The document discusses gardening with California native plants in the context of climate change, highlighting its impact on local gardens in Western Los Angeles County. It explains the nature of climate and weather, how climate models predict future changes in temperature and precipitation, and the increasing frequency of extreme heat days expected in California. The document also suggests various strategies for homeowners and urban planners to mitigate heat, including creating shade with hardscapes and planting trees, while emphasizing the importance of trees for cooling, air quality, and overall human well-being.

1. Out of the Wilds and Into Your Garden
Gardening with California Native Plants in Western L.A. County
Project SOUND – 2014 (our 10th year)
© Project SOUND

2. Climate Change:
how climate change may affect
local gardens & what you can do
to prepare
C.M. Vadheim and T. Drake
CSUDH & Madrona Marsh Preserve
Madrona Marsh Preserve
March 1 & 4, 2014
© Project SOUND

3. 2014: Bringing Nature Home - Lessons
from Gardening Traditions Worldwide
Today we’ll be visiting the gardens of Morocco
© Project SOUND

4. The ideal of the garden: Morocco style
 Gardens have great importance in
Morocco, as elsewhere in the Muslim
world.
 As an earthly version of the paradise
described in the Quran, they are
places of repose and reflection, but
also somewhere heaven meets earth,
where humans may encounter the
divine.
http://medomed.org/2012/the-jeb-of-rabat-in-springtime/
 In the hot areas of Morocco, they
are cool oases where people can find
rest and relief from the heat.
Al Andalus Garden in Rabat
© Project SOUND

5. The world climate is changing
© Project SOUND

6. First some definitions
 Weather is the mix of events that happen each day in our
atmosphere including temperature, rainfall and humidity.
Everyday, weather events are recorded and predicted by
meteorologists worldwide.
 Climate in your place on the globe controls the weather
where you live. Climate is the average weather pattern in a
place over many years.
 Climate modeling is the use of sophisticated computerbased models of the climate system to understand and
predict its behavior.
© Project SOUND

7. Climate models help us understand how
climate works
 Present:
 Effects of ocean temperature
on climate in CA – El Nino/
Southern Oscillation
 What causes the jet stream to
move
 Past:
 Why was climate much wetter
after the last Ice Age?
 Why do hot/cold or wet/dry
variations occur?
 Future: effects of global climate
change on local and larger scale
© Project SOUND

8. Predicting the future: always difficult
 Problems of scale:
 Dealing with large scale/global
causes & effects
 Small scale – what individuals/
states, etc. are interested in
 Many factors (and their
interactions) are important
 Don’t have long-term data on many
of these factors
 Some factors are unpredictable
(volcanic eruptions)
 We’ve never experienced changes
anything like this
© Project SOUND

9. atmosphere/ocean/sea-ice general circulation
models (AOGCMs)
 Three-dimensional models of the
global atmosphere used in climate
modeling
 Couple atmospheric GCMs (AGCMs),
oceanic GCMs (OGCMs) and
increasingly additional data.
 Based on laws of physics
 Complex – require big computers &
lots of time to run the simulations
http://en.wikipedia.org/wiki/General_Circulation_Model
Global atmospheric modeling began
in the mid-1950’s
 Results are ‘checked/verified’ by
comparing to past/present
 Used to predict the effects of
climate change
© Project SOUND

10. Factors that go into currant AOGCM models
 The hydrosphere: the oceans and
other bodies of water
 The cryosphere: including sea
ice, glaciers and ice sheets
 The atmosphere: composition and
behavior
 The biosphere: the amounts of
animals and plants
 The geosphere: tectonic
variations such as volcanic
eruptions and moving continents
http://scienceandtheworld.com/2013/04/29/wading-into-the-fire-episode-6-climate-modelling-is-atough-gig/
© Project SOUND

11. Most planners currently use data from several
models (and several scenarios) to predict
 When models concur, the
result is more likely to be
correct
 Can compare models and try
to understand the reason for
the differences – increases
our understanding of the
processes
 Allows to ‘bracket’ what the
likely effects will be
http://en.wikipedia.org/wiki/Effects_of_global_warming
© Project SOUND

12. Cal-Adapt: California’s climate change
data/mapping source
 Recommended in the 2009
California Climate Adaptation
Strategy report
 Developed by UC Berkeley's
Geospatial Innovation Facility
(GIF)
http://cal-adapt.org/blog/2011/apr/13/global-climate-models/
The data used within the Cal-Adapt
visualization tools have been gathered from
California’s scientific community, and
represent the most current data available
wherever possible.
 Provides data and maps to
planners, researchers and
the public – Climate Tools are
easy to use
© Project SOUND

13. Cal-adapt climate tools are easy to use
© Project SOUND

14. Cal-Adapt uses information from 4 AOGCM
models
 NCAR - National Center for
Atmospheric Research Parallel
Climate Model (PCM1)
 CCSM - Community Climate System
Model Version 3.0 (CCSM3) National Science Foundation and the
Department of Energy.
 GFDL - NOAA Geophysical Fluids
Dynamic Laboratory (GFDL)
 CM2.1 CNRM - Centre National de
Recherches Météorologiques,
Toulouse, France
© Project SOUND

15. Other commonly used models
 Hadley Centre Model (HadCM3)
 Canadian Model (CGCM4/CanCM4)
© Project SOUND

16. We’ll be considering several topics today
 Predicted changes in temperature
 Predicted changes in seasonality
 Predicted changes in precipitation/water availability
 Likely effects on wind
 Likely effects on air quality
 Other effects
© Project SOUND

