Tone (19/0) 16: 53-60. 53

N O K T H C A P E Q U A D R A T S 1969

by W. J . Rae*

S U M M A R Y

Vegetat ion maps of quadrats es tab l i shed by Gravatt (1966) at Kerr P t . in the North Cape Scenic Reserve are presented. Percentage cover of p lants present in the quadrats was estimated and i s provided in tables and figures. Changes which have occurred s ince previous surveys are d i s c u s s e d .

I N T R O D U C T I O N

In December 1965 Gravatt set up quadrats in the North Cape Scenic Reserve near Kerr P t . to a s s e s s any changes occurr ing i n the vegetation. C l e a r e d quadrats were es tab l i shed to determine the re-co lon izat ion pattern of bared areas in the P l a t e a u Scrub. (Area at X j ) . A quadrat was set up in a rush assoc ia t i on on a ridge which had been recently burnt. (Area at X 2 ) . At this time the vegetation in the uncleared quadrats at X j was mapped and the numbers and dominance of each spec i e s present at X 2 estimated (Gravatt 1966). In January 1967 Johnstone mapped the vegetation in the c leared quadrats at X j and re -estimated the vegetation i n the quadrat at X 2 . In August 1969, during an A u c k l a n d U n i v e r s i t y F i e l d C lub s c i e n t i f i c camp, the area was rev i s i ted and the quadrats inspected. The present paper deals with observations made and data compiled from these quadrats.

M E T H O D

Mapping of the vegetation was carried out after the method of Gravatt (1966) and Johnstone (1967). In addi t ion , percentage cover was estimated by dropping a needle at points taken at regular intervals along l i n e s running across the quadrats, and recording the f irst hit at each point. The number of h i ts per spec ies expressed as a percentage of the total number of points taken i s an estimate of the cover contributed by each part icular spec ies . Other spec ies present but not hit were a lso recorded.

•Department of Botany, University of Auckland.

54

R E S U L T S A N D DISCUSSION

Hie Quadrat at \\ (Gravatt,1966) Sited in the Plateau Scrub

Results

Figures 1 and 2 are the vegetation maps of the uncleared quadrats which measured 6 ft. x. 6 ft. F igures 3 and 4 are the vegetation maps of the c leared quadrats which measure 4 ft. x. 4 ft. These maps can be compared d irec t ly with those of Gravatt (1966) and Johnstone (1967).

Percentage cover and spec ies present for these quadrats are given in T a b l e 1. P o i n t s for the a n a l y s i s were taken every s i x inches along l i n e s which were s i x inches apart for the c leared quadrats, g i v ing 81 points , and twelve inches apart for the uncleared quadrats, g iv ing 91 points .

K E Y FOR FIGS. 1, 2, 3 & 4

Cassinia amoena Ca Cyathodes parviflora Cp C. fraseri Cy Phormium tenax F Gnaphalium luteo-album G Hypochaeris radicata H Haloragis cartilaginca He Hebe ligustrifolia He Haloragis procumbens Hp Lepidosperma laterale L Lobelia anceps La Leptospermum scoparium L s Pimelia prostratu P i Poa annua Po Pomaderris prunifoliii Pm

var. edgerleyi

P. phylicifolia Pp var. ericifolia

Pteridium aquilinum Pt var. esculcntum

Tkelymitra longi/olia T

U n f e n c e d F e n c e d

FIGS I and 2: Vegetation maps of the uncleared quadrats which can be compared directly to those of Gravatt (1966). Each quadrat measures 6 ft by 6 ft.

U n f e n c e d

Hp

Ls

Pt Pm

Hp >

Hp L * Pi

H p ^ P t

P. uHr HPPI

Cy T Cy Pi

Hp Hp

Pt U p ,

G

Po *

P.

H, L * T P l Pm Pt

T T

H ( P t Ls '

PI U n R Pi T

Hp Hp

Hp Ls Hp

Pi Hp

Hp Ho ft HP

Pt

" Po

r p| Pi

PI P m

P m P tp r

p P t p PL rm Km '

Po

Hp Hp Po

i r ,.

s * *

Hpjy Hp

LS

Pi

Ca

H P „ Pm Pi

Pt I pi Hp Br.

Ls Pi , 1 1 * .

