46 
IAN D. LUNT 
Fig. 6. Number of species recorded from quadrats in Themeda and Vulpia grassland, and boundaries drawn 
between species-poor, moderate and species-rich grassland. 
Grassland vegetation 
The minor grassland groups were differentiated 
by dominance rather than by floristics, as dis¬ 
crete floristic groups are not easily recognised 
from Table 2. Instead, it shows a gradual trans¬ 
ition from species-rich to species-poor quadrats, 
regardless of dominant species. Quadrats in 
which T. triandra cover was greater than 25% 
(i.e. Braun-Blanquet cover values 3 to 5) were 
defined as Themeda grassland; in all but four of 
such cases T. triandra cover exceeded 50% (i.e. 
obtained a cover value of 4 or 5). Quadrats in 
which T. triandra cover was less than 25% were 
defined as Vulpia grassland; T. triandra cover 
exceeded 5% (i.e. obtained a cover value of 2 to 
5) in only three such cases. Despite this arbitrary 
distinction, the two groups were generally easily 
recognizable in the field. Themeda and Vulpia 
grasslands were divided into three sub-units — 
species-poor, moderate and species-rich — in 
order to illustrate general patterns of species- 
richness in the reserve (Fig. 1). The boundaries 
between the sub-units were based on arbitrary 
discontinuities in species richness between 
quadrats (Fig. 6), and are indicated on the flor¬ 
istic table (Table 2) by dotted horizontal lines. 
Themeda grassland was the most widespread 
vegetation in the reserve (Fig. 1), and occurred 
in well-drained areas which were not ploughed 
last century and which were heavily grazed only 
briefly this century (see site history). In most 
areas T. triandra exceeded 90% cover (Fig. 7], 
On average, 17 species occurred in each quadrat, 
including nine exotics and eight natives (Fig. 3), 
but most quadrats possessed few individuals of 
few species. Discrete, species-rich patches 
occurred amongst areas that were generally spe¬ 
cies-poor. The patches were visually distinctive 
as tussocks of T. triandra were short and stunted 
and flowering culms were less abundant than in 
species-poor grassland. Native herbs such as 
Helichrysum apiculatum and Leptorhynchos 
squamatus were usually abundant. The patches 
were not associated with variations in physical 
soil features, such as soil texture, colour or pH. 
Fig. 7. Species-poor Themeda grassland with almost 
complete cover of T. triandra , December 1986; tape 
measure encloses a 5 x 3 m quadrat. 
