TEMPORAL SUCCESSION IN A DESERT STREAM ECOSYSTEM FOLLOWING FLASH FLOODING
TEMPORAL SUCCESSION IN A DESERT STREAM ECOSYSTEM FOLLOWING FLASH FLOODING
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DOI：
10.2307/2937346
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发表时间：
1982-01-01
影响因子：
6.1
通讯作者：
BUSCH, DE
中科院分区：
文献类型：
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作者：
FISHER, SG;GRAY, LJ;BUSCH, DE
在强烈的山洪暴发事件后，沙漠溪流的恢复被描述为生态系统时间演替的一个模型。夏末的洪水在美国亚利桑那州的Sycamore Creek，几乎消灭了藻类，无脊椎动物的立地作物减少了98%。洪水前典型的物理和形态条件在2天内恢复，生物群在2-3周内恢复。藻类群落反应迅速，在2周内实现了近100克/平方米的常绿产量。群落组成在演替早期以硅藻为主，后期以丝状绿和蓝绿为主。大型无脊椎动物也可以通过空中成虫的迁移和随后的产卵迅速重新定居于被剥落的基质上。在恢复的第1个月，主要的蜉蝣和双翅目类群完成了数代的生长发育。无脊椎动物的干生物量在1个月内达到7.3 g/m2。随着O2以类似的渐进方式增加，总初级生产量（Pg）在30天内达到6.6 g/m2。第5天Pg超过群落呼吸(R)，其余2个月Pg/R平均为1.46。序列。因此，这个生态系统是自养的，并通过横向干燥向下游输出有机物。NO3和P的吸收与净初级生产量成正比，且在光照期和暗期均表现出明显的下游下降趋势。将不同群落和生态系统属性的时间轨迹与Odum（1969）提出的用于诊断演替状态的轨迹进行了比较。在开放的、经常受到干扰的生态系统（如溪流）中，属性被特别修改的一致性较差。
Recovery of a desert stream after an intense flash flooding event is described as a model of temporal succession in lotic ecosystems. A late summer flood in Sycamore Creek, Arizona [USA], virtually eliminated algae and reduced invertebrate standing crop by 98%. Physical and morphometric conditions typical of the preflood period were restored in 2 days and the biota recovered in 2-3 wk. Algal communities responded rapidly and achieved a standing crop of nearly 100 g/m2 in 2 wk. Community composition was dominated by diatoms early in succession and by filamentous greens and blue-greens later. Macroinvertebrates also recolonized denuded substrates rapidly, largely by immigration of aerial adults and subsequent oviposition. Growth and development were rapid and several generations of the dominant mayfly and dipteran taxa were completed during the 1st mo. of recovery. Invertebrate dry biomass reached 7.3 g/m2 in 1 mo. Gross primary production (Pg) measured as O2 increased in a similar asymptotic fashion and reached 6.6 g.cntdot.m-2.cntdot.d-1 in 30 days. Pg exceeded community respiration (R) after day 5 and Pg/R averaged 1.46 for the remainder of the 2-mo. sequence. This ecosystem is thus autotrophic and exports organic matter downstream and by drying, laterally. Uptake of NO3 and P were proportional to net primary production and exhibited a marked downstream decline in concentration during both light and dark periods. Temporal trajectories of various community and ecosystem attributes are compared with those suggested by Odum (1969) to be diagnostic of successional status. Agreement was poor in attributes which are especially modified in open, frequently disturbed ecosystems such as streams.