Report on the Macquarie Island Collection

held in the ANBG seedroom (Nursery) and in the ANU Botany Dept. (Faculties) growth cabinets.

March 1989

Barrie Hadlow (barrie@anbg.gov.au)

When received in November 1989, this plant collection was divided unequally between both of the above venues. Differing temperature and light controls exist in each area. Potting mix for the hole collection was uniform (6 pts composted pinebark to 4 pts sharp quartz sand and fertilizer) and watering was manually applied when needed in both locations.

Temperature control:

At ANBG

Temperature was regulated within the room by two evaporative collecting units (1 wall fixed, the other mobile) set opposite each other and 4.5 metres apart. The plants between these 2 coolers receive cooled moist air which is constantly moving.

ANBG Average max. min. temp. nursery seed room

1989 December       22.3 deg C / 13.6 deg C
1990 January        22.7 deg C / 15.1 deg C
1990 February       20.6 deg C / 14.0 deg C

At ANU

The botany dept's growth cabinets are pre-set from Nov 1989 to provide an 8oc day and a 5oc night temperature resume. The photoperiod was set at 16 hrs (Nov - March). Observations for this March 1990 report were carried out 6-8/3/90 at both plant locations.

Parameters of importance recorded were:

Surviving popn nos per species
Average hight of a taxon.
General health and vigour (on a scale of 1-5)

Results:

Although not all species were represented in both moieties, the 20 spp that wee in both locations provided the following data:

Health and Vigour of Living plants. (Scale 1-5)

7 taxa were considered best at ANU
6 taxa were considered best at ANBG
7 taxa were considered equal for this criterion in a totally subjective analysis for comparison

The superior ANBG-grown taxa included:

Polystichium vestitum
Stilbocarpa polaris
Epilobium peduncalare
Blechnum penna-marine
Ranunculus biternatus

The superior ANU-grown taxa:

Montia fontana
Colobanthus (8910560 P)
Luzula
Poa foliosa
P. cookii
Acaena magellanica

Height

13 spp at ANBG have shown significant increases in height growth when compared with their ANU counterparts. (This criterion is however based upon the assumption that there was reasonable uniformity at arrival time).

Cotula plumosa was the only ANU-grown species showing increased comparative size, however its overall appearance was poorer than the ANBG population.

Leaf colour

Approximately half the ANBG taxa exhibited greener leaf colour than the ANU taxa. These included Ranunculus biternatus, Cotula, Polystichum vestitum, Colobanthus, Stilbocarpa polaris, Isolepis aucklandica, Epilobium brunnescens, E. pedunculare, Blechnum penna-marina.

One taxon in both locations demonstrated similar yellow-green colour, Coprosma perpusilla ssp. antarctica, with an overall less than healthy appearance.

Pleurophyllum hookeri similarly is very poor in both collections, with shrivelled and flaccid leaves.

A more glaucous leaf blade colour was observed for Poa cookii at ANBG in comparison with its ANU population.

Survival:

A separate check list of population sizes will be added.

Species represented in only one location:

ANU

Species                       Quantity    condition

Montia fontana                    1         Good
Colabanthus (8910560)             1         Good
Puccinellia macquariensis        11         Good
Luzual crinita varcrinita         3         Good

Single plant collections are to be divided to provide a larger population.

ANBG

Species                       Quantity    condition

Poa annua               more than 5         Good
Hytrocotyle novae-zealandia      14         Good

Summary

The 'softer' warmer average conditions at ANBG have produced increased metabolic activity and soft, lust growth for some taxa. This possibly from increased photosynthesis and respiratory rates with nutrient uptake.

Light quality and water availability have been similar in both locations, as have day length and potting mix quality.

The cooler temperature regime available at ANU has reduces the active growth experiences at the alternative venue where 'softer' conditions have also favoured predacious insects. Poa and Acaena spp. have been damaged by aphids.

*Incandescent light was added to the ANBG fluorescent system in February. This while aiding photoperiod extension if required by providing Red and Far Red light will not contribute to photosynthesis.

Both fluorescent and incandescent light are provided in ANU growth cabinets.