scholarly journals Effects of Scarification, Phytohormones, Soil Type, and Warming on the Germination and/or Seedling Performance of Three Tamaulipan Thornscrub Forest Species

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1489
Author(s):  
Paula Luera ◽  
Kimberly Wahl-Villarreal ◽  
Bradley O. Christoffersen ◽  
Abeny Treviño ◽  
Pushpa Soti ◽  
...  

The Tamaulipan thornforests of south Texas and northeast Mexico are an ecologically and economically important conservation hotspot. Thornforest restoration is limited by native tree and shrub seedling availability for planting. Seedling shortages arise from low seed availability and knowledge gaps regarding best practices for germinating and growing the 70+ thornforest species desired for restoration plantings. To fill key knowledge gaps, we investigated three ecologically important thornforest species with low or highly variable germination or seedling survival rates: Ebenopsis ebano, Cordia boissieri, and Zanthoxylum fagara. For each, we quantified the effects of different dosages of chemical seed treatments used to promote germination (sulfuric acid, SA; gibberellic acid, GA; indole-3-butyric acid, IBA) on germination likelihood and timing. We also quantified the effects that these chemical seed treatments, soil media mixture type, and soil warming had on seedling survival, growth, and root morphology. Ebenopsis germination peaked (>90%) with 40–60 min SA treatment. Cordia germination peaked (40%) with 100 mg/L GA treatment. Zanthoxylum germination was negligible across all treatments. Seed molding was rare but stirring during SA treatment reduced Ebenopsis molding by 4%. Ebenopsis seedling survival, height, leaf count, and root morphology were minimally affected by seed treatments, generally reduced by warming, and influenced by soil mix, which also mediated responses to warming. These results suggest improvements to existing practices that could increase Ebenopsis germination by 10–20% and potentially double Cordia germination.

2021 ◽  
Vol 8 ◽  
pp. 1-11
Author(s):  
Luiz Leonardo Ferreira ◽  
Ivan Ricardo Carvalho ◽  
Francine Lautenchleger ◽  
Tamires Silva Martins ◽  
Paulo Ricardo Viana Carvalho ◽  
...  

The objective of this work was to evaluate the performance of soybean seedlings in different seed treatments. The experiment was conducted in the municipality of Mineiros, GO. The soil was classified as Quartzarenic Entisol. The experimental design was randomized blocks in factorial 5x4, corresponding to seed treatments (Water, Cruiser, Fipronil Alta, Fortenza and Standak Top) in four soybean cultivars (Bonus, Ultra, Extra and BKS7830), in four replications. Before planting, pre-planting desiccation was performed. The fertilization used was 450 kg ha-1 of fertilizer 05-25-15 applied in the furrow and in a single dose next to the sowing. During the conduction of the experiment the control of pests, diseases and weeds were carried out as necessary, respecting the best practices and integrated management. The data obtained were subjected to the assumptions of the statistical model, verifying the normality and homogeneity of the residual variances, as well as the additivity of the model. Uni and multivariate tools were applied. The analysis were performed at the interface Rbio and R. The interaction of soybean cultivars and types of seed treatment showed variations in all analysis evaluated in soybean seedlings. The best performances were verified among the cultivars BKS7830 that expressed the largest shoot fresh matter when submitted to Cruiser seed treatment, while the highest root length was expressed in the cultivar Ultra in the Fortenza seed treatment.


2008 ◽  
Vol 32 (1) ◽  
pp. 44-45
Author(s):  
Brian P. Oswald ◽  
Kenneth W. Farrish ◽  
Micah-John Beierle

Abstract The practice of combining intensive timber and forage production on the same site, a silvopasture system, offers landowners the potential for diversification of income. The establishment of such a system in a pasture setting offers unique challenges compared with traditional timber or forage systems. In 2003, a silvopasture demonstration was established south of Carthage, Texas, in a pasture dominated by bahiagrass (Paspalum notatum). Four replications of treatments composed of open pasture, longleaf (Pinus palustris) and loblolly (Pinus taeda) pine planted at a traditional spacing, and longleaf and loblolly pine planted at a silvopasture spacing were established. Due to high mortality rates, replanting of trees occurred in 2004 and 2005. Third-year seedling survival was highest for loblolly pine in both planting systems, and forage production levels did not significantly differ among treatments. Wild hog damage contributed to the low longleaf pine seedling survival rates.


Author(s):  
Clemens Raabe ◽  
Michael M. Bornstein ◽  
Julien Ducommun ◽  
Pedram Sendi ◽  
Thomas von Arx ◽  
...  

