Valley Grassland and Riparian Woodland Flashcards

Flashcards covering key vocabulary and concepts related to Valley Grassland and Riparian Woodland ecosystems, based on lecture notes.

Valley Grassland

Formerly occupied the Great Central Valley; adjacent valleys surrounded by mountains still harbor Valley Grassland; characterized by an herbaceous flora, especially perennial grasses. Conversion to farmland

Native Perennial Grass Species

Keir Morse, Poa secunda, and Stipa pulchra.

Non-Native Annual Grassland

Dominated by a handful of genera; more flammable than perennial grasslands, impacting plant communities; dead, dry grasses carry fire into adjacent vegetation. Avena sp. & Bromus diandrus

Vernal Pools

Ephemeral pools occurring in poorly-drained grassland depressions, underlain by clay or hardpan, filling in winter and draining/evaporating in summer; usually found in Mediterranean areas. A highly endangered community in California, with >90% lost. Species are mostly annuals

Vernal Pools Plant Adaptations

Many endemic plant species are adapted to vernal pools, which are a type of freshwater wetland. No fish predators exist, enabling amphibian and invertebrate diversity. adapted to different inundation regimens, often in concentric rings.

Vernal Pools Hydrology

Pools will continue to survive as long as the complex hydrological properties of vernal pool areas are undisturbed. The inundation regime keeps many invasive species out.

Vernal Pools Ecology

The cyclical ecological succession is an annual regime. Disturbance is flooding, followed by soil drying. Plants and animals survive the dry period in dormant stages (seeds for plants).

Riparian Woodland

The corridor of trees along a creek or river, usually deciduous trees. Can have a dense understory of shrubs and vines. Broadens out considerably on valleys; easily seen on steep mountains or waterways.

Riparian Woodland Tree Species

Willow (Salix spp.), Big-leaf maple (Acer macrophyllum), Box elder (Acer negundo), Alder (Alnus spp.), Fremont cottonwood (Populus fremontii), and California sycamore (Platanus racemosa).

Riparian Woodland Disturbance

Primary ecological disturbance is flooding. Many trees can withstand inundation of their roots. Large floods can rip trees from banks, then deposit new sediments for colonization.