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What is generally known as serpentine vegetation occurs in localised areas throughout the world on soils derived from ultrabasic rocks. Such soils provide a difficult medium for plants, being highly infertile with low levels of potassium, phosphorus and calcium and often high concentrations of iron and magnesium and the toxic metals nickel and chrome.
As a result serpentine vegetation often has a very different appearance from that of surrounding areas, with fewer trees, and more sclerophyllous shrubs, grasses and sedges.
In higher latitudes, such as northern Europe, serpentine floras are usually impoverished with relatively few individuals and species. It is sometimes assumed that this is true of serpentine floras generally but, as Whittaker (1954) has pointed out, those in middle and tropical latitudes can be floristically rich with many endemic species.
Whittaker investigated a 400 sq. km. serpentine area at about 42° North in Oregon, U.S.A. and recorded 113 species, which was comparable to the 101 species in adjacent non-serpentine vegetation. It is not clear how many serpentine endemics were present, but three species and four varieties are mentioned.
In New Zealand there are localised areas of ultrabasic rocks in the south and the north of the mountain axis of the South Island. At one such area of about 150 sq.km. at 42° South (Red Hills), 120 species have been recorded, but only a few species and varieties are considered to be serpentine endemics.
At Kerr Point, the northernmost tip of the North Island at about 34° South, there are a few square kilometres of ultrabasic rock from which 144 species have been recorded and of these 10 varieties and two species are endemic (Druce et al. 1979).
These examples of middle latitude serpentine vegetation, then, are floristically quite rich, but have relatively few endemic species or varieties.
New Caledonia, lying between 20 and 23° South, has serpentine vegetation which is remarkable for its ecological diversity, floristic richness and high endemism. Ultrabasic rocks, dating from the Oligocene period 30
The different plant communities relate to soil types and altitude and include sclerophyllous shrub associations (maquis) (Figs. 2, 3); sedge associations, with or without shrubs; open forests dominated by conifers particularly species of Araucaria and Agathis (Fig. 4); and closed forests, mostly at higher moister altitudes, in which angiosperms predominate, including species of Nothofagus which commonly occur in distinct groves (Fig. 5).
Whittaker (1954) states “Most serpentine vegetations throughout the world appear to be dominated by some one or by some combination of three adaptable growth forms - coniferous trees, sclerophyllous shrubs, and grasslike plants.”
This is certainly true of New Caledonia. Conifers are prominent in most types of serpentine vegetation - Araucarias, of which New Caledonia has 13 of the 19 species in the genus, are particularly prominent and are a distinctive feature of many New Caledonian landscapes; podocarps too are well represented and include two unusual species - the small semi-aquatic Ducussocarpus minor with swollen trunk bases growing at stream and lake margins and the even more remarkable Parasitaxus ustus, the only known gymonsperm parasite, again a small shrub with an unusual reddish-purple colouration.
Sclerophyllous flowering shrubs are even more numerous, a number of them having relatively large, bright, red or yellow flowers.
Sedges are also conspicuous in some serpentine communities, particularly on swampy plains but also on drier hill slopes. Grasses however are uncommon, a puzzling feature of the New Caledonian flora.
Recently Jaffré (1974a and b) has made detailed studies of serpentine vegetation in new Caledonia and in his account of the Koniambo massif he says:
“The vegetation of Koniambo, like that of other massifs of ultrabasic rocks in New Caledonia, is clearly distinguished from the vegetation which covers the surrounding sedimentary or basaltic terrain. This difference involves a change in the flora and a more marked diversification of the plant formations…”
The list of the species recorded (453 species, undoubtedly far from exhaustive) representing approximately 15% of the species of the New Caledonian flora, demonstrates the richness of the flora of Koniambo whose area is about 170sq.m. (less than 1% of the area of the territory). This floristic richness, which is even more remarkable in the case of certain massifs whose plant cover has been less degraded (Boulinda massif, the great southern massif) seems to be a general characteristic of the vegetation of ultrabasic rocks in New Caledonia.
“Almost all the species recorded on the Koniambo massif are New Caledonian endemics and the majority are only found on ultrabasic rocks.”
So, according to Jaffré, more than half the species on Koniambo, i.e. more than 200, are serpentine endemics. He was not able to be more precise as there is still no complete account of the New Caledonian flora. However, a Flora is now in progress and revisions of several families have been published. This enables an estimate to be made of the number of serpentine endemics among about a sixth of the estimated 3000 species in the flora.
In Table I the first six entirely woody groups, of which all except the Sapotaceae are known to have a long history in the southern hemisphere, have more than half their species as serpentine endemics with an average of 65.5%. Mostly fewer than a third of the species in each group occur on both serpentine and non-serpentine - average 20.5% and less than a quarter have not been recorded on serpentine - average 13.5%.
Thus of the total of 287 species in these six woody groups 184 are serpentine endemics.
The three remaining groups of mostly herbaceous plants have less than half their species serpentine endemics, considerably less in the cases of the Tubiflorae and Pteridophytes, with an average of 24.5%. The proportion of species occurring on both serpentine and non-serpentine is much higher with an average of 58%. As with the woody groups the percentage of species not recorded on serpentine is low, average 17.5%, although the Tubiflorae at 40% are relatively high.
Combining all the groups gives a total of 569 species of which 253 (44%) are serpentine endemics, 225 (40%) occur on both serpentine and non-serpentine and only 91 (16%) have not been recorded on serpentine.
It is appropriate to conclude this article with a further quotation from Jaffré from his account of the Koniambo flora - “In the light of this study it is reasonable to suggest that the occurrences of ultrabasic rocks, which occupy a third of the territory and are distributed in several isolated massifs, have played an important role in the differentiation of the New Caledonian flora, one of the richest and most distinctive in the Pacific”.
(a) Position of Anthocerotae in the Plant Kingdom
The Anthocerotae (hornworts) is one class of the Division Bryophyta (bryophytes) and consists of a single order, Anthocerotales, and a single family, Anthocerotaceae. The better known classes of the Bryophyta are the Musci (mosses) and Hepaticae (liverworts). All bryophytes show the same type of life cycle which possibly arose independently in different groups. (Clarke & Duckett, 1979).
(b) Characteristic features of Anthocerotae
The Anthocerotae are readily distinguished from other bryophytes by certain characteristic features. The thallus is of homogeneous structure, with simple rhizoids and without ventral scales. Cavities occupied by blue-green algae are normally present. Antheridia are situated in chambers sunk in the thallus. Archegonia are also immersed and their jacket cells are indistinguishable from the surrounding tissue. The sporophyte is long and narrow, with a central columella of sterile tissue and a basal meristem. Its only protection is a basal collar (involucre) formed of tissue originating mainly in the thallus.
