10 research outputs found
Metrics of Growth Habit Derived from the 3D Tree Point Cloud Used for Species Determination-A New Approach in Botanical Taxonomy Tested on Dragon Tree Group Example
Detailed, three-dimensional modeling of trees is a new approach in botanical taxonomy. Representations of individual trees are a prerequisite for accurate assessments of tree growth and morphological metronomy. This study tests the abilities of 3D modeling of trees to determine the various metrics of growth habit and compare morphological differences. The study included four species of the genus Dracaena: D. draco, D. cinnabari, D. ombet, and D. serrulata. Forty-nine 3D tree point clouds were created, and their morphological metrics were derived and compared. Our results indicate the possible application of 3D tree point clouds to dendrological taxonomy. Basic metrics of growth habit and coefficients derived from the 3D point clouds developed in the present study enable the statistical evaluation of differences among dragon tree species.O
Seed Viability and Potential Germination Rate of Nine Endemic Boswellia Taxa (Burseraceae) from Socotra Island (Yemen)
The endemic Boswellia species (Burseraceae) on Socotra Island (Yemen) are of great local significance due to their various local ethnobotanical uses. However, despite the fact that these trees are endangered, little is known about their biology. We tested seed germination rates in controlled experiments (trials of 21 days) for two subsequent years and for nine endemic taxa of Boswellia occurring on Socotra Island. For this, seeds were collected island-wide from a wide range of localities and for several populations per species. We observed differences in germination among Boswellia species, among species and localities and among both years, which indicates that the development of seeds is strongly affected by external ecological factors. Although we noted a large variation in seed germination (relatively high in Boswellia socotrana), and half of the species showed relatively low mean daily germination, our study indicated that all endangered endemic Frankincense Tree taxa of Socotra harbor the potential for in situ conservation through recruitment, given that known impacts can be reduced in local replantation areas (e.g., grazing).O
Organic, integrated and conventional management in apple orchards: effect on plant species composition, richness and diversity
The study was conducted to assess the effect of conventional, integrated and organic management on differences in plant species composition, richness and diversity. The plants were studied in triads of orchards situated in three regions of the Czech Republic. Data about species occurrences were collected on 15 permanent plots in the tree rows and 15 plots between tree rows in each of the apple orchards during 2009. A total of 201 vascular plant species (127 native species, 65 archaeophytes, and 9 neophytes) were found. Management type and also different regional conditions had a significant effect on plant species composition and on diversity parameters of orchard spontaneous vegetation. Species richness and species pool was significantly higher in the organic orchards than in the differently managed orchards. Management type had significant effect on proportions of archaeophytes, and also neophytes in apple orchards. The results showed that a change from conventional to integrated and organic management in apple orchards lead to higher plant species diversity and to changes in plant species composition
Development of a population of Boswellia elongata Balf. F. in Homhil nature sanctuary, Socotra island (Yemen)
We assessed seven decades of change in the largest known population of the endangered endemic Boswellia elongata Balf. F. (Burseraceae) on Socotra Island (Yemen). To quantify the population change we evaluated tree number and locations on digitized images from various sources in the period 1956–2017 and combined this with direct field measurements of the population between 2011 and 2017. Our study reveals that the Homhil Nature Sanctuary B. elongata population shows a continuous decline since 1956. The steady but slow natural decline was strongly accelerated by two catastrophic cyclones in November 2015, when 38% of the trees were directly destroyed by strong winds. During the following 2 years 29% of the remaining trees died additionally. The remaining population has a bell-shaped size distribution; most trees are around 40 cm in diameter (range 18 to 70 cm). Tree ring analysis of 11 dead trees with a diameter of 29 to 44 cm without bark, resulted in estimated tree ages between 80 and 101 years. We estimate that similar-sized trees showing strong signs of senescence have a maximum age of a little over 100 years. The age structure of the Homhil population is, therefore, unbalanced with large sized trees prevailing. Natural regeneration is absent for decades. Viable seeds are available and have been shown to germinate, but the development of seedlings into saplings is a bottleneck. If the decline continues at the current rate, only 30 trees will remain there in 2036. Protection, planting and awareness activities are needed to keep this unique frankincense tree in Homhil Nature Sanctuary.</p
Metrics of Growth Habit Derived from the 3D Tree Point Cloud Used for Species Determination—A New Approach in Botanical Taxonomy Tested on Dragon Tree Group Example
Detailed, three-dimensional modeling of trees is a new approach in botanical taxonomy. Representations of individual trees are a prerequisite for accurate assessments of tree growth and morphological metronomy. This study tests the abilities of 3D modeling of trees to determine the various metrics of growth habit and compare morphological differences. The study included four species of the genus Dracaena: D. draco, D. cinnabari, D. ombet, and D. serrulata. Forty-nine 3D tree point clouds were created, and their morphological metrics were derived and compared. Our results indicate the possible application of 3D tree point clouds to dendrological taxonomy. Basic metrics of growth habit and coefficients derived from the 3D point clouds developed in the present study enable the statistical evaluation of differences among dragon tree species
Does Shade Impact Coffee Yield, Tree Trunk, and Soil Moisture on <i>Coffea canephora</i> Plantations in Mondulkiri, Cambodia?
Shade is a natural condition for coffee plants; however, unshaded plantations currently predominate in Asia. The benefits of shading increase as the environment becomes less favorable for coffee cultivation, e.g., because of climate change. It is necessary to determine the effects of shade on the yield of Coffea canephora and on the soil water availability. Therefore, three coffee plantations (of 3, 6, and 9 ha) in the province of Mondulkiri, Cambodia, were selected to evaluate the effect of shade on Coffea canephora yields, coffee bush trunk changes, and soil moisture. Our study shows that shade-grown coffee delivers the same yields as coffee that is grown without shading in terms of coffee bean weight or size (comparing average values and bean variability), the total weight of coffee fruits per coffee shrub and the total weight of 100 fruits (fresh and dry). Additionally, fruit ripeness was not influenced by shade in terms of variability nor in terms of a possible delay in ripening. There was no difference in the coffee stem diameter changes between shaded and sunny sites, although the soil moisture was shown to be higher throughout the shaded sites
Sustainable Land Use Management Needed to Conserve the Dragon’s Blood Tree of Socotra Island, a Vulnerable Endemic Umbrella Species
Unsustainable overgrazing is one of the most important threats to the endemic and endangered population of dragon’s blood tree (Dracaena cinnabari) on Socotra Island (Republic of Yemen). However, there is a lack of information about the exact population size and its conservation status. We estimated the population size of D. cinnabari using remote sensing data. The age structure was inferred using a relationship between crown projection area and the number of branch sections. The conservation importance of each sub-population was assessed using a specially developed index. Finally, the future population development (extinction time) was predicted using population matrices. The total population size estimated consists of 80,134 individuals with sub-populations varying from 14 to 32,196 individuals, with an extinction time ranging from 31 to 564 years. Community forestry controlled by a local certification system is suggested as a sustainable land management approach providing traditional and new benefits and enabling the reforestation of endemic tree species on Socotra Island