PLS 147 Lecture Notes - Lecture 22: Deserts Of California, Indicator Species, Succulent Plant
The California Deserts
●38% of the state's landmass
●2341 native taxa
○37% of CA native taxa
●375 listed plants
○15% of desert flora
●40% flower in fall
●35% are annuals
●90% on public lands
Mojave Desert
●'high' desert (cold!)
○mean 1000m
■range -85 to 1500m
●100-200mm precip
●cool winters
○200-250 frost-free days
●hot summers
●mostly winter rain, some monsoons
●Joshua trees (Yucca brevifolia)
○few succulents bc too cold
Sonoran Desert
●'low' desert
○mean 300m
■range -80 to 600m
●'warm' winters
○nearly 365 growing season
●hot summers
●100-200 mm precip
●50/50 monsoon and winter rains
●Saguaro cacti
○indicator species
Joshua Tree
●moth pollinates flower, lays eggs in ovaries. the young feed on the fruit, and yucca only
gives nutrients to pollinated flowers (therefore there is enough for both the moth and
the plant to reproduce)
●cover is shrinking, shifting
●also lack of dispersal mechanisms: giant sloth
Saguaro Cactus
●pollinated by bats
●grow under the protection of nurse plants
●threatened by frost, fire (invasives)
Ambrosia
species increase diversity in the deserts
- nurse plant for many species, providing shade → moisture
- Ambrosia grows in adequate soil, the seedlings use those resources as well
Document Summary
Moth pollinates flower, lays eggs in ovaries. the young feed on the fruit, and yucca only gives nutrients to pollinated flowers (therefore there is enough for both the moth and the plant to reproduce) Also lack of dispersal mechanisms: giant sloth. Grow under the protection of nurse plants. Ambrosia species increase diversity in the deserts nurse plant for many species, providing shade moisture. Ambrosia grows in adequate soil, the seedlings use those resources as well. Microhabitats allow for the small seeds to become established and eventually overtake the nurse plants through competition or through natural death. Nurse plants facilitate seedling establishment by reducing high temperatures near soil surface and provide microhabitat with a higher soil nitrogen level. Underlying soils gradients and basic plant physiognomy similar. Dark desert varnish often covers the rocks found on the soil surfaces of the mojave and.
