© Project SOUND
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
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
2014: Bringing Nature Home - Lessons
from Gardening Traditions Worldwide
© Project SOUND
Today we’ll be visiting the gardens of Morocco
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.
In the hot areas of Morocco, they are cool oases where people can find rest and relief from the heat.
© Project SOUND
http://medomed.org/2012/the-jeb-of-rabat-in-springtime/
Al Andalus Garden in Rabat
The world climate is changing
© Project SOUND
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 computer-based models of the climate system to understand and predict its behavior.
© Project SOUND
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
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
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
Results are ‘checked/verified’ by comparing to past/present
Used to predict the effects of climate change
© Project SOUND
http://en.wikipedia.org/wiki/General_Circulation_Model
Global atmospheric modeling began
in the mid-1950’s
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
© Project SOUND
http://scienceandtheworld.com/2013/04/29/wading-into-the-fire-episode-6-climate-modelling-is-a-
tough-gig/
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
© Project SOUND
http://en.wikipedia.org/wiki/Effects_of_global_warming
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)
Provides data and maps to planners, researchers and the public – Climate Tools are easy to use
© Project SOUND
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.
Cal-adapt climate tools are easy to use
© Project SOUND
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
Hadley Centre Model (HadCM3)
Canadian Model (CGCM4/CanCM4)
© Project SOUND
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
The models and current data all agree:
the world is getting hotter
© Project SOUND http://www.ncdc.noaa.gov/sotc/service/global/map-percentile-mntp/201401.gif
Hadley Model - average maximal yearly temperature
© Project SOUND
http://eos-earthdata.sr.unh.edu/thumbnail_pages/tairmaxtc-h2.jsp
Hadley Model - average yearly minimum temperature
© Project SOUND http://eos-earthdata.sr.unh.edu/thumbnail_pages/tairmintc-h2.jsp
Temperature predictions for CA: 2100
For CA as a whole, average summer temp. may increase 3.87-14.9°F; average winter temperatures between 3.87-7.2°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
Local effects: we’re protected by the
ocean, but we’ll be hotter
© Project SOUND
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 http://www.epa.gov/climatechange/impacts-adaptation/health.html
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
© Project SOUND
http://www.climatechoices.org/impacts_health/
The phenomenon of urban heat islands
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
http://heatisland.lbl.gov/
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
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
If you need new roofing,
consider a ‘cool roof’?
Roofing materials that reflect more irradiation & emit heat better than conventional materials
Make most sense in southern U.S. – and particularly in CA; summer cooling far outweigh costs of winter heating
© Project SOUND
http://heatisland.lbl.gov/coolscience/cool-science-cool-roofs
http://www.lbl.gov/Science-Articles/Archive/sb/Aug-2004/3_coolroofs-2.html
Cool colors – save energy
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.”
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 cool-roof ordinance.
© Project SOUND Owens Corning’s Duration Premium Cool series
http://bradyroofing.net/products/pitched-roof-materials/owens-corning/owens-corning-duration-premium-cool-series/
http://www.arcat.com/photos/eagleroo/141564.jpg
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
© Project SOUND
http://www.jardinmajorelle.com/jardin/
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
© Project SOUND
http://en.wikipedia.org/wiki/File:Moroc
co_(orthographic_projection).svg
Some Moroccan ideas on shade
© Project SOUND
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
Some ideas are directly applicable
© Project SOUND http://housetohome.media.ipcdigital.co.uk/96/000007ad7/7260_orh550w550/DCOR200.jpg
http://www.digsdigs.com/55-charming-morocco-style-patio-designs/
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
Creative shade using hardscape
© Project SOUND
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?
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
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
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.
