Climate change 2014


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How climate change may affect local (S. California) gardens & what you can do to prepare. This lecture is part of the 'Out of the Wilds and Into Your Garden' native plant gardening series (2014).

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Climate change 2014

  1. 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. 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. 3. 2014: Bringing Nature Home - Lessons from Gardening Traditions Worldwide Today we’ll be visiting the gardens of Morocco © Project SOUND
  4. 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.  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. 5. The world climate is changing © Project SOUND
  6. 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. 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. 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. 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 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. 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 © Project SOUND
  11. 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 © Project SOUND
  12. 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) 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. 13. Cal-adapt climate tools are easy to use © Project SOUND
  14. 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. 15. Other commonly used models  Hadley Centre Model (HadCM3)  Canadian Model (CGCM4/CanCM4) © Project SOUND
  16. 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. 17. The models and current data all agree: the world is getting hotter © Project SOUND
  18. 18. Hadley Model - average maximal yearly temperature © Project SOUND
  19. 19. Hadley Model - average yearly minimum temperature © Project SOUND
  20. 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. 21. Local effects: we’re protected by the ocean, but we’ll be hotter © Project SOUND
  22. 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 © Project SOUND
  23. 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 © Project SOUND
  24. 24. 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
  25. 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. 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. 27. 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 Cool colors – save energy © Project SOUND
  28. 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.”  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 © Project SOUND
  29. 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 © Project SOUND
  30. 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 co_(orthographic_projection).svg © Project SOUND
  31. 31. Some Moroccan ideas on shade Shady courtyards, tile/brick, fountains: places to sit, work and relax © Project SOUND
  32. 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 © Project SOUND
  33. 33. Creative shade using hardscape Think about how you use your outdoors. Would you use your garden more if it had a shady porch, pergola, arbor? © Project SOUND
  34. 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. 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. 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.  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
  37. 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 mmodation/jardins_de_skoura_morocco_sahara_desert59.jpg  Act as windbreaks to decrease windassociated drying © Project SOUND
  38. 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. 39. The human benefits of trees/vegetation  Improve human health and wellbeing  Reduce pollution/dust  Reduce noise levels  Decrease effects of extreme heat events    Provide habitat, food Provide oxygen ‘calm and rest the soul’ © Project SOUND
  40. 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. 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. 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. 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. 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 © Project SOUND
  45. 45. Climate warming will affect local plants © Project SOUND
  46. 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. 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. 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. 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. 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. 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. 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. 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. 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       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. 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. 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 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. 57. Precipitation change in the 20th century  Most of the U.S. saw increased precipitation  S. CA and Arizona saw significant decreases © Project SOUND
  58. 58. Monitoring & predicting drought © Project SOUND
  59. 59. Monitoring & predicting drought © Project SOUND
  60. 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. 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
  62. 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 © Project SOUND
  63. 63. Canadian Model: yearly precipitation © Project SOUND
  64. 64. Hadley Model: yearly precipitation © Project SOUND
  65. 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. 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. 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. 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.  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
  68. 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
  69. 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. 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. 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 © Project SOUND
  72. 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  Our gardens need to handle slightly more dry conditions, overall  Our gardens must handle the extremes: drought and abundance © Project SOUND
  73. 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 © Project SOUND
  74. 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. 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. 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 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. 77. Root characteristics of some common CA native shrubs © Project SOUND
  78. 78. Root systems are coordinated to make use of available water, nutrients Example from Coastal Sage Scrub Kummerow et al, 1977
  79. 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. 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. 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.’ © Project SOUND
  82. 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. 83. 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
  84. 84. Wind patterns: will they change? © Project SOUND
  85. 85. Santa Ana winds may actually decrease for a while But the likelihood of high wind events will likely increase in the future © Project SOUND
  86. 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  Annually prune dead or broken limbs; every 3-5 years thin  Plant trees less prone to wind damage © Project SOUND
  87. 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. 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. 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  The ‘fire season’ is longer than in the past – be prepared (many good resources on-line) © Project SOUND
  90. 90. Air quality: will it continue to improve in western L.A. county? © Project SOUND
  91. 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. 92. Santa Ana winds & pollution in western L.A. county  Wind patterns – Santa Anas (offshore 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
  93. 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 © Project SOUND
  94. 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: 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. 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      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
  96. 96. Effects of smog on Ponderosa Pine Ozone - damages needles causing mottling and loss of needles, leading to bark beetle attack and ultimately death
  97. 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
  98. 98. 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
  99. 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. 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 /index.html  Take action swiftly to limit damage  Use Integrated Pest Management – unless the experts suggest otherwise © Project SOUND
  101. 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. 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. 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. 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. 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. 106. Come visit us: Mother Nature’s Backyard We’ll show you many things you can do to prepare © Project SOUND
  107. 107. Humans (and their plants) have endured and thrived in difficult climates © Project SOUND
  108. 108. Prepared now – you/other living things depend on it Majorelle Botanic Garden - Morocco © Project SOUND