1. 3/2/2014
Out of the Wilds and Into Your Garden
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
Gardening with California Native Plants in Western L.A. County
Project SOUND – 2014 (our
10th
year)
© Project SOUND
2014: Bringing Nature Home - Lessons
from Gardening Traditions Worldwide
© Project SOUND
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/
Today we’ll be visiting the gardens of Morocco
 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
© Project SOUND
1

2. 3/2/2014
The world climate is changing
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
Climate models help us understand how
climate works
© Project SOUND
Predicting the future: always difficult
 Problems of scale:
 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
 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
2

3. 3/2/2014
atmosphere/ocean/sea-ice general circulation
models (AOGCMs)
Factors that go into currant AOGCM models
 The hydrosphere: the oceans and
other bodies of water
 Three-dimensional models of the
global atmosphere used in climate
modeling
 The cryosphere: including sea
ice, glaciers and ice sheets
 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
 The atmosphere: composition and
behavior
 The biosphere: the amounts of
animals and plants
 Results are ‘checked/verified’ by
comparing to past/present
 Used to predict the effects of
climate change
© Project SOUND
Most planners currently use data from several
models (and several scenarios) to predict
 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
Cal-Adapt: California’s climate change
data/mapping source
 When models concur, the
result is more likely to be
correct
 Recommended in the 2009
 Can compare models and try
to understand the reason for
the differences – increases
our understanding of the
processes
 Developed by UC Berkeley's
Geospatial Innovation Facility
(GIF)
 Allows to ‘bracket’ what the
likely effects will be
http://en.wikipedia.org/wiki/Effects_of_global_warming
© Project SOUND
California Climate Adaptation
Strategy report
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
3

4. 3/2/2014
Cal-adapt climate tools are easy to use
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
Other commonly used models
© Project SOUND
We’ll be considering several topics today
 Predicted changes in temperature
 Hadley Centre Model (HadCM3)
 Canadian Model (CGCM4/CanCM4)
 Predicted changes in seasonality
 Predicted changes in precipitation/water availability
 Likely effects on wind
 Likely effects on air quality
 Other effects
© Project SOUND
© Project SOUND
4

5. 3/2/2014
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
Hadley Model - average maximal yearly temperature
© Project SOUND
© Project SOUND
http://eos-earthdata.sr.unh.edu/thumbnail_pages/tairmaxtc-h2.jsp
Hadley Model - average yearly minimum temperature
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)
http://eos-earthdata.sr.unh.edu/thumbnail_pages/tairmintc-h2.jsp
© Project SOUND
© Project SOUND
5

6. 3/2/2014
Local effects: we’re protected by the
ocean, but we’ll be hotter
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
© Project SOUND
Extreme heat is not just annoying – it kills
http://www.epa.gov/climatechange/impacts-adaptation/health.html
© Project SOUND
The phenomenon of urban heat islands
 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://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).
http://www.climatechoices.org/impacts_health/
© Project SOUND
© Project SOUND
6

7. 3/2/2014
Urban heat islands: we need to decrease
the heat absorption
Homeowner strategies to combat heat
 Decrease the amount of heat
absorbed by the home:
 Are influenced by a city’s
geographic location and by local
weather patterns
 Attic/wall insulation; ‘cool’
windows
 Replace old roof with ‘cool roof’
alternatives
 Light colored walkways, mulch
 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.
 Increase shade with hardscape
 Increase shade with plants
 Bottom line: you (and your
neighbors) need to create shade
© Project SOUND
If you need new roofing,
consider a ‘cool roof’?
© Project SOUND
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.”
 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.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.
http://www.lbl.gov/Science-Articles/Archive/sb/Aug-2004/3_coolroofs-2.html
Cool colors – save energy
© Project SOUND
Owens Corning’s Duration Premium Cool series
© Project SOUND
http://bradyroofing.net/products/pitched-roof-materials/owens-corning/owens-corning-duration-premium-cool-series/
7