(c) Representation in New Zealand
In the family Anthocerotaceae, as represented in New Zealand, two main groups may be distinguished. In one the capsule wall has pores (stomata) (fig 3b) and the elaters (here usually termed pseudoelaters) lack a helical band of thickening. The other shows characters which are opposite of these. For members of the first group, which alone is known in Europe, the genus Anthoceros was established by Micheli as early as 1729 and the name was later adopted by Linnaeus (1753).
However, over the years, as explained by Schuster (1963), much nomenclatural confusion has arisen. It appears that the simplest solution is to retain the genus name Anthoceros and use it, as Linnaeus did, for both yellow-spored and black-spored taxa. This course is followed in the account below. The genus names, Phaeoceros and Aspiromitus, then become redundant. Within the second group confusion of nomenclature has arisen also. Two genera, Megaceros and Dendroceros, are usually recognised, but the boundary between them is ill-defined. Proskauer (1953) concludes that the only difference between the genera appears to be that Megaceros has broadly radiating thalli and Dendroceros has strap-shaped ones. Both genera are represented in New Zealand.
(d) Key to the genera in New Zealand
Distribution.
Anthoceros laevis is distributed world-wide in suitable habitats. In New Zealand it is found throughout, usually on the side of ditches or wet banks.
Main References.
Although references to A. laevis are made in many botanical works, to Proskauer (1948a, 1948b, 1951, 1954a, 1954b, 1958a) we are indebted for the assembly of much information based on his detailed studies of material collected at first in England and later throughout the world. More recently Hassel de Menendez (1962) has reported on the species in Argentina and Paton (1973) has provided notes on the species in Britain.
Morphology of the Gametophye.
The thallus is typically perennial and morphologically is exceedingly variable. It grows as dark green, irregular rosettes, 1-3 cm or more in
A. argentinus, a name which Hassel de Menendez (1962), after examining the type specimen, considers a synonym of A. laevis L. (She uses the name Phaeoceros laevis in her paper). Antheridial cavities, containing 1-(2-4)-7 antheridia, form at the dorsal surface behind the apices. Archegonia also are embedded in the dorsal surface behind the apices, each at first covered by a conspicuous mound of mucilage.
Anatomy of the Thallus.
The thallus in transverse section shows an epidermis composed of small, thin-walled cells and a compact ground tissue 5-8 layers deep. Each chlorophyllous cell contains a single large chloroplast. Situated in
Nostoc (fig. 3a). The pores arise close to the thallus apex where morphologically, although always open, they closely resemble stomata (fig. 3c). Further back the aperture becomes either more circular or 4-angled (fig. 3d). Goebel (1905), following on the earlier accounts by Janczewski in 1872 and by Leitgeb in 1874-81, describes the cavities in detail. Should a hormogonium of Nostoc penetrate the pore, it multiplies in the small substomatal chamber to form a globular colony and in so doing gradually enlarges the cavity. Meanwhile surrounding cells of the thallus grow into the cavity as filaments interwoven with the Nostoc trichomes and the pore becomes closed by what appears to be a mass of loose parenchyma. It has been shown that the blue-green alga present in A. punctatus can fix nitrogen and that an interchange of nitrogen and carbon takes place between the alga and the hornwort (Rodgers and Stewart 1977; Stewart and Rodgers 1977).
Morphology of the Sporophyte.
Dehiscing sporophytes are usually 3-7cm tall and fall within the range of 0.7-9cm determined by Proskauer (1948a). Opening takes place by one or two slits which do not reach the apex and in dry air the valves twist spirally (fig. 4). More detail is given by Proskauer (1948b). The ripe spores are a translucent yellow colour. They were found to have a maximum diameter of 40-50 microns so falling within the much wider range given by Proskauer (1958a). The markings of the spore coat are very varied but generally there is a fine granulation on all the faces and some larger conical projections, up to 2.5 microns high, mainly on the spherical face (fig. 5). However in some specimens the spore coat is almost smooth (Proskauer, 1958a, Hassel de Menendez, 1962). The pseudoelaters are either unbranched or slightly branched filaments, made of 1 to 5 cells, and show no helical thickening bands.
A Note on Sex Distribution.
In regard to the sexual condition Proskauer (1951) created two species, one dioecious and restricted to Europe and the other monoecious and essentially world-wide in distribution. He found also a difference in chromosome morphology. Later he reduced the species to subspecies
Certainly, for New Zealand material, any attempt to allocate specimens to subspecies is for practical purposes too time-consuming
2. on a seepage bank, had archegonia only in July and did not form sporophytes. In October the plants produced numerous bulbils which persisted when the older parts of the thallus dried up in summer. A population from the nearby Tiritea Valley had abundant antheridia in July, so much so that plants grown in full light appeared reddish whereas those in shade were yellowish. In October archegonia were forming on some of the plants and in December there were sporophytes. Still later bulbils made their appearance. In a population collected at
Comments on Synonymy.
There is no doubt that A. laevis is an exceedingly variable species. But it does not seem possible to split it into smaller, consistently uniform taxa. This situation is reflected in the number of synonyms which appear in the literature, a number which Proskauer (1958a) calculated to be some 200. Undoubtedly there is difficulty at times in distinguishing A. laevis from other species of Anthocerotales in New Zealand especially when using herbarium material and in the absence of reproductive structures.
There are suggestions in the literature that P. grayi is a rare or local species, that it is subalpine in its distribution and that its larvae compete better in colder lakes and streams. However, the combined use of museum material, field observations and literature records shows P. grayi to be a dragonfly which is widespread in its latitudinal and altitudinal distribution and indicates that cold-adaptation in its larvae cannot be substantiated.
New Zealand has an odonate fauna which is sparse in species. Only three zygopteran species were recognised in the fauna by Wise (1973) following the relegation by Tillyard (1913) of two species of Xanthocnemis as synonyms of X. zealandica (McL.). There are rather more Anisoptera: four endemic species- Uropetala carovei (White), Antipodochlora braueri (Selys), Procordulia smithii (White) and Procordulia grayi (Selys) - and four self-introduced species which are known to breed in New Zealand: Hemicordulia australiae (Rambur), Aeshna brevistyla Rambur, Hemianax papuensis (Burmeister) and Diplacodes bipunctata (Brauer). Pantala flavescens (Fabricius) has been recorded as a migrant on the North Island (Lieftinck, 1975) and on the South Island (Corbet, 1979). Another species in the New Zealand list, Tramea transmarina (Brauer) has been identified from the Kermadec Islands (Armstrong, 1973) but not yet from the mainland.
