{"id":27236,"date":"2025-07-27T15:39:41","date_gmt":"2025-07-27T09:54:41","guid":{"rendered":"https:\/\/www.revoscience.com\/en\/?p=27236"},"modified":"2025-07-27T15:39:44","modified_gmt":"2025-07-27T09:54:44","slug":"a-century-of-data-reveals-declining-forest-diversity","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/a-century-of-data-reveals-declining-forest-diversity\/","title":{"rendered":"A century of data reveals declining forest diversity"},"content":{"rendered":"\n
\"\"
Virginia bluebells at Trelease Woods. Credit: Jennifer \u00c1lvarez<\/sup><\/em><\/figcaption><\/figure>\n\n\n\n

URBANA, Ill.<\/strong>\u00a0\u2014 Researchers at the\u00a0University of Illinois Urbana-Champaign<\/u><\/a>\u00a0have analyzed 96 years of forest census data to gain a deeper understanding of ecological changes and inform effective management practices. <\/p>\n\n\n\n

Their\u00a0study<\/u><\/a>, published in\u00a0Forest Ecology and Management,<\/em>\u00a0reveals concerning homogenization trends. This means the forest has become less diverse over time, losing trees that played a critical role in its ecosystem.<\/p>\n\n\n\n

The researchers analyzed census data from Trelease Woods<\/u><\/a>, which the university acquired in 1917. Homogenization was linked to the spread of the emerald ash borer, an invasive beetle, and Ophiostoma<\/em> fungus, which causes Dutch elm disease. <\/p>\n\n\n\n

Many deciduous forests like Trelease Woods are losing diversity, co-author\u00a0Jennifer Fraterrigo<\/u><\/a>\u00a0said. Fraterrigo is a professor of\u00a0natural resources and environmental sciences. She worked on the study with her former graduate student, Jennifer \u00c1lvarez, who is currently an environmental assessment researcher at the\u00a0Illinois State Geological Survey<\/u><\/a>, part of the\u00a0Prairie Research Institute<\/u><\/a>\u00a0at Illinois. Integrative biology professor\u00a0James Dalling<\/u><\/a>\u00a0and former NRES forest ecologist John Edgington were also co-authors on the study.<\/p>\n\n\n\n

Dutch elm disease and the emerald ash borer have significantly decreased the abundance of elm and ash trees in Trelease Woods and across North America, Fraterrigo said. However, diseases and pests failed to fully explain homogenization trends: suppression of forest fires, whitetail deer overpopulation, and the introduction of invasive plants can also drive homogenization, she said. <\/p>\n\n\n\n

\u201cThe study was focused on biotic disturbances \u2014 disease, pests, and invasives \u2014 because we have data from before they arrived, so that’s something we knew was affecting the forest,\u201d \u00c1lvarez said. \u201cBut we can\u2019t isolate any single factor.\u201d<\/p>\n\n\n\n

Less diversity means less resilience<\/strong><\/p>\n\n\n\n

While the study focused on changes caused by Dutch elm disease and the emerald ash borer, these were not the only factors affecting the forest, and elm and ash were not the only species whose relative abundances changed.<\/p>\n\n\n\n

When elm and ash die, they leave gaps in the forest, which other species compete to fill in. That\u2019s when other factors come into play \u2014 fire suppression, for example. Wildfires also create space in the forest for new trees to grow. Without fire, forests become shadier and wetter, a process known as mesophication.<\/p>\n\n\n\n

So instead of a wide variety of species replacing declining ones, only a handful of plants spread \u2014 mostly sugar maple and Ohio buckeye, which are well adapted to the new conditions. Oak trees, which don\u2019t do well in the shade, have declined. <\/p>\n\n\n\n

\u201cThis can make the forest less resilient to future disturbances,\u201d Fraterrigo said. \u201cIf one species makes up 70% of a forest, and then a pest or disease targeting that species is introduced, then 70% of the forest trees would be gone, likely leading to functional collapse.\u201d<\/p>\n\n\n\n

Broad implications from a unique case<\/strong><\/p>\n\n\n\n

The study is unusual in that it follows a single forest, Trelease Woods, over a long period of time. Most forests in the Midwest have been clearcut at least once or have sustained other significant forms of damage and degradation. But Trelease has survived with relatively little human interference and related physical damage, and scientists have been collecting data from the site for over a century. It\u2019s a massive group effort, Fraterrigo said. Hundreds of NRES and integrative biology students have surveyed the site for class credit over the years.<\/p>\n\n\n\n

\u201cMost studies use space-for-time substitution to understand how ecosystems respond to disturbance over time. Researchers might not have long-term data for a specific site, so they\u2019ll compare many sites that have been exposed to the same kind of disturbance but at different times. We\u2019ll assume that any observed differences reflect how an ecosystem responds over time,\u201d Fraterrigo said. \u201cBut that approach has its problems. Having the Trelease Woods data allowed us to directly investigate how the forest responded to ecological changes.\u201d<\/p>\n\n\n\n

Research at Trelease might help inform forest management globally, as the exceptional site was added to the Forest Global Earth Observatory Network<\/u><\/a> in 2018. ForestGEO, as it\u2019s called, helps researchers standardize forest data and collect it in one place. As of today, the network monitors roughly 7 million trees compromising nearly 13,000 species, connecting insights from individual scientists to reveal broader trends.<\/p>\n\n\n\n

\u201cTrelease is a relatively undisturbed forest, yet we see this mesophication trend,\u201d Fraterrigo said. \u201cMore active management might be necessary to conserve certain species, even in places with little human activity.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"

Researchers at the\u00a0University of Illinois Urbana-Champaign\u00a0have analyzed 96 years of forest census data to gain a deeper understanding of ecological changes and inform effective management practices. <\/p>\n","protected":false},"author":2,"featured_media":27237,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[15],"tags":[],"class_list":["post-27236","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-environment"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods.webp",700,525,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods-200x200.webp",200,200,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods-675x506.webp",675,506,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods.webp",700,525,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods.webp",700,525,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods.webp",700,525,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods.webp",700,525,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods.webp",700,525,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods.webp",700,525,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods-600x525.webp",600,525,true],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods-600x525.webp",600,525,true],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods-700x490.webp",700,490,true],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods-550x360.webp",550,360,true],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods-95x65.webp",95,65,true],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods-640x525.webp",640,525,true],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods-96x96.webp",96,96,true],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/07\/Trelease-woods-150x113.webp",150,113,true]},"author_info":{"info":["RevoScience"]},"category_info":"Environment<\/a>","tag_info":"Environment","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/27236","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=27236"}],"version-history":[{"count":1,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/27236\/revisions"}],"predecessor-version":[{"id":27238,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/27236\/revisions\/27238"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/27237"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=27236"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=27236"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=27236"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}