Walters M B, Field C B
Department of Biology, University of Utah, 84112, Salt Lake City, UT, USA.
Department of Plant Biology, Carnegie Institution of Washington, 94305, Stanford, CA, USA.
Oecologia. 1987 Jun;72(3):449-456. doi: 10.1007/BF00377578.
Piper auritum (H.B. & K.), a pioneer tree restricted to open sites and Piper hispidum (Swartz), a shrub common in sites ranging from recent clearings to shaded understory, both adjust photosynthetic characteristics in response to light availability during growth. The sensitivity of photosynthetic capacity to light availability during growth was indistinguishable for the two species growing in their natural habitat. Photosynthetic capacity was strongly correlated with leaf nitrogen in both species, and the relationship was similar between species. Dark respiration and leaf specific mass were more sensitive to light during growth in P. hispidum, the species with the broad habitat ange, than in P. auritum. In general, similarities between the species were more striking than differences between them. The differences in dark respiration could have important implications for carbon balance. The difference in the responsiveness of leaf specific mass to light indicates that the broad-ranging species maintains access to modes of response little utilized by the open-site specialist. We did not and, in the gas exchange characteristics, any evidence that the open site specialist is better suited than the generalist to high-light sites.
阔叶胡椒（Piper auritum (H.B. & K.)）是一种先锋树种，仅限于开阔地带生长；糙果胡椒（Piper hispidum (Swartz)）是一种灌木，常见于从近期开垦地到阴暗林下等各种生境中。这两种植物在生长过程中都会根据光照条件调整光合特性。在自然栖息地生长的这两个物种，其光合能力对生长期间光照条件的敏感度并无差异。两个物种的光合能力均与叶片氮含量密切相关，且种间关系相似。在具有广泛生境范围的糙果胡椒中，暗呼吸和叶比质量在生长期间对光照更为敏感，而阔叶胡椒则不然。总体而言，这两个物种之间的相似性比差异更为显著。暗呼吸的差异可能对碳平衡具有重要影响。叶比质量对光照响应的差异表明，广适性物种保留了开阔地特有物种很少利用的响应方式。我们并未在气体交换特征方面发现任何证据表明开阔地特有物种比广适性物种更适合高光环境。