17. The models and current data all agree:
the world is getting hotter
http://www.ncdc.noaa.gov/sotc/service/global/map-percentile-mntp/201401.gif
© Project SOUND

18. Hadley Model - average maximal yearly temperature
© Project SOUND
http://eos-earthdata.sr.unh.edu/thumbnail_pages/tairmaxtc-h2.jsp

19. Hadley Model - average yearly minimum temperature
http://eos-earthdata.sr.unh.edu/thumbnail_pages/tairmintc-h2.jsp
© Project SOUND

20. Temperature predictions for CA: 2100
 For CA as a whole, average
summer temp. may increase
3.87-14.9°F; average winter
temperatures between 3.877.2°F.
 Temperature changes may be less
significant in the southwest
coastal region; increasing change
going north and northeast across
the state.
 The relative increases of minimum
temperatures may be the most
dramatic (although not all models
predict this increase)
© Project SOUND

21. Local effects: we’re protected by the
ocean, but we’ll be hotter
© Project SOUND

22. More ‘extreme heat’ (> 95° F)
days in the future
 Cal-Adapt projects that urban and rural
population centers throughout California
will experience:
 An average of 40 to 53 extreme heat
days by 2050 [LA = 78]
 An average of 40 to 99 days [LA = 110]
by 2099
 This compares to a historical average of 4
per year (average throughout the state).
 The number of “extreme heat” days is
projected to triple in downtown Los
Angeles, and quadruple in the San
Fernando and San Gabriel valleys
http://www.epa.gov/climatechange/impacts-adaptation/health.html
© Project SOUND

23. Extreme heat is not just annoying – it kills
 Greater risk of death from
dehydration, heat
stroke/exhaustion, heart
attack, stroke, and respiratory
distress
 By mid-century, extreme heat
events in urban centers such as
Los Angeles are projected to
cause two to three times as
many heat-related deaths as
there are today.
 That’s why the health
departments are planning
http://www.climatechoices.org/impacts_health/
© Project SOUND

24. The phenomenon of urban heat islands
http://heatisland.lbl.gov/
 Daytime temperatures in urban areas are on average 1-6° F
higher than in rural areas, while nighttime temperatures can
be as much as 22º F higher as the heat is gradually released
from buildings and pavement (U.S. EPA, 2008).
© Project SOUND

25. Urban heat islands: we need to decrease
the heat absorption
 Are influenced by a city’s
geographic location and by local
weather patterns
 The most intense urban heat
island effects are often seen in
neighborhoods where dense land
use and impervious, paved
surfaces predominate and trees,
vegetation and parks are less
common.
 Bottom line: you (and your
neighbors) need to create shade
© Project SOUND

26. Homeowner strategies to combat heat
 Decrease the amount of heat
absorbed by the home:
 Attic/wall insulation; ‘cool’
windows
 Replace old roof with ‘cool roof’
alternatives
 Light colored walkways, mulch
 Increase shade with hardscape
 Increase shade with plants
© Project SOUND

27. If you need new roofing,
consider a ‘cool roof’?
 Roofing materials that reflect
more irradiation & emit heat
better than conventional
materials
http://heatisland.lbl.gov/coolscience/cool-science-cool-roofs
 Make most sense in southern U.S.
– and particularly in CA; summer
cooling far outweigh costs of
winter heating
http://www.lbl.gov/Science-Articles/Archive/sb/Aug-2004/3_coolroofs-2.html
Cool colors – save energy
© Project SOUND

28. The city of Los Angeles goes ‘cool’
 Starting in 2014, thanks to an
update of the Municipal Building
Code, all new or refurbished
buildings will be equipped with
“cool roofs.”
http://www.arcat.com/photos/eagleroo/141564.jpg
 Compared to traditional roofs,
cool roofs can be as much as 50
degrees cooler on the roof
surface, and can lower interior
building temperatures by
several degrees.
 Los Angeles is the first major
American city to pass a coolroof ordinance.
Owens Corning’s Duration Premium Cool series
http://bradyroofing.net/products/pitched-roof-materials/owens-corning/owens-corning-duration-premium-cool-series/
© Project SOUND

29. Garden strategies to combat heat: create
shade with hardscape
 Benefits:
 May add beauty/style to the garden
 Long-lasting
 Often low maintenance (compared to
plants)
 Require no water
 Cost effective over time –
particularly with increasing
temperatures
http://www.jardinmajorelle.com/jardin/
© Project SOUND

30. People who live in hot places learned how
to create shade long ago: Morocco

Climate
 Mediterranean to extremely hot & dry

Gardening history
 Very long and complex
 Arabic, Moorish, Berber, Roman and European
influences
http://en.wikipedia.org/wiki/File:Moroc
co_(orthographic_projection).svg
© Project SOUND

31. Some Moroccan ideas on shade
http://www.inspirebohemia.com/2010/09/streets-of-morocco.html
http://www.freepik.com/free-photo/moroccan-architecture_663546.htm
Shady courtyards, tile/brick,
fountains: places to sit, work
and relax
© Project SOUND

32. Some ideas are directly applicable
Note the use of colors: the blues
and turquoises suggest the cool
of water; the contrast with the
warm colors makes them seem
even cooler
http://www.digsdigs.com/55-charming-morocco-style-patio-designs/
http://housetohome.media.ipcdigital.co.uk/96/000007ad7/7260_orh550w550/DCOR200.jpg
© Project SOUND

