FOREST REGENERATION QUALITY ASSESSMENT BY ASTA SYSTEM

2018 ◽  
Author(s):  
Karlis DUMINS ◽  
Toms STALS ◽  
Dagnija LAZDINA
Keyword(s):  
Survival Rate ◽  
Environmental Conditions ◽  
Forest Regeneration ◽  
Forest Type ◽  
Growth Parameters ◽  
Seedling Survival ◽  
Monitoring Methods ◽  
Annual Increment ◽  
Soil Preparation ◽  
Micro Topography

In Latvia one third of the total forest area is regenerated by planting tree seedlings and therefore it is important to choose the appropriate soil preparation method and the right type of regeneration material for each forest type. Usually the success of afforestation is evaluated by how high is the average seedling survival rate and growth parameters like height, annual increment, diameter at breast height while the location of the seedling is disregarded. This may be of great importance since in such stands the environmental conditions typically are not entirely homogenous. Micro topography differences impact seedling growth, because it modifies water regime, temperature, micronutrient availability, sun radiation and other factors. Therefore, aim of this work is to improve monitoring methods and determine the most efficient soil preparation and seedling preparation combination to improve the quality of forest regeneration. That could be done using ASTA documentation system originally developed to show seedling and mound location and density in planting area during mechanic planting. But it also allows to link the precise location of the seedling and growing conditions with its growing rate and survival and therefore it is easier to exclude seedlings that are affected by other factors than those that you are interested in, so you can gain more representative results. This also could be used in forest management. When using ASTA system it is also possible to display how different tree disease are distributed in the stand, if they have spread eventually or localized only in some parts of the stand, also it can be used for browsing and other tree damage monitoring in the stand. In conclusion: in harsh environmental conditions on unprepared forest soil and soil prepared in furrows made by disc trench larger seedlings show better survival rate. Survival of seedlings is significantly impacted by micro topography, whereas mounded micro sites equalize local environmental conditions that reduce impact of micro topography.

Lethal Dose (LD50) Fixation and Sensitivity of Fenugreek (Trigonellafoenum-graecumL.) to Gamma Radiation for Induction of Mutation

2017 ◽  
Vol 4 (04) ◽  
Author(s):  
ANURADHA PATEL ◽  
POONAM VERMA ◽  
SHARDA CHOUDHARY ◽  
ARVIND KUMAR VERMA
Keyword(s):  
Genetic Variability ◽  
Gamma Rays ◽  
Growth Parameters ◽  
Seedling Survival ◽  
Lethal Dose ◽  
Germination Percentage ◽  
Mutation Breeding ◽  
Vigour Index ◽  
Small Flower ◽  
Dose Dependent

Fenugreek (Trigonella foenum-graecumL.) is an annual crop, mainly used as a spiceand leafy vegetable crop in many parts of the world. Classical breeding in fenugreek is restricted due to its low genetic variability and small flower size which hamper manual emasculation and pollination. Mutation breeding is an effective way to enrich genetic variability in crop plants. An experiment was conducted to determine the lethal dose of the physical mutagen gamma rays in fenugreek. The dry seeds of fenugreek were exposed to different doses of gamma rays i.e. 150Gy, 200Gy, 250Gy, 300Gy and 350Gy. These irradiated seeds were sown in the Petri plates with non-irradiated seeds (control). As the dose of gamma rays increased, there was a decrease in germination percentage, seedling survival, root length, shoot length and vigour index. Among five doses of gamma rays, the maximum seed germination was observed at lowest dose 150Gy (93%), followed by 200Gy (83%), 250Gy (76%), 300Gy (76%) and 350Gy (64%). The seedling survival was decreased from 90% (in control) to 56% in 350Gy dose of gamma rays. The gamma rays dose of 150Gy gave stimulatory effect on seedlings growth. The growth parameters were dose dependent, as the dose of gamma rays increased from 200Gy to 350Gy. The gamma rays dose of 350Gy showed 64% seeds germination and 56% of seedlings survival. Therefore, it is concluded that the LD50 dose for fenugreek is close to 350Gy. This information would be highly useful for initiating mutation breeding programme in fenugreek

scholarly journals Ectomycorrhizal Community on Norway Spruce Seedlings Following Bark Beetle Infestation