HpPt Pp Lsr">

F i g u r e 3

F e n c e d Po

G

L

Pm

Ls Co

C a

G LS

Po

ft Pb G

Pm T

_ Ls P» Cj

ft, r

C o

p

Pm * P ~ P ° Hp

L S P .

p, * P -

P o P " P °

U P «

H P

* * P+ P> ii ^ . Hp Hp

G p m

Hp ft P m

Pi Pt

C y C v

Hp

* Ur Hp H , '

' Hp Pm

Pi P m

H M f P o H o Hp Pm

L s

Pm H

Pm P i P l P o

F i g u r e

FIGS 3 and 4: Vegetation maps of the cleared quadrats Johnstone (1967). Each quadrat measures 4 ft by 4 ft.

which can be compared directly to those of

57

T A B L E I: Percentage cover of species and species present in quadrats located in the plateau scrub.

P E R C E N T A G E C O V E R U N C L E A R E D C L E A R E D

Unfenced Fenced Unfenced Fenced Bare ground Pteridium aquilinum

var. csculentum

3.30

5.50

0

9.90

76.25

11.25

82.70

2.50 Haloragis procumbens 6.25 3.70 Poa annua 1.00 + 3.70 Pomadcrris prunifolia

var. edgerleyi 8.80 2.20 1.25 3.70

Lepidosperma laterale 4.40 3.30 2.50 Hebe ligustrifolia 5.50 6.60 Cassinia amoena 11.00 10.00 1.25 + Leptospermum scoparium 60.50 65.00 + 1.20 Cyathodes fraseri + + 1.25 + Cyathodes parviflora 1.00 Pimelia prostrata 1.00 + Gnaphalium lutco-album 1.00 + + Thelymitra longifolia + 1.25 + Cassytha paniculata + + 1.25 + Hypochaeris radicata + + Haloragis cartilaginea + Phormium tenax + Lobelia anceps + Pomaderris phylicifolia

var. ericifolia +

+ Species present but not hit.

D i s c u s s i o n

The plateau scrub in this area seems to have changed l i t t l e from that descr ibed by Gravatt (1966). The dif ferences in the uncleared quad­rats are mainly f luctuations in s i z e of Hebe ligustrifolia and Cassinia amoena bushes and the increase in s i z e of some clumps of Lepidosperma laterale. P l a n t s l abe l l ed Cladium junceum in f igures 2 and 3 by Gravatt (1966) are in i d e n t i c a l pos i t ions to those now occupied by clumps of Lepidosperma laterale, no Cladium junceum be ing observed i n these quadrats by the present author. The fenced quadrat now contains a young plant of Phormium tenax w i th leaves approximately 18 inches high.

In the c leared quadrats notable and important entries s ince the survey by Johnstone (1967) are: Haloragis procumbens, Cassinia amoena,

58

Cassytha paniculata in both quadrats, Haloragis cartilaginea, Lepido­sperma laterale in the fenced quadrat, and Leptospermum scoparium in the unfenced quadrat.

Any differences in percentage cover of the spec ies between fenced and unfenced quadrats is probably no greater than the variat ion which could be expected u s i n g the point a n a l y s i s technique.

Other features shown by data in Tab le I are as fo l lows:

The c leared quadrats s t i l l have about 80 per cent bare ground after three and a hal f years.

Pteridium aquilinum var. esculentum provides a s imi lar amount of cover in both the c leared and uncleared quadrats probably ind icat ing that the rhizomes were not removed on c l ear ing and that there has been l i t t l e difference in their subsequent growth.

The vegetation in the area of these quadrats i s a low scrub l e s s than 18 inches high dominated by Cassinia amoena and Hebe ligustrifolia with a background mat of Leptospermum scoparium 6 to 12 inches high. The extent of th is mat cannot be shown adequately with vegetation maps, but with the point ana lys i s technique used, it was found to provide 60 to 65 percent of the ground cover.

P l a n t s with prostrate habits such as Haloragis procumbens and Pomaderris prunifolia var. edgerleyi are among the f irst c o l on i s t s in the c leared quadrats, forming the major proportion of the total plant cover. Spec ies forming a major part of the cover in the uncleared quadrats are now present in measurable numbers in the c leared quadrats.

