【摘要】：草地生物量是草地生態(tài)系統(tǒng)的一個(gè)重要指標(biāo),也是研究草地生態(tài)系統(tǒng)變化規(guī)律的重要手段,具有重要的意義。目前關(guān)于草地生物量研究的主要方法是傳統(tǒng)的直接收獲法,遙感估測法使用也較多,但關(guān)于草量計(jì)的研究較少。本研究自制多種不同規(guī)格的草地地上生物量測量板,對白三葉草占優(yōu)勢的草地群落高度和生物量之間的相關(guān)關(guān)系進(jìn)行調(diào)查研究,建立了二者的回歸方程,通過對所建立模擬方程的決定系數(shù)(R2)、F-檢驗(yàn)、總相對誤差(RS)和平均相對誤差絕對值(RMA)等進(jìn)行綜合分析比對,從中篩選出最優(yōu)測量板規(guī)格和生物量估測模型。野外調(diào)查在陜西省楊凌區(qū)大寨鎮(zhèn)杜寨村,以白三葉占優(yōu)勢的草地群落中進(jìn)行。本研究的調(diào)查工具選擇了鋁塑板和高分子板兩種材質(zhì),圓形和正方形兩種形狀,正方形有邊長10cm、20cm、30cm、40cm四種,圓形直徑為10cm、20cm、30cm、35cm、40cm五種,進(jìn)行了草地植被調(diào)查。調(diào)查樣地選擇地面較為平緩的地帶,采取隨機(jī)取樣法,將測量板在接近草層上方時(shí),輕輕放置于植被上方,直至測量板平穩(wěn)地停止,盡可能保證測量板的水平,測量并記錄測量板下方到地面的植物群落高度,同一規(guī)格的測量板重復(fù)測量20次。隨后將測量板下對應(yīng)面積內(nèi)所有植物的地上部分齊地面剪下,裝入樣袋內(nèi),做好標(biāo)記,帶回實(shí)驗(yàn)室,稱重。在65℃恒溫干燥箱烘干至恒重,稱重得到生物量數(shù)量。再進(jìn)行數(shù)學(xué)模型建立和相關(guān)性分析,具體結(jié)果如下:1、以測量板下群落高度為自變量,群落地上生物量為因變量,建立多種回歸方程,發(fā)現(xiàn)測量板下的草地群落高度和生物量之間呈正相關(guān),R2介于0.3700~0.7630之間。2、測量板面積、重量過大過小都會影響回歸模型的穩(wěn)定性和擬合性。鋁塑板較高分子板重,變異系數(shù)和決定系數(shù)表現(xiàn)較好。3、綜合各項(xiàng)因素,得出最優(yōu)規(guī)格為鋁塑板直徑35cm,其最優(yōu)估測模型為y=1.6460x-3.3462,R2=0.7630,其預(yù)測精度可達(dá)到82.35%。
[Abstract]:Grassland biomass is not only an important index of grassland ecosystem, but also an important means to study the law of grassland ecosystem change. At present, the main method of grassland biomass research is the traditional direct harvesting method, remote sensing estimation method is also used more, but the research on grass meter is less. In this study, a variety of measurement boards for aboveground biomass of grassland with different specifications were made to investigate and study the correlation between the height and biomass of the grassland community in which the white clover was dominant, and the regression equation between them was established. The determination coefficient (R2) F- test, total relative error (RS) and average relative error absolute value (RMA) of the simulated equation were analyzed and compared. Field investigation was carried out in Duzhai Village, Dazhai Town, Yangling District, Shaanxi Province. In this study, two kinds of materials, round and square, were used to investigate the vegetation of grassland. There were four kinds of square with 10 cm long, 20 cm, 30 cm, 40 cm, and five kinds of circular diameter of 10 cm, 20 cm, 30 cm, 35 cm, 40 cm, 4 kinds of square, 10 cm, 20 cm, 30 cm, 40 cm, 10 cm, 20 cm, 30 cm The survey site selects the flat ground area, adopts the random sampling method, places the measuring plate gently over the vegetation when it is close to the grass layer, until the measuring plate stops smoothly, and ensures the level of the measuring plate as far as possible. The plant community height from the bottom of the measuring plate to the ground was measured and recorded. Then the above ground parts of all the plants in the corresponding area under the measuring board are cut off from the ground, put into the sample bag, marked, and brought back to the laboratory to weigh. The biomass was obtained by drying to constant weight in a constant temperature drying oven at 65 鈩，

本文編號：2121170