Roughly 250 publications comment in some way on this limited odonate fauna and one might suppose from such a volume of literature that the fauna is well-known. Until recent years, however, there has been no local observer, with the exception of Wolfe (1953) and Armstrong (1958a, 1958b, 1958c, 1975, 1978), who has made original, in-depth investigations into the ecology of the anisopteran fauna. One result has been that much that was anecdotal has become firmly fixed in this mass of literature by repetition and it becomes difficult to separate fact from fancy.
P. grayi is a species about which conflicting generalisations have been made: “it is a very rare dragonfly which has occurred at sub-alpine localities in the South Island” (Hudson, 1950); “it is localised and comparatively rare” (Miller, 1971); “it is a cold lake breeder which is probably the dominant Procorduli in the centre of the North Island and in the South Island lakes" (Armstrong, 1975); “it competes more successfully in colder habitats such as the lakes and mountain streams of Tongariro National Park” (Armstrong, 1978); “it is widely distributed in lakes” (Winterbourn and Lewis, 1975); and “it is restricted to relatively cool lakes and streams primarily in mountain areas” (Deacon, 1979). Is then P. grayi a common, widely-dispersed species or is it a rare, cold-adapted, upland species? My own field observations indicated P. grayi to be a more common and more widely distributed species than many of the foregoing remarks would imply. This paper reports my efforts, by scanning museum specimens and reliable published information, to assess the status of this species.
A combination of museum records, published accounts of authors known to be reliable in their identification of P. grayi, and my own field notes have been used to determine the distribution of the species. As is mentioned later, misidentification by some authors has been a problem in evaluating distribution records for P. grayi. Approximate localities from which P. grayi material has been examined are mapped in Figure 1.
All adult P. grayi specimens held in the British Museum (Natural History), London, England (n equals 16), the National Arthropod Collection, Department of Scientific and Industrial Research, Auckland, New Zealand (n equals 47), the National Museum, Wellington, New Zealand (n equals 14), and in the collection of the Ecology Division, Department of Scientific and Industrial Research, Lower Hutt, New Zealand (n equals 3) were examined in this study but for only 73 specimens were there adequate collection records. These localities are contained in the list which follows together with those for larval specimens of P. grayi in the National Museum collection (n equals 7). Following Watt (1979) the abbreviations BMNH, NZAC, NMNZ and EDNZ respectively are used later in this paper to identify the institutions holding specimens. The NZMS 1 map series sheet number, grid reference and altitude for individual collection localities are shown in parenthesis. Map references are necessarily approximate as are the altitudes estimated from the topographical maps. The localities from which P. grayi material has been examined are as follows:
Otatamarae, L. Rotoiti (N76 834190, 275m); Rotorua (N76 710060, 278m — 1 larva ex pond three miles E of Fitzgerald Glade); Matawai, East Cape (N88 946757, 540m—larva ex pond three miles N.E. Matawai);
Crumpton (1977) has recorded a number of larval habitats of P. grayi also: Clough Road Dredge Hole (S44 708823, 12m); Welshman's Mill Pond (S50-51 745769, 61m); Kumara Straight Pond (S50-51 688693, 54m); Lake Mahinapua (S57 465460, 15m); Lake Ida (S66 037927, 720m); Lake Grasmere (S66 240140, 582m); Leithfield Lagoon (S68-69 11595, 3m);
P. grayi at Isaacs Pond (S76 910637, 30m), and undertook a comprehensive emergence study, including this species at Lake Sarah, Cass (S66 245158, 579m).
Elsewhere I have recorded P. grayi from Pukepuke near Foxton (N148 780370, 9m) (Winstanley, 1979), Lake Waikaremoana (N105 577288,
P. grayi larvae from Lake Pounui (N165 640152, 30m, August 1978) and adults are common there in summer.
The data presented show that P. grayi is a widespread species south of 38°01′S. Within this study, its use of a lotic situation for larval development has been confirmed at only one site, the Cass Stream (Crumpton, 1977), although Armstrong (1975, 1978) was satisfied that larger pools in rivers and streams provide a tolerable habitat for the species. The preferred larval habitat appears to be in standing waters as others have indicated (Armstrong, 1958, 1975; Penniket, 1966; Winterbourn and Lewis, 1975) and adults appear to be localised to some extent on this account. They may, however, be found over grasslands many kilometres from water (Harrison and White, 1969) and indulge in “hilltopping”, a behaviour I have seen in P. smithii and H. papuensis also. Armstrong (1975) also reported this behaviour in H. papuensis. The dragonflies presumably visit hilltops to exploit the concentrations of other insects which occur there.
Hudson (1950) considered P. grayi to be sub-alpine in its distribution and Armstrong (1975) has observed that it has a tendency to be associated with larger bodies of standing water. Most large lakes in New Zealand lie at a similar and high altitude (Jolly and Irwin, 1975) and this might lead to the impression that an associated dragonfly is influenced in its habitat selection by altitude rather than the lacustrine environment per se. P. grayi larvae have been found in standing waters from close to sea level to 960m and it cannot therefore be considered entirely an upland species.
Adults emerge in large numbers from ponds as small as 0.2ha at Pukepuke; and I have found that both P. grayi and P. smithii emerge in moderate numbers from a much smaller pond, Ngutu Manu, near Waikaremoana (Winstanley, 1980), so that its association with large bodies of water only is unsupported by my observations. Size of the water body does not seem to be an important consideration.
It has been shown that P. grayi is widespread in its latitudinal and altitudinal distribution but is it nonetheless a rare species in terms of numbers as Hudson (1950) suggests? The combined collections in BMNH, NZAC, NMNZ and EDNZ contain 227 adult specimens of P. smithii against only 80 P. grayi. This might suggest that P. grayi is relatively rarer than P. smithii. Specimens of these species collected by the late J. S. Armstrong also show an imbalance (62 P. smithii/31 P. grayi), this despite the fact that he regarded P. grayi as more numerous at Taupo (Armstrong, 1958) and stated that P. grayi was the species with which he was most familiar (Armstrong, 1975). The combined collections also show
P. grayi, 62.9% P. smithii) but in his review of emergence studies overseas Lawton (1972) found a consistent excess of females over males in the Anisoptera. Sexual imbalance in the combined collections thus probably represents the relative catchability of the sexes rather than their relative abundance. In the same way, the greater abundance of P. smithii almost certainly represents the catchability of that species and reflects the different behaviour in the two species.