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 740 ◽  
Author(s):  
Petra Veselá ◽  
Martina Vašutová ◽  
Karolína Hofmannová ◽  
Magda Edwards-Jonášová ◽  
Pavel Cudlín
Keyword(s):  
Norway Spruce ◽  
Bark Beetle ◽  
Seedling Growth ◽  
Forest Type ◽  
Growth Parameters ◽  
Forest Disturbances ◽  
Phialocephala Fortinii ◽  
Exploration Types ◽  
Seedling Roots ◽  
Mycelial Network

Ectomycorrhizal (ECM) fungi importantly influence seedling growth, nutrition, and survival and create an extensive mycelial network interconnecting tree species and enabling resource redistribution. Due to their symbiotic relationship with trees, they are impacted by forest disturbances, which are of increasing relevance due to climate change. The effect of disturbance on seedling colonization and their morphology is still largely unknown. Seedling growth parameters and the ECM fungal assemblage on the roots of Norway spruce (Picea abies (L.) H. Karst.) seedlings were assessed in mature spruce forests attacked and destroyed by bark beetle and in a mature non-attacked forest as a reference. We did not detect significant differences in number of ECM species on seedling roots among forest types, but ECM species composition changed; Tylospora fibrillosa (Burt) Donk, Meliniomyces variabilis Hambl. & Sigler, and Phialocephala fortinii C.J.K. Wang & H.E. Wilcox were characteristic species in the forest destroyed by bark beetle, whereas Lactarius, Cortinarius, and Russula were in the mature forest. Forest type further significantly influenced the height, root length, and root collar thickness of seedlings and the proportion of exploration types of mycorrhizae.

scholarly journals Subcritical crack growth parameters in glass as a function of environmental conditions

2020 ◽  
Author(s):  
Christopher Brokmann ◽  
Stefan Kolling ◽  
Jens Schneider
Keyword(s):  
Crack Growth ◽  
Environmental Conditions ◽  
Subcritical Crack Growth ◽  
Growth Parameters ◽  
Crack Depth ◽  
Indentation Test ◽  
Soda Lime ◽  
Initial Crack ◽  
Chemical Compositions ◽  
Critical Crack

Abstract In the present work, subcritical crack growth in soda–lime silicate glass is investigated under different environmental conditions. Crack growth parameters as a function of temperature and humidity were determined by dynamic fatigue tests, which has been verified by using the in-situ method of filming crack growth during experiments. The specimens were pre-damaged for constant initial crack lengths in all specimens using the Vickers indentation test. The determined parameters were compared with those from literature in order to discuss existing deviations of sub-critical crack growth parameters in literature. These deviations may be caused by environmental conditions and different chemical compositions of the glass. Arrest lines were used to determine the ratio of crack width to crack depth in Vickers indented specimens. For the initial crack depth, images of fracture surfaces were taken using an scanning electron microscope. Furthermore, the influence of humidity and temperature on the failure stress of unindented specimens with a constant initial crack length was simulated.

Influence of Site Factors on Incidence of Vole and Lemming Feeding Damage to Forest Plantations

1991 ◽  
Vol 6 (3) ◽  
pp. 64-67 ◽  
Author(s):  
Thomas P. Sullivan ◽  
Wayne L. Martin
Keyword(s):  
Picea Glauca ◽  
Pinus Contorta ◽  
Forest Type ◽  
Lodgepole Pine ◽  
Seedling Survival ◽  
Meadow Vole ◽  
Abies Lasiocarpa ◽  
Feeding Damage ◽  
Site Factors ◽  
Average Survival

