【摘要】：在富營(yíng)養(yǎng)化水體中,磷被普遍認(rèn)為是浮游植物季節(jié)性增長(zhǎng)形成藍(lán)藻水華的限制因子。富磷區(qū)磷素雨季流失將對(duì)周邊水系環(huán)境構(gòu)成嚴(yán)重威脅。然而,在富磷區(qū),針對(duì)磷分布特征、磷流失特征、植被分布特征以及有效控磷植被群落的研究方面,研究工作還較少。而這方面的研究是當(dāng)前恢復(fù)富磷區(qū)植被、控制水土流失和磷流失的急需解決的重要問(wèn)題。 為此,我們以滇池東南部上蒜鎮(zhèn)柴河匯水區(qū)內(nèi)的富磷區(qū)域作為研究對(duì)象,對(duì)磷及其它土壤養(yǎng)分元素空間分布特征,以及相應(yīng)植被分布特征進(jìn)行了分析,設(shè)置3個(gè)匯水?dāng)嗝姹O(jiān)測(cè)雨季徑流輸出狀況；并選擇區(qū)域內(nèi)典型地被,建設(shè)馬桑群落、野古草群落、蔗茅群落、云南松群落、華山松群落、旱冬瓜群落、云南松-旱冬瓜針闊混交林群落、藍(lán)桉群落和黑荊群落等9個(gè)徑流小區(qū),對(duì)徑流小區(qū)植被覆蓋率、物種多樣性、土壤肥力、凋落物層覆蓋率、單位面積草本植物分蘗數(shù)等進(jìn)行調(diào)查分析,結(jié)合產(chǎn)流量、污染物輸出狀況等,確定控磷植物群落關(guān)鍵指標(biāo)；依據(jù)富磷區(qū)植被分布特征,確定植被恢復(fù)的理論。通過(guò)調(diào)查研究,得出以下主要結(jié)果與結(jié)論： (1)富磷區(qū)土壤環(huán)境變化復(fù)雜,植被分布受限于土壤環(huán)境 滇池流域東南富磷區(qū),土壤磷濃度以磷礦區(qū)為中心,向四周呈現(xiàn)遞減式擴(kuò)散。研究區(qū)內(nèi)土壤全磷濃度范圍在1.15～80.2g/kg,變化梯度較大。土壤N：P比變化幅度也大,范圍為0.006～0.98。土壤pH值、土壤有機(jī)質(zhì)、全氮、全磷以及堿解氮和速效磷,在空間上具有強(qiáng)烈的變動(dòng)性。土壤各養(yǎng)分元素的比值中,土壤N：P比值基本低于1,最小值為0.006。富磷區(qū)土壤特殊的肥力特征,影響著區(qū)域內(nèi)植被的分布。 (2)富磷區(qū)的高磷濃度的土壤地段,植物具有低氮需求下的高固碳能力特征 高磷濃度的土壤地段的植物組分中,戟葉酸模的C：N：P的比值為104：4.7：1,蔗茅的為132：4.3：1,紫莖澤蘭的為106：6：1,刺芒野古草群落的為189：6.4：1,馬桑群落的為118：6.2：1,白健桿的為193：6.5：1。相比Redfield比值系數(shù),這些植物體現(xiàn)出氮的比值相對(duì)較低的特征。表明這些植物在僅需要少量N素的補(bǔ)給下,具有對(duì)C的高效固定能力,這也是這類先鋒植物重要的適應(yīng)性特征。 (3)依據(jù)富磷區(qū)土壤肥力與群落物種數(shù)分析,土壤全氮是群落植被覆蓋率及物種豐富度指數(shù)的限制因子 各植物群落的各結(jié)構(gòu)特征指數(shù)與土壤全磷、土壤最高磷濃度及土壤pH值均呈現(xiàn)顯著負(fù)相關(guān)關(guān)系。植被覆蓋率與這3個(gè)指標(biāo)間相關(guān)系數(shù)分別為-0.793、-0.786和-0.714。植被覆蓋率與土壤全氮、土壤有機(jī)質(zhì)和土壤堿解氮呈現(xiàn)顯著的正相關(guān)關(guān)系,相關(guān)系數(shù)分別為0.786、0.736和0.727。這些肥力指標(biāo)與植被覆蓋率的相關(guān)性均為顯著相關(guān)。高濃度磷和低背景氮是影響植被覆蓋率的主要土壤因素。 各植物群落的物種豐富度指數(shù)與土壤全氮、土壤有機(jī)質(zhì)和土壤堿解氮呈現(xiàn)顯著的正相關(guān)關(guān)系,相關(guān)系數(shù)分別為0.904、0.893和0.724。各植物群落的物種豐富度指數(shù)與土壤pH值、土壤全磷呈現(xiàn)負(fù)相關(guān)關(guān)系,相關(guān)系數(shù)分別為-0.805、-0.635。植物群落物種豐富度指數(shù)最大限度受限于土壤全氮,其次為土壤有機(jī)質(zhì),并與土壤pH值呈現(xiàn)顯著的負(fù)相關(guān)關(guān)系。 主成分分析中,第一主成分貢獻(xiàn)率達(dá)70.7%,主要包含土壤有效氮、土壤全氮,土壤有機(jī)質(zhì),土壤全磷和土壤pH值信息,它們具有的載荷分別為0.925,0.894,0.859,-0.870和-0.840。富磷區(qū)植被及群落特征分布的首要影響因素是土壤氮素水平。 (4)磷礦開(kāi)采區(qū)及周邊裸露區(qū)域是富磷區(qū)磷流失的關(guān)鍵區(qū)域 研究區(qū)水土流失強(qiáng)度最大的區(qū)域?yàn)殛~酸模群落,水土流失強(qiáng)度為330t/ha2.a,其次為磷礦開(kāi)采區(qū)區(qū)域,為149t/ha2.a。研究區(qū)農(nóng)田面積相對(duì)最大,水土流失量也最大,土壤流失量為988t/a裸露地區(qū)域,土壤流失量為957t/a。根據(jù)表層土壤全磷含量測(cè)算,則土壤全磷年流失量最高的區(qū)域?yàn)榱椎V區(qū)及周邊裸露地區(qū)域,磷的年流失量達(dá)57.8t,占年總流失量65.3t的88.5%。農(nóng)田土壤磷流失也相對(duì)較嚴(yán)重,年流失量為4.98t。戟葉酸模群落,面積僅為0.1ha,但磷年流失量達(dá)1.15t。 磷礦區(qū)及周邊裸露區(qū)域面積為研究區(qū)的5.6%,但潛在磷流失量占了研究區(qū)年流失量的88.5%,本區(qū)域是富磷區(qū)磷流失的關(guān)鍵區(qū)域。 (5)雨季徑流輸出與植物群落覆蓋率、凋落物覆蓋率相關(guān)聯(lián) 徑流系數(shù)與植被覆蓋率為顯著負(fù)相關(guān)關(guān)系,相關(guān)系數(shù)為-0.837,顯著度p0.005,；群落徑流系數(shù)與凋落物覆蓋率之間也呈現(xiàn)極其顯著的負(fù)相關(guān)關(guān)系,相關(guān)系數(shù)為-0.810,顯著度p0.008。群落徑流系數(shù)與喬木層蓋度、灌木層蓋度、草本層蓋度、物種豐富度指數(shù)、草本層分蘗數(shù)、單位面積凋落物質(zhì)量等相關(guān)性不顯著。徑流系數(shù)(y)和植被覆蓋率(x%)之間的回歸方程為：y=4.29*10-7X3-0.011x+0.810。徑流系數(shù)(y)和群落凋落物覆蓋率(x%)之間的回歸方程為：y=e(b0+b1)/x=e11.342/x。 (6)控磷植物群落恢復(fù)策略 在富磷區(qū)關(guān)鍵區(qū)域(磷礦區(qū)及周邊裸露地區(qū)域)土壤因子中,與植被覆蓋率相關(guān)系數(shù)最高的是土壤全氮,相關(guān)系數(shù)為0.990,p0.0005；其次,為土壤有機(jī)質(zhì),為極其顯著正相關(guān)關(guān)系,相關(guān)系數(shù)均為0.959；在時(shí)間進(jìn)程上,植被覆蓋率(y%)的回歸方程為回歸方程為：y=-0.2304x2+9.3781x-7.5858, R2=0.9586。 利用徑流系數(shù)(y)和植被覆蓋率(x%)之間的回歸方程計(jì)算,如果把磷礦開(kāi)采區(qū)植被從0恢復(fù)到75%,則徑流量理論上則削減了80%。植被覆蓋率達(dá)75%時(shí),土壤全氮含量限值為0.890g/kg,依據(jù)磷礦區(qū)土壤發(fā)育進(jìn)程,當(dāng)土壤全氮從0.361g/kg提高到0.871g/kg時(shí),需要自然發(fā)育的年限是15.5年。 在富磷區(qū)雨季水土流失和污染物流失嚴(yán)重的關(guān)鍵區(qū)域,短期內(nèi)迅速恢復(fù)植被覆蓋率,是有效削減水土流失和徑流的最有效途徑。在富磷區(qū)的植被退化區(qū)域,影響植被恢復(fù)的首要限制因子為土壤氮素。此外,土壤機(jī)械組成、pH值、有機(jī)質(zhì)含量等也對(duì)植被恢復(fù)具有重要的影響作用。建議在新開(kāi)采的礦區(qū),保存發(fā)育較為完好的表層土壤,階段性利用儲(chǔ)存的表土逐步恢復(fù)地段植被。其次,在已經(jīng)遭受破壞的地段,氮素養(yǎng)分過(guò)低,可選擇戟葉酸模、蔗茅、野古草等先鋒植物,該類植物具有在低氮需求下,高固碳的能力,可逐步提高裸露地段的植被覆蓋率,并逐年有效改善土壤環(huán)境。