33. Creative shade using hardscape
http://genosgarden.blogspot.com/2010_08_01_archive.html
http://genosgarden.blogspot.com/2010_08_01_archive.html
Think about how you use your
outdoors. Would you use your
garden more if it had a shady
porch, pergola, arbor?
© Project SOUND

34. Strategies for combating urban heat:
becoming more common
 Solar panels placed on canopies over parking lots and other
paved surfaces
 Cool roofing & light-colored roofing
 Passive management of home heat: roof deck insulation,
wall insulation, high performance windows, and building
orientation; patios to provide shade
 Cool pavements
 Shading of buildings, asphalt and other dark surfaces
with trees
 Management and restoration of parks and riparian zones
in urban areas
© Project SOUND

35. Why are trees/other vegetation important?
 Provide shade
 Tree shade: decrease temperatures
20 to 45ºF (11-25ºC) for walls and
roofs; ~ 45ºF for parked cars
 Vines: reductions of up to 36ºF (20ºC).
 Provide evapotranspirational cooling
 Peak air temperatures in tree groves
are 9ºF (5ºC) cooler than over open
terrain.
 Suburban areas with mature trees are
4 to 6ºF (2 to 3ºC) cooler than new
suburbs without trees.
 Temperatures over grass sports fields
are 2 to 4ºF (1 to 2ºC) cooler than
over bordering areas.
© Project SOUND

36. Ouarzazate: The Skoura Palm Groves
 Shaded in the protective canopy of
tall palms, the Skoura Palm Groves
have roads that you can follow from
one Berber village to the next.
http://www.gmtours.com/post/view/the-secret-gardens-of-morocco
 Gardens and agricultural areas
beneath the palms are an important
source of food in the region
 During your walk, you will encounter
several varieties of fruit and nut
trees, vegetable gardens, and
perhaps even some goats and sheep.
 The palms are a source of cool,
native shade in the hot, dry climate
© Project SOUND
http://berbernomadadventure.com/tours/berber-villages-andkasbahs-tour/

37. But trees/other vegetation have other benefits that
will help us cope with climate change
 Filter out harmful UV
rays
 Allow for increased
water absorption
during rain/irrigation
events
http://www.lawrenceofmorocco.com/sites/lawrenceofmorocco.com/files/imagecache/gallery_acco
mmodation/jardins_de_skoura_morocco_sahara_desert59.jpg
 Act as windbreaks to
decrease windassociated drying
© Project SOUND

38. Benefits of trees/vegetation: more than heat
 Reduced Energy Use
 In Sacramento study: cooling energy savings ranged between 7
and 47 percent and were greatest when trees were planted to
the west and southwest of buildings
 Reduced Air Pollution and Greenhouse Gas Emissions
 Leaves remove various pollutants from the air, referred to as
“dry deposition”
 Shade trees reduce evaporative emissions from parked vehicles
 Trees and vegetation remove and store carbon
 Trees and vegetation reduce greenhouse gas emissions from
power plants by reducing energy demand.
 Enhanced Stormwater Management and Water Quality.
 Reduced Pavement Maintenance Costs
© Project SOUND

39. The human benefits of trees/vegetation
 Improve human health and wellbeing
 Reduce pollution/dust
 Reduce noise levels
 Decrease effects of extreme heat
events
http://jeffreygardens.blogspot.com/2011_01_01_archive.html



Provide habitat, food
Provide oxygen
‘calm and rest the soul’
http://www.classictravel.com/hotels/dar-ahlam
© Project SOUND

40. Garden strategies to combat heat: create
shade with trees, large shrubs & vines
 Look closely at your
existing trees
 Are they healthy?
 Young enough to survive
your lifetime?
 In the right places to
provide needed shade?
 Plant trees to S & W of
buildings – and plant NOW
© Project SOUND

41. Garden strategies to combat heat: create
shade with trees, large shrubs & vines
 Choose trees/large shrubs
that provide ‘value added’;
fruits; flowers; additional
habitat value
 Choose water-wise native
species if possible
 Use vines and trellises
creatively; native vines have
many good attributes in
addition to their shade
© Project SOUND

42. What trees should I choose? The
answers are not all available
 Need to weigh the effects of heat as
well as those of intermittent drought
& other factors
 Need for empirical studies in the local
setting – role of CSUDH, local gardens
© Project SOUND

43. Current favorites (based on last two years)
 Citrus fruits: ‘Moro’ and other blood oranges;
lemons,; grapefruits
 Local natives:













Mulefat - Baccharis salicifolia
Mountain mahagony – Cercocarpus spp.
Fremontodendron spp.
Toyon - Heteromeles arbutifolia
Boxthorns – Lyceum spp.
Catalina ironwood - Lyonothamnus floribundus
Laurel sumac - Malosma laurina
Catalina Island cherry - Prunus ilicifolia ssp. lyonii
Local Quercus (oaks)
Rhus (especially Lemonadeberry)
? Chaparral currant - Ribes malvaceum
Blue elderberry - Sambucus nigra ssp. cerulea
? Mission manzanita - Xylococcus bicolor
© Project SOUND