P. smithii males will attend a small territory in which flight is slow, with frequent hovering, over a regular flight path. P. smithii adults may also form mixed-sex feeding-swarms and I have also seen them in a mixed-species swarm with H. australiae (Winstanley, 1981). They can be taken easily when they swarm. In contrast, P. grayi is a stronger flying, more solitary species and not so easily caught. Armstrong (1975) believed that if P. grayi and P. smithii occurred in equal numbers at a lake, five P. smithii would be taken to each P. grayi. Collections of final-instar exuviae at Lake Waikaremoana in February 1979 showed that P. grayi was
P. smithii in the lake (Winstanley, 1980), in the ratio of about 100: 1, yet P. smithii adults in collections made at that time outnumbered P. grayi by 5:1. The collections themselves then are unreliable indicators of relative abundance.
Quantitative studies on the Anisoptera are as yet few in New Zealand. Mylechreest (1978) found P. grayi larvae at winter densities of over 300 per sq.m. in the shallow littoral of Lake Waikaremoana where it was the only anisopteran he recorded. Deacon (1979) found only 30 final-instar exuviae of P. smithii against 145 for P. grayi at Lake Sarah in the two years 1976-77 and 1977-78. In qualitative terms, Armstrong (1958c) implied that at Taupo P. smithii was more widespread but P. grayi more numerous. Later, he stated that P. smithii was never very numerous, and that P. grayi is probably the dominant Procordulia in the centre of the North Island and in the South Island lakes; but he qualified this by saying that practically all of his observations had been made on the Volcanic Plateau (Armstrong, 1975). Martin (1948) evidently considered P. grayi to be common since he applied the title “the common dragonfly” to the male specimen he illustrated. Stout (1969) recorded P. grayi as common in Canterbury. She also listed it as one of the less numerous of the “dominant” organisms of sheltered shores in the lakes of Nelson, Canterbury and Westland (Stout, 1975). In the section on distribution, I listed a number of sites at which I had seen P. grayi: at each body of standing water mentioned I would regard P. grayi as common.
Deacon (1979) attributes to Armstrong (1958c) the statement that Procordulia species are usually restricted to mountain habitats or lowland areas undisturbed by man. All of the larger lakes in New Zealand are very young, and the smaller lakes and ponds are relatively ephemeral (Watt, 1973, 1975) so that the pastoral practices of man, and impoundments for irrigation, domestic water supplies and hydro-electric developments should have favoured the resident lentic species. P. grayi certainly exploited rapidly the lowland man-made and manipulated ponds with which I am familiar at Pukepuke. Amongst the larval records given earlier are those of a larva taken from a Martinborough fish pond and one from a gravel pit at Oreti Beach, both man-made ponds. Deacon (1979) found final-instar exuviae at Isaacs Pond which is also man-made. It seems likely that the species would readily colonise chemically and physically suitable manmade ponds elsewhere in upland areas or in lowland habitats such as the examples just given.
The published data on temperature regimes in New Zealand lakes is limited but from the information summarised by Jolly and Irwin (1975) it appears that temperatures in standing waters are inversely related to altitude. If this is so, the hypothesis that a species with a broad altitudinal tolerance such as P. grayi is exclusively cold-adapted becomes untenable.
Deacon (1979) gave preliminary results which showed that P. grayi eggs did not hatch at temperatures below 9.5°C, and that ova of this species exposed to temperatures of 8.7°C failed to develop. Such a high minimum, survival temperature is not what I would expect in a cold-adapted species and, in contrast, P. smithii has an egg-diapause (Deacon 1978, 1979) which enables it to overwinter successfully in this stage in the cooler
P. grayi was attuned to a cool environment by its pattern of emergence earlier in the season than P. smithii which he thought provided a sufficient period of warm conditions for the maturation of adults, reproduction, the completion of egg development and hatching. However, Lake Sarah, one of Deacon's study areas, has a fickle summer climate. Severe temperature falls there after emergence can lead to mass mortality in Uropetala carovei (Wolfe, 1953; Winstanley and Rowe, 1980) and no doubt early-emerging Procordulia specimens would succumb to the same fate. The combination of early emergence and its requirement for high temperatures for egg development must make P. grayi's survival precarious at Lake Sarah in some years.
Each of the corduliid species present in New Zealand can be identified unequivocally by its abdominal colour pattern or wing venation (Armstrong, 1958; Penniket, 1966), or by the morphology of the terminal abdominal appendages (Figure 2). Nevertheless mistaken identity must have played a part in the generalisations made about P. grayi. The confusion seems to stem mainly from the work of Hudson (1892, 1904, 1950) who clearly had difficulty in identifying the Corduliidae. For example, Hudson (1892) illustrated a male P. grayi which he identified as P. smithii stating that it occurs almost everywhere. In his book on the New Zealand Neuroptera (Hudson, 1904), he stated that he was unacquainted with P. grayi and obviously was unaware of his earlier error. In his final publication (Hudson, 1950) he gave diagnoses for the field identification of three corduliids which he regarded as rare or local, and “which might easily be passed over as examples of the common and generally distributed P. smithii” commenting that he had seen only two specimens of P. grayi.
An examination of the sixteen corduliid specimens in the Hudson collection (NMNZ) revealed a male P. grayi (Governor's Bush, Mt Cook 28 January 1945) identified as a male P. smithii, and a male P. smithii (“locality uncertain, probably Wellington”) identified as a female A. braueri. From the foregoing, Hudson's comments on the three endemic corduliids must be treated with reservation. Salmon (1950) attempted to synonymise P. smithii and P. grayi although Armstrong (1958 c) was able to show how the species can even be determined on the wing. Powell (1967) illustrated a male P. grayi, which he identified as P. smithii, calling it “the common dragonfly”, the name which Martin (1948) also applies to P. grayi.
It appears from museum collections, field observations and the reliable literature reports that P. grayi is a common species, widespread in both latitudinal and altitudinal distribution, the larvae of which occur in both lotic and lentic situations, but mainly in lentic waters. Cold adaptation in the species has not been substantiated.
I record my thanks to T. K. Crosby, J. S. Dugdale, R. Kleinpaste and Annette K. Walker (NZAC),
Collections of final-instar exuviae of Uropetala carovei carovei from six sites near Wellington in January-March 1980 showed that the emergence duration is similar to that in U. c. chiltoni in the South Island but emergence commenced and finished later in the season at the sites studied. The study reveals a slight preponderance of males over females (54%).
As has been described for all petalurids with the exception of U. c. chiltoni, the rectal plates in all exuviae have been found to be open distally. The emergence stance, including novel aspects of the larva's attachment to the emergence support is described and notes are incorporated on oviposition, habitat and larval behaviour.
