The Effectiveness of Different Buffer Widths for Protecting Headwater Stream Temperature in Maine
The Effectiveness of Different Buffer Widths for Protecting Headwater Stream Temperature in Maine
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缅因州不同缓冲区宽度保护源头水流温度的有效性
DOI：
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发表时间：
2006
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影响因子：
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通讯作者：
A. Whitman
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作者：
Ethel Wilkerson;J. Hagan;D. Siegel;A. Whitman
我们评估了木材采伐对缅因州西部一级水源夏季水温的影响。15条河流被分配到以下5种处理中的一种：(1)无河流缓冲的砍伐；(2)两侧均有11米的部分采伐缓冲区；(3)砍伐面积为23米、部分采伐的缓冲区；(4)局部切割，无指定缓冲；(5)未收获的对照。在3年的时间里，我们在收获前后、收获区上下每小时测量一次夏季水温。没有缓冲区的溪流在收获后平均每周最高温度增幅最大（1.4-4.4°C）。缓冲层为11 m的河流温度升高幅度较小，但不显著（1.0 ~ 1.4°C）。具有23 m缓冲层的河流、部分收获处理的河流和对照河流在收获后没有变化。在任何处理组中，平均每周最高温度从未超过布鲁克鳟鱼的热应力极限（25°C）。无缓冲带的河流日平均温度波动从1.5°C/天增加到3.8°C/天，而有11 m缓冲带的河流日平均温度波动增加不显著，为0.5-0.7°C/天。在无缓冲处理下，采收区以下100 m的水温高于采收前水平。我们得出的结论是，小源头溪流的水温受到11米缓冲带（树冠保留率为60%）的保护，不受砍伐的影响。
We evaluated the effect of timber harvesting on summer water temperature in first-order headwater streams in western Maine. Fifteen streams were assigned to one of five treatments: (1) clearcutting with no stream buffer; (2) clearcutting with 11-m, partially harvested buffers, both sides; (3) clearcutting with 23-m, partially harvested buffers; (4) partial cuts with no designated buffer; and (5) unharvested controls. Over a 3-year period we measured summer water temperature hourly before and after harvesting, above and below the harvest zone. Streams without a buffer showed the greatest increase in mean weekly maximum temperatures following harvesting (1.4–4.4°C). Streams with an 11-m buffer showed minor, but not significant, increases (1.0–1.4°C). Streams with a 23-m buffer, partial-harvest treatment, and control streams showed no changes following harvest. The mean weekly maximum temperatures never exceeded the thermal stress limit for brook trout (25°C) in any treatment group. The mean daily temperature fluctuations for streams without buffers increased from 1.5°C/day to 3.8°C/day, while with 11-m buffers fluctuations increased nonsignificantly by 0.5–0.7°C/day. Water temperatures 100 m below the harvest zone in the no-buffer treatment were elevated above preharvest levels. We concluded that water temperature in small headwater streams is protected from the effects of clearcutting by an 11-m buffer (with >60% canopy retention).