{"id":21149,"date":"2022-01-18T13:30:02","date_gmt":"2022-01-18T21:30:02","guid":{"rendered":"http:\/\/occupysf.net\/?p=21149"},"modified":"2022-01-18T13:30:04","modified_gmt":"2022-01-18T21:30:04","slug":"the-environmental-danger-of-preferring-native-plants","status":"publish","type":"post","link":"http:\/\/occupysf.net\/index.php\/2022\/01\/18\/the-environmental-danger-of-preferring-native-plants\/","title":{"rendered":"The Environmental Danger of Preferring Native Plants"},"content":{"rendered":"\n<p>Posted on\u00a0<a href=\"https:\/\/sfforest.org\/2022\/01\/17\/the-environmental-danger-of-preferring-on-native-plants\/\">January 17, 2022<\/a>\u00a0by\u00a0<a href=\"https:\/\/sfforest.org\/author\/sfforest\/\">SF Forest Alliance<\/a> (SFForest.org)<\/p>\n\n\n\n<blockquote class=\"wp-block-quote\"><p>This article is republished with permission and minor edits from Conservation Sense and Nonsense, an environmental blog about current ecological topics including \u201cnative plant restorations.\u201d We are publishing it here because we think the opposition to \u201cinvasives\u201d by nativist activists \u2013 and the focus on \u201cnative\u201d plants \u2013 is not just a waste of resources but actually dangerous to the environment.<\/p><\/blockquote>\n\n\n\n<p>***<\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><a href=\"https:\/\/milliontrees.me\/2022\/01\/01\/the-need-for-diverse-urban-forest-and-the-obstacles-to-achieve-that-goal\/\">The need for diverse urban forest and the obstacles to achieve that goal<\/a><\/h1>\n\n\n\n<p><a href=\"http:\/\/www.mattritter.net\/bio\" target=\"_blank\" rel=\"noreferrer noopener\">Matt Ritter<\/a>&nbsp;is a professor of biology at Cal Poly San Luis Obispo and Director of Cal Poly Plant Conservatory. He is the author of several books about California\u2019s unique flora, including&nbsp;<em>A Californian\u2019s Guide to the Trees Among Us.&nbsp;<\/em>He is considered an expert on the horticulture, ecology and taxonomy of the&nbsp;<em>Eucalyptus&nbsp;<\/em>genus.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><a href=\"https:\/\/caufc.org\/conference-2021-recordings\/\"><img decoding=\"async\" src=\"https:\/\/milliontrees.files.wordpress.com\/2021\/12\/ritter-urban-trees-8.png?w=1024\" alt=\"\" class=\"wp-image-12189\"\/><\/a><figcaption>Click on picture to view Professor Ritter\u2019s presentation<\/figcaption><\/figure>\n\n\n\n<p>In October 2021, Professor Ritter gave a presentation to the California Urban Forests Council, entitled \u201cUnderutilized Species for the Future of Urban Wood and Urban Forestry.\u201d He began by explaining why it is important to identify new tree species for our urban forest.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><a href=\"https:\/\/milliontrees.files.wordpress.com\/2021\/12\/ritter-urban-trees-7.png\"><img decoding=\"async\" src=\"https:\/\/milliontrees.files.wordpress.com\/2021\/12\/ritter-urban-trees-7.png?w=1024\" alt=\"\" class=\"wp-image-12192\"\/><\/a><\/figure>\n\n\n\n<ul><li><em>\u201cBaja is moving to Oregon,\u201d<\/em>&nbsp;said Ritter to set the stage. Within 50-80 years trees living in California now will no longer be adapted to the anticipated warmer, drier climate. Trees killed by wildfire in California are not returning. Forests are quickly converting to grassland and shrub. As of 2018, California had lost 180 million trees to drought, disease, bark beetles, heat, and wildfire, which is nearly 5% of the total tree population in California. Adding subsequent years to date, we have probably lost 7% of all of our trees.<\/li><li>Trees in urban areas will help Californians cope with warmer conditions because they cool our cities and reduce energy consumption. Fewer trees will mean a lower quality of life, for us and for birds. The loss of our trees reduces carbon storage, which contributes to more climate change.<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image\"><a href=\"https:\/\/milliontrees.files.wordpress.com\/2021\/12\/ritter-urban-trees-2.png\"><img decoding=\"async\" src=\"https:\/\/milliontrees.files.wordpress.com\/2021\/12\/ritter-urban-trees-2.png?w=1024\" alt=\"\" class=\"wp-image-12193\"\/><\/a><\/figure>\n\n\n\n<p>Ritter then explained why we must diversify tree species in our urban forests.