[Abstract]:In eutrophic waters, phosphorus is generally regarded as a limiting factor for the seasonal growth of phytoplankton to form cyanobacterial bloom. Phosphorus loss in rainy season in phosphorus-rich areas will pose a serious threat to the surrounding water system environment. There are few studies on this subject, which is an important problem to be solved urgently for restoring the vegetation and controlling soil erosion and phosphorus loss in phosphorus-rich areas.
Therefore, the spatial distribution characteristics of phosphorus and other soil nutrients and their corresponding vegetation distribution were analyzed in the area rich in phosphorus in Chaihe catchment area of Shanglianzhen, southeastern Dianchi Lake, and three catchment sections were set up to monitor the runoff output in rainy season. The vegetation coverage, species diversity, soil fertility, litter layer coverage, and the number of herbaceous tillers per unit area in 9 runoff plots were investigated and analyzed. According to the characteristics of vegetation distribution in phosphorus-rich areas, the theory of vegetation restoration was determined. Through investigation and study, the following main results and conclusions were obtained:
(1) the soil environment in the phosphor rich area is complicated and the vegetation distribution is limited by the soil environment.
The total phosphorus concentration ranged from 1.15 g/kg to 80.2 g/kg, and the variation gradient was large. The soil N:P ratio also varied widely, ranging from 0.006 to 0.98. The ratio of soil N:P was lower than 1 and the minimum was 0.006. The special fertility characteristics of the soil in the phosphorus-rich region affected the distribution of vegetation in the region.
(2) in the high phosphorus concentration soil area of the phosphorus rich area, plants have the characteristics of high carbon sequestration under low nitrogen demand.
The ratio of C:N:P of Euphorbia officinalis was 104:4.7:1, that of Sugarcane Festuca was 132:4.3:1, that of Eupatorium adenophorum was 106:6:1, that of Eupatorium adenophorum was 189:6.4:1, that of Masao was 118:6.2:1, and that of White Robin was 193:6.5:1. The relatively low nitrogen yield indicates that these plants have the ability to fix C efficiently with only a small amount of N, which is also an important adaptive characteristic of these pioneer plants.
(3) According to the analysis of soil fertility and community species number in phosphorus-rich areas, soil total nitrogen is the limiting factor of community vegetation coverage and species richness index.
The correlation coefficients between vegetation coverage and soil total nitrogen, soil organic matter and soil alkali-hydrolyzable nitrogen were - 0.793, - 0.786 and - 0.714, respectively. The correlation coefficients were 0.786, 0.736 and 0.727, respectively. The correlation between these fertility indices and vegetation coverage was significant.
The species richness index of each plant community was positively correlated with soil total nitrogen, soil organic matter and soil alkali-hydrolyzable nitrogen, and the correlation coefficients were 0.904, 0.893 and 0.724, respectively. The species richness index was limited by soil total nitrogen, followed by soil organic matter, and was negatively correlated with soil pH.
The contribution rate of the first principal component was 70.7%, mainly including available nitrogen, total nitrogen, soil organic matter, total phosphorus and soil pH information. Their loads were 0.925, 0.894, 0.859, -0.870 and-0.840 respectively. The primary influencing factor of the distribution of vegetation and community characteristics in phosphorus-rich areas was soil nitrogen level.