44. Other candidates (provide feedback)
 Common garden trees/shrubs from other areas:







Manzanitas – Arctostaphylos S. CA spp. (incl. cultivars)
Ceanothus – S. CA species
Summer holly - Comarostaphylis diversifolia
Tecate cypress - Hesperocyparis forbesii
Nevin’s barbarry - Mahonia nevinii
Pinyon - Pinus monophylla
Coffeeberry/Redberry – Rhamnus/Frangula spp. & cultivars
 Desert trees/large shrubs






Fairy dusters – Calliandra spp
Desert willow - Chilopsis linearis
Desert lavender - Hyptis emoryi
Desert olive - Forestiera pubescens
Mesquite – Prosopis spp.
Jojoba - Simmondsia chinensis
http://en.wikipedia.org/wiki/Mesquite
© Project SOUND

45. Climate warming will affect local plants
© Project SOUND

46. Some potential effects of global warming
on productivity
  productivity – up to a point and if (and only if)
other requirements are met
 Some plants will have  flowering, pollination and
seedset – including some important agricultural
crops (rice; soybeans; ‘cool season’ plants)
 Changes in thermoperiod (daily temperature
change) may effect some plants
 Lower winter temperatures (and longer winters) 
growth/productivity
 Temperature fluctuations may affect dormancy

47. Potential effects of global warming on
productivity, continued
 Optimum growth temperature  with  CO2
  drought tolerance (if plant can partially close stomata)
 However, some plants will have  growth at high
temp/CO2
  temperatures in some important agricultural
areas may adversely affect world food supply
 High temperatures + drought
  plant health – more vulnerable
  fire vulnerability
  growth of non-native weedy species

48. Effects of increased temperature on food
plants: effects not all the same
Food Plant
Effects (shown by research)
Tomato
Reduced fruit number (with only slight ↑ temp)
Lettuce
 Shortened growing season
 Increased incidence of tipburn
 Early bolting (flowering onset)
Stone fruits
Decreased fruit size and quality (effects of
both higher temps & decreased chill hours)
Citrus
Reduced frost losses and increased yields in N.
CA; possible decreases in S. CA)
Grapes
 Premature ripening and possible quality
reduction
 Increased yield variability
© Project SOUND

49. Decreasing hours of chill: bad for agriculture
DECREASING CHILL HOURS,
2070-2099
 Probably won’t have as much
effect on local gardens;
most local native plants will
not be affected
 May affect those of us that
grow ‘low chill’ fruits in
home gardens [Anna apple;
Fuji apple; Black Mission fig;
Santa Rosa plum]
© Project SOUND

50. Possible effects of increased temperatures
on pollinators: much to learn
 Temperatures might exceed the
tolerance level – ? more a problem in
the tropics, but more research needed
 Heat stress might make pollinators
more vulnerable to disease
 Decreased food due to loss of habitat
plants
 May be problematic for some specialist
pollinators
 Changes in seasonality may result in
‘mis-matches’ between flowering and
pollinator activity
© Project SOUND

51. Effects of temperature on birds
 Observed effects: 1965 to 2005
 Birds moved north in winter
 Among 305 widespread North
American bird species, the
average mid-December to early
January center of abundance
moved northward
 The average species shifted
northward by 35 miles during this
period (see Figure 1). Trends in
center of abundance are closely
related to winter temperatures.
 Birds moved further from the
coast
 Effects vary by species
© Project SOUND

52. Temperature extremes: cold/frosts
 We’ll likely have years that are
colder than usual – and
experience frosts
 Know how to deal with frosts:
 Know which plants are sensitive
– often the natives that are
white-colored; tropicals
See Feb/2013 posting on the
subject – Mother Nature’s
Backyard Blog
 Heed the frost warnings; cover
plants or be sure they are well
hydrated before frost
 Don’t cut back too quickly – let
plants recover a few weeks
© Project SOUND

53. Increasing temperatures are already
affecting the seasons (seasonal creep)
 Spring is occurring
earlier – but
somewhat irregularly
 Fall/Winter is arriving
later
 Increased length of
growing season since
1900
© Project SOUND

54. Implications of the changing seasonal patterns

Many living things (plants & animals)
use temperature cues:
Hibernate
Migrate
Nesting; hatching
Enter winter dormancy; leaf out in
spring
 Flowering, fruiting






http://en.wikipedia.org/wiki/Bird_migration
Timing of the rainy season is also
changing in many places around the
world, leading to famines
But not everything is changing
together, leading to complex results
Mismatches:




Pollinator/plant
Predator/prey
Seeds/dispersers
Breeding/food sources
© Project SOUND

55. Implications of seasonal creep for our
gardens
 Planting:
 Seeds:
 Fall planting is later
 Spring planting earlier
 Native plants:
 The timing of rains will be less predictable –
still, try to plant with rains
 Dec-Feb best planting months
 In dry years, best to plant with cool weather
 Need to plan habitat to provide nectar/
pollen/food through the seasons
 Plant native plants to attract a wide range
of pollinators
 Note & respect changing nesting seasons
© Project SOUND

56. Implications of seasonal creep for our
gardens
 Supplemental irrigation:
 Winter/spring
 May be required for fall/winter planting
 May be needed earlier: December if garden is dry
 Watch for hot, windy, dry periods of 2+ weeks
 Summer:
 Likely need to start earlier in some years; May
rather then June/July
http://www.organicswgardening.com/article14.html
For more on irrigation go to
Mother Nature’s Backyard Blog
 Fall dormancy/little water period should still begin
in mid-late August
 ‘Monsoonal’ irrigation (for Sonoran Desert and S.
CA chaparral plants) should still be in mid-August
(but need to watch changing weather patterns &
plant responses)
© Project SOUND