At the completion of its aquatic larval stages, an odonate larva leaves the water, clamps upon some suitable surface and the winged adult emerges from the larval skin. When the adult departs, a durable record of emergence remains in the form of the final-instar exuviae which can be identified to species and to sex. Thus as Corbet (1962) has demonstrated ably, regular collections of final-instar exuviae can provide information on the duration of the emergence period, the numbers and species of dragonflies and damselflies emerging, and the sex ratios for the population.
Seasonal patterns in the New Zealand dragonflies (Suborder Anisoptera) are not yet well understood. Wolfe (1953) reported briefly on emergence in Uropetala carovei chiltoni Tillyard near Lake Sarah, Cass, (43°03′S 174°46′E, S66 245155) and Deacon (1978, 1979) investigated emergence patterns at Lake Sarah in two damselfly species, Austrolestes colensonis (White) and Xanthocnemis zealandica (McL.), and two endemic corduliid anisopterans, Procordulia grayi (Selys) and P. smithii (White). Except for P. grayi in one year, however, Deacon's anisopteran samples were small.
There have been no emergence studies published on the Anisoptera in the North Island. I am involved in a study, at Gollans Valley near Wellington, on the biology of a further endemic corduliid, Antipodochlora braueri (Selys), and the lack of information on the other species locally against which to compare its behaviour was a serious hiatus from my point of view. To overcome this, I have made emergence studies on P. grayi, P. smithii, Hemicordulia australiae (Rambur), Aeshna brevistyla Rambur, and Hemianax Papuensis (Burmeister) at Pukepuke Lagoon (40°20′S 175°16′E, N148 782368) near Foxton which will be reported separately, and this present paper incorporates the results of emergence studies on Uropetala carovei carovei (White) at six sites around Wellington.
The Petaluridae comprises a small family in the Anisoptera with only nine known species in five genera. Svihla (1959) reported the distribution of eight species: Petalura gigantea Leach, P. ingentissima Tillyard and P. pulcherrima Tillyard in Australia; Tanypteryx hageni (Selys) in western U.S.A. and British Columbia and T. preyeri (Selys) in Japan; Tachopteryx thoreyi (Selys) in eastern U.S.A.; Phenes raptor Rambur in Chile; and U. carovei in New Zealand. Watson (1958) described the ninth species, Petalura hesperia from Western Australia; and Fernet and Pilon (1968) reported the range of T. thoreyi to include Canada.
Detailed life history investigations have been published for P. gigantea (Tillyard 1909, 1911), U. carovei chiltoni (Wolfe 1953), T. pryeri (Taketo 1960, 1971a) and T. hageni (Svihla 1959, 1960); and a contribution on T. thoreyi is in preparation (S. W. Dunkle, pers. comm.). Our understanding of the ecology and behaviour of the various species in the Petaluridae is, however, still far from complete. Additional information on the behaviour and morphological adaptations of U. c. carovei became available in the course of this study and the opportunity has been taken to include comments on these topics in this paper.
Six study sites were selected all close to Wellington and within 12.5km of each other. Site 1 was chosen for its proximity to Victoria University of Wellington, and the remaining sites are all close to the route I follow into my A. braueri study area in Gollans Valley, 41°19′E 174°45′S, N164 257147. Each site comprises a water seep on sloping ground in the shade of indigenous evergreen forest, the composition of which varies at each site but is basically coastal broadleaf forest at site 1, mixed beech (Nothofagus spp.)-coastal broadleaf forest at site 2, and beech-podocarp-broadleaf forest at sites 3-6. An understorey of shrubs, ferns and saplings is developed at each site. The sites conform to the general descriptions given elsewhere for U. c. carovei habitat (Winstanley and Rowe 1980). The six sites, identified by latitude and longitude, NZMS 1 series map sheet number and grid reference in parenthesis are as follows:
Site 1 — Botanical Gardens, Wellington, approximately 100m from the Meterological Office, Kelburn (41°17′S 174°46′E, N164 327221). An area of approximately 4m x 10m containing several hundred burrows was searched, part only of a more extensive colony in a gully facing NNE.
Site 2 — 50m north of the upper end of Cheviot Road, Lowry Bay (41°15′S 174°55′E, N164 463261). The area of 5.4m x 9.0m searched contained several hundred burrows on an ESE facing slope.
Site 3 — on the Kowhai Street-Butterfly Creek Track, Eastbourne, 60m north of the junction with the Muritai Park Track, (41°19′S 174°45′E, N164 447191). A wedge shaped area 4.6m x 3.5m about a slight trickle in a gully facing east. Less than 100 burrows present.
Site 4 — on the Kowhai Street-Butterfly Creek Track 49m south of the Muritai Park Track (41°19′S 174°45′E, N 164, 448189). A more or less equilateral wedge 11m long on the slopes of a small stream facing SSE. Several hundred burrows present.
Site 5 — on the Kowhai Street- Butterfly Creek Track 22m north of Buttterfly Creek (41°19′S 174°45′E, N164 448187). A steep bank 0.5m high and 2.7m long facing east. Only 11 burrows over 10mm wide counted.
Site 6 — on the true right bank of Gollans Stream 102m downstream from its junction with Butterfly Creek and extending 13m further south (41°19′S 174°45′E, N164 447186). An area about 5m wide on an east facing slope. Several hundred burrows.
Each of the sites was searched at intervals of a few days to a week from early November to 28 December 1979 (site 1) and to 2 January 1980 (sites 2-6) without final-instar exuviae being found. All sites were searched on 7 January 1980 and final-instar exuviae were found that day at sites 1 and 6. Thereafter site 1 was searched on January 15, 18, 22, 24, 29, February 4, 7, 12, 14, 19, 21, 26 and March 4, 11 and 18, and sites 2-6 on January 9, 11, 14, 21, 23, 25, 28, February 1, 4, 8, 11, 18, 27, March 5, 12, 19. The maximum and minimum emergence period for each site is shown in Table 1. The total numbers of exuviae collected and their distribution between the sites are shown in Table 2. The cumulative emergence figures for each site are graphed separately in Figure 1, and for all sites combined in Figure 2.
Fifty percent of the combined populations had emerged (EM 50) by the 16th day after emergence was detected. Peak emergence occurred on the 18th day, and the observed duration of emergence (EM 100) was 58 days. Emergence commenced and finished much later than expected: I observed my first two U. c. carovei for the season on 21 November 1979, along the south Wellington Coast, (41°21′S 174°41′E, N164 257147). I saw the first adults active at Gollans Stream on 28 January 1980 and the last record I have for the season near Wellington is a sighting by U. c. carovei for the season was seen on 30 October 1972 and the last on 12 April 1973 (M. J. Meads, pers. comm.).
