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Návrh naučné a turistické stezky na ostrově Sokotra
Kaplánek, Tomáš
The thesis focuses on designing an educational trail and tourist routes on the island of Socotra. The educational trail is located in the forest of dragon's blood trees (Dracaena cinnabari) on the Firmihin plateau. The route is approximately 6 km long with an elevation gain of 300 m. Ten information boards have been designed to describe the dragon's blood trees and the environmental issues affecting this area. The information provided includes issues such as land degradation, erosion, climate change and its impacts, inhibition of natural tree regeneration, and how local people influence this ecosystem. The same topics are also described in a 24-page brochure created in both Czech and English. Additionally, four tourist routes have been proposed in the work, which are color-coded, with three located in the Haggeher Mountains and one in the Homhil area. Information on the educational trail and tourist routes is also provided through the ArcGIS StoryMaps web platform.
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Klíčivost semen Dracaena cinnabari v kontrolovaných podmínkách
Bauerová, Lucie
Bachelor thesis is focused on germinability of Dracaena cinnabari seeds under different temperature conditions, in addition with seeds collected in different ways and from different localities as well. At first, a germination process is described and in addition the factors that have a substantial effect on seed germination and germinability. In another part of the work the methods that are used for germinability testing under laboratory conditions are presented. And in the last part of this section there are summarized current informations about germinability of D. cinnabari seeds and other species of Dracaena genus and related genus Sansevieria. In the practical part, four seed sections were used. These sections were collected either directly from the fruits of a cut panicle or from the ground, and moreover they were from different localities differing in altitude. The sections were named as PL, SB, NN, PE. Seeds were tested in Petri dishes under three different temperatures - 22, 26 and 30 °C, where 4 replicates of 25 seeds of each section were used. The highest germinability was achieved at 26 °C and 30 °C (of 2nd attempt) with germinability 84,6 % and 82,5 % respectively. In addition, a germination energy was calculated for each test. Seeds showed the highest germination energy at 26 °C. The results show a higher germinability of D. cinnabari seeds particularly at higher temperatures. The germinability was evaluated also for individual seed sections and because the sections were collected in different ways and from different localities, the influence of both of these factors was assessed on resulting seed germinability. Finally is concluded that this species probably has a relatively high potential ability of natural regeneration, implying that there is also a potential for regeneration of populations by an artificial way.
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Perspektivy vývoje populace Boswellia elongata Balf. f. na lokalitě Homhil (Socotra) a možnosti její ochrany
Hušková, Karolína
The bachelor thesis focuses on the development of the Boswellia elongata population in the protected area of Homhil on Socotra. Digitized aerial, satellite and panoramic images were used to evaluate the number of individuals in certain years, along with increment core and trunk bolts to determine the age of randomly selected individuals from the population. The results suggest that the population is relatively uniform, represented by only one age class. The population is able to produce seedlings, but they are unable to withstand negative influences such as extensive grazing of goats and sheep, soil degradation and strong wind in the monsoon season. If there is no change in ecological conditions or artificial interference from the outside, the population will probably die within 25 years.
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Project and establishment of forest nursery on Socotra Island - transfer of European forestry know-how
Bauerová, Lucie
Diploma thesis is focused on establishment of forest nurseries and seedling production on Socotra Island where a natural regeneration of many endemic species is limited by overgrazing and has been moreover affected by cyclone that hit the island in 2015. Planting stock of Dracaena cinnabari, Boswellia elongata, Boswellia ameero, Boswellia dioscorides, Punica protopunica, Aloe perryi and mangrove Avicennia marina was planned to be propagated in nurseries located in three areas of interest – Firmihin, Homhil and Niyt. Therefore data about the species seed germination or growth rate were gathered and mentioned in the literature section. The species selection was always firstly preceded by dendrological survey of the area. Individual pilot areas were also described together with climatic data and moreover, soil samples were analysed as the substrate for the seedling production comes from local sources. Finally, the projects for forest nurseries establishment were created and according to them were individual nurseries established.
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Vliv dračince rumělkového (Dracaena cinnabari) jako "nurse plant" na diverzitu cévnatých rostlin
Rejžek, Martin
Dracaena cinnabari, the dominant endemic tree of Socotra Island (Yemen), is in serious decline. The effect this will have on the island's plant diversity remains unknown. This dissertation aimed to assess the possible role of Dracaena as a nurse plant by identifying plants associated with Dracaena understorey and by assessing the importance of Dracaena for maintaining plant diversity. In the first part of the dissertation, relevés sampled in Dracaena understorey and in open sites to record the number of individuals of vascular plants were analysed. Species richness and composition were compared between understorey and open sites, and species associated with each of these habitats were identified. Additionally, the effects of shading and leaf litter on species richness and abundance were analysed. The second part of dissertation focused on mature woody species composition of Dracaena stands and investigated spatial relations between Dracaenas and other mature woody plants. The last part of the dissertation aimed to assess the fine scale spatial relationships between stones and plants in Dracaena stands and evaluated the differences of these relationships between understorey and open sites. The results confirmed the Dracaena role as an important nurse plant. The tree enhances the environmental heterogeneity and its presence creates two distinct microhabitats (understorey and open sites). The understorey habitat, compared with open site, harbours higher number of species, including endemics. The species in Dracaena stands can be classified as either understorey specialists, open-site specialists or generalists. The decline of Dracaena will negatively affect plant diversity, will reduce abundance of rare endemic plants and will lead to homogenization of vegetation. As no other tree species exists which could replace the Dracaena, our findings underline the importance of conservation efforts to preserve Dracaena stands on Socotra and identify this species as a key umbrella species whose conservation would ensure also the protection of a number of other associated species.