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://www.gmtours.com/post/view/the-secret-gardens-of-morocco
http://berbernomadadventure.com/tours/berber-villages-and-
kasbahs-tour/
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
Act as windbreaks to decrease wind-associated drying
© Project SOUND
http://www.lawrenceofmorocco.com/sites/lawrenceofmorocco.com/files/imagecache/gallery_acco
mmodation/jardins_de_skoura_morocco_sahara_desert59.jpg
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
The human benefits of trees/vegetation
Improve human health and well-being
Reduce pollution/dust
Reduce noise levels
Decrease effects of extreme heat events
© Project SOUND http://www.classictravel.com/hotels/dar-ahlam
Provide habitat, food
Provide oxygen
‘calm and rest the soul’
http://jeffreygardens.blogspot.com/2011_01_01_archive.html
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
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
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
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
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
© Project SOUND http://en.wikipedia.org/wiki/Mesquite
Climate warming will affect local plants
© Project SOUND
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
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
Decreasing hours of chill: bad for agriculture
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
DECREASING CHILL HOURS,
2070-2099
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
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
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
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
See Feb/2013 posting on the
subject – Mother Nature’s
Backyard Blog
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
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
But not everything is changing together, leading to complex results
Mismatches: Pollinator/plant
Predator/prey
Seeds/dispersers
Breeding/food sources
© Project SOUND
Timing of the rainy season is also
changing in many places around the
world, leading to famines
http://en.wikipedia.org/wiki/Bird_migration
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
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
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
Implications of seasonal creep for our
gardens
http://www.organicswgardening.com/article14.html
For more on irrigation go to
Mother Nature’s Backyard Blog
Precipitation change in the 20th century
Most of the U.S. saw increased precipitation
S. CA and Arizona saw significant decreases
© Project SOUND
http://www.epa.gov/climatechange/science/indicators/weather-climate/precipitation.html
http://pauldouglasweather.blogspot.com/2014/01/winds-ease-travel-improves-another.html
Monitoring & predicting drought
http://www.drought.gov/drought/
© Project SOUND
Monitoring &
predicting drought
© Project SOUND
http://www.drought.gov/drought/
These have not been a good 2 years
But they are probably a good indicator of what dry periods will look like in the future
Precipitation a meager 10-30% of normal across coastal southern California and deficits of 4-12 inches in the past 2-year cycle
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
Feb 2012-Jan 2014 – driest on record for
coastal CA from Santa Barbara Co. to San
Diego border (State Division 6)
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
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
© Project SOUND
http://www.climatechoices.org/impacts_water/
Canadian Model: yearly precipitation
© Project SOUND http://eos-earthdata.sr.unh.edu/thumbnail_pages/ppttc-c1.jsp
Hadley Model: yearly precipitation
© Project SOUND
http://eos-earthdata.sr.unh.edu/thumbnail_pages/ppttc-h2.jsp
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
El Niño–Southern Oscillation (ENSO) cycle
Coherent year-to-year variations in sea- surface temperatures, convective rainfall, surface air pressure, and atmospheric circulation across the equatorial Pacific Ocean.
El Niño: above-average sea-surface temperatures in the east-central equatorial Pacific (the warm phase of the ENSO cycle). Due to decreased normal up-welling 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
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.
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensost
uff/ensofaq.shtml#ENSO
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.
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.pmel.noaa.gov/tao/elnino/impacts.html#part5
http://www.cpc.ncep.noaa.gov/products/predictions/threats2/enso/elnino/USprank/nd.gif
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
Why predicting S. CA
precipitation is particularly
challenging
© Project SOUND
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
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
Slight decrease?
Probably wisest to assume somewhat drier conditions – and less water available for home gardens
Likely year-to-year variability with increase Plan for drought years
Plan enough flexibility to deal with wet years: Plant choices
Water infiltration/ conservation
© Project SOUND http://cal-adapt.org/precip/decadal/
PV peninsula
Much of South Bay
Los Angeles average since 1877
thru 2012 (135 years): 14.98 inches
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 re-charging our aquifers/ground water; decrease water to the storm drains
Our gardens need to handle slightly more dry conditions, overall
Our gardens must handle the extremes: drought and abundance
© Project SOUND
http://www.epa.gov/climatechange/impacts-adaptation/southwest.html
© Project SOUND
Be sure your garden is designed based on Water
Zone principles: grouping plants by water needs
http://www.taunton.com/finegardening/pages/g00101.asp
Pretty dry drought-tolerant plants
Regular water
‘Water-wise’ ; occasional summer 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]
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
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
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 Combination of deep and
shallower roots
Root growth in spring/ summer
Root:shoot ratio increases with water & nutrient stress
© Project SOUND
http://www.rmrs.nau.edu/watersheds/highlands/vegetation/chaparral/chpla
ntwater.html
Individual species have
characteristic root growth patterns
Root characteristics of some common CA
native shrubs
© Project SOUND
Root systems are coordinated to make use of available water, nutrients
Kummerow et al, 1977
Example from Coastal Sage Scrub
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
Perhaps the best choices are those with
wide tolerances: 1-2 to 2-3
Smallest shrubs/sub-shrubs Constancea (Eriophyllum)
nevinii
Epilobium canum
Eriodictyon crassifolium
Eriogonum cinereum
Eriogonum fasciculatum
Euphorbia misera
Grindelia camporum var. bracteosa
* Verbena lilacina
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)
© Project SOUND
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.’