The duration of emergence is similar to that determined for U. c. chiltoni by Wolfe (1953) at Cass. Emergence commenced there sometime in the first week of December 1948 and the last exuviae was collected on 2 February, 1949, thus emergence spanned a maximum of 62 days. Peak emergence occurred in the second and third weeks of December and only scattered emergences thereafter. Wolfe stated that emergence in North Island localities (he cited North Auckland and Coromandel Peninsula) was
U. carovei is protracted when compared with other petalurids. In Japan, Taketo (1960) found that with a natural population of T. pryeri the EM 50 was eight days and EM 100 13 days, but a laboratory population had an EM 50 of 14 days and EM 100 of 60 days. T. hageni was found to emerge from early July 1958 to the end of that month (Svihla 1959) and from the end of July to the end of August 1959 (Svihla 1960) at Tipsoo Lake, Washington. In contrast, Meyer and Clement (1978) reported an emergence period of at least five weeks, commencing in late May 1976, for this species in California.
There is no statistically significant difference in the mean emergence dates for males and females in the combined records of all sites. Nor is there a statistically significant departure from a 1: 1 ratio of males against females but the slight preponderance of males (54%) is of interest. Many studies — reviewed by Corbet (1962) and Lawton (1972) — have shown a
It is interesting to speculate on possible explanations for the high level of emergence at site 5, in relation to the size of the colony, and the low level at site 3. Those from site 5 probably represent a single age cohort and could be the progeny of one female. The solitary emergence from site 3 occurred late — the female exuviae was found on 27 February — and might have resulted from precocious development. If there were an element of fidelity on the part of females to the sites of their own larval development (philopatry), a level of synchrony would persist in each colony for a considerable time in a species such as U. c. carovei in which larval development may span more than four years.
Emergence in P. gigantea occurs about dawn (Tillyard 1917) as it does in U. c. chiltoni (Wolfe 1953). T. pryeri also emerges in the early morning (Eda 1959, Taketo 1960) and T. hageni emerges from early morning to early afternoon (Svihla 1960). S. W. Dunkle (pers. comm.) found T. thoreyi to emerge from mid to late morning.
The duration of emergence in individual specimens varies with different odonate species and with different environmental conditions but generally ranges from 40 minutes to four hours (Eda 1959). In the late stages of
T. pryeri (Eda 1959) and about 2 1/2 hours in T. hageni (Svihla 1960); one might expect U. carovei to require a similar length of time for its emergence. Each species usually has a particular time of day at which emergence occurs, dusk and dawn being two phenomena with which it is often correlated. Inclement weather may interfere with the typical pattern so that some members of an emergence group will complete emergence at the normal time whilst others will not do so until later in the day when conditions are more favourable: this phenomenon has been described as “divided emergence” (Corbet 1962). The time of emergence was not determined in this study but Wolfe (1953) stated that emergence in the genus Uropetala occurs about dawn. At site five on 21 January, 1980, I found one male specimen close to its exuviae with its wings still in the vertical position six hours 45 minutes after dawn and 25 minutes before the solar noon. If a typical dawn emergence holds good for Uropetala throughout its range, this record represents an example of divided emergence.
The teneral adult observed with its wings erect on 21 January 1980 had its full adult colouring — blackish-brown and a vivid buttercup yellow. P. gigantea also achieves full colour before flight (Tillyard 1917) in contrast with T. hageni which requires a further post-flight period for adult colour maturation (Svihla 1960).
Of the 105 exuviae recovered, I am aware that my searching activities displaced five exuviae from the vegetation before I noticed them, and 36 others were also found displaced. All 64 attached exuviae were on vegetation: exposed roots, tree trunks, tree fern caudices, fern stripes, rachides and laminae, sapling stems, small twigs and branches, petioles, leaf surfaces and stout lianes. All other petalurids studied have been shown to select a wide variety of vegetation for their emergence supports (Tillyard 1909, 1911, 1917; Svihla 1960; Watson 1958; S. W. Dunkle pers. comm.), and T. pryeri shares a penchant for leaf surfaces (Taketo 1960) with U. c. carovei.
All exuvae were found within an estimated horizontal distance of 0.5m from a burrow but the burrows from which emergence occurred were not determined. Two exuviae were found 0.7m above ground level but most were below 0.3m and some almost touching the ground. Other petalurids vary in the height at which they emerge: T. hageni will emerge whilst the distal segments of the abdomen are still in water (Svihla 1960); T. thoreyi has a mean emergence height of 0.6m and a range of 0.2-1.4m (S.W. Dunkle pers. comm.); P. hesperia may climb as much as 15 feet (4.5m) (Watson 1958).
U. carovei larvae at emergence are much larger than those of other species in New Zealand. Green (1977) reported a mean weight of 2.68g for final-instar larvae and I obtained a weight of 2.99g for one surface-dried female cleaned of mud. A striking feature in this study was the very frail supports such a large larva would use for emergence which is presumably related to its sheltered habitat within the forest.
Four anisopteran families are represented in New Zealand: Aeshnidae, Corduliidae, Libellulidae and Petaluridae. The emergence stance in the first three families is similar and certain generalisations can be made about it: the larva chooses a site where it can support itself at an angle between 90° and 180° (Figures 3b and 3d); a firm grip must be obtained by the tarsi on each side of the body, that is, the grip must have radial or lateral integrity otherwise the contortions of the emerging adult will lead to displacement and failure; on a slender support, the limbs may overlap behind the support; and finally, if any tarsi are not attached to the substrate at emergence, it is usually those of the forelimbs. There are subtle differences between the Aeshnidae-Corduliidae-Libellulidae pattern and that of U. c. carovei.