(4) the bare area of the phosphate mining area and the surrounding area is the key area of phosphorus loss in the phosphorus rich area.
The area with the highest soil erosion intensity was Euphorbia officinalis community, the soil erosion intensity was 330 t/ha 2.a, followed by phosphate mining area, 149 t/ha 2.a. The area of farmland in the study area was the largest, the amount of soil erosion was also the largest, the amount of soil erosion was 988 t/a in the exposed area, and the amount of soil erosion was 957 t/a. The highest annual loss of total phosphorus was in the phosphorus mining area and the surrounding bare areas. The annual loss of phosphorus reached 57.8 t, accounting for 88.5% of the total annual loss of 65.3 t. The annual loss of phosphorus in farmland soil was relatively serious. The annual loss of phosphorus was 4.98 t. Euphorbia folica community, with an area of only 0.1 ha, but the annual loss of phosphorus reached 1.15 t.
The area of phosphorus mining area and its surrounding bare area is 5.6% of the study area, but the potential phosphorus loss accounts for 88.5% of the annual phosphorus loss in the study area.
(5) runoff output in rainy season is related to plant community coverage and litter coverage.
The correlation coefficient between runoff coefficient and vegetation coverage was - 0.837 and significance p0.005, and the correlation coefficient between runoff coefficient and litter coverage was - 0.810 and significance p0.008. The regression equation between runoff coefficient (y) and vegetation coverage (x%) was y = 4.29 * 10-7X3-0.011x + 0.810. The regression equation between runoff coefficient (y) and litter coverage (x%) was y = e (b0 + b1) / x = e11.342 / X.
(6) restoration strategy of plant communities controlled by phosphorus
Among the soil factors in the key areas of phosphorus-rich areas (phosphorus mining areas and surrounding bare areas), the highest correlation coefficient with vegetation coverage was soil total nitrogen, the correlation coefficient was 0.990, p0.0005; secondly, for soil organic matter, the correlation coefficient was extremely significant positive correlation, the correlation coefficient was 0.959; in the time course, the regression equation of vegetation coverage (y%). The regression equation is: y=-0.2304x2+9.3781x-7.5858, R2=0.9586.
The regression equation between runoff coefficient (y) and vegetation coverage (x%) was used to calculate the runoff. If the vegetation in the phosphorus mining area was restored from 0 to 75%, the runoff would be reduced by 80% theoretically. When the vegetation coverage reached 75%, the limit of soil total nitrogen content was 0.890 g/kg. According to the process of soil development in the phosphorus mining area, when the soil total nitrogen increased from 0.361 g/kg to 0.871 g/kg. The natural development period is 15.5 years.
Rapid restoration of vegetation coverage is the most effective way to effectively reduce soil erosion and runoff in the key areas with severe soil erosion and pollutant loss during rainy season in phosphorus-rich areas. It is suggested that in the newly mined mining area, the surface soil should be preserved and well developed, and the stored surface soil should be used to gradually restore the vegetation. Secondly, in the damaged area, the nitrogen nutrient is too low, and the pioneer plants such as Euphorbia officinalis, Sugarcane maw and Ancient Wild Grass can be selected. Under the condition of low nitrogen demand and high carbon sequestration capacity, the vegetation coverage of bare land can be gradually increased and the soil environment can be effectively improved year by year.
【學(xué)位授予單位】：云南大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2015
【分類號(hào)】：Q948