8. 3/2/2014
Garden strategies to combat heat: create
shade with hardscape
People who live in hot places learned how
to create shade long ago: Morocco

Climate

 Benefits:
Gardening history
 Mediterranean to extremely hot & dry
 May add beauty/style to the garden
 Very long and complex
 Arabic, Moorish, Berber, Roman and European
influences
 Long-lasting
 Often low maintenance (compared to
plants)
http://en.wikipedia.org/wiki/File:Moroc
co_(orthographic_projection).svg
 Require no water
 Cost effective over time –
particularly with increasing
temperatures
http://www.jardinmajorelle.com/jardin/
© Project SOUND
Some Moroccan ideas on shade
© Project SOUND
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.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
http://www.digsdigs.com/55-charming-morocco-style-patio-designs/
© Project SOUND
http://housetohome.media.ipcdigital.co.uk/96/000007ad7/7260_orh550w550/DCOR200.jpg
© Project SOUND
8

9. 3/2/2014
Creative shade using hardscape
http://genosgarden.blogspot.com/2010_08_01_archive.html
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
http://genosgarden.blogspot.com/2010_08_01_archive.html
 Shading of buildings, asphalt and other dark surfaces
with trees
 Management and restoration of parks and riparian zones
in urban areas
Think about how you use your
outdoors. Would you use your
garden more if it had a shady
porch, pergola, arbor?
© Project SOUND
Why are trees/other vegetation important?
© Project SOUND
Ouarzazate: The Skoura Palm Groves
 Provide shade
 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.
 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.
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
© Project SOUND
http://berbernomadadventure.com/tours/berber-villages-andkasbahs-tour/
9

10. 3/2/2014
But trees/other vegetation have other benefits that
will help us cope with climate change
Benefits of trees/vegetation: more than heat
 Reduced Energy Use
 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
 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
The human benefits of trees/vegetation
© Project SOUND
Garden strategies to combat heat: create
shade with trees, large shrubs & vines
 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’
 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
http://www.classictravel.com/hotels/dar-ahlam
© Project SOUND
© Project SOUND
10

11. 3/2/2014
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
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
 Use vines and trellises
creatively; native vines have
many good attributes in
addition to their shade
© Project SOUND
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
© Project SOUND
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
11

12. 3/2/2014
Climate warming will affect local plants
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
© Project SOUND
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
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
12

13. 3/2/2014
Decreasing hours of chill: bad for agriculture
DECREASING CHILL HOURS,
2070-2099
Possible effects of increased temperatures
on pollinators: much to learn
 Probably won’t have as much
effect on local gardens;
most local native plants will
not be affected
 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
 May affect those of us that
grow ‘low chill’ fruits in
home gardens [Anna apple;
Fuji apple; Black Mission fig;
Santa Rosa plum]
 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
Effects of temperature on birds
© Project SOUND
Temperature extremes: cold/frosts
 Observed effects: 1965 to 2005
 Birds moved north in winter
 We’ll likely have years that are
colder than usual – and
experience frosts
 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
 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
 Effects vary by species
© Project SOUND
© Project SOUND
13

14. 3/2/2014
Increasing temperatures are already
affecting the seasons (seasonal creep)
Implications of the changing seasonal patterns

Hibernate
Migrate
Nesting; hatching
Enter winter dormancy; leaf out in
spring
 Flowering, fruiting




 Spring is occurring
earlier – but
somewhat irregularly
 Fall/Winter is arriving
later
 Increased length of
growing season since
1900
Many living things (plants & animals)
use temperature cues:

But not everything is changing
together, leading to complex results

Mismatches:
http://en.wikipedia.org/wiki/Bird_migration
Timing of the rainy season is also
changing in many places around the
world, leading to famines