In the 64 attached U. c carovei exuviae examined the stance was always vertical irrespective of the orientation of the emergence support. The tip of the abdomen was usually curved dorsally. The limbs never crossed behind the support and were more often than not held spreadeagled. Sixteen exuviae (25%) were found to be attached by the tarsi on one side of the body only. A closer examination showed that the tarsi and tibial spurs are used antagonistically to achieve a vice-like grip, the mechanical principle being similar to that applied in a cant-hook (Figure 4d). Any pressure applied to the tibiae will increase the tenacity of the grip. This type of grip has not been reported in other petalurids but each species has well-developed tibial spurs which would make it possible. The illustrations of
For 32 exuviae, detailed records were kept of which tarsi were attached to the substrate. The results are summarised in Table 3. The rear tarsi were the least frequently attached. In 7 exuviae (22%) the hind tarsi were attached each side, in 11 (34%) they were attached on one side only and in 14 (44%) they were free from the substrate. A chi-squared test confirms a significant difference between the attachment of the hind and other limbs (chi-square equals 8.799 p less than .05%). Taketo (1971 b) has illustrated a T. pryeri exuviae with the hind tarsi below and free from the emergence support. The anterior tibial spurs are more developed than the posterior spurs on the prothoracic and mesothoracic legs which are held prograde during emergence. In contrast, the interior and posterior spurs are equally developed on the metatibiae which are usually held laterigrade or retrograde (Figure 4).
In all 105 exuviae examined, the tips of the wing cases had been widely separated by the withdrawal of the adult wings. Wolfe (1953) stated that, other than in points he enumerated, emergence in U. carovei did not differ from that described for P. gigantea by Tillyard (1917). Tillyard, however, illustrates the exuvial wing cases being held parallel throughout emergence, which is exceptional in a petalurid. In his earlier description of the exuviae in this species (Tillyard 1909), he also described the wing cases as lying parallel along the back of the abdomen but remarked that in some exuviae they are turned in all directions. In various collections I have examined exuviae of P. gigantea, P. hesperia, T. thoreyi, T. hageni, T. pryeri, P. raptor and both U. carovei subspecies: invariably, the wing cases were widely separated distally. J.A.L. Watson (pers. comm.) has confirmed that all the petalurid exuviae in the C.S.I.R.O. collection at Canberra — including P. ingentissima, the larva of which has not yet been described—have the wing cases separated also.
Eda (1959, 1963, 1964) observed that two different emergence patterns occur in the Odonata, the “upright” type and the “hanging” type (Figure 3). In the upright type, the head and thorax are withdrawn from the exuviae and, during the recess or resting period which follows, the head and thorax are held more or less parallel to the exuvial head and thorax. In the hanging type, the head and thorax are held at an obtuse angle from the exuvial head and thorax during the resting period. The descriptions of Tillyard (1917) for P. gigantea, Wolfe (1953) for U. c. chiltoni, and Svihla (1960) for T. hageni suggest that emergence in these species is of the hanging type. On the other hand, Eda (1959) has shown with a series of photographs that P. pryeri has an upright emergence stance and S. W. Dunkle (pers. comm.) has found that T. thoreyi also follows this pattern. It is otherwise unknown for species in the same genus, or for those in the same family, to have such radically different emergence behaviours and I
P. gigantea, T. hageni and U. carovei warrants re-examination.
Emergence had not been completed in only 4 (3.8%) of the 105 exuviae collected. One of the four had been displaced, which might explain the failure, otherwise the cause of mortality was not established. Two of the attached specimens had ants feeding on them but there is no evidence, such as Kiauta (1971) found in Aeshna juncea (L.), to implicate the ants as predators.
The wings of a predated teneral specimen were found at site 2 on 8 February, 1980, but the predator was not identified. Removing wings from the prey is a trait of small passerines and Corbet (1957) found blackbirds (Turdus merula L.) a common predator on Anax imperator Leach. Blackbirds were heard frequently at each of my study sites and one was observed searching on the ground at site 4. Wolfe (1953) and Winstanley and Rowe (1980) have listed some of the birds which prey on U. carovei adults. Kingfishers (Halcyon sancta vagans (Lesson)) may be the main avian predators of U. carovei adults in the forest (B. M. Fitzgerald, pers. comm.). Prey remains collected from three kingfisher nests in the Orongorongo Valley (41°21′S 174°59′E, N164 717148) by M. J. Meads and B. M. Fitzgerald contained remains of many Uropetala. However movie films taken by G. J. H. Moon (pers. comm.) show that a kingfisher swallows aeshnid and corduliid adults without removing the wings hence it could not be implicated as the predator at site 2.
The morepork (Ninox novaeseelandiae (Gmelin)) is another potential predator: Moon (1957, 1967, pers. comm.) has shown that it may catch corduliid dragonflies in the forest at night. Fitzgerald and Karl (1979) established that feral cats (Felis catus L.) catch and eat U. carovei adults, and three other observers have presented me with information about cat predation on the species. Cannings (1978) has reported cat predation on T. hageni.
Dr F. Ris observed that the rectal plates in P. gigantea exuviae were open leading him to suspect that the larvae were not aquatic, but air breathers (Tillyard 1911). Tillyard confirmed aquatic respiration in the larva but suggested that final-instar larvae were able to breathe air through the rectal chamber when above water. Wolfe (1953) after examining 2000 exuviae of U. c. chiltoni in which he found the rectal plates closed, stated that air breathing could only be spiracular in the final-instar larva near emergence. Svihla (1960) determined that the rectal plates are open in exuviae of T. hageni, T. pryeri and T. thoreyi. Taketo (1971a) has shown that the rectal plates are in fact held together in T. pryeri exuviae but their truncated tips form a tube which leaves the rectal chamber permanently open. J. A. L. Watson (pers. comm.) has intimated that the rectal plates are open in this sense in P. hesperia and P. ingentissima and two exuviae of P. raptor which I examined in the British Museum (Natural History) had a similar opening at the tip. In a sample of 46 U. c. carovei exuviae in my collection, 8 (17%) had the rectal plates apart and all were open at the tip (Figure 5). All final-instar exuviae I have examined of each U. carovel subspecies have had an opening at the tip of the rectal plates and I must conclude that Wolfe (1953) was mistaken in his pronouncement.
Svihla (1959) described rectal air breathing in T. hageni larvae and Taketo (1971a) has done the same for T. pryeri. Final-instar U. c. carovei placed in shallow water bend the tip of the abdomen dorsally placing the rectal opening at the surface as does P. gigantea (Tillyard 1911).
Wolfe (1953) described the oviposition behaviour of U. c. chiltoni. The female alights on Schoenus tussock, struggles down amongst the tangled stems to the bog surface, lays a few eggs in one place and then flutters to another tussock to repeat the process. Abrasion against the tussock leaves leads to chronic wing wear.
I have seen oviposition in U. c. carovei on only one occasion but the behaviour differed in detail from that which Wolfe recorded. The female stood directly on the ground, arched the abdomen and moved backwards over the wet ground probing repeatedly with her ovipositor. Throughout oviposition the wings were gently vibrated so that the hind wings touched the ground. Presumably, wing vibration would accelerate abrasion on contact with any rough surface. The oviposition stance is similar to that which Asahina and Eda (1957) illustrate for T. pryeri where the wings also contact the ground. T. hageni lands directly on the ground to oviposit (Svihla 1959) as does T. thoreyi (Williamson 1901, S. W. Dunkle, pers. comm.).