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Ekologická studie dračince rumělkového (Dracaena cinnabari) na lokalitách Firmihin a Scand, ostrov Sokotra
Hubálková, Irena
The results of Dracaena sub-populations research are submitted in this dissertation. Dragons Blood Tree is an endemic plant species growing on the Socotra Island. The thesis contains four scientific papers published or submitted for review in journals with impact factor and in peer-reviewed journal. The first article predicts sub-population dynamics on Firmihin where the ha sample plot inventory was carried out. Tree growth and mortality simulation has been created using a time horizon of 100 years. The second article is focused on growth dynamics of seedlings growing ex situ under controlled conditions. One hundred plants from Firmihin and Skand have been measured once a week for two years. The differences in growth dynamics and mortality for both groups of young plants in ex situ were evaluated. The third article also relates to Dragons Blood Tree regeneration and deals with a possibility of in-situ regeneration in the fenced area on Shibehon Plateau compared to Oam al-Cora school grounds. The team from Mendel University in Brno planted hundreds of seedlings in 2006, ever since the monitoring of growth dynamics and mortality continues. The fourth article deals with anatomy of secondary thickening plant organs. Xylem, phloem, parenchyma and vessels area of root, stem and branch was determined using 70 permanent microscope slides and processed by image analysis. The results were evaluated, compared and graphically interpreted.
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Zhodnocení úspěšnosti výsadeb autochtonních dřevin do domácích zahrad na Sokotře
Nováková, Petra
The thesis is aimed to evaluate the success of the growth of trees planted in home gardens on the Yemeni island of Socotra with support of the Mendel University in the time range of years from 2001 to 2014. Since 2001 indigenous tree species have been planted in selected home gardens. These gardens were supplied with everything needed for smooth operation - fences, tubes, hoses and water reservoirs were built on the site as well. In subsequent years, planting went further and further, home gardens were gradually expanded to include gardens in schools. At the turn of March and April 2014 field survey was conducted and in this thesis the measured values of individual indigenous species were compared with measurements from previous years. These measurements from previous years and measurements that have been performed by our group were divided according to individual gardens and species. We studied height of group of trees, calculated average and measured height of individual trees, one tree was selected from different each species. When comparing averages of more species, a bar chart was used. When monitoring growth of one individual tree, obtained individual data were plotted in the circuit graph that shows the growth curve of the species and it is possible to track increment for certain period. The results are better than expected and show a relatively great success of these gardens. It should be noted that the vitality of trees is in close connection with the care of garden owners. Part of the work focuses on the arid areas in the global perspective, as plantings take place not only on Socotra, but also in other areas of arid zones, and these can be an example for other attempts at cultivation in these difficult natural conditions.
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Možnosti eradikace nepůvodního a potenciálně invazivního druhu Calotropis procera na ostrově Sokotra
Šteflová, Gabriela
Calotropis procera, tree native in northern Africa and western and southern Asia, was introduced to Socotra for more than a century ago and is one of 87 non-native species of the local flora. Although in some places of the planet the species has invasive character, on Socotra it is not considered as dangerous. Especially in the north of the island near the capital Hadibo it is however abundantly represented in home gardens and could have an impact on local vegetation. During the field investigation, it has been found that as long as the vegetation of the island would be under intensive pressure of livestock, especially goats, Calotropis procera would not have invasive character outside fenced gardens. Mature individuals from the wild would be appropriate to reduce mechanically using common tools, mainly by cutting them because potential shoots would be rapidly eliminated by grazing.
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Endangered tree species and their populations: a case study Dendrosicyos socotrana
Ali, Abdulwahab Saad Saeed
The study was performed on 24 localities throughout Socotra Island to approach the threatened tree species of Dendrosicyos socotrana (DS, Cucumber tree), its population and regeneration. 14 localities out of these localities contain DS individuals. This survey studied the land-cover classes of High Shrubland with Succulents, Low Croton-Jatropha Shrubland, Sparse Dwarf Shrubland, Wadies, Submontane Grassland, Submontane Shrubland, Frankincense Woodland, Dracaena Woodland, Urban land, Date Palm Plantation, and Frankincense Forest. Studied localities form an area of 96 square kilometres and 204 individuals have been found (excluding seedlings). The basic measurement of specimens had been taken (height, GBH, fertility and coordinates) as well as collected data about biotope site and regeneration. Regeneration occurred approximately on 36 % of all localities. Dendrosicyos socotrana could be fertile on height of 2 m. The estimation of total number of DS population on Socotra Island could be 8 113 individuals. It is conspicuously showing that High Shrubland with Succulents and Wadies are the best habitat for Dendrosicyos socotrana, the reason is that the northern-slopes and wadies protect Dendrosicyos socotrana from the strong monsoon wind in the Island. As for others land-cover, DS species prefers wind-protected locations. In conclusion the DS population are decreasing in whole Island and I am suggesting to seek for a solution for this unique species.
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