Litterfall Mass, Chemistry, and Nutrient Retranslocation in a Monodominant Forest on Maracá Island, Roraima, Brazil 1
Litterfall Mass, Chemistry, and Nutrient Retranslocation in a Monodominant Forest on Maracá Island, Roraima, Brazil 1
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巴西罗赖马州马拉卡岛单一优势森林的凋落物质量、化学和养分再转移 1
DOI：
10.1111/j.1744-7429.1999.tb00132.x
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发表时间：
1999
期刊：
影响因子：
2.1
通讯作者：
J. Proctor
中科院分区：
文献类型：
--
作者：
D. M. Villela;J. Proctor
马拉加岛位于亚马逊雨林和Rio Branco‐Rupunini热带草原的边界。年降雨量约为。1800毫米，旱季从10月至3月，雨季从4月至9月。岛上部分地区和邻近大陆的森林类型以细柄盾叶草（学名：Peltogyne gracilipes）为主，是巴西亚马逊河流域物种最少的森林类型（树木直径大于10厘米）。本研究的目的是检验这一假设，即Peltogyne的优势是与一个不寻常的凋落物质量，营养浓度，或易位。在三种森林类型中的每一种中设置三个样地（50 × 50 m）：（1）Peltogyne丰富的森林（PRFa），以Peltogyne gracilipes为主;（2）Peltogyne贫乏的森林（PPF），Peltogyne稀疏出现;（3）没有Peltogyne的森林（FWPa）。在每个小区的11个随机放置的陷阱（0.32 m2）中，以约15-d的间隔收集凋落物360 d。成熟的Peltogyne叶随机收集从三个随机选择的林下Peltogyne树在每一个的三个PRFa地块在早旱季和早雨季。此外，在雨季早期收集Peltogyne嫩叶。化学分析散装（2个月的基础上）凋落物样品和年轻和成熟Peltogyne叶。PRFa（7.9 t/ha）、PPF（9.1 t/ha）和FWPa（8.6 t/ha）之间的年凋落量估计值相似;然而，PRFa的凋落量季节性不同，因为落叶Peltogyne，其Ca（9.3 mg/g，FWPa中为6.5 mg/g）和Mg（3.2 mg/g，FWPa中为1.9 mg/g）浓度较高。约40- 50%的N和P、25- 41%的K和2- 13%的Mg从盾叶草叶片中转移。
Maracá Island is on the boundary of the Amazon rain forest and the Rio Branco‐Rupunini savanna. The annual rainfall is ca. 1800 mm, with a dry season from October‐March and a wet season from April‐September. A forest type dominated by Peltogyne gracilipes (Caesalpiniaceae) occurs on parts of the island and the adjacent mainland, the least species‐rich (for trees > 10 cm DBH) of any recorded in Brazilian Amazonia. The goal of this study was to test the hypothesis that the dominance by Peltogyne is associated with an unusual litterfall mass, nutrient concentrations, or retranslocation. Three plots (50 × 50 m) were set up in each of three forest types: (1) Peltogyne‐rich forest (PRFa), dominated by Peltogyne gracilipes; (2) Peltogyne‐poor forest (PPF), with a sparse occurrence of Peltogyne; and (3) forest without Peltogyne (FWPa). Litterfall was collected for 360 d at ca 15‐d intervals in 11 randomly positioned traps (0.32 m2) per plot. Mature Peltogyne leaves were collected at random from three randomly selected understory Peltogyne trees in each of the three PRFa plots during the early dry and early wet season. Additionally, young Peltogyne leaves were collected during the early wet season. Chemical analyses were made on bulked (on a 2‐mo basis) litterfall samples and young and mature Peltogyne leaves. The estimated annual litterfall was similar among PRFa (7.9 t/ha), PPF (9.1 t/ha) and FWPa (8.6 t/ha); however, PRFa was distinguished by its litterfall seasonality, because of the deciduous Peltogyne, and its higher concentrations of Ca (9.3 compared to 6.5 mg/g in FWPa) and Mg (3.2 compared to 1.9mg/g in FWPa). About 40–50 percent of N and P, 25–41 percenr of K, and 2–13 percent of Mg were rerranslocated from Peltogyne leaves.