Once the location of a colony is known, exuviae are easily found. Mud-coated final instar exuviae which have had time to dry are light coloured and easily detected against vegetaton. Not all exuviae are mud-coated however, which may mean that not all larvae sit covered in silt in their burrows as Wolfe (1953, p.265) has described. Perhaps the mud-covered exuviae are those of larvae which have recently repaired the burrow. Clean
I have examined several hundred larval colonies of U. carovei and a general description of the larval habitat has appeared elsewhere (Winstanley and Rowe 1980). In many colonies, a few larval burrows, perhaps ten per cent, have the burrow opening occluded in some way, usually by tailings ejected from the burrow. Burrow obstructions may be less ephemeral however. I have found burrows with tree roots across the mouth and, in colonies on level ground, leaf and other plant debris may form a deep cover over the burrows. R. J. Rowe (pers. comm.) also observed blockages of the latter type in the U. c. carovei colony at the Dome, near Warkworth (36°21′S 174°38′E). Clearly the larvae cannot leave the burrows to hunt at the surface under such circumstances and it may be that the larva is not only pit-dwelling (as Taketo (1958) described T. pryeri) but also pit-trapping. Perhaps the larva has to rely on its prey tunnelling through the ground or litter to penetrate the burrow. Remarks made by Wolfe (1953, p.265) on the excavation of a winter feeding chamber by U. c. chiltoni larvae appear to support this hypothesis. When spiders, harvestmen or beetles are disturbed at the surface, they will frequently take shelter in an open burrow where they may be preyed upon.
The material ejected from a burrow can accumulate to form a durable, steep-sided cone as much as 10cm or more above the level of the surrounding ground. Emerging from such a structure to feed would pose problems for the larva: the apex rarely provides a large enough perching surface on which the larva can sit, and one imagines that the cone would reduce the numbers of prey which might simply stumble into the burrow opening. Those burrows which open onto wet, vertical faces must also impose problems for surface feeding.
Larvae maintained in the laboratory have proved to be negatively phototactic and positively thigmotactic. Larvae kept in an inclined aquarium with the choice of resting on soil either above or below water level have been observed at night to assume a stance submerged in a corner of the aquarium where they have stood almost vertically with the head at the water surface and the antennae and foretarsi just penetrating the surface film. They also leave the water freely and eventually will construct a burrow, commencing their excavations above water level. Larvae kept in deep circular containers on wet leaf mould usually assume a more or less vertical stance against the side of the container at night also.
Harding (1977) found that light of all the wavelengths she tested modified behaviour in U. c. carovei larvae in some way. I have used a red light for observations at night. The reaction to white light at night is either immobility or a rapid backward retreat with the abdomen thrashing from side to side. This behaviour may be related to the normal mode of locomotion within the burrow. Tillyard (1921) has described the hair tufts on the dorsolateral surfaces of the abdomen in U. carovei larvae and most other petalurid larvae have similar tufts on the abdomen. A side to side movement of the abdomen inside the burrow would cause these projections to contact the burrow walls and would facilitate movement, particularly in the vertical sections. Analogous abdominal structures abound in burrowing or wood boring insect larvae; the Tipulidae, Cicindellidae and Cerambycidae provide good examples.
Wolfe (1953, p.265) observed that the burrows in Uropetala are of constant diameter throughout their length. I have found the burrow may be oval in cross section near its mouth with the wide axis-corresponding to the horizontal and this applies particularly to burrows opening onto steep faces. The burrows of final-instar larvae may be much shorter than those which Wolfe (1953, p.266) illustrates. In an extreme case, I found one final-instar larva in a simple vertical burrow, slightly expanded at its base, which was only 15 cm long. This particular burrow was not water filled and was no damper than would normally be expected in the root zone. I have found one other intermediate stage larva in a burrow which lacked free water. S. W. Dunkle (pers. comm.) has shown that T. thoreyi is one species which does not burrow and he located final-instar larvae in the wild hiding under leaves in seepage areas either in the water or just above the water-line, thus demonstrating in them a measure of independence from constant immersion.
This paper has refuted several minor points which have appeared to emphasise heterogeneity of behaviour and morphological divergence in the Petaluridae. The likelihood is that further research will reinforce the essential homogeneity of behaviour and adaptation in this ancient group of dragonflies.
I am grateful to all those people acknowledged in the text who have provided me with their personal observations. In particular I am indebted to Professor Shigeo Eda, Matsumoto Dental College, Nagano, Japan, and to Dr Akira Taketo, Kanazawa University, Ishikawa, Japan, for information on T. pryeri and for papers published in Japan on that species. Dr J. A. L. Watson, C.S.I.R.O., Canberra, Australia, provided me with information on Australian petalurids and Dr S. W. Dunkle, University of Florida, Gainsville, U.S.A., made his unpublished observations on T. thoreyi and other petalurids freely available to me. Dr Dunkle also commented on an early version of this paper as did Dr
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Juniper Hall, Dorking, Surrey RH5 6DA; Tel: Dorking (0306) 883849. Biology, contrasting chalk and heathland ecosystems, geography and geology of South-East England, conservation and public pressure.
Leonard Wills, Nettlecombe Court, Williton, Taunton, Somerset TA4 4HT; Tel: Washford (098-44) 320. Freshwater and terrestrial biology, geography, the Bristol Channel coast and estuary, Exmoore National Park.
Malham Tarn, Settle, North Yorkshire BD24 9PU; Tel: Airton (072-93) 331. Biology, contrasting limestone and acid sandstone ecosystems, freshwater, moorland, conservation, geology, geography, National Park management.
Orielton, Pembroke, Dyfed SA71 5EZ; Tel: Castlemartin (061-681) 225. Coastal biology and geography; oil pollution research unit.
Preston Montford, Montford Bridge, Shrewsbury, Salop SY4 1DX; Tel: Montford Bridge (0743) 850380. Geography, archaeology, biology.
Slapton Ley, Slapton, Kingsbridge, Devon TQ4 2QP; Tel: Kingsbridge (054-580) 466. Coastal and terrestrial biology, large nature reserve with deciduous woodlands and freshwater lake, geography and conservation problems.
Epping Forest Conservation Centre, High Beach, Loughton, Essex IG10 5AF; Tel: (01-508) 7714. A purpose built non-residential centre; visitors and many London school children attend courses; displays on conservation and an information desk.