Abstract The incidence of meadow vole (Microtus pennsylvanicus) and brown lemming (Lemmus sibiricus) feeding damage to young plantations of lodgepole pine (Pinus contorta var. latifolia) and interior spruce (Picea glauca × Picea engelmannii) was studied in west-central British Columbia. Fifty-eight plantations were surveyed for seedling survival and stocking, and an additional 21 older plantations of lodgepole pine were surveyed for tree damage. Average survival of pine (47.7%) was significantly lower than that of spruce (56.0%). Because of mortality from vole feeding, 24 of the 58 plantations were not satisfactorily restocked. Planted trees were attacked significantly more than natural regeneration. Severely attacked plantations occurred in the spruce-subalpine fir (Abies lasiocarpa) forest type at elevations > 800 m on N to NE aspects. Susceptible plantations generally had mechanical or no site preparation with complex post-harvest debris and limited vegetation cover. West. J. Appl. For. 6(3):64-67.

scholarly journals How to evaluate diagnosis and management of biliary atresia in the era of liver Transplantation in China

2018 ◽  
Vol 1 (1) ◽  
pp. e000002
Author(s):  
Jianghua Zhan ◽  
Yajun Chen ◽  
Kenneth K Y Wong
Keyword(s):  
Liver Transplantation ◽  
Survival Rate ◽  
Early Diagnosis ◽  
Biliary Atresia ◽  
Further Education ◽  
Monitoring Methods ◽  
Kasai Operation ◽  
First Choice ◽  
Choice Of Treatment ◽  
Hepatobiliary Diseases

BackgroundBiliary atresia (BA) is one of the most challenging hepatobiliary diseases in children. Notwithstanding the reasonable outcome of liver transplantation (LT), portoenteral anastomosis (Kasai operation) is still the first choice of treatment for patients with BA. How to improve the survival rate of the patients with BA in the era of LT is a new challenge.Data sourcesBased on recent original publications and the experience with the BA in China, we review many factors that influence BA survival situation, including early diagnosis and screen plan, defects of early treatment, Kasai operation, and LT and indicate present questions about BA diagnosis and treatment in China.ResultsBA diagnosis may also be delayed due to insufficient understanding of BA and lack of jaundice monitoring methods at different levels of the hospitals in China. Further education of the physicians at smaller city hospitals about BA, neonatal jaundice and cholestasis would be helpful in improving early diagnosis of BA. Early surgical intervention is still the only guarantee to improve the survival rate of BA with native liver.ConclusionsIn the era of LT, especially in China, Kasai operation can provide waiting time for living donor LT and improve the success rate of LT and minimize the rapid deterioration of liver function of the children with BA and decrease the mortality in patients with BA.

scholarly journals Early response of Nothofagus antarctica forests to thinning intensity in northern Patagonia

2020 ◽  
Author(s):  
Matias G. Goldenberg ◽  
Marcos Nacif ◽  
Facundo Oddi ◽  
Lucas Garibaldi
Keyword(s):  
Forest Type ◽  
Volume Growth ◽  
Early Response ◽  
Annual Increment ◽  
Basal Diameter ◽  
Stand Volume ◽  
Thinning Intensity ◽  
Northern Patagonia ◽  
Silvicultural Treatments ◽  
Nothofagus Antarctica

Nothofagus antarctica (G. Forst.) Oerst. stands of northern Patagonia (Argentina) have great potential to provide multiple ecosystem services. Nonetheless, the lack of basic information limits the application of silvicultural treatments to this forest type. This study reports the early response to three systematic strip thinning treatments (30, 50, and 70%) carried out during 2013 in a 30-year N. antarctica stand, where control plots (i.e. no thinning) were also established. Subplots were located within each plot. Basal diameters (BD) of all retained stems were measured in the non-vegetative season (winter) of 2016, 2017 and 2018, to calculate basal diameter annual increment (BDI), and stand volume growth. BDI ranged from 1.9 mm year-1 in the control plots to 2.7 mm year-1 at 70% thinning. Relative BDI also responded positively to thinning intensity. Stand volume growth decreased non-linearly with thinning intensity, from 3.36 m3 ha-1 year-1 in the control plots, and 0.71 m3 ha-1 year-1 when thinning was 70%. Smaller differences were observed between control plots, 30% thinning and 50% thinning. Our results show that Nothofagus antarctica forests, in the stem exclusion stage, respond to strip thinning. Thus, silviculture based on this management system could favor the development of retained trees without losing productivity if it remains under 50% intensity. This outcome represents an important incremental contribution to the design of silvicultural interventions in northern Patagonia.

