Table 10.— Mean increase in penetration resistance (kg/cm^) (treatment value minus 



control value) after various amounts of trampling for each habitat type and for 

 all types combined^ 



Number 







Habitat type^ 







All 



of 



ABLA/ 



ABLA/CLUN- 



FESC- 



PSME/ 



ABLA/ 



ABLA/ 



habitat 



passes 



CLUN 



VACA phase 



FEID 



SYAL 



VACA 



XETE 



types 



D 



U. 1 out^ 



u. ^ 



O.Olab 



0.06ab 



n M^hr 



U. ^3vj 



U. 1 u 



1 





Ud 



.10a 



.49a 





K4a 







91 a 





.25a 



.21a 



"^Da 

 . OUa 



. / od 



.Oc. 



zn 







.38b 



.39b 





fifth 



.O 1 



1 D 



• ODd 



Ada 



.21a 



.44a 



Qfia 



Tia 



47 



ou 



1 Rah 



Cilia 



.38ab 



.66bc 



4Tah 

 .HOaU 





S9 



. 



1 uu 



.UOaU 



Ha 



.16ab 



.35ab 





1 nrir 





onn 





ft^iah 

 .o Jdu 



.51a 



.84ab 



1 . 1 yu 



1 1 Rah 

 1 . 1 OdU 



Q7 



oUU 





.57*rCI 



1.39a 



1.35a 



1 9Ra 



1 1 4a 

 1 . 1 Hd 



1 iq 



1 . 1 y 



400 



.83ab 



I.IOab 



1.78bc 



.75a 



1.91 be 



2.53c 



1.59 



600 



.43a 



.33a 



1.06ab 



2.43c 



1.65bc 



2.10c 



1.52 



800 



.93a 



2.33a 



1.93a 



1.16a 



2.08a 



2.68a 



1.89 



900 



.71a 



1.05ab 



2.28b 



.98a 



I.SOab 



2.03ab 



1.59 



1,200 



.81a 



1.63ab 



2.08b 



2.89b 



2.29b 



2.31b 



2.16 



1,600 



.03a 



1.68b 



1.93b 



1.65b 



2.58b 



2.45b 



1.89 



All 



.38a 



.63a 



.93b 



.94b 



1.17bc 



1.33c 



.97 



amounts 

















'Any two values in 



the same row followed by the same letter are not significantly different 



(Duncan's 



multiple range test, « = 0.05). 

 ^Habitat types are: 



ABLA/CLUN = Abies lasiocarpa/Clintonia uniflora 



ABLA/CLUN-VACA = Abies lasiocarpa/Clintonia uniflora-Vaccinium caespitosum phase 



FESC-FEID = Festuca scabrella-F. idahoensis 



PSME/SYAL = Pseudotsuga menziesii/Symphoricarpos albus 



ABLA/VACA = A£i;es lasiocarpa/Vaccinium caespitosum 



ABLA/XETE = Abies lasiocarpa/Xerophyllum tenax. 



CONCLUSIONS AND MANAGEMENT 

 IMPLICATIONS 



Before discussing conclusions and management impli- 

 cations, it is important to reemphasize that these results 

 apply to only the first-year effects of trampling. They 

 are useful for understanding the initial effects of recrea- 

 tion use on undisturbed sites. The results presented 

 here— as well as those of all the other experimental tramp- 

 ling studies reviewed— cannot be extended to sites where 

 use occurs year after year. That will only be possible 

 after evaluating the effects of several years of trampling 

 and recovery. 



The first-year results corroborated the following: 



1. For most habitat types there is a curvilinear rela- 

 tionship between trampling intensity and both vegeta- 

 tion loss and soil compaction. The additional impact 

 caused by heavier trampling decreases as trampling inten- 

 sity increases. This has significant implications for 

 managing the distribution of human use. 



2. The grassland was much more resistant to vegeta- 

 tion loss than any of the forested habitat types. Of the 

 forested types, those suffering the most cover loss were 

 those with large proportions of erect, leafy-stemmed 

 forbs. Mosses and Xerophyllum tenax (beargrass) were 

 the major resistant plants in the forested types. Conse- 



quently, ABLA/XETE was the most resistant forested 

 habitat type. 



3. In contrast to vegetation loss and soil compaction, 

 mineral soil was exposed only after a large amount of 

 trampling. As surveys of existing campsites show (Cole 

 1982c), all but the most infrequently used recreation 

 sites will suffer vegetation loss, but only the most fre- 

 quently used sites will experience significant baring of 

 mineral soil. This suggests that selecting a site with 

 resistant vegetation is important at low to moderate use 

 levels, but where use is heavy it would be better to select 

 sites less prone to exposure of mineral soil— sites with 

 relatively thick organic horizons and low surface erosion 

 potential. 



4. Variations in trampling frequency had considerably 

 less effect on vegetation loss than the total amount of 

 trampling, differences between habitat types, and even 

 local variations in species distribution within habitat 

 types. Consequently, trying to influence whether a given 

 number of visits are concentrated in time or spread 

 throughout the use season will, in most cases, have little 

 effect on how much vegetation is lost. 



The information generated from this study can be 

 most usefully applied in deciding how to distribute use 

 spatially in order to minimize impacts. As these results 

 show, impact is dependent upon both amount of use and 



31 



