Investigation And Analysis Of The Characteristics Of Taohuaxi's Vegetation And Water Environment

In this paper,the Taohua Creek in near-natural state in Jiu longpo province are selected as the research object,starting from the research basis of the spatial and temporal heterogeneity of the river geomorp Hology and the overall characteristics of the river ecosystem,through field investigation,sample collection,plot division and laboratory analysis to obtain the basic data of water environment and plants.Many multivariate statistical methods are used,such as single-factor analysis of variance,community similarity analysis,cluster analysis,principal component analysis,canonical correlation analysis and regression analysis,and construct a water quality-difference model on data processing.on the basis of investigations in the three seasons such as the winter,spring and summer,much quantitative research were conducted on the basis of water environment factors,vegetation community growth,geomorp Hic heterogeneity and seasonal changes of Taohuaxi River.The main content and the results of the research are as follows:(1)In order to make the experiment more convenient,the study area was divided into three parts including near-natural river section,channelized section and built-up section based on the different characteristics of the riparian form and plant community type in the upper and middle reaches.The survey results of plant species in the three seasons showed that the number of plant species in the study area was 68,112 and 82 in winter,spring and summer(construction in summer study area and incomplete plant survey).Under the comparison of community similarity coefficients,the average similarity of community samples in spring-summer is the highest(75%).At the same time,the differences in plant community characteristics are not only reflected in the composition of the community structure,but also in the impact of geomorp Hic heterogeneity on the ecological characteristics of the plant community,including the number of plant species,vegetation coverage,and root distance from water,etc.With the change of landform,there are significant difference,while the height of plants is not statistically different.(2)Selecting the river hydrological factors and dissolved oxygen as the classification indicators of river geomorp Hology,and through the cluster analysis method,according to the principle of unity of classification,the river geomorp Hology types of the 30 experimental sample points in the study area are divided into 5types:deep pond,shallow shoal,concave-convex shore,falling water—deep pool,and flood dike.Due to the complexity of the water environment,there are cross-overlaps between the different river geomorp Hic features shown in the classification results.For example,the geomorp Hic types under similar water environmental features may have distinct river bed morp Hological features.Based on the analysis of variance,the differences between the above hydrological factors used for cluster analysis were studied.The results showed that the hydrological factors including water depth and flow velocity showed extremely significant differences under the change of landform shape,and the proof basis included water depth,The flow rate and other hydrological factors are reasonable and feasible for the classification of river geomorp Hology;and p H value and temperature may be one of the reasons for the overlapping of classification.At the same time,the influence of a small number of trees on the river bank in spring and a large number of trees on the understory water temperature is based on the difference between the temperature of the water body without trees covering-0.82? and-1.70?;the summer temperature differences are-0.23? and-0.60?,respectively;+0.07?and +0.71?,the overall appearance is to cool down in spring and summer,and keep warm in winter.(3)Drawing on previous research achievements and deficiencies,combining the measurement data of water environment factors and landform classification results,based on the construction of water quality difference model,the differences in the impact of different river landforms on water quality were studied.The study shows that the average dissolved water content of each falling landform increases to 4.322mg/L,so the falling landform is the best landform form for increasing dissolved oxygen in the river,and the shoal immediately follows +2.3874 mg/L;The deep pool and the uneven bank are-0.2190mg/L and-0.7681mg/L in sequence.Regardless of whether it is a shoal,a deep pond,or a rugged shore or a falling landform,the degree of influence on the total p Hosp Horus and ammonia nitrogen content is extremely small,and the degree of influence is less than 10% of the original value of the water body.For river ecosystems under dynamic changes,the effects of different landforms on water quality changes obviously exist,but based on the principle of ecosystem integrity,research cannot ignore the fundamental effects of plants on water quality.than 10% of the original water content value.For dynamically changing river ecosystems,the effects of water quality changes brought by geomorp Hic heterogeneity obviously exist,but based on the principle of ecosystem integrity,the basic role of plants on water quality cannot be ignored.(4)Based on the principal component analysis,the article analyzes the correlation between the water environment factors of rivers in different seasons and the typical correlation analysis.Studies have shown that temperature changes brought by seasonal changes are the key factors affecting the entire river ecosystem.Based on typical correlation analysis,the loadings of p H,dissolved oxygen,ammonia nitrogen and total p Hosp Horus reached 0.991,0.629,0.740,0.486.This result shows that the temperature factor is not only the main factor affecting the river water quality,but also that it is a key variable that essentially differentiates the seasonal changes of the river,making Taohua Creek more changes in water quality in winter and more in spring and summer.Is a change in hydrology.(5)All the research results are excellent to enrich the concept of the overall structure and functional integrity of the river ecosystem.In experiments that explored the changes in the vegetation community characteristics of small and medium-sized river banks and floodplains with landform heterogeneity and their ecological effects,they revealed The functions and laws of similar rivers and creek ecosystems are shown and their reference value is displayed.At the same time,it provides reference ecological samples for the construction of waterfront ecological green spaces in mountain cities.