scholarly journals Provenance Variation on Early Survival Rate and Growth Performance ofOxytenanthera abyssinica(A. Rich.) Munro Seedlings at Green House: An Indigenous Lowland Bamboo Species in Ethiopia

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Tinsae Bahru ◽  
Berhane Kidane ◽  
Yigardu Mulatu
Keyword(s):  
Survival Rate ◽  
Growth Performance ◽  
Growth Parameters ◽  
Evaluation Criteria ◽  
Provenance Variation ◽  
Mean Values ◽  
Green House ◽  
Multipurpose Species ◽  
Collar Diameter ◽  
Early Survival

Background. Lowland Bamboo (O. abyssinica) is an indigenous multipurpose species in Ethiopia and endemic to Africa.Aims. The present study was aimed at investigating provenance variation on early survival rate and growth performance ofO. abyssinicaseedlings so as to obtain suitable provenance for production of high quality seedlings.Methods. Seeds were collected from Pawe and Sherkole districts. Following raise of seedlings data on survival count, culm height, root collar diameter (RCD), number of leaves, and biomass were recorded.Results. Pawe provenance had slightly higher survival rate (91%). Except seedlings RCD, rhizomes length, and roots fresh and dry weights, higher mean values of other morphological parameters were recorded in Sherkole provenance. Biomass of leaves and culms was higher in Shekole provenance, while root biomass was exceeded by the Pawe provenance. However, significant variations (P<0.05) between provenances were observed in RCD, rhizomes length, weight of fresh culms, and fresh and dry root system. Seedlings growth parameters (height and RCD) were positively and significantly correlated with Biomass variables and hence could be considered as better evaluation criteria for seedling quality at green house.Conclusion. Sherkole provenance should be considered for raisingO. abyssinicaseedlings at green house.

Testing pathogen host specificity: a reciprocal field experiment in two types of tropical forest on Hainan, China

2013 ◽  
Vol 29 (6) ◽  
pp. 541-549 ◽  
Author(s):  
Wen Zheng ◽  
He He ◽  
Lin Xiao ◽  
Shixiao Yu
Keyword(s):  
Seed Germination ◽  
Host Specificity ◽  
Tree Species ◽  
Rain Forest ◽  
Forest Type ◽  
Seedling Survival ◽  
Cloud Forest ◽  
Soil Pathogens ◽  
Montane Rain Forest ◽  
Adult Trees

Abstract:The Janzen–Connell hypothesis suggests that highly specific pathogens decrease seedling survival close to the parent plant; however, the underlying mechanism remains unclear. Here, we tested the host specificity of soil pathogens to germinating seeds of Cyclobalanopsis fleuryi and Cryptocarya chinensis in tropical montane rain forest and cloud forest on Hainan, south China. Rhizospheric soils surrounding eight adult trees per species were collected in each forest type and divided into five soil treatments: parent, fungicide-sterilized, autoclave-sterilized, Fusarium-added and Pythium-added soils. Surface-sterilized seeds were sown in each of the five soil treatments and grown in two forest types. The seed germination percentages were significantly higher in sterilized soils (C. fleuryi, 41.5%; C. chinensis, 29.4%) than in non-sterilized soils (C. fleuryi, 28.3%; C. chinensis, 17.1%) in montane rain forest. The seed germination percentages in rhizospheric soil of conspecific parent trees were significantly lower in montane rain forest (C. fleuryi, 17.3%; C. chinensis, 10.5%) than in cloud forest (C. fleuryi, 37.1%; C. chinensis, 21.1%). Our results also suggest that the level of pathogen activity in each tree species varies depending on the environment. Our results support the hypothesis that host-specific pathogens shape tree species composition by differentially affecting seed germination under different environmental conditions.

