COOPERATIVE NATIONAL PARK RESOURCES STUDIES UNIT UNIVERSITY OF HAWAII AT MANOA Department of Botany Honolulu, Hawai'i 96822 (808) 956-821 8 Technical Report 76-78 STUDIES IN MONTANE BOGS OF HALEAKALA NATIONAL PARK 76. Aspects of the History and Biology of the Montane Bogs by Lloyd L. Loope, Arthur C. Medeiros, and Betsy H. Gagn6- 77. Recovery of Vegetation of a Montane Bog Following Protection From Feral Pig Rooting by Lloyd L. Loope, Arthur C. Medeiros, and Betsy H. Gagn6 78. Degradation of Vegetation In Two Montane Bogs: 1982-1 988 by Arthur C. Medeiros, Lloyd L. Loope, and Betsy H. Gap6 August 1991 UNIVERSITY OF HAWAII AT MANOA NATIONAL PARK SERVICE STUDIES IN THE MONTANE BOGS OF HALEAKALA NATIONAL PARK 76. Aspects of the History and Biology of the Montane Bogs Lloyd L. Loope, Arthur C. Medeiros, and Betsy H. Gagnt Haleakala National Park, P.O. Box 369, Makawao, Maui, Hawai'i 96768, U.S.A. ABSTRACT Montane bogs occur on northeastern Haleakali volcano at 1450-2270 m elevation, with a distinctive, largely endemic flora dominated by the sedges Carex alligata, Carex echinata, Cara nzotltis-eeka, Oreobokts furcatus, and Rhynchospora rugosa subsp. lavarum, the grass Deschampsia nubigena, and the moss Racontitrium lanuginosunt. Although these treeless areas, surrounded by cloud forest, occupy less than 20 ha within Haleakali National Park, 15 endemic plant species are largely confined to bog habitats. A mostly water-impervious substrate layer and an annual rainfall of ca. 10,000 mm create nearly permanently flooded conditions. Invasion of forest species into these bogs may be limited primarily by waterlogged and nutrient-poor soils, but moisture stress caused by prolonged periods of high solar irradiation or infrequent short-term freezing conditions may be contributing factors. Disturbance by feral pigs, beginning in the 1970s, has resulted in destruction of native plant cover and invasion of alien species. Exclusion of feral pigs by fencing selected areas has proved to be an effective strategy for protecting native bog vegetation. Haleakali National Park History and Biology of Bogs Frontispiece: Bare ground exposed by pig digging in Mid-Camp Bog. June 1982.Cmex echinrrta and Argyrariphhium pymurn are the uprooted native species. The alien grass Holclrr lunatus (shown in flower at lower right and background), invades exposed soil and progressively dominates such sites. (ACM photo) Haleakalii National Park History and Biology of Bogs TABLE OF CONTENTS TABLE OF CONTENTS .............................................................................................................................3 LIST OF TABLES .......................................................................................................................................... 4 LIST OF FIGURES ........................................................................................................................................4 e INTRODUCTION......................................................................................................... ............................... 5 HISTORY .....................................................................................................................................................5 LOCATION AND ENVIRONMENT ...........................................................................................................8 VEGETATION PATTERNS .....................................................................................................................12 FLORA ............................................................................................................................................................. 16 FAUNA ............................................................................................................................................................20 IMPACT OF FERAL PIGS ...........................................................................................................................24 BIOLOGY AND CONSERVATION OF GREENSWORD ...................................................................... 24 CONCLUSIONS............................................................................................................................................. 27 ACKNOWLEDGMENTS ..........................................................................................................................28 LITERATURE CITED ................................................................................................................................... 29 APPENDIX I: The field notes of C.N. Forbes ............................................................................................31 APPENDIX 11: Native vascular plant species ...........................................................................................37 APPENDIX 111: Introduced vascular plant species ................................................................................. 41 -3- TABLE OF CONTENTS Haleakali National Park History and Biology of Bogs LlST OF TABLES Table 1: Major montane bogs of East Maui................................................................................................ 8 LlST OF FIGURES Frontispiece. Bare ground exposed by pig digging in Mid-Camp Bog ...................................................2 Figure 1: Montane bogs within and immediately adjacent to Haleakali National Park ......................9 Figure 2: Freeze damage to multibranched plants of greensword. Argyroxiphium grayanum . Mid-Camp Bog. Haleakali National Park. elevation 1660 m . February 1987 ........................11 Figure 3: Woven wire (hogwire) being unrolled in the fencing of New Bog. December 1983.......... 13 Figure 4: Symmetrical. isolated tussock of Oreobolusfurcatus in an East Maui bog ............................13 Figure 5: Stand of Carex echinata with scattered native ferns and clumps of the alien velvetgrass......................................................................................................................................... 14 Figure 6: The rare and localized endemic sedge Carex thunbergii in Mid-Camp Bog.......................... 14 Figure 7: The local endemic Geranium hanaense in habitat at Mid-Camp Bog................................... 17 Figure 8: Maui violet. Kola maviensis. an endemic species found only in bogs of East and West Maui and Moloka'i................................................................................................................. 17 Figure 9: Rosette of Lobelia gloria.montis. a species characteristic of bog margins and wind- swept ridgetops in rain forests of Moloka'i and Maui............................................................... 18 Figure 10: Flowering individuals of Lobelia gloria.montis ........................................................................18 Figure 11: The native tephritid fly Neotephntispaludosae. known only from greensword (Argyroxiphium grayanum) in bogs of northeastern Haleakali.................................................. 22 Figure 12: Multibranched individual of greensword (Argyroxiphium grayanum).................................. 22 Figure 13: Unbranched flowering individual of greensword with a large. woody base .........................23 Figure 14: Rare long-horned beetle (Cerambycidae). an as yet undescribed species of Plagithmysus. known only from upper Haleakali volcano on greensword............................... 23 Figure 15: Feral boar in Mid-Camp Bog .................................................................................................. 25 Figure 16: Alien earthworm aggregation taken from ground surface. Waiho'i Bog. East Maui. elevation 1450 m ...............................................................................................................................25 Figure 17: Flowering individuals of greensword........................................................................................ 26 Figure 18: Greensword plant pig damaged as it started to send up its flowering stalk ........................26 -4- LIST OF TABLES Haleakali National Park History and Biology of Bogs INTRODUCTION Hawaiian bogs occur, mostly at higher elevations, as openings in cloud forest on the islands of Kaua'i, O'ahu, Moloka'i, Maui, and Hawai'i. The vegetation of these areas contains native taxa thought to be derived from ancestors in bogs, wet places, and alpine habitats elsewhere in the world and from Hawaiian wet forests (Carlquist 1970). At the generic level, affinities are particularly strong with taxa in bogs of Malesia, New Zealand, and southern Chile (Godley 1978, Canfield 1986). Because of their remote locations and extremely wet climates, most Hawaiian montane bogs have until recently been little disturbed. This report deals with the history, environment, and species composition of the bogs of East Maui, where substantial disturbance by feral pigs has occurred only during the past decade. It serves as a basis for further studies on vegetation changes related to the impacts of feral pigs. Nomenclature and taxonomy of flowering plant species follows Wagner, Herbst and Sohmer (1990). HISTORY Unlike other Hawaiian bogs (Selling 1948), East Maui bogs were largely unknown until the 1970's. Because of their isolated location, with difficult access, the bogs and cloud forest of northeastern Haleakali were not explored by the earlier Hawaiian naturalists. MacCaughey (1916) stated regarding Haleakali bogs: "Of comparatively recent exploration are the boggy flats that lie at the extreme