French Polynesia, UA-HUKA COMMUNE, NULL, Vaikivi summit region and drainage, boulder-strewn stream-bed running South and West below Hitikau.
-8.9 -139.516667
meters
700
Freycinetia-Hibiscus shrubland/fernland.
wet
Thick tangle of Freycinetia impavida and Hibiscus tiliaceus with Crossostylis biflora and Weinmannia marquesana var. marquesana, uncommon trees of Ficus prolixa, Boehmeria virgata, Cyclophyllum barbatum, and Metrosideros collina, common herbs and shrubs include Peperomia pallida, Adenostemma viscosum, and Macropiper latifolium, dominant pteridophytes in their general order of abundance include Asplenium nidus, Nephrolepis biserrata, Cyathea affinis, Blechnum vulcanicum, Dicranopteris linearis, Elaphoglossum marquisearum, Elaphoglossum tovii, Sphaerostephanos cf subpectinatus, Hymenophyllum polyanthos, Trichomanes endlicherianum, Trichomanes minutum, Trichomanes pallidum, Belvisia mucronata, Lycopodium cernuum, Lindsaea propinqua, Lindsaea repens var. marquesensis, Sphenomeris chinensis, Selaginella arbuscula, Selaginella banksii, Histiopteris incisa, Diplazium harpeodes, Polystichum marquesense, Tectaria jardinii, Tectaria marchionica, Asplenium horridum, Pteris comans, Angiopteris evecta, Marattia salicina, Phymatosorus nigrescens, Selliguea feeioides, Arachniodes aristata, Asplenium tenerum, Asplenium oblongifolium, Asplenium quaylei, Ophioglossum pendulum var. pendulum, Paesia rugulosa, Oleandra sibbaldii, Amphineuron opulentum, Chingia longissima, Plesioneuron marquesicum, Coryphopteris quaylei, and Vittaria rigida, rare pteridophytes include Calymmodon grantii, Doodia marquesensis, Deparia timetensis, Psilotum nudum, Lomogramma sp., Dryopteris fatuhivensis, and undescribed Polystichum and Dryopteris.
Young plant, 35 cm tall, single leaf collection, leaves opposite pale green-white, single plant seen.
NULL
NULL
NULL
The Ecology of the Vaikivi Summit Region and Drainages Ua Huka, Marquesas Islands (500—884 m elev.) K. R. Wood P. O. Box 745, ‘Ele‘ele, Kaua‘i, HI 96705, kenwood@pelea.org [region explored by the author 28 Jun 1997; 5-6 Dec 2003; 14-16 Jun 2004; 26-28 Jun 2004] MARQUESAS: Ua Huka, (8°S/139°W), lies 312 kilometers from the Marquesas Fault Line hot spot, volcanic island of 3.24 million years, 82 sq kilometer area, maximum altitude of 884 meters. Vaikivi summit region, the author ascended the Vaikivi summit region three times via the Matukuoha Ridge over-looking Hane. On another occasion he ascended the summit via the steep precipitous slopes above the eastern valley of Hanahouua. Vaikivi, with its highest location being Hitikau (i.e., 884 m), constitutes the summit of the single crater of Ua Huka. The area forms a small plateau of around four sq kilometers which is gently divided with around seven small ridges which are dissected by their respective drainages which run to the north at a gentle slope and have running water and small plunge pools in lower sections and range between 700 and 884 m elev. (2300—2900 ft). On the southwest side Vaikivi also constitutes the upper headwater drainages that eventually flow down through Vaipae`e. The summit constitutes a Freycinetia-Hibiscus shrubland/fernland vegetation which is dominated by Freycinetia impavida and Hibiscus tiliaceus and is extremely thick in most areas as to make it difficult to traverse. Other common trees include Crossostylis biflora and Weinmannia marquesana var. marquesana; all other trees are rare including Ficus prolixa var. prolixa, Boehmeria virgata, Cyclophyllum barbatum, and surprisingly Metrosideros collina. On the windward eastern rim the author discovered a white-flowered species of Ixora and located a few trees of Psychotria, both appear to be undescribed species. Also of interest, Cyrtandra jonesii was observed in flower on the southern rim to the east of Hitikau and a single tree of Trimenia was for the first time documented on Ua Huka. Herbs and shrubs include Peperomia pallida, Adenostemma viscosum, and Macropiper latifolium, whereas Cyrtandra ootensis var. quaylei, Bidens uapensis, and Procris pedunculata are only occasionally seen. The only common grass or sedge was Centosteca lappacea, with Carex feani and Leptochloa marquisensis being only occasional. Dicots and monocots are poorly represented in this region, yet the author was impressed with a rich and diverse assemblage of pteridophytes totaling over 50 taxa, dominant pteridophytes in their general order of abundance include Asplenium nidus, Nephrolepis biserrata, Cyathea affinis, Blechnum vulcanicum, Dicranopteris linearis, Elaphoglossum marquisearum, Elaphoglossum tovii, Sphaerostephanos cf subpectinatus, Hymenophyllum polyanthos, Trichomanes endlicherianum, Trichomanes minutum, Trichomanes