Untitled e ISSN 2582 5208 International Research Journal of Modernization in Engineering Technology and Science Volume 03/Issue 04/April 2021 Impact Factor 5 354 www irjmets com www irjmets com @Inter[.]
e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:03/Issue:04/April-2021 Impact Factor- 5.354 www.irjmets.com SURVEYING FACTORS AFFECTING THE VARIATION OF PLANT SPECIES Le Thi Thu Trang*1, Le Thi Thu Thuy*2, Vo Thi Diem Kieu*3 *1National *2,3Dong Central University, Taoyuan 32001, Taiwan Nai Technology University, Dong Nai 76000, Vietnam Correspondence e-mail: lethithuthuy@dntu.edu.vn ABSTRACT Vegetation cover on the surface of an area reflects the current state of plant resources and other biological resources coexisting in it In this study, the route systematic survey method combined with the collected data evaluation was applied We surveyed the factors affecting the variation of flora species along the Saigon River The stastitics show that there were significant changes in the composition and number of plant species according to seasons and water bodies, which has practical implications for the management agencies to implement the sustainable planning, utilization, and development of this natural resource Keywords: Vegetation along rivers, biological diversity, ecosystem, Saigon River I INTRODUCTION Plant diversity research is also known as flora surveys [1], which are field surveys that provide information on the number of existing plant species and their distribution by different habitats types The natural features of an area are shown through the vegetation cover and the vegetation layer partly reflects back the natural features of that region due to the relationships and interactions of the natural factors with vegetation layer [2] This study surveyed factors affecting the variation of plant species It was significant in determining species composition, life forms, geographic characteristics, use-value, and conservation value, as a basis for biodiversity conservation of riparian vegetation Saigon River - a tributary of Dong Nai River (Figure 1), originating from Dau Tieng Lake in Tay Ninh province, is one of the important water sources for Tay Ninh, Binh Duong, Binh Phuoc provinces, and especially for Ho Chi Minh City The study was conducted on the vegetation layer along the Saigon River, the section crossing Hoc Mon and Cu Chi districts, Ho Chi Minh City, Vietnam This area is an interference between natural factors and artificial factors (e.g., human – related activities) Therefore, water resources in the Saigon river basin play a very important role in the economic and social development of the provinces/cities in the basin, especially in Ho Chi Minh City [3], [4] Figure Location of Saigon river basin in Dong Nai river system www.irjmets.com @International Research Journal of Modernization in Engineering, Technology and Science [1333] e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:03/Issue:04/April-2021 Impact Factor- 5.354 II www.irjmets.com METHODS 2.1 Sampling method There are many methods to investigate vegetation According to the research scope of this topic, we applied a linear survey method based on the forest vegetation research method of Cabacinha and Castro (2009) [5], and “Tropical Forest Ecosystems in Vietnam” of Thai Van Trung (1999) [6] During field trips, characteristics of vegetation types, different habitats were surveyed and recorded Besides, higher plant species and nature's impacts on the vegetation cover were also studied 2.2 Data evaluation method Data analysis software was used throughout the research process Information and images were regularly updated to write comprehensive reports III RESULTS AND DISCUSSION 3.1 Seasonal variation of plant species The Saigon River is located in the tropical monsoon subequatorial area The general characteristic of climate in this region is the stable high temperature throughout the year There are two seasons, the rainy and dry seasons, which caused landscape changes [2] Through the surveys of the study area, the results show that the species richness was greater and plant life was getting easier in the rainy season than the dry season In the rainy season, the soil had high humidity, many species of moisture-loving plants began to thrive such as Heliotropium indicum, Hyptis rhomboidea, Polygonum tomentosum, Mimosa pigra, Sagittaria sagittaefolia, Eichhornia crassipes The rainy season was also the flowering and fruiting season for most of the plants in the Poaceae family and Cyperaceae family In the flood season, there were plants that lived and thrived by its adaptive mechanism: - Some species such as Hymenachne amplexicaulis, Polygonum tomentosum, Ludwigia adscendens, Ipomoea aquatica could be made into floating rafts (Figure 2) - Aquatic plants such as Eichhornia crassipes, Lemna minor were floating on the water surface, so they could survive both during rainy and dry seasons (Figure 3) Figure Ludwigia adscendens and Ipomoea aquatica thrived in the rainy season www.irjmets.com @International Research Journal of Modernization in Engineering, Technology and Science [1334] e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:03/Issue:04/April-2021 Impact Factor- 5.354 www.irjmets.com Figure Eichhornia crassipes thrived in the rainy season When the flood rose, the number of the herbaceous plants and the sedge plants was sharply decreased In low water bodies (fields, pond banks, ditches), many species of plants were significantly reduced after floods such as Alternanthera sessilis, Marsilea quadrifolia, Lindernia pierreana In the dry season, the number and composition of plant species experienced a considerable reduction, focusing mainly on some moisture-loving plants The surface area of the river covered with aquatic plants such as Eichhornia crassipes, Ludwigia adscendens was narrowed When the floodwaters completely receded at the beginning of the dry season, the coastal land of Saigon river