Abstract Objectives To assess survival rates and frequency of complications for immature and mature autotransplanted teeth after at least 1 year in function. Materials and methods All consecutive patients who had undergone tooth autotransplantation between 2000 and 2018 were invited to a clinical and radiographic follow-up examination. First, survival rates were calculated on the basis of a phone inquiry. A clinical follow-up examination allowed for the calculation of the success rate, i.e., absence of any potentially adverse clinical and radiographic findings of the autotransplanted teeth. Moreover, the effect of demographic, dental, and surgical variables on survival/success was analyzed statistically. Results Thirty-eight teeth in 35 patients were transplanted during the study period. Three teeth in 3 patients were excluded due to missing records. All other patients were successfully contacted and interviewed by phone. Out of these 35 transplants, 32 were still in function, and 3 had been extracted, yielding a 91.4% survival probability after a median follow-up of 3.4 years. Of the 32 teeth qualifying for the success analysis, 20 (62.5%) showed absence of potentially adverse findings, while 3 (9.4%) required root canal treatment (RCT). Out of the 9 mature, root-end resected transplants, 4 exhibited ongoing pulp canal obliteration, all with a single root canal. Postoperative and potentially adverse findings or failures were found more frequently in the group of mature transplants (55.6%) than immature transplants (30.4%) and for molars (72.7%) than premolars (17.6%) or canines (25%). None of the potential predictors had a statistically significant effect on survival or success. Conclusion Autotransplanted teeth yielded a satisfying midterm survival rate regardless of their stage of development. An additional, extraoral root-end resection of mature transplants may lead to rates of revascularization and postoperative pulp canal obliteration higher than the data reported on unmodified mature transplants. Clinical relevance Extraoral root-end resection of mature teeth shows promising outcomes for transplants especially with a single root canal and uncomplicated root morphology.


1995 ◽  
Vol 25 (10) ◽  
pp. 1639-1651 ◽  
Author(s):  
Sybille Haeussler ◽  
John C. Tappeiner II ◽  
Brian J. Greber

Effects of forest disturbance and soil moisture levels on establishment of red alder (Alnusrubra Bong.) seedlings were studied at four sites representing a climatic moisture gradient within the central Coast Range of Oregon. On average, there was no difference in seedling emergence between recent clearcuts and second-growth forests, but emergence was much higher on mineral soil than on organic seedbeds. Emergence, on both types of seedbed, was positively correlated with spring soil moisture conditions (R2 = 0.60). Seedling survival, on the other hand, differed greatly between clearcut and forest. In clearcuts, heat and drought injuries were the primary causes of seedling mortality. In the forest, seedlings had poor vigour and quickly succumbed to pathogens, herbivores, and rain splash. First-year survival rates were strongly correlated with minimum summer soil moisture levels (R2 = 0.71). Height growth of seedlings on clearcuts (2–5 cm after 1 year; 8–23 cm after 2 years) was much slower than rates typically described for red alder. Best establishment occurred on skid trails and landings, suggesting that young seedlings may suffer less from heat or moisture stress on these heavily disturbed microenvironments.


2021 ◽  
Author(s):  
Irene Ruano ◽  
Valentín Pando ◽  
Felipe Bravo

Abstract Background: There is growing interest in mixed-species forests but a lack of studies that analyse them for regeneration phases or any stage other than mature stands. Information is scarce about relatively unproductive species such as Pinus pinaster and Pinus halepensis in Mediterranean ecosystems. The objective of this study was to investigate inter- and intra-specific interactions of both species in different tree densities during the first years of establishment. Five Nelder wheel plots were planted to test densities ranging from 1000 to 80000 seedlings/ha and simulate establishment sub-processes at high densities. Pinus pinaster and Pinus halepensis were mixed along the spokes, to obtain three mixture levels in which 100%, 80% or 60% of the seedlings were of the same species. Cox proportional-hazards models and binomial logistic regressions were fitted to analyse seedling survival. Early growth (basal diameter and height at one and four years after plantation) was analysed by fitting linear mixed-effects models. Results: Pinus halepensis showed higher survival rates and basal diameter increments but more time is needed to know how Pinus pinaster responds to density and mixture. Conclusions: Both competitive and facilitating seedling interactions were observed at higher densities, which facilitate seedling survival but decrease early growth. Pinus halepensis showed higher survival rates and basal diameter increments but more time is necessary to determine Pinus pinaster response to density and mixture.


