{"id":10850,"date":"2026-04-21T20:55:04","date_gmt":"2026-04-21T20:55:04","guid":{"rendered":"https:\/\/globalnewstoday.uk\/index.php\/2026\/04\/21\/california-hollys-climate-change-resiliency-offers-insight-for-its-impact-on-chaparral-csun-prof-says-csun-newsroom\/"},"modified":"2026-04-21T20:55:04","modified_gmt":"2026-04-21T20:55:04","slug":"california-hollys-climate-change-resiliency-offers-insight-for-its-impact-on-chaparral-csun-prof-says-csun-newsroom","status":"publish","type":"post","link":"https:\/\/globalnewstoday.uk\/index.php\/2026\/04\/21\/california-hollys-climate-change-resiliency-offers-insight-for-its-impact-on-chaparral-csun-prof-says-csun-newsroom\/","title":{"rendered":"\u2018California Holly\u2019s\u2019 Climate-Change Resiliency Offers Insight for Its Impact on Chaparral, CSUN Prof Says – CSUN Newsroom"},"content":{"rendered":"

Media Contact:<\/strong> Carmen Ramos Chandler, carmen.chandler@csun.edu<\/a>, (818) 677-2130
With the help of their own TARDIS, California State University, Northridge environmental biologists have been studying climate change\u2019s impact on the state\u2019s iconic toyon plants \u2014 popularly known as \u201cChristmas Berry\u201d or \u201cCalifornia Holly\u201d \u2014 to get an understanding of chaparral and oak woodland communities\u2019 resiliency.
What they found is that while toyon has experienced variations in its habitat quality over the course of 125 years, most populations remain healthy. That gives researchers Jeremy Yoder and Daniel Dakduk hope about the future of other members of California\u2019s chaparral and oak woodland communities.
\u201cToyon is a keystone, or foundational, species, in our oak woodlands and chapparal,\u201d said Yoder, who teaches in CSUN\u2019s Department of Biology<\/a> in the College of Science and Mathematics<\/a>. \u201cKnowing how it is experiencing changing climate tells us something about how the larger plant community might be dealing with things. If the toyon is doing well, we\u2019re hoping that its natural, indigenous\u00a0\u00a0plant neighbors are also doing well.\u201d
The study, \u201cTemporal analysis of reproduction distributed in space illuminates the climate-change resiliency of toyon (Heteromeles arbutifolia<\/em>)<\/a>,\u201d was published last month in\u00a0The American Journal of Botany. The project was started by Dakduk while he was an undergraduate student at CSUN.\u00a0
Dakduk took a modeling methodology developed by Yoder called TARDIS, \u201ctemporal analysis of reproduction distributed in space,\u201d to understand the health of the toyon.\u00a0
Yoder developed TARDIS to study Joshua tree populations across California, Nevada, Arizona and Utah. The analysis uses machine learning models trained on data collected by members of the public who capture photos of a particular species and upload them onto the smartphone app iNaturalist to paint of picture of what is happening with a species across time and space. The methodology\u2019s name was inspired by British science fiction television\u2019s \u201cDoctor Who,\u201d who travels across time and space in a blue police box known as the TARDIS, which stands for \u201cTime And Relative Dimension in Space.\u201d
\u201cWhat our TARDIS does is take advantage of the power that we get if we have data about a plant\u2019s population status distributed across time and space,\u201d Yoder said. \u201cPhotos from iNaturalist records tell us whether a plant is flowering or whether it\u2019s bearing fruit or whether it\u2019s not doing anything. There are thousands of them for many species, and they all add up.\u201d
Using photos taken between 2008 and 2025 across toyon’s range from the Bay Area to San Diego, Dakduk and Yoder were able to link that information to weather data for those years and locations.\u00a0
\u201cWe can then use that information to train a machine-learning model that predicts whether or not weather conditions are suitable for toyon to flower,\u201d Yoder said.\u00a0
The researchers asked TARDIS to review historical weather data and determine the conditions for toyon health going back decades.
