Related items
Showing items related by metadata.
-
ArticleSpatial distribution model of phragmanthera plant parasite in Rift Valley Ecoregion of Kenya
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Genus Phragmanthera (Loranthaceae) family is in one of the families of mistletoes which are parasitic plants that solely depend on their hosts for nutrients and water once attached. The parasitism leads to wilting and drying up of the infested part and in cases of high infestation mortality of the tree affected. Members of the genus were observed to parasitize tree hosts in the Rift Valley ecoregion through a transect survey. The locations of the parasitic plant were recorded and used for Maximum Entropy (Maxent) modelling to determine environmental conditions making up the niche of the parasite and to develop suitability maps of the parasitic plant within Rift Valley ecoregion. 27 occurrence records representing 102 trees were correlated to the 19 Bioclimatic variables representing temperature and precipitation conditions globally. The species identified in this study is Phragmanthera cornetti (Dewevre) Polhill & Wiens with key host species being Cupressus sempevirens var. pyramidalis, Schinus molle and Jacaranda mimisifolia which are ornamental trees. Maximum Entropy software (Maxent) version 3.4 was used to determine the species suitability of Phragmanthera cornetti identifying Baringo, Nakuru, Uasin Gishu, Transnzoia and Elgeyo Marakwet as hot spots for infestation by the parasitic plant. Environmental variables weighed as most critical to Phragmanthera cornetti distribution in the sampled area were precipitation of coldest quarter, precipitation of driest month, Temperature seasonality, Isothermality and minimum temperature of coldest month. These variables were ranked using their individual contribution to the model (AUC=0.935) computed on MaxEnt correlating the occurrences to Bioclimatic variables. The identified counties within the predicted ranges of Phragmanthera cornetti infestation should begin using more resistant or less susceptible tree species for their tree growing programs. All infested trees and branches should be pruned for short term control of the spreading of Phragmanthera cornetti in the upcoming coldest quarter. Further studies into more effective control measures for the parasitic plants are being investigated for a more integrated approach. This includes use of selective herbicides and management by utilization. Key words: Species Distribution Modelling, Phragmanthera, Bioclimatic variables, ecological niche ID: 3623688 -
DocumentSpatial distributions pattern and associations of dead woods in natural spruce-fir secondary forests
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Natural secondary forest is the main part of forest resources in China. Studying dead woods (DW) could better reveal the community succession rule and promote the healthy development of them. We investigated basic characteristics and coordinates of each tree (DBH≥1 cm) within a plot (100 m×100 m) using the adjacent grid method and studied the spatial distributions pattern and associations of DW (in the last five years) in a typical natural spruce-fir secondary forest in Jingouling Forest Farm, Wangqing Forestry Bureau, Jilin Province, China. The results showed that the diameter class distribution of DW showed the pattern of left-single-peak curve, while the logs showed the pattern of multi-peak curve. DW number was related to the mixing degree of one species, but not to the total number of it. The distribution of DW was concentrated at 0~8m scale. As the scale increases, it changed to random or uniform. The aggregation distribution of DW of medium (10 cm≤DBH<20 cm) and small (1 cm≤DBH<10 cm) DBH at small scale below 8 m was the main reason for the aggregation distribution of DW. The DW of large (DBH≧20 cm) DBH and Saplings (1 cm≤DBH<5 cm) showed a significant positive association at 2~25 m scale. There was no significant spatial association between DW and Small trees(5 cm≤DBH<15 cm). At 0~3m scale, there was a positive association between Medium trees (15 cm≤DBH<25 cm) and DW of small and medium DBH. At the 9 m, 11~14 m scale and the 15 m, 42~45 m scale, the DW of small and medium DBH were significantly negatively associated with Large trees (DBH≥25 cm). In conclusion, the biological traits, diameter class distribution and spatial distribution affected the abundance and diameter class distribution of DW of one species. The spatial distributions of DW and the associations between DW and standing trees varied across diameter classes and scales. Rational utilization of spatial information could optimize stand structure and promote positive community succession. Keywords: Deforestation and forest degradation, Sustainable forest management, Adaptive and integrated management ID: 3618474 -
ArticlePrediction of distribution changes of carpinus laxiflora and C. tschonoskii based on climate change scenarios using MaxEnt model in the Republic of Korea
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Hornbeams (Carpinus spp.), which are widely distributed in South Korea, are recognized as one of the most abundant species at climax stage in the temperate forests. Although the distribution and vegetation structure of the C. laxiflora community have been reported, little ecological information of C. tschonoskii is available. Little effort was made to examine the distribution shift of these species under the future climate conditions. This study was conducted to predict potential shifts in the distribution of C. laxiflora and C. tschonoskii in 2050s and 2090s under the two sets of climate change scenarios, RCP4.5 and RCP8.5. The MaxEnt model was used to predict the spatial distribution of two species using the occurrence data derived from the 6th National Forest Inventory data as well as climate and topography data. It was found that the main factors for the distribution of C. laxiflora were elevation, temperature seasonality, and mean annual precipitation. The distribution of C. tschonoskii, was influenced by temperature seasonality, mean annual precipitation, and mean diurnal rang. It was projected that the total habitat area of the C. laxiflora could increase by 1.05% and 1.11% under RCP 4.5 and RCP 8.5 scenarios, respectively. It was also predicted that the distributional area of C. tschonoskii could expand under the future climate conditions. These results highlighted that the climate change would have considerable impact on the spatial distribution of C. laxiflora and C. tschonoskii. These also suggested that ecological information derived from climate change impact assessment study can be used to develop proper forest management practices in response to climate change. Keywords: Carpinus laxiflora, C. tschonoskii, Climate change, Distribution change, MaxEnt ID:3619140
Users also downloaded
Showing related downloaded files
No results found.