2009 Status Report for the Makua and Oahu Implementation Plans
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Chapter 1 Ecosystem Management 1.4 ECOSYSTEM RESTORATION MANAGEMENT UNIT PLANS 1.4.1 Ekahanui Ecosystem Restoration Management Plan MIP Year 6-10, Oct. 2009 – Sept. 2014 OIP Year 3-7, Sept. 2009 - Sept. 2014 MU: Ekahanui Subunit I, II, III, IV and Ekahanui No MU 1.4.1.1 Overall MIP/OIP Management Goals: • Form a stable, native-dominated matrix of plant communities which support stable populations of IP taxa. • Control ungulate, rodent, arthropod, slug, snail, fire, and weed threats to support stable populations of IP taxa. Implement control methods by 2013. 1.4.1.2 Background Information Location: Southern Waianae Mountains Land Owner: State of Hawaii Land Manager: DOFAW (State Forest Reserve) Acreage: 3100 acres Elevation Range: 1800-3100 ft Description: Ekahanui MU is located in the Southern Windward Waianae Mountains. Puu Kaua is at the apex of many sub drainages that make up Ekahanui. The summit of Puu Kaua is 3127 ft high. Three major drainages are encompassed in the MU. Overall the area is characterized by steep vegetated slopes and cliff especially at higher elevations. Much of the MU is dominated by alien vegetation. There are only small pockets of native vegetation worth intensive management. The alien dominated areas were included in the MU boundary to ensure management options for Elepaio. Most of this alien dominated area fenced for Elepaio management falls into the Subunit II fence. The MU is accessed via the Kunia road through the Kunia village. Native Vegetation Types Waianae Vegetation Types Mesic mixed forest Canopy includes: Acacia koa, Metrosideros polymorpha, Nestegis sandwicensis, Diospyros spp., Pouteria sandwicensis, Charpentiera spp., Pisonia spp., Psychotria spp., Antidesma platyphylum, Bobea spp. and Santalum freycinetianum. Understory includes: Alyxia oliviformis, Bidens torta, Coprosma spp., and Microlepia strigosa Mesic-Wet forest Canopy includes: Metrosideros polymorpha polymorpha. Typical to see Cheirodendron trigynum, Cibotium spp., Melicope spp., Antidesma platyphyllum, and Ilex anomala. Understory includes: Cibotium chamissoi, Broussasia arguta, Dianella sandwicensis, Dubautia spp. Less common subcanopy components of this zone include Clermontia and Cyanea spp. 2009 Makua and Oahu Implementation Plan Status Report 21 Chapter 1 Ecosystem Management Vegetation Types at Ekahanui Mesic Mixed Forest Mesic-Wet Forest 2009 Makua and Oahu Implementation Plan Status Report 22 Chapter 1 Ecosystem Management MIP/OIP Rare Resources Organism Species Pop. Ref. Code Population Unit Management Wild/ Type Designation Reintroduction Plant Abutilon sandwicense EKA-A, B HUL-A Ekahanui and MFS (OIP) Both Huliwai Plant Alectryon macrococcus EKA-A, B, C, D, E, Ekahanui N/A Wild var macrococcus F Plant Cenchrus agrimonioides EKA-A, B, C, D† Central Ekahanui MFS Both var. agrimonioides Plant Cyanea grimesiana EKA-A* North Branch of N/A Wild subsp. obatae South Ekahanui Plant Cyanea grimesiana EKA-B, C North Branch of Genetic Reintroduction subsp. obatae South Ekahanui Storage Plant Delissea subcordata EKA-A, B*, C*, D Ekahanui MFS Both Plant Phyllostegia mollis EKA-A*, B*, C Ekahanui N/A Wild Plant Phyllostegia mollis EKA-C Ekahanui MFS (OIP) Reintroduction Plant Plantago princeps var EKA-A, B, C Ekahanui MFS (OIP) Wild princeps Plant Schiedea kaalae EKA-A, B, C*, D South Ekahanui MFS Both Snail Achatinella mustelina EKA-A, B, ESU-E MFS Wild C,D,E,F,G Bird Chasiempis N/A Ekahanui None Wild sandwichensis ibidis MFS= Manage for Stability *= Population Dead GSC= Genetic Storage Collection †=Reintroduction not yet done Other Rare Taxa at Ekahanui MU Organism Species Status Comments Type Plant Chamaecyce herbstii Endangered Population gone (2001) Plant Diellia falcata Endangered Scattered individuals Plant Diellia unisora Endangered Hybridizing w/ D. falcata Plant Phyllostegia hirsuta Endangered Population gone (2000) Plant Phyllostegia kaalaensis Endangered Population gone (2000) Plant Platydesma cornuta var decurrens Candidate Plant Schiedea hookeri Endangered Small wild population in Subunit I, larger TNC reintroduction elsewhere in Subunit I. Plant Schiedea pentandra Candidate Plant Urera kaalae Endangered Wild plants in Subunit II, reintroduction established by TNC in Subunit I. Plant Tetramolopium lepidotum var. Endangered Small wild location at crestline, Subunit I lepidotum Plant Solanum sandwicense Endangered Reintroduction established by TNC in Subunit I. Founder from Palawai Plant Cyanea pinnatifida Endangered Reintroduction established by TNC in Subunit I. Founder from Kaluaa. Plant Dissochondrus biflorus Species of Concern One location Plant Pleomele forbesii Candidate Scattered individuals Plant Pteralyxia macrocarpa Species of Concern