Pollinator/plant
Predator/prey
Seeds/dispersers
Breeding/food sources
© Project SOUND
Implications of seasonal creep for our
gardens
 Planting:
© Project SOUND
Implications of seasonal creep for our
gardens
 Supplemental irrigation:
 Seeds:
 Winter/spring
 Fall planting is later
 Spring planting earlier
 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
 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
 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
14

15. 3/2/2014
Precipitation change in the 20th century
Monitoring & predicting drought
http://www.drought.gov/drought/
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
Monitoring &
predicting drought
© Project SOUND
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.
http://www.drought.gov/drought/
© Project SOUND
© Project SOUND
15

16. 3/2/2014
The trend isn’t pretty
Decreasing Sierra snowpack: almost a
certainty
 Consequences of drought:
 Temperature rise will lead to
more precipitation falling as
rain instead of snow
 Gardens less ‘pretty’
 Crops damaged or fail
altogether; livestock can’t
survive – food prices rise

 The snow that does fall will
melt earlier, thus decreasing
the spring snowpack in the
Sierra Nevada by as much as
90 percent.
Less water from snowpack
 Stored reserves of water
(lakes; reservoirs) are low
 This would pose extreme
challenges to water managers,
hamper hydropower generation
and eliminate snow recreation
 Ground water depletion due
increased pumping
http://www.climatechoices.org/impacts_water/
© Project SOUND
© Project SOUND
http://www.epa.gov/climatechange/science/indicators/weather-climate/drought.html
Canadian Model: yearly precipitation
http://eos-earthdata.sr.unh.edu/thumbnail_pages/ppttc-c1.jsp
Hadley Model: yearly precipitation
© Project SOUND
© Project SOUND
http://eos-earthdata.sr.unh.edu/thumbnail_pages/ppttc-h2.jsp
16

17. 3/2/2014
Predicting precipitation: more difficult than
predicting temperature
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.
 Effects of clouds – not well
integrated into current models
 Difficult to integrate the
effects of local conditions:
topography; human-altered
landscapes; etc.
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensost
uff/ensofaq.shtml#ENSO
 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
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
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.
Local effects of
ENSO
 Driest years:
 Low amounts; equally
distributed between Nov-Dec
& Jan-Mar
 Medium years:
 With La Nina, winters are always
drier (ever since these events have
been recorded (~ 70 years)
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.
 Wettest years:
 Is there a tie between ENSO and
global climate change? No one knows
 Good rain early (Nov-Dec) –
almost equivalent to wet years
 Severe deficit Jan-Mar
 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/USprank/nd.gif
© Project SOUND
http://www.cpc.ncep.noaa.gov/products/predictions/threats2/enso/elnino/ca_bar.html
17

18. 3/2/2014
Why predicting S. CA
precipitation is particularly
challenging
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;
 We have complex topography
 Role of El Nino events is not well
understood – and they have a
role in our precipitation
 Some models suggest slightly
less precipitation
 Our area lies right between two
areas on which most models
agree:
 Some models suggest slightly
more
 More extreme year-to-year
variability will likely become
more common
 an area of more precipitation
to the north
 an area of significantly less
precipitation to the south
© Project SOUND
© Project SOUND
Much of South Bay
Slight decrease?
Consequences for our local gardens
 Probably wisest to assume
somewhat drier conditions –
and less water available for
home gardens
 Less irrigation water will be available
for watering gardens in the future
 We need to use garden water better
– starting now!
 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
 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
Los Angeles average since 1877
thru 2012 (135 years): 14.98 inches
http://cal-adapt.org/precip/decadal/
© Project SOUND
© Project SOUND
18

19. 3/2/2014
Be sure your garden is designed based on Water
Zone principles: grouping plants by water needs
Regular water
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]
Pretty dry
droughttolerant
plants
 Consider increasing non-planted areas [seating/dining areas;
utility areas]
 As you replace older plants, consider replacements carefully:
‘Water-wise’ ; occasional summer water
http://www.taunton.com/finegardening/pages/g00101.asp
 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
Why S. California plants may do better
than N. CA plants in dry (and wet) times
© Project SOUND
Root characteristics: especially important
with CA native plants
 Coastal sage scrub shrubs
 Are more drought tolerant (on the whole)
 Primarily fibrous roots
 Primarily shallow roots (< 3 ft)
 Root:shoot ratio increases with
water & nutrient stress
 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
 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
19