HortScience ◽  
2012 ◽  
Vol 47 (8) ◽  
pp. 1029-1033 ◽  
Author(s):  
Mark H. Brand ◽  
Jessica D. Lubell ◽  
Jonathan M. Lehrer

Winged euonymus [Euonymus alatus (Thunb.)] is an important landscape shrub that has demonstrated its potential to be invasive in numerous states across the central and northern United States. Nine cultivars were evaluated for their potential to produce fruits and seeds in a randomized, replicated field planting. Seeds from all cultivars were evaluated for germination rate and initial survival in a deciduous woodland. Seeds collected from ‘Compactus’ were also sown in five natural environments (full sun meadow, edge of woods, moist woods, dry woods, pine woods) to determine which habitat types support its germination and establishment. Seed production for cultivars varied from 981 to 6090 seeds per plant. The dry deciduous woods and pine woods were the only environments that supported significant germination rates that could be as high as 37.8%. Seedling survival was at least 77% in the deciduous dry woods and at least 55% in the pine woods. In the first replication, establishment rates for cultivars in the dry deciduous woods ranged from a low of 6.5% for ‘Odom’ Little Moses™ to a high of 42.5% for ‘Monstrosus’. In the second replication, all cultivars achieved over 30% establishment and most exceeded 40% establishment. An estimate of the annual seedling contribution per plant per cultivar was calculated by combining seed production data with establishment data for each cultivar. This estimate was predicted to range from 588 to 3763 and therefore none of the nine cultivars evaluated should be considered non-invasive based on our findings. Our findings show that germination and seedling survival rates are high for E. alatus and because the species is long-lived, cultivars will likely have to be completely seed-sterile to be considered non-invasive according to demographic models.


2015 ◽  
Vol 68 ◽  
pp. 187-192
Author(s):  
S.D. Jackman ◽  
P.G. Peterson ◽  
A.W. Robertson ◽  
C. Van_Koten

The leaf beetle Neolema ogloblini was released in 2011 as a biological control agent for Tradescantia fluminensis a major warm temperate forest environmental weed in New Zealand To assess whether N ogloblini can suppress T fluminensis and improve native seedling growth and survival a glasshouse experiment was established Kawakawa (Macropiper excelsum) and mahoe (Melicytus ramiflorus) seedlings were planted underneath uncontrolled T fluminensis and compared with seedlings (1) under T fluminensis damaged by N ogloblini (2) under T fluminensis sprayed with herbicide (triclopyr) and (3) released from competition by manually removing T fluminensis Seedlings did not grow faster in response to reduced T fluminensis biomass and increased light levels following feeding by N ogloblini over the 12 week experiment However seedling survival rates were higher (kawakawa 87 and mahoe 93) with N ogloblini feeding than herbicidetreatment (kawakawa 17 and mahoe 3) T fluminensis Survival in uncontrolled T fluminensis (kawakawa 90 and mahoe 57) varied for the two species This experiment suggests that regeneration of native plants may benefit from damage to T fluminensis caused by N ogloblini feeding in the field


1991 ◽  
Vol 21 (11) ◽  
pp. 1559-1566 ◽  
Author(s):  
Douglas P. Brown ◽  
Thomas K. Pratum ◽  
Caroline Bledsoe ◽  
E. David Ford ◽  
J. Steven Cothern ◽  
...  

An artificial soil mix suitable for magnetic resonance imaging was developed. This soil mix, consisting of quartz sand, peat moss, and kaolinite clay (5:3:2, by volume), has a natural texture and consistence and produces high-contrast images in soil media with up to 15% water content. Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were grown in this soil mix in 12.5 cm diameter containers and periodically imaged over a 12-month period. These images showed roots growing undisturbed in the soil mix and initiation of numerous lateral roots. From these images, root lengths and growth rates were calculated. Calculated root lengths were in close agreement with measured lengths of excavated roots. Undisturbed lateral roots had measured growth rates of about 1 mm/day. Roots that reached the container wall and then grew down along the wall had significantly higher growth rates, over 2 mm/day. This phenomenon may have important implications for growth rate data from root window and minirhizotron experiments.


Hematology ◽  
2011 ◽  
Vol 2011 (1) ◽  
pp. 76-81 ◽  
Author(s):  
Eva C. Guinan

Abstract Aplastic anemia remains a diagnosis of exclusion. Our ability to reliably diagnose, and therefore exclude, a variety of inherited or acquired diseases with similar phenotypes has improved markedly. An efficient diagnostic plan is important because time from diagnosis to treatment is related to outcome regardless of the therapeutic option chosen. HSCT remains the mainstay of therapy for those with matched sibling donors, and results have improved even further in recent years. For those without a sibling donor, the high response and overall survival rates of combined immunosuppressive therapy (IST) have proven robust. Nonetheless, incomplete response, relapse, and progression to myelodysplasia/leukemia have more clearly emerged as significant long-term issues. Improvements in outcome of alternative donor transplantation and the use of established and novel immunosuppressive agents provide multiple alternatives for treating refractory or relapsed patients. Best practices in this regard are not yet clearly established and may vary by a variety of demographic and treatment-specific factors. Regardless of the type of therapeutic approach, patients require ongoing monitoring for occurrence of disease and/or therapy-related side effects.


Sign in / Sign up

Export Citation Format

Share Document