ARTICLE | doi:10.20944/preprints202002.0446.v1
Subject: Biology And Life Sciences, Forestry Keywords: Kafta-sheraro national park; woody species structure; regeneration status
Online: 28 February 2020 (16:24:09 CET)
The natural vegetation study was conducted in Kafta-sheraro national park (KSNP) North, Ethiopia to explore floristic composition, structure and regeneration of woody species in the home of African elephant. In the park, the above information is not well documented which is necessary for conservation. Data were collected From August to December 2018. The vegetation data were collected from 161 quadrats of size 20m×20m, 5mx5m for shrub ̸ tree, sapling and seedling respectively. Individual trees and shrubs DBH >=2.5cm and height >=2m were measured using Tape meter and Clinometer respectively. DBH, frequency, density, basal area, and IVI were used for vegetation structure. A total of 70 woody species 46 (65.7%) trees, 18 (25.7%) shrubs and 6 (8.6%) tree ̸ shrub) were identified. The total basal area and density of 79.3 m2 ha-1, and 466 ±12.8 (S.E.) individuals ha-1 were calculated for 64 woody species. Fabaceae was the most dominant family occupied 16 species (23.0%) followed by Combretaceae 8 species (11.4%). Acacia mellifera and Combretum hartmannianum were the most dominant and frequent species. Abnormal patterns of selected woody species were dominantly identified. Regenerating status all the woody plant species was categorized as “Fair” (18.75%), “Poor” (7.81 %) and “None” (73.44%). However, there is good initiation for conservation of the park; still the vegetation of the park was threatened by firewood collection, charcoal production, fire, intensive farming, mining and over grazing. Therefore, the study area as the habitat for the population of the African elephant; the KSNP should be recommended the highest conservation priority and studied the soil seed bank of species having poor regeneration condition.
ARTICLE | doi:10.20944/preprints202307.1190.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Arabica coffee; drought; genotype; seed; germination; moisture content; seedling vigor; gas exchange; cell membrane stability
Online: 18 July 2023 (08:51:01 CEST)
The coffee plant is highly susceptible to drought, and different genotypes exhibit varying degrees of tolerance to low soil moisture. The current study aims to investigate the connection between drought tolerance and sensitivity in terms of seed traits, germination, and post-germination events, and their influence on the growth and physiology of young coffee plants. Two consecutive experiments were conducted to examine the impact of these factors. In the first experiment, germination performance was examined for three groups of coffee genotypes: relatively tolerant (Ca74140, Ca74112, and Ca74110), moderately sensitive (Ca74158, Ca74165, and CaJ-21), and sensitive (Ca754, CaJ-19, and CaGeisha). The subsequent experiment focused on the growth and physiological responses of two relatively tolerant (Ca74110 and Ca74112) and two sensitive (CaJ-19 and Ca754) genotypes under drought stress condition. The relatively tolerant genotypes showed quicker and more complete germination compared to other groups. This was associated with higher moisture content, higher seed surface area to volume ratio, and higher coefficient of velocity of germination, coefficient of variation of germination time, and germination index. Additionally, the relatively tolerant genotypes showed higher seedling vigor. The results of the second experiment demonstrated superior growth performance in relative tolerant genotypes compared to the sensitive groups. Young plants of coffee belonging to relatively tolerant genotypes exhibited higher growth performance than the sensitive genotypes, with a net assimilation rate strongly correlated to relative water content, leaf number, stomatal conductance, and chlorophyll-a. In addition, a strong correlation was exhibited between the growth of young coffee plants and the surface area to volume ratio of the seeds, as well as the germination percentage. The seedling vigor index showed a strong correlation with net assimilation rate, chlorophyll content, seedling growth, and cell membrane stability. Furthermore, principal component analysis illustrated distinct clustering of genotypes based on their germination and growth-physiological performance. Overall, the findings of this study suggest the importance of seed traits, germination, and post-germination events are integral factors in determining drought tolerance and sensitivity, as well as the growth and physiological responses of adult coffee plants.