A woodland is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the plurale tantumwoods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see differences between British, American, and Australian English explained below). Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of primary or secondary succession. Higher-density areas of trees with a largely closed canopy that provides extensive and nearly continuous shade are often referred to as forests.
Woodlot is a closely related American term which refers to a stand of trees generally used for firewood. While woodlots often technically have closed canopies, they are so small that light penetration from the edge makes them ecologically closer to woodland than forest.
In Australia, a woodland is defined as an area with sparse (10-30%) cover of trees, and an open woodland has very sparse (<10%) cover. Woodlands are also subdivided into tall woodlands, or low woodlands, if their trees are over 30 m (98 ft) or under 10 m (33 ft) high respectively. This contrasts with forests, which have greater than 30% cover by trees.
Sudden oak death (SOD), an oak disease, results from Phytophthora ramorum, a pathogen that thrives in moist, humid conditions. This causal agent attacks the phloem and cambium of oaks, allowing beetle and fungi infestation. It has killed millions of tanoaks since it was discovered in the mid-1990s. SOD does not affect white oaks and drier areas like foothill woodlands, but affects forests and more moist conditions like live oak woodlands and forests, which have been significantly impacted.
^"A simplified look at Australia's vegetation". Information about Australia's Flora: The Australian Environment. Canberra: Australian National Botanic Gardens and Centre for Australian National Biodiversity Research. 24 December 2015. Retrieved 2017.
^ abMooney & Zavaleta (2016). Ecosystems of California. University of California Press, Oakland. p. 515.