© Project SOUND
http://www.homelidia.com/beautiful-moroccan-garden-design-ideas/
http://medomed.org/2012/the-jeb-of-rabat-in-springtime/
S. CA gardeners need to
develop an appreciation for
normal variability in gardens
© Project SOUND
Early March – good rain year
Fall
Early March – dry year
Water in the garden: a hint of cool
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
http://static.panoramio.com/photos/large/49303992.jpg
Wind patterns: will they change?
© Project SOUND
Santa Ana winds may actually decrease
for a while
© Project SOUND
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
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
Annually prune dead or broken limbs; every 3-5 years thin
Plant trees less prone to wind damage
© Project SOUND
http://gotsoil.blogspot.com/2011/12/go-hug-tree.html
Plant the right tree Least resistant
Boxelder
Tree of Heaven Ailanthus altissima*
Carob, carrotwood and Brazilian peppertree
Silk floss tree - Albizia julibrissin
Eucalyptus
Ficus - Ficus benjamina
Jacaranda - Jacaranda mimosifolia
Elms, esp. Chinese elm, Siberian elm
Melaleuca - Melaleuca quinquenervia
Norfolk Island pine - Araucaria heterophylla
Coral tree
Chinese lantern
Firs & spruces
Poplar/cottonwood
CA Bay laurel -
Ornamental pear - Pyrus spp
Washingtonia palm
Avocado - Persea americana
Autralian pine - Casuarina
Most resistant
Ash
Sycamore
Crape myrtle - Lagerstroemia indica
Magnolia
Beech
White oaks (incl. native)
Magnolia
Sweetgum
Native live oaks
© Project SOUND
* Bolded trees also prone to summer branch drop
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
© Project SOUND
Hedgerow and windbreaks take time – start now
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
The ‘fire season’ is longer than in the past – be prepared (many good resources on-line)
© Project SOUND
http://www.predictiveservices.nifc.gov/outlooks/monthly_seasonal_outlook.pdf
Air quality: will it continue to improve in
western L.A. county?
© Project SOUND
Air quality monitoring: The Air Quality Index (AQI)
© Project SOUND
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.
The AQI focuses on health effects you may experience within a few hours or days after breathing polluted air.
Santa Ana winds & pollution in western
L.A. county
Wind patterns – Santa Anas (off-
shore flow) mean more air
pollution in our area
? Longer season for Santa Anas
Maybe 20% fewer Santa Ana
events as winter temps in desert
increase
But even past records suggest
more extremes
© Project SOUND http://www.achangeinthewind.com/2008/10/good-news-friday-global-warming-lessening-santa-
ana-wind-conditions.html
http://blogs.kqed.org/climatewatch/2011/12/01/santa-ana-
wind-season-may-be-stretched-by-climate-change/
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
© Project SOUND http://www.climatechoices.org/impacts_health/
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:
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
Much still to learn –
particularly for CA native
plants
http://www.serc.si.edu/labs/co2/marsh.aspx
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
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
© Project SOUND http://scienceblogs.com/gregladen/2013/01/29/whispers-from-the-ghosting-trees/
http://scienceblogs.com/gregladen/2013/01/29/whispers-from-the-ghosting-trees/
http://www.yosemite.org/naturenotes/AirQuality2.htm
Effects of smog on Ponderosa Pine
http://www2.nature.nps.gov/air/pubs/Core_Slides/effects.htm
Ozone - damages needles causing mottling
and loss of needles, leading to bark beetle
attack and ultimately death
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/how-
does-ozone-air-pollution-hurt-plants
Weeds, pests & diseases: will they
change?
Changes will be due in large part to changes in temperature and precipitation patterns
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
https://apps.rhs.org.uk/advicesearch/Profile.aspx?pid=108
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
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
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
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
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
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
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
Come visit us: Mother Nature’s Backyard
© Project SOUND We’ll show you many things you can do to prepare
Humans (and their plants) have endured
and thrived in difficult climates
© Project SOUND
http://www.earth-cultures.com/images/ww/auto-crop/MORARG%20Dar%20al%20Housson.jpg
Prepared now – you/other living things depend on it
© Project SOUND http://blog.travel-exploration.com/2009/02/11/majorelle-blue/
Majorelle Botanic Garden - Morocco