57. Precipitation change in the 20th century
http://pauldouglasweather.blogspot.com/2014/01/winds-ease-travel-improves-another.html
http://www.epa.gov/climatechange/science/indicators/weather-climate/precipitation.html
 Most of the U.S. saw increased
precipitation
 S. CA and Arizona saw significant
decreases
© Project SOUND

58. Monitoring & predicting drought
http://www.drought.gov/drought/
© Project SOUND

59. Monitoring &
predicting drought
http://www.drought.gov/drought/
© Project SOUND

60. These have not been a good 2 years


Precipitation a meager 10-30% of
normal across coastal southern
California and deficits of 4-12
inches in the past 2-year cycle

Feb 2012-Jan 2014 – driest on record for
coastal CA from Santa Barbara Co. to San
Diego border (State Division 6)
But they are probably a good
indicator of what dry periods will
look like in the future
The Twitchell Reservoir, along the
Santa Barbara/San Luis Obispo
County line, is at less than 1%
capacity. Ranchers are reducing
their herds due to the lack of
water and food sources.

As of Feb. 18, the Sierra Nevada
basin average snow water content
ranged from 32 to 53% of normal.
© Project SOUND

61. The trend isn’t pretty
 Consequences of drought:
 Gardens less ‘pretty’
 Crops damaged or fail
altogether; livestock can’t
survive – food prices rise

Less water from snowpack
 Stored reserves of water
(lakes; reservoirs) are low
 Ground water depletion due
increased pumping
© Project SOUND
http://www.epa.gov/climatechange/science/indicators/weather-climate/drought.html

62. Decreasing Sierra snowpack: almost a
certainty
 Temperature rise will lead to
more precipitation falling as
rain instead of snow
 The snow that does fall will
melt earlier, thus decreasing
the spring snowpack in the
Sierra Nevada by as much as
90 percent.
 This would pose extreme
challenges to water managers,
hamper hydropower generation
and eliminate snow recreation
http://www.climatechoices.org/impacts_water/
© Project SOUND

63. Canadian Model: yearly precipitation
http://eos-earthdata.sr.unh.edu/thumbnail_pages/ppttc-c1.jsp
© Project SOUND

64. Hadley Model: yearly precipitation
© Project SOUND
http://eos-earthdata.sr.unh.edu/thumbnail_pages/ppttc-h2.jsp

65. Predicting precipitation: more difficult than
predicting temperature
 Effects of clouds – not well
integrated into current models
 Difficult to integrate the
effects of local conditions:
topography; human-altered
landscapes; etc.
 Likely to be much more
variability than for
temperature
 Need to look at all the
models – the average is likely
better than individual models
© Project SOUND

66. El Niño–Southern Oscillation (ENSO) cycle
 Coherent year-to-year variations in seasurface temperatures, convective
rainfall, surface air pressure, and
atmospheric circulation across the
equatorial Pacific Ocean.
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensost
uff/ensofaq.shtml#ENSO
The fluctuations in ocean temperatures
during El Niño and La Niña are
accompanied by even larger-scale
fluctuations in air pressure known as
the Southern Oscillation. These are
what influence our rainfall.
 El Niño: above-average sea-surface
temperatures in the east-central
equatorial Pacific (the warm phase of the
ENSO cycle). Due to decreased normal upwelling of cold, deep water
 La Niña: periodic cooling of sea-surface
temperatures across the east-central
equatorial Pacific. It represents the cold
phase of the ENSO cycle, and is
sometimes referred to as a Pacific cold
episode.
© Project SOUND

67. ENSO: effects on local weather
 With El Nino, Oct-Mar tends to be
wetter than usual in a swath extending
from southern CA eastward across AZ,
southern NV and UT, NM, and into TX.
http://www.pmel.noaa.gov/tao/elnino/impacts.html#part5
 There are more rainy days, and there
is more rain per rainy day. El Nino
winters can be two to three times
wetter than La Nina winters in this
region.
 With La Nina, winters are always
drier (ever since these events have
been recorded (~ 70 years)
 Is there a tie between ENSO and
global climate change? No one knows
© Project SOUND
http://www.cpc.ncep.noaa.gov/products/predictions/threats2/enso/elnino/USprank/nd.gif

68. Local effects of
ENSO
 Driest years:
 Low amounts; equally
distributed between Nov-Dec
& Jan-Mar
 Medium years:
 Good rain early (Nov-Dec) –
almost equivalent to wet years
 Severe deficit Jan-Mar
 Wettest years:
 Good rain early (Nov-Dec)
 High rain totals Jan-Mar –
equivalent to N. and Central CA
© Project SOUND
http://www.cpc.ncep.noaa.gov/products/predictions/threats2/enso/elnino/ca_bar.html

69. Why predicting S. CA
precipitation is particularly
challenging
 We have complex topography
 Role of El Nino events is not well
understood – and they have a
role in our precipitation
 Our area lies right between two
areas on which most models
agree:
 an area of more precipitation
to the north
 an area of significantly less
precipitation to the south
© Project SOUND

70. The best estimates for western L.A. County
(based on several models) suggest
 The overall precipitation changes
for our area won’t be dramatic,
at least for the next 50 years;
 Some models suggest slightly
less precipitation
 Some models suggest slightly
more
 More extreme year-to-year
variability will likely become
more common
© Project SOUND

