是否低估了本地热带蝴蝶区系成分的丰富度?样带观察结果的剖析(英文)

Is richness of local tropical butterfly faunas underestimated? Perspectives gained from biases in transect observations

作者利用在菲律宾吕宋岛Calumpang Lejos (Indang, Cavite) 地区以样带法收集的蝴蝶种数记录, 检验了类群记录是否低估了当地种数丰富度和多样性。在两年间长达340 h的457个样带调查中, 没有出现种数积累曲线突破情况。折叠估计、有偏纪录、丰富度的地区变化以及与群落生境有关的相对多度均支持当地蝴蝶区系丰富度被低估的观点。在样带调查中, 多样性及体色类型记录具有误差。这些误差反映在发现日期以及同种的科学命名日期, 并且涉及到菲律宾吕宋岛发现的所有物种, 且与蝴蝶的体型大小有关。数量较少、体型较小和不显眼的种类发现得较晚。在分类上亦有误差, 弄蝶科和灰蝶科比粉蝶科和蝶科稀少、体小且不显眼, 发现和命名较晚。翅型特征不明显的种类具有体型较小的趋势, 使所做的形态特征记录产生错误。我们发现菲律宾吕宋岛Calumpang Lejos (Indang, Cavite) 地区的稀有种类体型明显较小和特征较不明显。由于区域性样带调查偏差包括了灰蝶科但未包括弄蝶科, 因此偏差源于对树冠型蝴蝶种类的记录偏低。本文讨论了在其它生物区系以及热带蝴蝶保育上的应用, 认为今后需要使用误差小的新技术进行动物区系中物种丰富度的可靠估计。

We use cumulative species records of butterflies from transects collected locally at Calumpang Lejos (Indang, Cavite) on Luzon, Philippines, to test whether inventories of taxa underestimate local species richness and diversity. No limit emerges in species cumulative curves despite 457 transects carried out over two years, including 340 hours of observation. Jackknife estimates, biased recording, and local variation in richness, relative abundances and diversity associated with contrasts in biotopes, all support the notion of the richness of local butterfly faunas being underestimated. Bias was recorded locally in transect records for abundance and colour pattern. This bias was mirrored for find dates and dates of scientific naming for the same species, as well for all species found on Luzon and throughout the Philippines and extended to butterfly size. Less abundant, smaller and duller species are discovered significantly later. Bias is taxonomically based; Hesperiidae and Lycaenidae have significantly later find dates and scientific naming dates than Papilionidae, Pieridae and Nymphalidae and are also significantly less abundant, smaller and duller. Biased recording may be exacerbated by the reinforcement of physical apparency:species with less apparent wing patterns tend to be smaller. It was found that rarer species were significantly smaller and duller for Luzon and at Calumpang Lejos. As bias for the local transects involves Lycaenidae but not Hesperiidae, it is suggested that bias, in this study, is caused by under-recording of canopy species. The implications for faunal inventories of other organisms and conservation of tropical butterflies are discussed; there is a need for new techniques, which account for bias, to provide suitable estimates of species richness from faunal samples.