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><a href=\"https:\/\/milliontrees.files.wordpress.com\/2021\/12\/ritter-urban-trees-6.png\"><img decoding=\"async\" src=\"https:\/\/milliontrees.files.wordpress.com\/2021\/12\/ritter-urban-trees-6.png?w=1024\" alt=\"\" class=\"wp-image-12199\"\/><\/a><\/figure>\n\n\n\n<ul><li>There are over 60,000 tree species in the world and only 7% of tree species are found in urban areas around the world. In California our urban forests are even less diverse. There are only 234 tree species on average in California\u2019s urban forests. The average number of approved tree species for planting in California\u2019s municipalities is only 49 and few species on those approved lists are native to California.<\/li><li>Diversity of tree species ensures greater resiliency that enables our urban forests to survive changing conditions.<\/li><li>Only 9% of tree species in California\u2019s urban forests are native.<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image\"><a href=\"https:\/\/milliontrees.files.wordpress.com\/2021\/12\/ritter-urban-trees-5.png\"><img decoding=\"async\" src=\"https:\/\/milliontrees.files.wordpress.com\/2021\/12\/ritter-urban-trees-5.png?w=1024\" alt=\"\" class=\"wp-image-12196\"\/><\/a><figcaption>The native ranges of tree species in California\u2019s urban forest.<\/figcaption><\/figure>\n\n\n\n<p>An&nbsp;<a href=\"https:\/\/www.publicinput.com\/Customer\/File\/Full\/d635e0ef-053a-47cd-abb8-1c3f62db165e\" target=\"_blank\" rel=\"noreferrer noopener\">inventory of Oakland\u2019s urban forest<\/a>&nbsp;(street trees, medians, and landscaped parks only) was recently completed. With 535 tree species, the diversity of Oakland\u2019s urban forest is greater than average for California. With 14% native trees, Oakland\u2019s urban forest is more native than average. There are 59 species on Oakland\u2019s list of approved trees, of which only 4 are native to Oakland. The most significant finding of Oakland\u2019s tree inventory is that our urban forest is only 64% \u201cstocked,\u201d meaning that of existing tree wells, only 64% are currently planted with trees. When trees die in Oakland, they aren\u2019t being replaced. I don\u2019t doubt there is a will to plant trees in Oakland. I assume it is a question of means in a city with more pressing needs than resources.<\/p>\n\n\n\n<p>Ritter and his colleagues at Cal Poly have created a website called&nbsp;<a href=\"https:\/\/selectree.calpoly.edu\/\" target=\"_blank\" rel=\"noreferrer noopener\">SelecTree<\/a>&nbsp;to help Californians choose the right tree for the right site and conditions. There are 1,500 tree species described on SelecTree, using 60 characteristics, such as drought tolerance. SelecTree rates blue gum eucalyptus \u201cmedium\u201d for drought tolerance, the same rating as native coast live oak and bay laurel. Ritter clarified that drought tolerance on SelecTree is a measure of how much water the tree species uses. Claims that eucalyptus uses more water than native trees is bogus, like most bad raps about eucalyptus.<\/p>\n\n\n\n<p>Ritter recommended specific tree species, based on their drought and heat tolerance. He said that when diversifying our urban forests&nbsp;<strong>\u201cwe have to think about Australia\u201d<\/strong>&nbsp;because it is the hottest, driest, flattest, and oldest place on the planet, which is another way of saying that tree species in Australia have survived terrible conditions that are comparable to the challenging conditions in urban environments.<\/p>\n\n\n\n<p>Ritter recommended oak species that are native to Texas; eucalyptus and closely related tree species; and several tree species in the legume family, especially acacia. In each case he mentioned the suitability of tree species based partly on the quality of its wood. Apparently, I\u2019m not the only person in California who is disturbed by huge piles of wood chips wherever trees have been destroyed. Ritter also thinks we should be thinking about how we can use wood when trees are destroyed, rather than building potential bonfires.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"obstacles-to-diverse-urban-forests-in-california\"><strong>Obstacles to diverse urban forests in California<\/strong><\/h3>\n\n\n\n<p>When Professor Ritter took questions from the audience, we learned that the main obstacle to a diverse urban forest in California, adapted to our climate conditions, is the myopic focus of native plant advocates:<\/p>\n\n\n\n<p><strong>Question:&nbsp;<\/strong>\u201cAre we introducing new pathogens to our natives by importing new species?