71. Much of South Bay
Slight decrease?
 Probably wisest to assume
somewhat drier conditions –
and less water available for
home gardens
 Likely year-to-year
variability with increase
PV peninsula
 Plan for drought years
 Plan enough flexibility to
deal with wet years:
 Plant choices
 Water infiltration/
conservation
Los Angeles average since 1877
thru 2012 (135 years): 14.98 inches
http://cal-adapt.org/precip/decadal/
© Project SOUND

72. Consequences for our local gardens
 Less irrigation water will be available
for watering gardens in the future
 We need to use garden water better
– starting now!
 We all need to participate in recharging our aquifers/ground water;
decrease water to the storm drains
http://www.epa.gov/climatechange/impacts-adaptation/southwest.html
 Our gardens need to handle slightly
more dry conditions, overall
 Our gardens must handle the
extremes: drought and abundance
© Project SOUND

73. Be sure your garden is designed based on Water
Zone principles: grouping plants by water needs
Regular water
Pretty dry
droughttolerant
plants
‘Water-wise’ ; occasional summer water
http://www.taunton.com/finegardening/pages/g00101.asp
© Project SOUND

74. What you can do now to become more
‘water-wise’
 Read Mother Nature’s Garden series ‘Designing your New
California Garden’ (2013-14) and ‘Harvesting Rain’ (2013)
 Consider decreasing areas that receive regular water – limit
regular water to only high priority plants [vegetable garden;
prize rose bush; etc]
 Consider increasing non-planted areas [seating/dining areas;
utility areas]
 As you replace older plants, consider replacements carefully:
 Do they have flexible/drought-tolerant needs?
 Do they fit into the water zone plan?
 What else do they provide: shade? food? habitat? other?
© Project SOUND

75. Why S. California plants may do better
than N. CA plants in dry (and wet) times
 Are more drought tolerant (on the whole)
 Are more water-flexible on the whole; have ‘grown
up’ in a variable climate
 Have a number of adaptations that make them
suited for our variable climate:
 Deep and/or net-like roots
 Lifestyle: summer dormancy
 Leaf characteristics: thick; waxy coat or leaf hairs;
small leaf area; ability to close stomata during hot
dry periods (or during the day)
© Project SOUND

76. Root characteristics: especially important
with CA native plants
 Coastal sage scrub shrubs
 Primarily fibrous roots
 Primarily shallow roots (< 3 ft)
 Root:shoot ratio increases with
water & nutrient stress
 Chaparral shrubs
http://www.rmrs.nau.edu/watersheds/highlands/vegetation/chaparral/chpla
ntwater.html
Individual species have
characteristic root growth patterns
 Combination of deep and
shallower roots
 Root growth in spring/ summer
 Root:shoot ratio increases with
water & nutrient stress
© Project SOUND

77. Root characteristics of some common CA
native shrubs
© Project SOUND

78. Root systems are coordinated to make
use of available water, nutrients
Example from Coastal Sage Scrub
Kummerow et al, 1977

79. My recommendations for plant choices
 At least 1 tree
 Several evergreen shrubs as
evergreen backdrop: S. CA
chaparral species best
 Evergreen; provide height,
habitat, interest
 Hardy: take drought, heat, water
 Plants from Zone-spanner list:
tolerances from water zone 1-2
to 2-3
 Zone 1 to 1-2: many of the local
natives – may have more tolerance
to wet years than we think!
© Project SOUND

80. Perhaps the best choices are those with
wide tolerances: 1-2 to 2-3

Trees/large shrubs





Baccharis salicifolia
** Ceanothus ‘Ray Hartman’
* Cercis occidentalis
Salix exigua
Smaller shrubs
 * Amorpha fruticosa
 ** Arctostaphylos densiflora
'Howard McMinn‘
 * Frangula/Rhamnus californica
 Hazardia squarrosa
 Isocoma menziesii
 Rhus trilobata
 Ribes aureum var. gracillimum
 Ribes californicum var. hesperium
 Ribes malvaceum (& cultivars)

Smallest shrubs/sub-shrubs
 Constancea (Eriophyllum)
nevinii
 Epilobium canum
 Eriodictyon crassifolium
 Eriogonum cinereum
 Eriogonum fasciculatum
 Euphorbia misera
 Grindelia camporum var.
bracteosa
 * Verbena lilacina
© Project SOUND

81. Gardens : reflections of god in nature

‘One of the things that makes
the gardens of Morocco so
enchanting is the effort put
into maintaining the natural
elements of the land while
displaying the gardens in an
aesthetically-pleasing manner.

By creating a perfect balance
between wildlife and the lush
foliage of the land and the
addition of man-made gardens
and structures, the area is
captured in a wondrous
harmony of man-meets-earth.’
http://www.homelidia.com/beautiful-moroccan-garden-design-ideas/
http://medomed.org/2012/the-jeb-of-rabat-in-springtime/
© Project SOUND

82. S. CA gardeners need to
develop an appreciation for
normal variability in gardens
Fall
Early March – good rain year
Early March – dry year
© Project SOUND

83. Water in the garden: a hint of cool
http://static.panoramio.com/photos/large/49303992.jpg
 Moroccan gardens – and those of
other hot climates – emphasize the
sight and sound of water
 If you haven’t already, consider a
water-wise water feature for your
garden
© Project SOUND