B y comparing the present survey with those by Gravatt (1966) and Johnstone (1967) it i s evident that there are minor seasonal dif ferences. In this survey Anagalis arvensis, Erichtites atkinsonii, Odontites viscosa and Dichondra repens were not recorded. A few stunted plants of Hypo-chaeris radicata were found, and most plants of Poa annua were very stunted.

T h i s seasonal difference i s not considered to be a compl icat ing one as recording establ ishment of perennial herbs and shrubs i s the long term object ive i n this study.

Further a n a l y s i s of the above type w i l l enable changes in the composit ion of the quadrat to be fo l lowed more readily than is poss ib l e

59

T A B L E 2: Percentage cover of species found in the 'rush' quadrat.

Percentage Cover

Schoenus brevifolius 46.40 Leptospermum scoparium 16.85 Poa annua 13.85 Cyathodes fraseri 3.01 Pomaderris phylicifolia

var. ericifolia 1.82 Cassinia amoena 1.82 Lepidosperma laterale 0.60 Pomaderris kumeraho 0.60 Pteridium aquilinum

var. esculentum 0.60 Bare ground 14.45

by mapping. It w i l l be interest ing to see how c l o s e l y the percentage cover values of spec ies in the c leared quadrats approach those of spec ies in the uncleared quadrats as the area becomes co lon ized .

The quadrat at X 2 (Gravatt, 1966) Sited in Rushes

Results

The percentage cover of each spec ies in this quadrat, which meas­ures 12 ft. x. 12 ft. was est imated. P o i n t s were taken every 12 inches along l i n e s 12 inches apart, g iv ing 169 po ints . T a b l e 2 shows the results of th is a n a l y s i s .

Other spec ies present but not hit were Pomaderris prunifolia var. edgerteyi, Cassytha paniculata, and Drosera auriculata.

Discussion

One very important correction to be made i s that the dominant spec ies in this quadrat, providing 46 per cent of the cover, i s Schoenus brevifolius not Cladium junceum as ident i f ied by Gravatt (1966) and Johnstone (1967). Gravatt (1966) described the dominant spec ies in this quadrat as "Cladium junceum . . . not in c lumps but evenly spread throughout." The habit , general morphology, and stem anatomy are those of Schoenus brevifolius. Schoenus brevifolius s t i l l dominates numerical ly and in height.

60

A s a count of the other main spec i e s was not carr ied out no further direct comparison with earl ier surveys can be made. However, one import­ant plant , new to th is quadrat, i s Cassinia amoena which i s a co-dominant in the area at

The low value for Poa annua, which was reported by Gravatt (1966) to be numerical ly co-dominant with Schoenus, i s almost certa in ly due to a seasonal var iat ion .

C O N C L U S I O N

There i s l i t t l e evidence from the fenced ana unfenced quadrats to suggest that large grazing animals are act ive in this northern area of the North Cape Scenic Reserve . Regeneration of the bared areas i s s low with 80 per cent of the area s t i l l bare ground.

The est imation of percentage cover for a l l the quadrats has pro­vided a quantitat ive bas is for comparison with future invest igat ions i n the area.

A C K N O W L E D G E M E N T S

I wish to thank M i s s J e a n Ferguson and Mr. C. Qui l ter for a s s i s t ­ance i n the f i e l d , and M i s s e s E l i z a b e t h D i c k s o n and R o s a l i e Lambert and Mr. J . Braggins for help with the ident i f i ca t i on of certain spec i es .

R E F E R E N C E S

A L L A N , H. H. 1961

B E E V E R , R. E . , 1967 J A N E , G. T .

C H E E S E M A N , T. F . 1925

G R A V A T T , D. J . 1966

JOHNSTONE, I. M. 1967

" F l o r a of New Z e a l a n d " . Volume 1. Govt. Printer, Wellington.

Additional Plant Records From North Cape. Tane 13: 147-148.

"Manual of the New Zealand F l o r a " . Govt. Printer, Wellington.

Establishment of Permanent Quadrats in Plateau Scrub at North Cape. Tane 12:87- 91.

A Report on the Permanent Quadrats at North Cape. Tane 13:143-146.

W H E E L E R , J . M. 1963 The Vegetation of the North Cape Area. Tone 9:63-83.