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 汪濤;楊元合;馬文紅;;中國(guó)土壤磷庫(kù)的大小、分布及其影響因素[J];北京大學(xué)學(xué)報(bào)(自然科學(xué)版);2008年06期

2 鮑全盛,王華東;我國(guó)水環(huán)境非點(diǎn)源污染研究與展望[J];地理科學(xué);1996年01期

3 劉付程,史學(xué)正,潘賢章,于東升;太湖流域典型地區(qū)土壤磷素含量的空間變異特征[J];地理科學(xué);2003年01期

4 李恒鵬,劉曉玫,黃文鈺;太湖流域浙西區(qū)不同土地類型的面源污染產(chǎn)出[J];地理學(xué)報(bào);2004年03期

5 黃滿湘,周成虎,章申,張秀梅;北京官?gòu)d水庫(kù)流域農(nóng)田地表徑流生物可利用磷流失規(guī)律[J];湖泊科學(xué);2003年02期

6 段昌群;何峰;劉嫦娥;和樹(shù)莊;張國(guó)盛;;基于生態(tài)系統(tǒng)健康視角下的云南高原湖泊水環(huán)境問(wèn)題的診斷與解決理念[J];中國(guó)工程科學(xué);2010年06期

7 和麗萍;王玉杰;方向京;孟廣濤;李貴祥;;昆陽(yáng)磷礦植被恢復(fù)地土壤肥力狀況分析及評(píng)價(jià)[J];長(zhǎng)江流域資源與環(huán)境;2012年12期

8 馮慕華;鄭錦;李文朝;潘繼征;柯凡;張世濤;;云南省撫仙湖流域帽天山磷礦區(qū)磷流失過(guò)程模擬研究[J];環(huán)境化學(xué);2007年06期

9 ;Phosphorus sorption capacities in a headstream landscape—The pond chain structure[J];Journal of Environmental Sciences;2006年05期

10 宋澤芬;王克勤;孫孝龍;和甲秋;李紅波;依佼傳;;澄江尖山河小流域不同土地利用類型地表徑流氮、磷的流失特征[J];環(huán)境科學(xué)研究;2008年04期

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