20. 3/2/2014
Root characteristics of some common CA
native shrubs
Root systems are coordinated to make
use of available water, nutrients
Example from Coastal Sage Scrub
Kummerow et al, 1977
© Project SOUND
Perhaps the best choices are those with
wide tolerances: 1-2 to 2-3
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

Trees/large shrubs
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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
20

21. 3/2/2014
Gardens : reflections of god in nature

http://www.homelidia.com/beautiful-moroccan-garden-design-ideas/

‘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.’
S. CA gardeners need to
develop an appreciation for
normal variability in gardens
Fall
Early March – good rain year
Early March – dry year
http://medomed.org/2012/the-jeb-of-rabat-in-springtime/
© Project SOUND
Water in the garden: a hint of cool
© Project SOUND
Wind patterns: will they change?
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
© Project SOUND
21

22. 3/2/2014
Santa Ana winds may actually decrease
for a while
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
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
Least resistant
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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
© Project SOUND
Plant a windbreak/hedgerow: many
benefits in addition to breaking the wind
Most resistant
© Project SOUND

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
22

23. 3/2/2014
If you live in a fire-prone area: heed the
warnings
Air quality: will it continue to improve in
western L.A. county?
 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
Air quality monitoring: The Air Quality Index (AQI)
© Project SOUND
Santa Ana winds & pollution in western
L.A. county
The AQI focuses on
health effects you may
experience within a few
hours or days after
breathing polluted air.
 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/

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
 ? 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
23

24. 3/2/2014
Predicting future air quality: difficult
 ↑ emissions ??
Elevated CO2 levels will increase growth
rates for many (C3) plants
 Smoke from fires
 Increases in photosynthesis for most
C3 species due to elevated CO2
 ? More stagnant air
 However, the direct outcome of
increased photosynthetic rates is
uncertain:
 ? 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.serc.si.edu/labs/co2/marsh.aspx
Much still to learn –
particularly for CA native
plants
© Project SOUND
http://www.climatechoices.org/impacts_health/
Ozone exposure & 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
Effects of smog on Ponderosa Pine
 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
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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/
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
© Project SOUND
24

25. 3/2/2014
Ozone-sensitive plants
Weeds, pests & diseases: will they
change?
 Vegetables
 bean, grape, peanut, potato, soybean,
tomato
 Changes will be due in large part to
changes in temperature and
precipitation patterns
 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
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Oaks
Maples
Many pines
????? Mechanisms poorly understood
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
© Project SOUND
http://www.slu.edu/sustainability/center-for-environmental-sciences/ozone-garden-home/howdoes-ozone-air-pollution-hurt-plants
Weeds, pests, etc.
Advice to the weary gardener
 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
 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
25

26. 3/2/2014
Summary: Climate change
Summary: Climate change
 Precipitation/water availability:
 Temperature:
 What we can expect
 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
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?
 What can we do about it?

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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
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
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© Project SOUND
Summary: Climate change
© Project SOUND
Summary: Climate change
 Wind/wind patterns:
 Air quality/pollution:
 What we can expect
 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
 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
26

27. 3/2/2014
Come visit us: Mother Nature’s Backyard
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?

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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
Humans (and their plants) have endured
and thrived in difficult climates
We’ll show you many things you can do to prepare
© Project SOUND
Prepared now – you/other living things depend on it
Majorelle Botanic Garden - Morocco
http://www.earth-cultures.com/images/ww/auto-crop/MORARG%20Dar%20al%20Housson.jpg
© Project SOUND
http://blog.travel-exploration.com/2009/02/11/majorelle-blue/
© Project SOUND
27