scholarly journals Volatilization of 1,3-Dichloropropene in Florida Plasticulture and Effects on Fall Squash Production

2001 ◽  
Vol 126 (4) ◽  
pp. 496-502 ◽  
Author(s):  
S.D. Nelson ◽  
C. Riegel ◽  
L.H. Allen ◽  
D.W. Dickson ◽  
J. Gan ◽  
...  
Keyword(s):  
Methyl Bromide ◽  
Growth Parameters ◽  
Seedling Survival ◽  
Cropping System ◽  
Polyethylene Film ◽  
Growth And Yield ◽  
Vegetable Production ◽  
Severe Problem ◽  
Application Rates ◽  
Summer Squash

One of the proposed alternative chemicals for methyl bromide is 1,3-D. The most common forms of 1,3-D products are cis- or trans-isomers of 1,3-D with the fungicidal agent, chloropicrin, containing such mixtures as 65% 1,3-D and 35% chloropicrin (C-35). Soil fumigants are commonly applied under a polyethylene film in Florida raised bed vegetable production. Much of the research regarding cropping system effects of alternative fumigants to methyl bromide has focused primarily on plant growth parameters, with little regard to the atmospheric fate of these chemicals. The objective of this research was to determine both the atmospheric emission of 1,3-D under different plastic film treatments and to evaluate effects of application rates of 1,3-D and C-35 on plant pests, growth, and yield of Sunex 9602 summer squash (Cucurbita pepo L.). Results showed that use of a high barrier polyethylene film (or virtually impermeable film - VIF) greatly reduced fumigant emission compared to ground cover with conventional polyethylene films or uncovered soil. Summer squash seedling survival was a severe problem in several of the 1,3-D alone treatments where no fungicidal agent was added, whereas C-35 resulted in excellent disease control at both full and one-half of the recommended application rates for this chemical. Both 1,3-D and C-35 provided good plant stands and higher yields when applied at their recommended application rates. However, all squash yields were lower than typical squash production levels due to late planting and early winter frost kill. Chemical names used: 1,3-dichloropropene (1,3-D); trichloronitropropene (chloropicrin).

scholarly journals Modeling the Emergence and Growth of Alligatorweed at Different Field Capacity Levels

2020 ◽  
Vol 38 ◽  
Author(s):  
T. AHMAD ◽  
A. TANVEER ◽  
M.A. NADEEM ◽  
M. YASEEN
Keyword(s):  
Growth Rate ◽  
Survival Rate ◽  
Growth Parameters ◽  
Field Capacity ◽  
Moisture Regime ◽  
Emergence Time ◽  
Submerged Soils ◽  
Sprouting Capacity ◽  
Dry Conditions ◽  
Survival And Growth

ABSTRACT: A study focusing on different field capacity levels was planned in the Weed Science Lab, Department of Agronomy, University of Agriculture Faisalabad. Fresh alligatorweed was harvested from the Agronomy fields and cuttings (2 cm length) were made from it. These cuttings were placed at 25%, 50%, 75% and 100% field capacity levels in pots for 25 days. The results of the experiments revealed that at all field capacity levels, fragments of alligatorweed were able to sprout and grow. Increased moisture levels significantly increased the emergence ability and survival of the alligatorweed plants upto a certain level. Compared with the control (25% FC), emergence time of the sprouts in the maximum moisture regime (100% of FC) decreased by 40% (12.94 days vs.7.17 days). By contrast, the survival rate of the fragments decreased by 60% (5 vs. 1.75) although survival and growth rate increased at first with 50% FC and 75% FC. Maximum sprouting and growth were found at 50% field capacity. Field capacity does affect the sprouting capacity of alligatorweed fragments but it has only a little influence on growth parameters. The results suggest that alligatorweed can sustain dry conditions to a great extent and also has the ability to sprout and grow in fully submerged soils.

Sign in / Sign up

Export Citation Format

Share Document