BIO 114- Grassland and Wildflowers lecture

Grasslands

• Cover 13% of CA

• Form ecotones, coastal scrub, chaparral, oak woodlands

• Dominated by members of grass

Grass Vegetative Characteristics

• Herbaceous

• Alternate, distichous leaf

• Grows from intercalary meristems between nodes

In grass flowers and inflorescences, glumes

Subtend each spikelet

Floret

= 2 bract + flower

2 bracts =

Lemma and palea

Lodicules

Modified perianth (expand and push lemma and palea apart)

Awn

a bristle on a glume or lemma

Bran

Pericarp + seed coat

Germ

Embryo

Caryopsis

One-seeded dry fruit with the pericarp fused to the seed coat

Grassland Invasion by Non-native

Pre-colonial CA grasslands were dominated by perennial bunch grass

Scattered relic

Only ___________ areas of native grassland still exist in CA

What impacts invasion of grassland by non-natives

• Urban development

• Agriculture

• Grazing

• Annuals reproduce quickly, perennials not so quickly

Grazing

• Only 36% of grassland is left

• Caused drastic community disturbance

• Favors annual grasses

Forbs

In addition to dominant grasses, communities contain a large variety of _______ (herbaceous non-grass plants)

Vermal pools

Depressions in flat plain underlain by clay pan or hardpan soil layer that promotes long-term pooling of water

Vernal pools in the early spring

• Deepest sections retain water for weeks to months

• Over time, pools dry up exposing more and more soil in successive rings

• Zonation of different species

Geophytes

• “Earth plants”

• Fleshy stems underground to store water and energy

• Dry season, plants survive underground

• Sprout new stems, leaves, flowers during favorable conditions

• Some reproduce “clones” wuth bublets