* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download COMMON SPECKLED ALDER (Alnus rugosa)
Plant stress measurement wikipedia , lookup
Plant secondary metabolism wikipedia , lookup
Plant breeding wikipedia , lookup
Plant defense against herbivory wikipedia , lookup
Plant use of endophytic fungi in defense wikipedia , lookup
History of herbalism wikipedia , lookup
History of botany wikipedia , lookup
Evolutionary history of plants wikipedia , lookup
Plant evolutionary developmental biology wikipedia , lookup
Plant morphology wikipedia , lookup
Plant physiology wikipedia , lookup
Historia Plantarum (Theophrastus) wikipedia , lookup
Plant ecology wikipedia , lookup
Plant nutrition wikipedia , lookup
Flowering plant wikipedia , lookup
Ornamental bulbous plant wikipedia , lookup
Plant reproduction wikipedia , lookup
Sustainable landscaping wikipedia , lookup
River-Lab 5 Guide Manual COMMON SPECKLED ALDER (Alnus rugosa) Alders contribute to basin productivity by stabilizing the stream banks where they stand; by enriching soil, including making nitrogen available to other plants; and by providing food and habitat. Alders are fast-growing shrubs that branch out over the ground. They spread rapidly as new plants sprout from the base of established plants and from underground stems. Even branches can produce new plants. When a drooping branch touches the ground, it may send down roots and send up new shoots. With many trunks clumped together, thickets of alder plants can protect streambanks from the erosive attack of floodwater. The dense mat of roots and underground stems helps hold soil to keep streambanks stable. Soil enrichment is an alder specialty. Alders enrich soil by trapping mulch, including their own dropped leaves and flowering parts, under the low branches. Even more importantly, alders are one of a special group of plants that have bacteria in nodules (swellings) on their roots that convert nitrogen into forms plants can use. Nitrogen is an essential element for plant growth. Air pockets in soil contain nitrogen gas, but this gas must be changed into ammonia or nitrates before plants can use it. The bacteria that live on alder roots make this necessary conversion, which benefits all plants in the alder’s immediate area. Alders provide food and habitat for many animals. Seeds are eaten by birds, especially chickadees and goldfinches. Goldfinches and redwing blackbirds nest in the alder branches in spring. Other wildlife find cover in alder thickets. Deer and muskrats browse on twigs. Muskrats and shrews tunnel among the roots underground. In spring, insects such as beetles eat the leaves and lay eggs on them. In late summer and early autumn, woolly aphids cover stems and eat the sap of the alder. A small, brown and orange butterfly, the wanderer, feeds on the aphids. The speckled alder may grow as a small tree, up to twenty feet tall, or as a large woody shrub six to fifteen feet tall. It prefers wet, spongy areas such as the banks of streams. A relative of the birch, the alder’s dark grayish-brown bark is marked with white speckles. The dull, dark green leaves, two to four inches long, are egg-shaped, with the base broader than the tip. © 1999 Mill River Wetland Committee, Inc. 5GM - 14 River-Lab 5 Guide Manual COMMON SPECKLED ALDER, cont’d. The alder’s flowering parts, its male and female catkins, develop on the same plant, which makes alders monoecious. New male catkins look like miniature brown fox tails, grouped near the tips of the alder branches. They develop into long, drooping, soft greenish-yellow tassels of tiny blossoms. These tassels grow longer and longer as they mature (to 1 1/2 – 1 5/8 inches), swelling and finally bursting with yellow grains of pollen. Female catkins resemble small pinecones. They grow in clusters above the male catkins. In the spring these small cone-like catkins (1/2 – 5/8 inch long) have dark “hairs” that stick out. These are the stigmas that catch wind-blown pollen. Like the male catkins, these catkins will grow larger as they mature (to about 3/4 inch). In autumn they will be filled with tiny seeds, which will be dispersed by winds and animals. In spring, the old female catkins can still be seen on the same shrub with the new smaller ones. Most of the old ones are empty, but some may still contain seeds. Whether they are dropped to the ground in wastes of animals that have eaten them or dropped directly from the catkins, fertilized alder seeds will give rise to new alder shrubs, ensuring that the special benefits of this plant’s contributions to the basin system will continue. 5GM – 15 © 1999 Mill River Wetland Committee, Inc.