毛柄小勾儿茶(Berchemiella wilsonii var. pubipetiolata)为我国分布于浙江、安徽局部地区的特有珍稀物种，由于自身和人为干扰的原因，该种受到灭绝威胁。该文在2×2联列表基础上，应用χ2检验、联结系数(AC)分别检测了毛柄小勾儿茶在4个分布点与群落中乔、灌两层植物的种间联结性。综合比较χ2检验与AC值的测定结果，在4个分布点，毛柄小勾儿茶与群落中其它种群的关联情况十分相似：1)绝大多数种群与毛柄小勾儿茶的AC值在-0.2至0.2之间，即无关联；2)与毛柄小勾儿茶存在显著关联的种群仅有一个或无；3)优势种群与毛柄小勾儿茶关联小。这说明4个分布点毛柄小勾儿茶在群落中都具有很大的独立性或随机性，它只是群落的伴生种或偶见种。研究结果对为该物种制定合适的就地保护措施和恢复计划具有参考价值。
Berchemiella wilsonii var. pubipetiolata is a local endemic species distributed discontinuously throughout the Mt. Dabieshan region of the Anhui Province and Mt. Qingliangfeng region of Zhejiang Province, eastern China. Because of the human impacts on natural ecosystems, it is under the threat of extinction and has been ranked as an endangered species. In this study, we assessed the community status of B. wilsonii var. pubipetiolata as a basis for its conservation. Based on 2×2 contingency tables, the interspecific correlation of B. wilsonii var. pubipetiolata in the tree layers and shrub layers with other species analyzed in four different communities were studied by using χ2 tests and association coefficients (AC). The results indicated that the interspecific correlations of B. wilsonii var. pubipetiolata to other species were very similar in each of the four sites. The value of AC between most species and B. wilsonii var. pubipetiolata ranged from -0.2 to 0.2, which indicated that there was no relationship between B. wilsonii var. pubipetiolata and other species. The χ２ analysis indicated that either no species or only one species in a community had a significant relationship with B. wilsonii var. pubipetiolata. There were no significant relationships between the dominant species and B. wilsonii var. pubipetiolata in any of the communities. All of the above results imply that B. wilsonii var. pubipetiolata was distributed independently or had random occurrence in the different communities indicating that it is an incidental or rare species. This case study highlights the importance of having a good understanding of the ecological characteristics of uncommon plants as a basis for making decisions regarding their conservation.