\u201cWe did that for over the span of the whole 20th<\/sup>\u00a0century, from 1900 to present day,\u201d Yoder said. \u201cThere\u2019s been pretty substantial global climate change since then. On a global average, it’s about a degree and a half centigrade warmer than it was at the beginning of the 20th<\/sup>\u00a0century. We used TARDIS to ask how that change in the weather impacted the conditions that toyon was experiencing and how that impacted its opportunity to reproduce and renew their populations.\u201d
Armed with that information, Yoder and Dakduk then considered toyon\u2019s future.
\u201cWhat we learned suggests that, for the most part, places that are suitable for toyon will probably remain suitable for toyon, which is good news,\u201d Yoder said. \u201cFor the most part, across most of the range of the species, there hasn\u2019t been a great deal of change in the frequency or intensity of flowering.\u201d
However, the researchers did find some interesting patterns, including the fact that toyon were not moving north to avoid some of the effects of climate change.
\u201cIf a species is being impacted by climate change, you expect that conditions suitable for it are going to shift north and uphill because that\u2019s where it\u2019s cooler,\u201d Yoder said. \u201cWe would expect to see that flowering intensity is maybe more stable or increasing if you go further north. In toyon, we\u2019re not seeing that pattern. With conditions overall being pretty stable, maybe that\u2019s not a concern.\u201d
Overall, the findings of the study were good news for the toyon and other chaparral plants, Yoder said.
\u201cOn average, populations of toyon are going to be doing about the same, but they\u2019re experiencing bigger fluctuations from year to year that could make things a little less stable,\u201d he said. \u201cTo the extent toyon are representative of other important chaparral shrubs like California lilacs and greasewood, the news is pretty hopeful for those plant communities as they share a lot of ecological and physiological features. We might see something similar to toyon for other chaparral shrubs. 
\u201cBut everyone has a different biological story,\u201d Yoder continued. \u201cOne thing we do see consistently in studies is that there may be shifts in the composition of California\u2019s plant diversity because of climate change.\u201d
Media Contact: carmen.chandler@csun.edu – (818) 677-2130
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California State University, Northridge University Advancement Marketing and Communications 18111 Nordhoff Street, Northridge, CA 91330 Phone: (818) 677-2130 \/ Contact Us<\/a>\t\t\t\t<\/p>\n

source<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Media Contact: Carmen Ramos Chandler, carmen.chandler@csun.edu, (818) 677-2130With the help of their own TARDIS, California State University, Northridge environmental biologists have been studying climate change\u2019s impact on the state\u2019s iconic toyon plants \u2014 popularly known as \u201cChristmas Berry\u201d or \u201cCalifornia Holly\u201d \u2014 to get an understanding of chaparral and oak woodland communities\u2019 resiliency.What they found […]<\/p>\n","protected":false},"author":1,"featured_media":10851,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[],"class_list":{"0":"post-10850","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science"},"_links":{"self":[{"href":"https:\/\/globalnewstoday.uk\/index.php\/wp-json\/wp\/v2\/posts\/10850","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/globalnewstoday.uk\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/globalnewstoday.uk\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/globalnewstoday.uk\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/globalnewstoday.uk\/index.php\/wp-json\/wp\/v2\/comments?post=10850"}],"version-history":[{"count":0,"href":"https:\/\/globalnewstoday.uk\/index.php\/wp-json\/wp\/v2\/posts\/10850\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/globalnewstoday.uk\/index.php\/wp-json\/wp\/v2\/media\/10851"}],"wp:attachment":[{"href":"https:\/\/globalnewstoday.uk\/index.php\/wp-json\/wp\/v2\/media?parent=10850"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/globalnewstoday.uk\/index.php\/wp-json\/wp\/v2\/categories?post=10850"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/globalnewstoday.uk\/index.php\/wp-json\/wp\/v2\/tags?post=10850"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}