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<div><i> E a r t h S u r f a c e P r o c e s s e s a n d
L a n d f o r m s </i> 1 8 S e p t e m b e r 2 0 0 7 </div>
<div> D O I : 1 0 . 1 0 0 2 / e s p . 1 5 9 3 </div>
<div><br></div>
<div><b> C h a r a c t e r i s t i c s , d i s t r i b u t i o n
a n d g e o m o r p h i c r o l e o f l a r g e w o o d y
d e b r i s i n a m o u n t a i n s t r e a m </b></div>
<div><b> o f t h e C h i l e a n A n d e s </b></div>
<div> A n d r e a A n d r e o l i et al</div>
<div><br></div>
<div> K e y w o r d s : l a r g e w o o d y d e b r i s ;
c h a n n e l m o r p h o l o g y ; v a l l e y j a m s ;
l o g - s t e p s ; A n d e s</div>
<div><br></div>
<div> A b s t r a c t <br>
T h e p a p e r p r e s e n t s a n a n a l y s i s o f
a m o u n t s , c h a r a c t e r i s t i c s a n d
m o r p h o l o g i c a l i m p a c t o f <br>
l a r g e w o o d y d e b r i s ( L W D ) i n t h e
T r e s A r r o y o s s t r e a m , d r a i n i n g a n
o l d - g r o w t h f o r e s t e d b a s i n </div>
<div> ( 9 … 1 k m 2 ) o f t h e C h i l e a n
S o u t h e r n A n d e s . L a r g e w o o d y d e b r i s
h a s b e e n s u r v e y e d a l o n g a </div>
<div> 1 … 5 k m l o n g c h a n n e l s e c t i o n
w i t h a n a v e r a g e s l o p e o f 0 … 0 7 a n d
a g e n e r a l s t e p- p o o l / c a s c a d e </div>
<div> m o r p h o l o g y . S p e c i f i c w o o d
s t o r a g e i s v e r y h i g h ( 6 5 6 7 1 0
m 3 h a" 1 ) , c o m p a r a b l e t o t h a t
r e c o r d e d <br>
i n o l d - g r o w t h f o r e s t e d b a s i n s i n
t h e P a c i f i c N o r t h w e s t . H a l f o f t h e
L W D e l e m e n t s w e r e l o c a t e d <br>
o n t h e a c t i v e f l o o d p l a i n , a n d
a r o u n d t w o - t h i r d s o f L W D e l e m e n t s
w e r e f o u n d i n a c c u m u l a t i o n s . <br>
D i f f e r e n t t y p e s o f l o g j a m w e r e
o b s e r v e d , s o m e h e a v i l y a l t e r i n g
c h a n n e l m o r p h o l o g y <br>
( l o g - s t e p s a n d v a l l e y j a m s ) , w h i l e
o t h e r s j u s t l i n e t h e c h a n n e l e d g e s
( b a n k f u l l b e n c h j a m s ) . <br>
L o g - s t e p s r e p r e s e n t a p p r o x i m a t e l y
2 2 % o f a l l s t e p s , w h e r e a s t h e
e l e v a t i o n l o s s d u e t o L W D <br>
( l o g - s t e p s a n d v a l l e y j a m s )
r e s u l t s i n 2 7 % l o s s o f t h e t o t a l
s t r e a m p o t e n t i a l e n e r g y . A b o u t </div>
<div> 1 6 0 0 m 3 o f s e d i m e n t i s s t o r e d i n
t h e m a i n c h a n n e l b e h i n d L W D
s t r u c t u r e s , c o r r e s p o n d i n g t o </div>
<div> a p p r o x i m a t e l y 1 5 0 % o f t h e a n n u a l
s e d i m e n t y i e l d .</div>
<div><br></div>
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<div><font face="Lucida Grande" size="-1"
color="#000000"> </font><font face="Bookman Old Style"
color="#000000"
>=============================================================<br>
"The outlines of the carbon cycle, in organisms at any rate,
have been evident since Joseph Priestley's day. The critical step,
'obviously', is the photosynthetic reduction of carbon dioxide."<br>
<br>
"What can be said with assurance is that there is a unique and
nearly ubiquitous compound, with the empirical formula<b>
H</b>(2960)<b>O</b>(1480)<b>C</b>(1480)<b>N</b>(16)<b>P</b>(1.8)<b>S</b
> called living matter. Its synthesis, on an oxidized and
uncarboxylated earth, is the most intricate feat of chemical
engineering ever performed - and the most delicate operation that
people have ever tampered with."<br>
<br>
Edward S. Deevey, Jr. Mineral Cycles.<br>
<i>Scientific American</i>, September 1970</font><br>
<font face="Bookman Old Style" color="#000000"></font></div>
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