Spatial And Temporal Variability ◽  
Seed Bank Dynamics

Four Eleocharis species exhibit habitat partitioning in both extant vegetation and in the soil seed bank of upland temporary wetlands on the Northern Tablelands of New South Wales. Explanations for this partitioning were sought in seed-bank dynamics at three shore levels in two wetlands. Habitat partitioning (zonation) was explained in part by seedling recruitment but not by either persistence of seeds in the soil or by dormancy patterns. All four species recruited at wetland edges but only the deepwater species, Eleocharis sphacelata, recruited in deeper water. Viability of buried seeds was consistently high and species had very low decay rates and half-lives greater than 50 years. Two types of dormancy patterns with burial were shown. Most seeds of Eleocharis sphacelata and E. pusilla were non-dormant after a 3-month burial, whereas for E. acuta and E. dietrichiana seed germination percentages gradually increased over a number of years. These two dormancy patterns may contribute to coexistence, since coexistence is enhanced by a long-lived resistant phase in the life history of species and by temporal variability in germination. There were also spatial inconsistencies in patterns of dormant fractions. Burial in the deeper zones of the marsh-like Billybung Lagoon had an inhibitory effect both on germinability and on germination rates of E. acuta and E. dietrichiana seeds. All but E. acuta showed some degree of seasonal dormancy, but this pattern was also not consistent in space. Explanations for zonation should concentrate on other life-history phases, such as dispersal and seedling survival.

Determining the factors affecting seed germination in Livistona australis (Arecaceae) for the recovery of fragmented populations

2012 ◽  
Vol 60 (7) ◽  
pp. 575 ◽  
Author(s):  
Nicholas Carlile ◽  
David Priddel ◽  
Tony D. Auld ◽  
David A. Morrison
Keyword(s):  
Seed Germination ◽  
Seedling Recruitment ◽  
Seed Viability ◽  
Factors Affecting ◽  
Light Levels ◽  
In Situ Experiments ◽  
Germination Success ◽  
Buried Seed ◽  
Potential Success

Understanding seed germination and seedling recruitment is important for managing long-lived plant species, particularly palms that are transplanted from the wild and where regeneration is suppressed by seed predators and exotic herbivores. Seed viability, the timing of germination, and the factors influencing germination were investigated for the cabbage tree palm, Livistona australis (R.Br.) Mart. Greenhouse studies were combined with in situ experiments conducted on the Australian mainland and on a nearby mammal-free island. Under greenhouse conditions, >90% of seed germinated within 4 months. In the field, burial rather than surface sowing of seed increased germination success. Seed without mesocarp and in sunlight had increased germination when compared with fruits in shade on the island, whereas neither presence/absence of mesocarp or light levels had any effect on the mainland. Germination success was substantially lower on the mainland, primarily because of high seed predation from the native bush rat, Rattus fuscipes. When caged to exclude vertebrates, 44% of seed were damaged over time by pathogens and invertebrates, with losses greater in sunlight than in shade. Results from the present study indicate that freshly buried seed with the mesocarp removed would have the greatest potential success in promoting the restoration of L. australis at degraded sites.

scholarly journals Factors affecting germination and establishment success of an endemic cactus of the Chihuahuan Desert

Plant Ecology ◽  
2021 ◽  
Author(s):  
Eder Ortiz-Martínez ◽  
Jordan Golubov ◽  
María C. Mandujano ◽  
Gabriel Arroyo-Cosultchi
Keyword(s):  
Chihuahuan Desert ◽  
Establishment Success ◽  
Factors Affecting

Variation in vegetation cover and seedling performance of tree species in a forest-savanna ecotone

2019 ◽  
Vol 35 (2) ◽  
pp. 74-82 ◽  
Author(s):  
Hamza Issifu ◽  
George K. D. Ametsitsi ◽  
Lana J. de Vries ◽  
Gloria Djaney Djagbletey ◽  
Stephen Adu-Bredu ◽  
...  
Keyword(s):  
Vegetation Cover ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Tree Cover ◽  
First Year ◽  
Transplant Experiment ◽  
Tree Seedling ◽  
Savanna Woodland ◽  
Specific Effects ◽  
Species Specific

AbstractDifferential tree seedling recruitment across forest-savanna ecotones is poorly understood, but hypothesized to be influenced by vegetation cover and associated factors. In a 3-y-long field transplant experiment in the forest-savanna ecotone of Ghana, we assessed performance and root allocation of 864 seedlings for two forest (Khaya ivorensis and Terminalia superba) and two savanna (Khaya senegalensis and Terminalia macroptera) species in savanna woodland, closed-woodland and forest. Herbaceous vegetation biomass was significantly higher in savanna woodland (1.0 ± 0.4 kg m−2 vs 0.2 ± 0.1 kg m−2 in forest) and hence expected fire intensities, while some soil properties were improved in forest. Regardless, seedling survival declined significantly in the first-year dry-season for all species with huge declines for the forest species (50% vs 6% for Khaya and 16% vs 2% for Terminalia) by year 2. After 3 y, only savanna species survived in savanna woodland. However, best performance for savanna Khaya was in forest, but in savanna woodland for savanna Terminalia which also had the highest biomass fraction (0.8 ± 0.1 g g−1 vs 0.6 ± 0.1 g g−1 and 0.4 ± 0.1 g g−1) and starch concentration (27% ± 10% vs 15% ± 7% and 10% ± 4%) in roots relative to savanna and forest Khaya respectively. Our results demonstrate that tree cover variation has species-specific effects on tree seedling recruitment which is related to root storage functions.

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