Long-Term Sediment Accretion in Bottomland Hardwoods Following Timber Harvest Disturbances in the Mobile-Tensaw River Delta, Alabama, USA
Long-Term Sediment Accretion in Bottomland Hardwoods Following Timber Harvest Disturbances in the Mobile-Tensaw River Delta, Alabama, USA
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美国阿拉巴马州莫比尔-滕索河三角洲木材采伐干扰后洼地硬木的长期沉积物堆积
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发表时间：
2012
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通讯作者：
Erik B. Schilling
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作者：
W. Aust;S. E. McKee;John R. Seiler;B. Strahm;Erik B. Schilling
漫滩洪水的沉积物堆积是低地森林的一个重要功能，但很少有长期的数据存在。一项长期研究项目（1986-2010）调查了扰动对水tupelo（尼萨aquatica L.）沉积物淤积的影响。落羽杉（Taxidistichum L.）Rich.）位于亚拉巴马南部莫比尔-滕索河三角洲的一个低地。皆伐后的干扰处理是直升机提取（HELI），集材机模拟地面提取（SKID），和去除再生与草甘膦除草剂（GLYPH）。原始支架的相邻部分提供了参考（REF）。定期测量的沉积物针（324针下降到252通过磨损）表明，REF捕获19.2厘米的沉积物在1986年和2010年之间。在同样的24年中，HELI、SKID和GLYPH分别捕获了31.2、28.9和40.8厘米的沉积物。各处理间的年淤积量与草本植物生物量呈正相关（r = 0.6624），而累积淤积量与漫滩天数呈正相关（r = 0.8673）。1986年和2010年进行的现场高程调查与1964年至1986年扰动前的总体沉积物堆积和137 Cs评估密切相关。所有的方法表明，长期的沉积物堆积率为0.7-1.25厘米/年，这是在其他低地硬木系统中发现的堆积率相似。这项研究表明，河岸森林管理的做法，增加草本植被是至关重要的沉积物淤积率。
Sediment accretion from overbank floodwaters is an important function in bottomland forests, yet few long-term data exist. A long-term research project (1986–2010) investigated effects of disturbances on sediment accretion in a water tupelo (Nyssa aquatica L.)-baldcypress (Taxodium distichum L. Rich.) bottomland in the Mobile-Tensaw River Delta, southern Alabama. Disturbance treatments subsequent to clearcutting were helicopter extraction (HELI), skidder simulation of ground based extraction (SKID), and removal of regeneration with glyphosate herbicide (GLYPH). An adjacent portion of the original stand provided a reference (REF). Periodic measurements of sediment pins (324 pins declined to 252 through attrition) indicate that REF trapped 19.2 cm of sediment between 1986 and 2010. During the same 24 years, HELI, SKID, and GLYPH trapped 31.2, 28.9, and 40.8 cm of sediment, respectively. Annual sediment accretion within the treatments was positively correlated to herbaceous biomass (r = 0.6624) while cumulative sediment accretion was positively correlated with days of overbank flooding (r = 0.8673). Site elevation surveys conducted in 1986 and 2010 matched closely with overall sediment accretion and 137Cs evaluations of the pre-disturbance period between 1964 and 1986. All methods indicated a long-term sediment accretion rate of 0.7–1.25 cm/yr, which is similar to accretion rates found in other bottomland hardwood systems. This study indicates that riparian forest management practices that increase herbaceous vegetation are of critical importance to sediment accretion rates.