\u201d<\/p>\n\n\n\n<p><strong>Answer:&nbsp;<\/strong>There are many laws and rules that restrict the importation of plants to prevent that from happening. We also import only the seeds of plants, not grown plants. The seeds are sterilized and they don\u2019t carry the pathogens that may exist on grown plants in their native ranges.<\/p>\n\n\n\n<p><strong>Question:&nbsp;<\/strong>\u201cDo we know how quickly birds and insects adapt to new species?\u201d<\/p>\n\n\n\n<p><strong>Answer:&nbsp;<\/strong><em>\u201cNo we don\u2019t, but&nbsp;<strong>who cares<\/strong>? We are facing a climate emergency. We have 50 years before life in our cities becomes hell. We have a responsibility to protect the quality of life in our cities. We should stop developing the wild, but cities are different.\u201d<\/em><\/p>\n\n\n\n<p>Ritter anticipated a question that is often a concern of native plant advocates by saying we should not be concerned about \u201cweediness,\u201d AKA \u201cinvasiveness.\u201d He said,&nbsp;<em>\u201cThat should be far down on our list of priorities of what to worry about. We need to be primarily concerned about what tree species will grow in our changed climate.\u201d<\/em><\/p>\n\n\n\n<p><strong>Rhetorical Question:&nbsp;<\/strong>\u201cBut insects need native plants!<strong>\u201d<\/strong><\/p>\n\n\n\n<p><strong>Answer:&nbsp;<\/strong>Ritter instantly recognized the mantra of Doug Tallamy. He replied that it is not well established that there are more insects living on native plants than on introduced plants. He mentioned a single study that inventoried plant and animal species in eucalyptus compared to oak forests, presumably&nbsp;<a href=\"http:\/\/milliontrees.me\/2011\/02\/04\/biodiversity-another-myth-busted-2\/\" target=\"_blank\" rel=\"noreferrer noopener\">Dov Sax\u2019s study<\/a>&nbsp;which concluded:&nbsp;<em>\u201cSpecies richness was nearly identical for understory plants, leaf-litter invertebrates, amphibians and birds; only rodents had significantly fewer species in eucalypt sites.&nbsp;<strong>Species diversity patterns\u2026were qualitatively identical to those for species richness<\/strong>, except for leaf-litter invertebrates, which were significantly more diverse in eucalypt sites during the spring.\u201d<\/em><\/p>\n\n\n\n<p><strong>Rhetorical Question: \u201c<\/strong>We are still dealing with a legacy of blue gum eucalyptus in the Bay Area. Why should we repeat that mistake?\u201d<\/p>\n\n\n\n<p><strong>Answer:&nbsp;<\/strong>Ritter agreed that blue gum eucalyptus is \u201cinappropriate\u201d in many places where it was planted in the Bay Area, but we\u2019re not planting blue gums. There are 800 eucalyptus species and many are ideal for our conditions. He said, \u201c<em>Why not plant eucalyptus?&nbsp;<strong>It would be dumb not to plant suitable eucalyptus species<\/strong>&nbsp;just because it shares a name.\u201d<\/em><\/p>\n\n\n\n<p>Ritter added that,&nbsp;<em>\u201cPlanting only natives just doesn\u2019t work in San Francisco. There would be no trees in Southern California because&nbsp;<strong>we don\u2019t have very many native trees in California<\/strong>.\u201d&nbsp;<\/em>The&nbsp;<a href=\"http:\/\/milliontrees.me\/2017\/10\/01\/the-consequences-of-dune-restoration-in-coastal-california\/\" target=\"_blank\" rel=\"noreferrer noopener\">pre-settlement coast of California was virtually treeless<\/a>&nbsp;in most places and that\u2019s a fact. For example, a study of historic vegetation in Oakland, California reported that only 2% of pre-settlement Oakland was forested with trees.&nbsp;<em>\u201cVegetation before urbanization in Oakland was dominated by grass, shrub, and marshlands that occupied approximately 98% of the area.