Scattered clusters Plant Zanthoxylum dipetalum var. Species of Concern Scattered individuals dipetalum Fly Drosophila montgomeryi Endangered One location, Subunit II Snail Philonesia sp. Species of Concern Snail Amastra spirizona Species of Concern Subunit I 2009 Makua and Oahu Implementation Plan Status Report 23 Chapter 1 Ecosystem Management Locations of Rare Resources at Ekahanui 2009 Makua and Oahu Implementation Plan Status Report 24 Chapter 1 Ecosystem Management Rare Resources at Ekahanui Mature Cyanea grimesiana subsp. obatae at reintroduction D. subcordata recruitment Abutilon Sandwicense flower under reintroduced plants Plantago princeps var. princeps with Wild Schiedea kaalae patch infructescense 2009 Makua and Oahu Implementation Plan Status Report 25 Chapter 1 Ecosystem Management MU Threats to MIP/OIP MFS Taxa Threat Taxa Affected Localized Control MU scale Control Control Method Sufficient? required? Available? Pigs All No Yes MU fenced Rats All Yes for Elepaio, Yes MU-wide snap trap Unknown for plants grid to be tested and snails Predatory Achatinella mustelina Unknown Unknown No. Limited to hand- snails removal and physical barriers Slugs C. grimesiana subsp. Yes No Currently under obatae, D. subcordata, P. development princeps var princeps, S.kaalae, P. mollis Ants Potential threat to Unknown Unknown Some available, Drosophila montgomeryi depends on species Weeds All Yes Yes Yes Fire All Yes Yes Yes Management History • 1998-2002: Biological surveys by TNC Staff and Joel Lau. • 1999: Elepaio management begins with banding and rodent control of about 6 pairs. By 2006, the number of territories protected is about 20. By 2009, over 25 pairs are known and protected by rat control efforts. • 2000: Subunit I fence completed (40 acres). TNC eradicated the last pigs through the use of volunteer and staff hunters. • 2001-2006: Catchment tanks and field nursery installed. Other common native restoration efforts done by TNC/Army staff. • 2002: Achatinella mustelina surveys by Army Staff and Joel Lau. • 2005: 120 acre fire burns into the forest, well into the adjacent gulch to the south of Ekahanui as well as into the lower reaches of Ekahanui Gulch itself. • 2007: Most restoration and active management by TNC stops due to staff reductions. • 2008: Subunit II fence completed. • 2009: James Campbell Co. sells Honouliuli Preserve to The Trust for Public Land with goal of eventual transfer to the State of Hawaii. 2009 Makua and Oahu Implementation Plan Status Report 26 Chapter 1 Ecosystem Management 1.4.1.3 Ungulate Control Identified Ungulate Threats: Pigs Threat Level: High Primary Objective: • Maintain Subunit I and II as pig free. • Complete the construction of Subunit III and IV. Strategy: • Maintain Subunit I and II as pig free by maintaining fences. • Volunteer hunters were used initially to eliminate the majority of the pigs. • Snares are now employed in Subunit II to get the last of the animals and trapping will soon commence. Monitoring Objectives: • Conduct fence checks and read transects quarterly. GPS and mark the fence at ten meter intervals so that the fence will be one large transect. • Monitor for pig sign while conducting other management actions in the fence. Management Responses: • If any pig activity is detected within the fenced unit, implement hunting and/or trapping/snaring program. • When DOFAW takes over the management of Honouliuli, OANRP will fully support the institution of a hunting program to help reduce the amount of pressure from pigs on fences. Fence Completions: • Subunits III and IV are scheduled to be completed in 2013, but III should be completed by 2010. Maintenance Issues: • There is a perimeter fence around Subunit I and II. The major threats to the perimeter fence include fallen trees and vandalism. There are no “major” gulch crossings but rather three smaller crossings that have potential to carry a large amount of debris. Special emphasis will be placed on checking the fence after extreme weather events. There have been relatively few incidences of vandalism in the past. Ungulate Control Actions: Year Action Quarter MIP YEAR 6 • Check MU fence for breaches, maintain integrity of fence • 1-4 Oct 2009-Sept 2010 • Install two 500m transects within the fence • 1 • Clear and herbicide grassy sections of fence to maintain ability to • 1, 3 monitor MIP YEAR 7 • Check MU fence for breaches, maintain integrity of fence • 1-4 Oct 2010- Sept 2011 • Read ungulate transects quarterly • 1-4 through • Clear and herbicide grassy sections of fence to maintain ability to • 1, 3 MIP YEAR 10 Oct 2013- monitor Sept 2014 • Subunit III construction to be completed by 2010 , Subunit IV by 2013 • 1-4 2009 Makua and Oahu Implementation Plan Status Report 27 Chapter 1 Ecosystem Management 1.4.1.4 Weed Control Weed Control actions are divided into 4