Alder trees are deciduous, growing about two feet per year. They have sticky, shiny leaves that turn brown in fall. Produce wind-pollinated catkins and strobiles. Have grayish, rough bark that develops fissures
About 500 species of oak trees exist in the Querus genus. Oaks are known for their acorns and lobed leaves. They support biodiversity and provide shade in landscapes
Populus genus contains around 35 species, none suitable for landscape use. Trees typically have gray, white, or black bark with diamond-shaped marks. Most poplar trees are large, columnar, and require full sun
Grasslands are vegetation dominated by grasses in environments conducive to grass growth. They lie between forests and deserts in the global climate gradient. Grasslands evolved during Cenozoic Era (65.5 million years ago to present). Some grasslands expanded only during ice ages in northern temperate regions
Invasive species are introduced organisms that harm their new environments. Human-facilitated introductions have greatly increased invasion rates since 20th century. Humans have been both accidental and deliberate dispersal agents for millennia
Domestication is a mutualistic relationship where humans control other species for resources. First domesticated animal was dog 15,000 years ago. Process occurred gradually and geographically across 13 centers worldwide