\u201d<\/em>&nbsp;(1)<\/p>\n\n\n\n<figure class=\"wp-block-image\"><a href=\"https:\/\/milliontrees.files.wordpress.com\/2011\/09\/san-francisco-1806.jpg\"><img decoding=\"async\" src=\"https:\/\/milliontrees.files.wordpress.com\/2011\/09\/san-francisco-1806.jpg\" alt=\"\" class=\"wp-image-2307\"\/><\/a><figcaption>San Francisco in 1806 as depicted by artist with von Langsdoff expedition. Bancroft Library<\/figcaption><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"oakland-as-a-case-in-point\"><strong>Oakland as a case in point<\/strong><\/h3>\n\n\n\n<p>The&nbsp;<a href=\"https:\/\/www.sfchronicle.com\/bayarea\/article\/Oakland-s-oaks-are-largely-gone-He-s-leading-16650398.php?cmpid=gsa-sfgate-result\" target=\"_blank\" rel=\"noreferrer noopener\">San Francisco Chronicle recently published an article<\/a>&nbsp;about a guerilla tree-planter in Oakland who is planting native oak trees on public land, wherever he wants. Oakland\u2019s Director of Tree Services, David Moore, gently suggests that many of these tree plantings are ill-advised:&nbsp;<em>\u201c\u2018There is a part of all of us that loves with our hearts the coast live oak tree because of its heritage, the symbolism of our city, and just the legacy that they have,\u2019 Moore said. \u2018But we have to diversify, and we are diversifying to other ones that are recommended to be more adaptable to climate change\u2026<\/em><strong><em>The reality is that we have created a world that is not the native conditions of these plants,\u2019 Moore said. \u2018If we want trees to survive in these non-native conditions, we have to pick trees from around the world that can survive these conditions.\u2019<\/em><\/strong><em>\u2026Moore said oaks, while beautiful, are not the ideal tree for today\u2019s hot, dry and cramped urban landscape. Without careful and costly maintenance, he said, oaks could destroy sidewalks, block light from streetlamps and grow their branches into streets and walkways, creating hazards for motorists and pedestrians. The city still plants oaks, but mainly in parks rather than streets because that\u2019s where they do better, Moore said\u2026\u201d<\/em><\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"stalemate\"><strong>Stalemate<\/strong><\/h3>\n\n\n\n<p>So, here we are. We have a pressing need for a more diverse urban forest that is adapted to present and anticipated conditions, but we are paralyzed by the ideological commitment of native plant advocates who are demanding that we destroy our urban forest because it is predominantly non-native. In a recent edition of Nature News, Jake Sigg [considered a doyen of Nativism in San Francisco, who runs a long-lived newsletter] said, \u201c<em>Hysterical tree planting is worse than a waste of time and resources\u2026\u201d<\/em><\/p>\n\n\n\n<p>I am grateful to Professor Ritter for being bluntly frank with members of the arborist community who should know better. Dare we hope they learned something from that presentation?<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p>(1)&nbsp;<a href=\"https:\/\/www.nrs.fs.fed.us\/pubs\/jrnl\/1993\/ne_1993_nowak_002.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">Nowak, David, \u201cHistorical vegetation change in Oakland and its implications for urban forest management,\u201d&nbsp;<em>Journal of Arboriculture<\/em>, 19(5): September 1993<\/a><br><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Posted on\u00a0January 17, 2022\u00a0by\u00a0SF Forest Alliance (SFForest.org) This article is republished with permission and minor edits from Conservation Sense and Nonsense, an environmental blog about current ecological topics including \u201cnative plant restorations.\u201d We are publishing it here because we think the opposition to \u201cinvasives\u201d by nativist activists \u2013 and the&#8230; <a class=\"continue-reading-link\" href=\"http:\/\/occupysf.net\/index.php\/2022\/01\/18\/the-environmental-danger-of-preferring-native-plants\/\"> Continue reading <span class=\"meta-nav\">&rarr; <\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"_links":{"self":[{"href":"http:\/\/occupysf.net\/index.php\/wp-json\/wp\/v2\/posts\/21149"}],"collection":[{"href":"http:\/\/occupysf.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/occupysf.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/occupysf.net\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/occupysf.net\/index.php\/wp-json\/wp\/v2\/comments?post=21149"}],"version-history":[{"count":1,"href":"http:\/\/occupysf.net\/index.php\/wp-json\/wp\/v2\/posts\/21149\/revisions"}],"predecessor-version":[{"id":21150,"href":"http:\/\/occupysf.net\/index.php\/wp-json\/wp\/v2\/posts\/21149\/revisions\/21150"}],"wp:attachment":[{"href":"http:\/\/occupysf.net\/index.php\/wp-json\/wp\/v2\/media?parent=21149"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/occupysf.net\/index.php\/wp-json\/wp\/v2\/categories?post=21149"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/occupysf.net\/index.php\/wp-json\/wp\/v2\/tags?post=21149"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}