North Temperate Lakes LTER Northern Highland Lake District Coarse Woody Debris Logs

Coarse woody debris (CWD) is an important, but often neglected, component of lake
ecosystems. It is ecologically valuable because it creates littoral habitat
complexity but it is susceptible to manipulation by riparian process, in particular
removal by property owners. The objective of this study is to determine the spatial
scales at which human and environmental factors contribute to coarse woody debris
input and output dynamics. Coarse woody debris, boat docks, and riparian trees (with
the potential of becoming CWD) around the five lakes of the NTL-LTER site (Trout
Lake, Allequash Lake (north basin), Sparkling Lake, Crystal Lake, and Big
Muskellunge Lake) were measured in 1996 and 1997. CWD was defined as logs: greater than 2 m
length, greater than 15 cm diameter, mostly submersed in lake, less than 25 m from shore, and
less than 2 m water depth. Locations were determined as average of greater than 30 dGPS
positions. Numbered aluminum tags were attached to each log to facilitate the
long-term study of CWD. Return visits to Sparkling and Trout Lakes in 1997 found
some tags had been removed by ice or vandals. Heavier tags were attached to these
logs. The 1997 re-survey and tag check was not complete.

粗木质残体（Coarse Woody Debris, CWD）是湖泊生态系统中一类重要却常被忽视的组成部分。其具有重要生态价值，可塑造沿岸生境的复杂性，但易受河岸带过程干扰，尤其常被沿岸物业所有者移除。本研究旨在明确驱动粗木质残体输入与输出动态的人类与环境因子的空间作用尺度。研究人员于1996年与1997年，对NTL-LTER长期生态研究站点的5个湖泊（鳟湖、阿莱夸什湖北盆地、火花湖、水晶湖及大马斯凯尔隆吉湖）周边的粗木质残体、船坞以及具备发育为粗木质残体潜力的河岸带树木开展了系统性测量。本研究中粗木质残体的定义为：长度大于2米、直径大于15厘米、大部分浸没于湖水之中、距岸线小于25米且所处水深小于2米的原木。采样点位通过至少30次差分GPS（dGPS）定位结果的平均值确定。研究人员为每根原木加装带编号的铝制标签，以支撑粗木质残体的长期监测研究。1997年对火花湖与鳟湖的回访发现，部分标签已被冰层或蓄意破坏者移除，研究人员随即为这些原木更换了更为坚固的标签。1997年的复测与标签核查工作并未完全完成。