became drier, then the plants such as Fimbristylis miliacea, Fuirena umbellata, Cynodon dactylon developed by growing seeds or roots in the soil (Figure 4) Figure Plant development when the floodwaters receded Variation of plant species according to water body 3.2.1 Water bodies of wetlands frequently In the 10 year period 2000 - 2010, the land use structure in the Saigon River basin underwent a significant change (Table 1) www.irjmets.com @International Research Journal of Modernization in Engineering, Technology and Science [1335] e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:03/Issue:04/April-2021 Impact Factor- 5.354 www.irjmets.com Table The land use structure in the Saigon River Type of land use Year 2000 2005 2010 Agricultural land 72,4% 68,5% 66,6% Aquaculture land 0,2% 0,2% 0,2% Forestry land 6,8% 4,6% 2,9% Specialized land 4,6% 8,7% 10,2% Residential land 10,8% 15,5% 19,6% Unused land 5,2% 2,5% 0,5% Total: 100,0% 100,0% 100,0% Source: GSO; year 2000, 2005, 2010 [7] In the study area, the water body was defined as a wetland frequently filled with water and directly affected by high tide [8] Beside herbaceous plants, there were also large trees and liana species that created the water body with species diversity (Figure 5) Aquatic plants such as Eichhornia crassipes, Lemna minor, Ludwigia adscendens The shrubs and herbaceous plants such as Colocasia esculenta, Crinum asiaticum, Sagittaria sagittaefolia, Polygonum tomentosum, Hymenachne amplexicaulis, Acrostichum aureum, Phragmites karka, Pandanus kaida, Caryota mitis, Nypa fruticans, Melastoma affine, Glochidion littorale The timber species such as Horsfieldia irya, Ficus microcarpa, Calophyllum inophyllum, Cerbera odollam, Barringtonia macrostachya, Hibiscus tiliaceus Besides the timber species, there were also lianas such as Flagellaria indica, Aniseia martinicensis, Cayratia trifolia, Lygodium japonicum, Zanonia indica, Dioscorea glabra Figure Habitat along Saigon river 3.2.2 Coastal water bodies This is the transitional zone between the so-called water-frequently-filled wetland and the dry zone In this area, in addition to plants adapted to the water environment, there are also aquatic species that often grow near water bodies [9] The timber species such as Barringtonia macrostachya, Horsfieldia irya, Euodia lepta, Syzygium cochinchinensis, Annona glabra, Gardenia jasminoides The shrub species such as Melastoma affine, Phyllanthus urinaria, Phyllanthus reticulatus, Ficus hirta, Senna alata, Pandanus kaida The herbaceous plants such as Phyllanthus amarus, Panicum repens, Ceratopteris siliquosa, Acrostichum aureum, Heliotropium indicum, Hyptis rhomboidea The lianas such as Aniseia martinicensis, Flagellaria indica, Vigna adenantha, Lygodium japonicum www.irjmets.com @International Research Journal of Modernization in Engineering, Technology and Science [1336] e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:03/Issue:04/April-2021 Impact Factor- 5.354 IV www.irjmets.com CONCLUSIONS The seasonal variation of the higher plant species is quite important In the rainy season, the number of species was more abundant and the plant life was stronger than the dry season The number and composition of herbaceous species were much reduced during the flood season and regenerated strongly after the flood receded Water bodies of the so-called water-frequently-filled wetlands contained all the typical plant life forms, and this was the water body with the highest species diversity in the study area Although the coastal water body was not as diverse as the flora species in the water body of the so-called water-frequently-filled wetland, the plants here also contributed a part to the species composition of the study area V REFERENCES [1] R E P J W Sermolli, "A survey of the pteridological flora of the Mediterranean Region," Webbia, vol 34, no 1, pp 175-242, 1979 [2] S de Blois, G Domon, and A Bouchard, "Environmental, historical, and contextual determinants of vegetation cover: a landscape perspective," Landscape Ecology, vol 16, no 5, pp 421-436, 2001 [3] W Grayman, H Day, and R Luken, "Regional water quality management for the Dong Nai river basin, Vietnam," Water Science Technology, vol 48, no 10, pp 17-23, 2003 [4] T T Nguyen et al., "Nutrient budgets in the Saigon–Dongnai River basin: Past to future inputs from the developing Ho Chi Minh megacity (Vietnam)," River Research Applications, vol 36, no 6, pp 974-990, 2020 [5] C D Cabacinha and S S de Castro, "Relationships between floristic diversity and vegetation indices, forest structure and landscape metrics of fragments in Brazilian Cerrado," Forest ecology management, vol 257, no 10, pp 2157-2165, 2009 [6] T Van Trung, Tropical forest ecosystems in Vietnam Hanoi: Science Technique Publisher, 1999, p 297 [7] G S Office, The land use structure in the Saigon River 2000, 2005, 2010 [8] L Zhang, M.-H Wang, J Hu, and Y.-S Ho, "A review of published wetland research, 1991–2008: ecological engineering and ecosystem restoration," Ecological Engineering, vol 36, no 8, pp 973-980, 2010 [9] E Tabacchi and A.-M Planty-Tabacchi, "Exotic and native plant community distributions within complex riparian landscapes: a positive correlation," Ecoscience, vol 12, no 3, pp 412-423, 2005 www.irjmets.com @International Research Journal of Modernization in Engineering, Technology and Science [1337] ... in the rainy season When the flood rose, the number of the herbaceous plants and the sedge plants was sharply decreased In low water bodies (fields, pond banks, ditches), many species of plants... In the rainy season, the number of species was more abundant and the plant life was stronger than the dry season The number and composition of herbaceous species were much reduced during the. .. moisture-loving plants The surface area of the river covered with aquatic plants such as Eichhornia crassipes, Ludwigia adscendens was narrowed When the floodwaters completely receded at the beginning of the