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30. Interplanting Indigenous Forests.- —In pursuance of the policy mentioned in recent reports under which this operation is being tapered off pending a complete investigation of results, only 115 acres of cut-over podoearp forest were interplanted to shadetolerating exotics. Partly failed areas were blanked up on 26 acres. In addition, 17 acres were interplanted to kahikatea, totara, ritnu, and matai. 36. Afforestation. —Only 1,408 acres of new area were planted to exotics, mixed species being used on 78 acres, but serious failures of recent years were replanted over 1,828 acres and partial failures blanked over 1,975 acres. Planting and silvicultural statistics are presented in Appendix 11. Thirty-four pounds of indigenous seed and 4251b. of exotic-tree seed were collected and extracted. 37. Nursery Operations.—A total of 4501b. of tree seed was sown, yielding 887,000 seedlings as at 15th March, 1943; 6*] lb. of indigenous seed are included Trees lifted for planting, transfer, &c., totalled 3,898,000, while 234,000 were lined out. Tree stocks in all nurseries at the close of the year amounted to 10,700,000. 38. Tending of Indigenous Forests.—ln Warawara Kauri Forest some of the time of the caretaking personnel was occupied in releasing kauri saplings from overtopping shrubs Extensive work of this nature is urgent, but must be postponed until after the war. _ Release cutting of exotics interplanted in podoearp stands comprised 31 acres and pruning of double leaders 35 acres. 3!). Tending of Exotic Forests.— On 1,440 acres tree plants were released from fern &c, Ijow pruning of stems to 8 ft. from, ground-level was done on 2,265 acres, while high pruning of final-crop trees comprised 729 acres. Thinning treatment covered 444 acres of first or light thinning and 1,024 acres medium to heavy thinning. One hundred and thirty-four acres were clear-felled; and damage clearances of stands harmed by gales, snow, or fire accounted for 329 acres partial clearance (virtually an uncontrolled thinning)' and 92 acres total clearance—necessitating re-establishment. 40 Silvicultural Investigations.—Ln Rotnrua Conservancy 36 acres of cultivated "-round were planted to redwood spaced at 16 ft. by 16 ft., to ascertain the relation between costs of pre-cultivation, wide spacing, and successive green prunings, as against costs ot normal close spacing on uncultivated ground, normal low and high pruning of dead branches, and several thinnings; and, of course, a comparison between the stem form and timber value under each method. In Wellington Conservancy small trial plantings m the National Park district (altitude, 2,900 ft.) were made with several tree species but a severe January frost destroyed most of these, thus limiting future plantings to the hardy pme species previously used for planting at that inhospitable altitude On a block newly acquired for an afforestation project in connection with post-war rehabilitation ? aercs . wer ? P\ aT,te( l tu six tree species in order to observe, prior to commencement of large-scale planting, their early growth in the locality concerned. Good progress was made with Hie collection of data for a set of bulletins on the silvicultural characteristics requirements and treatment, and the utilization value of the fifteen principal exotic conifers planted m New Zealand. 41. Experimental Plots ami Statistical.- -Five new sets of plots were established in connection with the study of natural regeneration of exotics, more particularly the conditions under which natural regeneration takes place, the relative density rate of growth, and species distribution. A set of replication plots was established in 1942' plantings on Rotoehu lor est to study the effect of various planting spacings upon height development, stem form and pruning requirements, and thinning periods of Pinus radiata,. Eight different spacings were adopted, ranging from 3 ft. to 15 ft., the total area involved bein- + f forest subject to occasional windthrow a new plot was established to study the effect of. thinning upon subsequent windthrow Four sets of plots were re-examined. Pinus radiata propagated from cuttings showed at thirteen years of age no differences m dimensions or form from normal stands Ihirty-six kahikatea representative of 0,000 planted in 1937 to restock a windthrown stand showed a mean annual height growth of 5 in. (soil —a rich river-flat loam) In a Canterbury forest natural regeneration from a twelve-year-old Pinus muricata st-mrf completely destroyed by fire in February, ,1939, tallied as follows in winter 1940 1941 and 1942: 126,000, 105,000, and 85,000 plants per acre respectively ' ' Re-examinations of plots in a clear-felled Pinus radiata compartment in Whakarewarewa Forest revealed an average net increase in naturally regenerated seedlings of from 1,860 per acre in late spring, 1941, to 2,630 in autumn,'l942, and 3 360 in late spring, 1942 grange, 210 to 6,210). During the year the average number per acre killed by the bark-beetle, Hylastes ater, was 170 (range, nil to 260). Only one of the six i)lots is still understocked, with 210 plants per acre. Six newly established plots in felling onT%'t VG il a U i ye ™ t0 re S ener 'ate average 3,590 plants per acre (range 80 to J 400) after allowing for 90 plants per acre killed by the bark-beetle. Three of he e plots are not yet satisfactorily stocked. Three plots were established in portions that were experimentally burned to a fierce, moderate, and light degree respectively and no regeneration has so far appeared on any of these. To date, the season of clear-felliii" appears to be of no significance, while understocking is characteristic of ground heavily consolidated by logging activity, some portions of which will require to be regenerated artificially by planting once the stumps and tops have dried out sufficiently to reduce the local Hylastes population to insignificant levels. 42. Forest Botany.—The following projects, relating to the main exotic and indigenous liwTT' Wer ° c °ntinucd under control plan: organized collection and testing of seedseffect of storage on % viability of seeds; recording of seed crops according to an arbitrary scale denoting degree of abundance (on the whole, 1942 was a poor seed year) ■ variation m inal'fy of insignis-pine seed collected from cones of different ages (seed from sixteen year-old cones was found to be still viable) ; and collection of phonological records on the main exotic tree species. . 1 rom two years' observations on juvenile stages of some of the native podocarps, a tentative method of recording their growth has been devised Seed oi species of Araucana has been received from Australia and South America and seedlings raised for planting out in an arboretum m North Auckland. &

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