pallidum, Belvisia mucronata, Lycopodium cernuum, Lindsaea propinqua, Lindsaea repens var. marquesensis, Sphenomeris chinensis, Selaginella arbuscula, Selaginella banksii, Histiopteris incisa, Diplazium harpeodes, Polystichum marquesense, Tectaria jardinii, Tectaria marchionica, Asplenium horridum, Pteris comans, Angiopteris evecta, Marattia salicina, Phymatosorus nigrescens, Selliguea feeioides, Arachniodes aristata, Asplenium tenerum, Asplenium quaylei, Ophioglossum pendulum var. pendulum, Paesia rugulosa, Oleandra sibbaldii, Amphineuron opulentum, Chingia longissima, Plesioneuron marquesicum, Coryphopteris quaylei, and Vittaria rigida, rare pteridophytes include Calymmodon grantii, Doodia marquesensis, Deparia timetensis, Psilotum nudum, Lomogramma sp., Dryopteris fatuhivensis, Vittaria zosterifolia, in addition to an undescribed Polystichum and Dryopteris. The main threats to this ecosystem include competition with non-native plant taxa or animals that could make their way up from the lower regions. The area should be biologically monitored periodically for any such threats. The only non-native plant species observed were Ageratum conyzoides, Cordyline fruticosa, Dioscorea pentaphylla, Musa paradisiaca, and Zingiber zerumbet, with Zingiber being the only species that has the potential to spread rapidly and cover effectively large areas in the forest understory. The others are relatively benign and non-invasive. Of the five non-native taxa one was a dicot and the other four were monocots, while no weedy ferns were seen. Additional threats include human disturbance, and for the rare species reduced reproductive vigor as the result of limited numbers of existing individuals. There were no signs of habitat degradation and destruction by feral pigs or goats, yet the author did observe the Polynesian Rat (i.e., Rattus exulans) which is known to be a seed predator and has been documented to alter the population dynamics of smaller birds. Bryophytes were common terrestrially and also in the shrub layer. The Hitikau region constitutes a dynamic watershed where a diversity of native plants, birds, snails, and insects can continue to survive in a relative balance with no major threats at this time. Ultramarine lorikeet, Vini ultramarina (Loriidae); (pihiti) the author observed numerous pairs along the Matukuoha Ridge trail. In addition, during the early evening of 5 Dec 2003, a pair was observed on the northern rim of the plateau that looks over Hanaeo and Katoahu bay (UTM 0661980 – 9015938 ca 700 m elev. [2300 ft]). Several pairs were also observed while ascending the summit along the eastern slopes above Hanahouua on 27 June 2004. Iphis Monarch, Pomarea iphis (Monarchinae); (pati`oti`o) the author estimates he observed around 30 pair during the course of two days in the plateau and Matukuoha region (Dec 2003), mostly females and immatures (light brown above, white below) were curious enough to approach me as I made noise struggling a course through the Freycinetia, males (black with white mottled bellies) were less curious but more superb singers, birds were seen in both the plateau and along the summit cliff zones where dense shrubland or forest patches occur. During the June 2004 research, around 50 pairs were observed around the summit and drainages to the southwest and at least 50 pairs were observed during my research along the eastern slopes and rim of the plateau. Marquesas Swiftlet, Aerodramus ocistus (Apodidae); (kopekapeka) the author estimates he observed around 200 pair of the dark blackish-brown swiftlet around the summit region of the Hitikau plateau hunting over the low canopy, mostly in groups of 5—10 yet occasionally alone. White-capped Fruit-Dove, Ptilinopus dupetithouarsii (Columbidae); (kuku) several pair of the white-capped fruit-dove were observed making strait passage through the summit plateau and dozens were observed in the southwestern drainages below Hitikau. Occasional sightings were made on the eastern rim also Tahiti Petrel, Pseudobulweria rostrata, (Procellariidae); several individuals were observed on occasion circling the summit zone during the mid-morning and early afternoon of 15 June and 27 June 2004. Mollusca; Samoana snails were seen in great abundance especially on Asplenium nidus and Freycinetia impavida and constitute the largest species observed (i.e., 2 cm long). In addition, the author observed at least half a dozen other species of mollusca in the Hitikau region. Odonata; Megalagrion-like damselflies were observed along plunge-pools with a bright turquoise blue color. A larger dark blue-black Odonata species was observed on the Matukuoha ridge trail. Prawns; (non-native) were observed in pooling water along drainages.