BIG ISLE COMPOSTING — Learn how to compost green waste and kitchen scraps from 1-3 p.m. Saturday at The Barn in Hawi, with intermediate/advanced composting 2-4 p.m. Saturday at Pa'auilo School; $10 for adults, children free. To reserve a spot: www.PiperSelden.com or (808) 937-2233.

WEED WARRIORS — Student volunteers can help the Maui Invasive Species Committee survey and control invasive weed populations, learn scientific protocol and assist with conservation efforts. Catch coqui frogs next Monday night. Reservations and parent approval required. Contact Shannon Wianecki at (808) 573-6472 or hoikeinfo@yahoo.com.

MAKIKI WAI HELPERS — The state Department of Land and Natural Resources and the Hawai'i Nature Center are looking for help 9 a.m.-2 p.m. June 24 to make trail improvements, remove weeds and plant native plants along the Makiki trail, as part of the Makiki Wai (Watershed Awareness Initiative). Bring long pants, long-sleeved shirt, shoes or boots, gloves, insect repellent, water and lunch. Meet at the Makiki Forestry Baseyard. For directions and information: 973-9782, www.hawaiitrails.org /trail.asp?TrailID=OA+19+004 &island=Oahu.

KOKUA KALIHI VALLEY — June 24 is the next workday to help the Sierra Club clear a former nursery site for a park in upper Kalihi Valley. Call Arlene Buchholz at 988-9806.

HALEAKALA VOLUNTEERS — Haleakala National Park has a variety of volunteer opportunities for youths, high school classes, college students and adults. Available positions include visitor center and naturalist docents, receptionist, cultural demonstrator, sunrise visitor assistant, workers in trail maintenance and interns. For more information, see www.nps .gov/hale; call (808) 572-4487; or e-mail HALE_VIP_Coordinator @nps.gov.

WEED & POT CLUB — Maui Nui Botanical Garden's Weed & Pot Club meets 8:30-10:30 a.m. Wednesdays at 150 Kanaloa Ave. in Kahului to weed, rake, trim or transplant nursery plants, and perform other work. Tools, gloves and drinking water provided; bring sunscreen, wear shoes.

KANAHA POND — Join Native Hawaiian Plant Society volunteers at Kanaha Pond Wildlife Sanctuary 7:30-11 a.m. every Thursday for weeding and brush cutting; work also done at Maui Ocean Land Trust wetlands. Call 572-6338.

MAUI TRAIL CREWS — Na Ala Hele volunteers meet Saturdays, Sundays and Tuesdays to build and clean Maui trails. Leave from Kahului Baseyard at 7:30 a.m.; bring lunch, water and sturdy shoes; tools and transportation provided. (808) 873-3509 or mark.a.peyton@hawaii.gov.

Send listings to: For the Environment, P.O. Box 156, Wailuku, HI 96793; cwilson@honoluluadver tiser.com; or fax (808) 242-1520.