84. Wind patterns: will they change?
© Project SOUND

85. Santa Ana winds may actually decrease
for a while
http://www.energy.ca.gov/2005publications/CEC-500-2005-204/CEC-500-2005-204-SF.PDF
But the likelihood of high wind events will likely increase
in the future
© Project SOUND

86. Planning for wind events: better than
dealing with the consequences
 Keep trees as healthy as possible
 Remove diseased or damaged
trees; replace
 Provide better infiltration around
trees; promotes better roots
http://gotsoil.blogspot.com/2011/12/go-hug-tree.html
 Annually prune dead or broken
limbs; every 3-5 years thin
 Plant trees less prone to wind
damage
© Project SOUND

87. Least resistant



















Plant the right tree
Boxelder
Tree of Heaven Ailanthus altissima*
Carob, carrotwood and Brazilian
peppertree
Silk floss tree - Albizia julibrissin
 Ash
Eucalyptus
 Sycamore
Ficus - Ficus benjamina
Jacaranda - Jacaranda mimosifolia
 Crape myrtle - Lagerstroemia indica
Elms, esp. Chinese elm, Siberian elm
 Magnolia
Melaleuca - Melaleuca quinquenervia
 Beech
Norfolk Island pine - Araucaria
 White oaks (incl. native)
heterophylla
 Magnolia
Coral tree
 Sweetgum
Chinese lantern
Firs & spruces
 Native live oaks
Poplar/cottonwood
CA Bay laurel Ornamental pear - Pyrus spp
Washingtonia palm
Avocado - Persea americana
Autralian pine - Casuarina
* Bolded trees also prone to summer branch drop
Most resistant
© Project SOUND

88. Plant a windbreak/hedgerow: many
benefits in addition to breaking the wind

Create shade

Provide an evergreen background for
other plants

Provide seasonal color

Provide food – for you, for birds, for
pollinators/other insects

Provide nesting places

Create their own functioning
ecosystem – in a relatively small area
Hedgerow and windbreaks take time – start now
© Project SOUND

89. If you live in a fire-prone area: heed the
warnings
 Get rid of Eucs & palm
trees (and non fire
resistant roof)
 Plant a fire resistant zone
 Consider your plant
choices
http://www.predictiveservices.nifc.gov/outlooks/monthly_seasonal_outlook.pdf
 The ‘fire season’ is longer
than in the past – be
prepared (many good
resources on-line)
© Project SOUND

90. Air quality: will it continue to improve in
western L.A. county?
© Project SOUND

91. Air quality monitoring: The Air Quality Index (AQI)
The AQI focuses on
health effects you may
experience within a few
hours or days after
breathing polluted air.

The EPA calculates the AQI for 5 major air pollutants regulated by the Clean Air Act
1. Ground-level Ozone (O3)
2. Particle Pollution, also known as particulate matter (PM10 and PM2.5)
3. Carbon Monoxide (CO)
4. Sulfur Dioxide (SO2) and
5. Nitrogen Dioxide (NO2).

For each of these pollutants, EPA has established national air quality standards to protect
public health. Ground-level ozone and airborne particles pose the greatest threat to human
health.
© Project SOUND

92. Santa Ana winds & pollution in western
L.A. county
 Wind patterns – Santa Anas (offshore flow) mean more air
pollution in our area
http://blogs.kqed.org/climatewatch/2011/12/01/santa-anawind-season-may-be-stretched-by-climate-change/
 ? Longer season for Santa Anas
 Maybe 20% fewer Santa Ana
events as winter temps in desert
increase
 But even past records suggest
more extremes
http://www.achangeinthewind.com/2008/10/good-news-friday-global-warming-lessening-santaana-wind-conditions.html
© Project SOUND

93. Predicting future air quality: difficult
 ↑ emissions ??
 Smoke from fires
 ? More stagnant air
 ? More particulates (due to decreased
precipitation)
 Because warm, stagnant air tends to
increase the formation of ozone,
climate change is likely to increase
levels of ground-level ozone in
already-polluted areas of the United
States and increase the number of
days with poor air quality
http://www.climatechoices.org/impacts_health/
© Project SOUND

94. Elevated CO2 levels will increase growth
rates for many (C3) plants
 Increases in photosynthesis for most
C3 species due to elevated CO2
 However, the direct outcome of
increased photosynthetic rates is
uncertain:
http://www.serc.si.edu/labs/co2/marsh.aspx
Much still to learn –
particularly for CA native
plants
 Other limitations: lack of water;
increased heat; etc.
 Plants may actually suffer nutrient
deficiencies due to faster growth rates
– effects those that eat the plants
© Project SOUND

95. Ozone exposure & plants
 Leads to:
reduced plant growth and crop yields
hindered nitrogen fixation
compromised disease resistance
increased susceptibility to insect
damage
 Susceptibility to wide range of
stressors
 Decreased seed production




http://scienceblogs.com/gregladen/2013/01/29/whispers-from-the-ghosting-trees/
 Threshold concentrations, generally
between 50–70 parts per billion
(ppb) for agricultural crops and 35
ppb for native vegetation
 Levels in San Bernardino Natl.
Forest already ~ 90 ppb
http://scienceblogs.com/gregladen/2013/01/29/whispers-from-the-ghosting-trees/
© Project SOUND

96. Effects of smog on Ponderosa Pine
http://www2.nature.nps.gov/air/pubs/Core_Slides/effects.htm
http://www.yosemite.org/naturenotes/AirQuality2.htm
Ozone - damages needles causing mottling
and loss of needles, leading to bark beetle
attack and ultimately death

