(A) Carex bigelowii (B) Leersia oryzoides 



100 200 300 400 500 100 200 300 400 500 



Number of Passes 



Figure 20 — Relative vegetation cover after trampling and after 1 year of recov- 

 ery in four vegetation types in New Hampshire's White Mountains. Vertical 

 bars represent 1 standard error above and below the mean. 



Of the four vegetation types, the three types with 

 abundant ferns and forbs — Leersia, Lycopodium, and 

 Maianthemum — lost cover rapidly (fig. 20); their differ- 

 ences in relative cover after trampling were not statisti- 

 cally significant. In all three types, relative cover was 

 less than 40 percent after 75 passes and less than 10 

 percent after 500 passes. In contrast, the graminoid- 

 dominated Carex turf had a relative cover of 76 per- 

 cent after 75 passes and 20 percent after 500 passes. 



During the year after trgimpling, relative cover in- 

 creased on all trampling treatments in all types. The 

 increase was greatest in Maianthemum, the type that 

 lost the most cover initially. In the Leersia type, cover 

 also increased substantially; it increased more mod- 

 estly in the Lycopodium and Carex types. One year 

 after trampling, differences in relative cover among 

 Carex, Leersia, and Maianthemum were not signifi- 

 cant; all three had significantly more cover than Lyco- 

 podium. The relatively high tolerance of Carex came 

 fi'om its initial resistance to disturbance; the tolerance 



Leersia and Maianthemum reflected their ability to 

 recover following substantial disturbance. Lycopodium 

 was neither resistant nor resilient. 



Vegetation Height 



Before trampling, the ground cover was tallest in the 

 Leersia type (mean height of 31 cm, table 16). Heights 

 were moderate in the other three types (means of 10 to 

 15 cm). Even low levels of trampling caused immedi- 

 ate, substantial reductions in vegetation height. The 

 most dramatic was in the taU vegetation of the Leersia 

 type, 35 cm before 25 passes, reduced to just 3 cm after- 

 ward. Relative height differed significantly both with 

 the amount of trampling and with the vegetation type. 

 The interaction between these effects was not signifi- 

 cant (table 17). Differences were generally more pro- 

 nounced after trampling than after the year of recovery. 

 After recovery, only the 500-pass lane was different 

 fi-om the others. The only significant difference be- 

 tween vegetation types was that relative height was 

 less in Lycopodium than in Leersia and Maianthemum. 



Initially, height reduction was most pronounced in 

 Leersia and least pronoimced in Carex and Lycopodium 

 (fig. 21). In Leersia, the relative height was 9 percent 

 after 25 passes and 1 percent after 500 passes. In 

 Carex and Lycopodium, the relative height was about 



29 



