Review of provision for buffer strip width and extent

There are several areas of difficulty associated with the application of the results of research on the width and extent of filter strips.

Firstly many of the studies are site specific. This of course is a matter of necessity but nevertheless some of the measured parameters are not well defined. For example 'well stocked hardwood forest' in Trimble and Sartz (1957) with no indication of understory, 'steep slopes of granitic soil' in Haupt (1959), 'a strip of vegetation' in Cormack (1949), 'full length of stream' and 'major spring' in Van Groenewoud (1977), 'perennial and intermittent streams' in Cameron and Henderson (1979). The difficulties of definition are illustrated by the gaps and generality of Table 2.4 after Clinnick (1985).

Secondly there is a paucity of monitoring studies of logging operations carried out under standard practice.

Thirdly many of what are seen as the most valuable studies, because of their quantitative basis, do not raise the question of the frequency of occurrence of erosion at the actual boundary of the filter strip. For example Haupt (1959), Trimble and Sartz (1957), Ohlander (1976), Packer (1967) and Chalmers (1979).

Therefore a methodology was developed to provide information on the performance of buffer strips, as filter strips, around extensive areas of logging operations. The methodology incorporates measurement of the frequency and length of sediment deposition at the boundaries and within filter strips around logging coupes and the longevity of erosion as a consequence of logging operations. The results of the Field studies applying the methodology are reported in Chapter Three.

A u th o r/s L o c a tio n S o il ty p e G e o lo g y E ro d ib ility S lo p e % B uffer w id th (m ) B u ffer e x te n t (m ) B aim er e t al. U .S .A N .S N .S Low 0 ,3 0 ,6 0 * 9 ,3 2 , 5 5 N .S

( 1 9 8 2 ) M o d erate 0 , 3 0 , 6 0 1 2 ,4 3 ,7 1 N .S

S ev ere 0 ,3 0 , 6 0 1 4 ,5 2 ,8 8 N .S B ren & T u rn er V ic . C lay lo am S e d im e n ta ry Low N .S 2 0 S p rin g h e a d (1 9 8 0 ) C h a lm e rs N .S .W N .S G ra n ite S ev ere < 3 3 < 4 0 N .S ( 1 9 7 9 ) C o rb e tt e t al. U .S .A O rg a n ic lo am N .S N .S N .S 2 0 - 3 0 N .S ( 1 9 7 8 ) C o rm a c k C an ad a N .S S e d im e n ta ry N .S N .S 2 0 S p rin g h e a d (1 9 4 9 ) E p h e m e ra l stre a m C o r n is h N .S .W N .S N .S N .S N .S 2 0 C a tc h m e n t> 1 0 -1 0 0 (1 9 7 5 ) (H azard dep en d en t)

G ra y n o th N ew Z ealand C lay lo am N .S M od erate N .S 3 0 2 0 0 -3 0 0 m

(1 9 7 9 ) u p stre a m o f p o in t

o f p e re n n ia lity

H au p t U .S .A N .S G ra n ite S ev ere 2 0 -2 8 6 N .S

( 1 9 5 9 ) G ra n ite S ev ere 6 0 4 3 N .S

H aupt & Kidd U .S .A S an d y lo am G ra n ite S ev ere N .S 3 - 1 0 N .S (1 9 6 5 )

E rm an et al. U .S .A N .S N .S N .S N .S 3 0 N .S

(1 9 7 7 )

O 'L o u g h lin A u st. N .S N .S N .S V a ria b le V a ria b le S p rin g h e a d e t al.( 1982) P a c k e r U .S .A N .S G ra n ite S ev ere N .S 46 N .S ( 1 9 6 7 ) B a s a lt M o d erate N .S 11 N .S P a lm o n d o n C an ad a N .S Q u artzite N .S N .S 1 0 -1 5 N .S (1 9 8 2 ) T rim b le U .S .A S an d y lo am N .S N .S 0 8 F .U . N .S & 0 15 D .U . N .S S a rtz 3 0 26 F .U . N .S (1 9 5 7 ) 3 0 52 D .U . N .S 6 0 44 F .U . N .S 6 0 88 D .U . N .S V an C anada N .S N .S N .S F la t 15 N .S G ro e n e w o u d (1 9 7 7 ) N .S N .S N .S S te e p 6 5 N .S

W y lie ( 1 9 7 5 ) N ew Z ealand N .S G ra n ite S ev ere N .S 3 0 N .S

N.S = Not Specified; F.U = Water for farm use; D.U = Water for domestic use. * The three figures for slope correspond with those of buffer width.