97. Ozone-sensitive plants
 Vegetables
 bean, grape, peanut, potato, soybean,
tomato
 Many important tree species are
affected by ozone
 aspen, birch, cottonwood, Ponderosa
pine, black cherry, white ash, sycamore,
London plane tree,
Sweetgum/Liquidambar, and yellow
poplar).
 Tolerant plants




Oaks
Maples
Many pines
????? Mechanisms poorly understood
© Project SOUND
http://www.slu.edu/sustainability/center-for-environmental-sciences/ozone-garden-home/howdoes-ozone-air-pollution-hurt-plants

98. Weeds, pests & diseases: will they
change?
 Changes will be due in large part to
changes in temperature and
precipitation patterns
https://apps.rhs.org.uk/advicesearch/Profile.aspx?pid=108
 Disease-causing microbes are
dependent on temperature and
moisture optima for establishment
and reproduction, with most
diseases occurring in warm and wet
conditions
 Other factor like plant health and
predators will also be important
© Project SOUND

99. Weeds, pests, etc.
 Climate change, both within California globally is likely to
have a significant impact upon the types, abundance and
impacts of weeds, plant pests, and diseases.
 Mechanisms:
 Increased competition of some weeds: higher CO2 – favor C3
plant; higher temps – favor C4 plants
 Range shifts: example: weedy C4 grasses extending northward;
 Changes in life cycle of insect pests
 The survival, range, and abundance of many invertebrate pest
species is mediated by temperature.
 Furthermore, temperature is the dominant abiotic factor that
directly affects herbivory
 Natural controls (birds/insects) may not be available
 Decreased resistance in environmentally-stressed hosts
© Project SOUND

100. Advice to the weary gardener
 Be vigilant: keep an eye out for new
weeds/pests
 Keep you plants healthy – water
appropriately
 When you see a new pest:
 Learn about it on-line
 If appropriate, report it: see California
Report a Pest Hotline http://www.cdfa.ca.gov/plant/reportapest
/index.html
 Take action swiftly to limit damage
 Use Integrated Pest Management – unless
the experts suggest otherwise
© Project SOUND

101. Summary: Climate change
 Temperature:
 What we can expect




Temperatures overall will get hotter
More extreme heat days
Earlier springs and later falls
Probably an increase in frosts/cold extremes
 What can we do about it?






Take steps now to create shade
When replacing plants, choose ones that can tolerate heat/drought
Consider birds and pollinators when choosing new plants
Know what to do in case of frost
Know the rules for summer watering
Realize that you may need to deep water in winter
© Project SOUND

102. Summary: Climate change
 Precipitation/water availability:
 What we can expect
 Less water available from traditional sources: Sierra Nevada snowpack
and Colorado River
 Likely slight decrease in local precipitation; but might be slight increase
 Combined with increasing temperatures – less effective water
 Likely more extreme precipitation events – both droughts & excess
 What can we do about it?
Take steps now to convert garden based on water zone principles
Decrease area that requires regular water
Use all the water that falls on your property: infiltration/storage
Plant choice is increasingly important:
 Choose S. CA natives for their drought tolerance/adaptability
 Carefully consider ‘value added’ when making each choice
 Need more research on prudent use of recycled water; encourage use
for replenishing aquifer




© Project SOUND

103. Summary: Climate change
 Wind/wind patterns:
 What we can expect
 Perhaps fewer Santa Ana events – but over more months of the year,
and with ? increasing yearly variability
 More storms with strong winds
 What can we do about it?
 Notice the wind patterns in your yard – in all seasons
 Consider the consequences of stronger winds:
 Check trees: branches/tree characteristics/tree age & health
 Improve water infiltration for existing trees
 Plant wind resistant trees
 Consider shelter hedges/hedgerows or other means of shelter for
areas that are vulnerable or used frequently
 Check strength/integrity of fences/trellises etc.
 If you live in a fire-prone area, take reasonable precautions
© Project SOUND

104. Summary: Climate change
 Air quality/pollution:
 What we can expect
 Perhaps better overall air quality in L.A. Basin
 Effects of Santa Ana winds on western L.A. County
 Effects of increased temperatures/decreased rainfall – both may
increase pollution levels (particularly N-compounds; particulates)
 What can we do about it?
 Do everything we can to decrease our carbon footprint
 .Plant trees/shrubs/other plants to improve air quality
© Project SOUND

105. Summary: Climate change
 Weeds/pests/diseases:
 What we can expect
 Changes in temperature and precipitation will influence the types of
weeds/pests/diseases we experience in our gardens
 Higher temperatures & drier conditions will decrease the effects of
fungal disease and some weeds in dry years
 Hot, moist conditions will bring with them a host of new problems
 What can we do about it?





Remain vigilant: get out in your garden a look for changes
Report new invasives/pests
Keep on top of weeds; keep them from going to seed
Use IPM – more in June class
Keep plants healthy; water appropriately
© Project SOUND

106. Come visit us: Mother Nature’s Backyard
We’ll show you many things you can do to prepare
© Project SOUND

107. Humans (and their plants) have endured
and thrived in difficult climates
http://www.earth-cultures.com/images/ww/auto-crop/MORARG%20Dar%20al%20Housson.jpg
© Project SOUND

108. Prepared now – you/other living things depend on it
Majorelle Botanic Garden - Morocco
http://blog.travel-exploration.com/2009/02/11/majorelle-blue/
© Project SOUND