Seed Yield Predictions Based on the Habitat niche-fitness of Microula sikkimensis, an Endemic Oil Crop in the Qinghai-Tibet Plateau

微孔草(M. sikkimensis)是隸屬於紫草科微孔草屬的兩年生草本植物，主要分佈于青藏高原東緣的退化草甸和草原，作為新興的在地油料作物種，其在醫藥、保健、飼草料等方面均具有多方面的新應用，因此，在青藏高原日益退化的高山草甸和草原放牧生態系統中，利用微孔草草籽生產，建立可持續的生產生態系統，不失為一種既取得生產效益又利於生態恢復的理性選擇之一。自1994年4月至2004年9月，先後在青藏高原東緣的3省11縣進行了大範圍的野外調查和移栽試驗，收集了各研究位點的大量生境參數，通過相關與偏相關分析篩選出描述生境的七個關鍵生境因子。引入生態棲位理論，定義微孔草生境生態棲位適宜度是現實生境供給與微孔草對生境的最適需求之間的相似程度，在對各關鍵生境因子對生境生態棲位適宜度的權重進行界定的基礎上，構建了微孔草生境生態棲位適宜度模型，對野外調查和移栽試驗的計算結果表明：生境生態棲位適宜度較好地反映了不同研究位點的生境差異。在推薦的農藝措施下，因改善了生境促進了微孔草生長，各移栽試驗點的生境生態棲位適宜度都有不同程度地提升，平均提升率達14.26%，亦促使草籽產量平均增長99.61%；生境生態棲位適宜度作為諸多環境因子的綜合指標與草籽產量間存在顯著的雙對數回歸關係，經實驗數據驗證，觀測記錄的草籽產量與該回歸關係模擬估計值之間的平均絕對離差百分數是5.46%，意味著該回歸方程在大尺度預測草籽產量上的可用性，並且以生境生態棲位適宜度為自變量建立草籽產量預測模型的方法，比之於傳統產量預測模型而言，具簡便準確之利，是一種新的嘗試。通常農藝措施通過調控可控關鍵生境因子逼近最優值，實現生境改善，從而提高了生境生態棲位適宜度值和草籽產量，然而這種提升力並不是無限的，因此每個位點都有其生境生態棲位適宜度上限值和相應的草籽產量上限。生境生態棲位適宜度模型、草籽產量預測模型及其研究結果對選擇微孔草適宜生長區，進行栽培、生產、管理具有指導意義。

關鍵字

生境生態棲位適宜度HNF ；微孔草Microula sikkimensis ；草籽產量；青藏高原

並列摘要

Microula sikkimensis is a biennial herb, found only in the eastern rims of the Qinghai-Tibetan Plateau, and lends itself to multiple applications in medicine, food and fodder. Utilizing the seed production of M. sikkimensis to develop a sustainable production ecosystem is a logical option for the degraded alpine grassland in the Qinghai-Tibet Plateau. From 1994 to 2004, a field survey and transplanting trials were conducted in eleven counties of three provinces for collection of habitat factor data. By multivariate statistical analysis the habitat factors were condensed into seven key habitat factors which described an actual habitat state. Introducing the niche theory into the research of M. sikkimensis, habitat niche-fitness (HNF) is defined as the degree of similarity of an actual habitat state to the optimum habitat. A new model of HNF is constructed to evaluate the adaptive extent of M. sikkimensis and the influence of habitat on seed yield with the key habitat factors as dependent variables and factor weights as parameters. The results showed that the values of HNF had a reasonable distribution and better reflected the varied differences under different habitat conditions, and that the cultivation measures had the effect of increasing the value of HNF and seed yield, increasing 14.26% and 99.61% at an average level, respectively. A seed yield prediction model was constructed with HNF as a surrogate for composite environmental factors. The estimated seed yield agreed well with the observed data, and the average of the absolute deviation percent was 5.46%, demonstrating the validity of the model in predicting seed yield. The HNF model and seed yield prediction model evaluated the threshold value of HNF, predicted the upper limit of seed yield for each study site and the limit seed yield, and have a wide range of prospects for practical application in the similar regions of the Qinghai-Tibet Plateau.

並列關鍵字

Habitat niche-fitness HNF ； Microula sikkimensis ； Seed yield ； The Qinghai-Tibet Plateau

國際替代計量

Seed Yield Predictions Based on the Habitat niche-fitness of Microula sikkimensis, an Endemic Oil Crop in the Qinghai-Tibet Plateau

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