{"id":228195,"date":"2025-09-15T07:43:07","date_gmt":"2025-09-15T07:43:07","guid":{"rendered":"https:\/\/www.europesays.com\/us\/228195\/"},"modified":"2025-09-15T07:43:07","modified_gmt":"2025-09-15T07:43:07","slug":"spring-is-arriving-later-for-new-york-city-trees-study-finds","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/228195\/","title":{"rendered":"Spring is arriving later for New York City trees, study finds"},"content":{"rendered":"

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\n According to a study by Yale researchers, city park trees are experiencing a delay in seasonal change, which may lead to increased seasonal allergies. <\/p>\n

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Michelle So<\/a><\/p>\n

1:49 am, Sep 15, 2025<\/p>\n

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Staff Reporter\n <\/p>\n

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Baala Shakya, Photography Editor<\/p>\n

In a concrete jungle like New York City, urban trees offer refuge: they\u2019re living cooling systems and shade for parked cars. But the seasons are changing for trees in the Big Apple.\u00a0<\/p>\n

According to a new study published by Yale researchers in Environmental Research Letters<\/a>, climate change is causing urban trees in New York City to turn green later in the year, potentially shifting pollen season and affecting seasonal allergies.<\/p>\n

\u201cOur findings show that climate change and the urban heat island effect are shifting the timing of tree leaf-out in parks,\u201d Juwon Kong, the lead author of the paper, said.<\/p>\n

Kong and her team utilized satellite images taken over a 19-year period to measure the start of the growing season, or the day of the year when the trees start \u201cleafing out in spring.\u201d\u00a0<\/p>\n

The drastic temperature transition from winter to spring is a key trigger for springtime leaf growth. Because winters are getting warmer due to climate change<\/a>, the significant temperature hike is dampened, and, thus, trees experience delayed leaf growth.<\/p>\n

According to Kong, medium-sized parks are especially vulnerable to climate change because they have both high edge-to-area ratios and smaller interiors. This means more of the park\u2019s trees are exposed to surrounding heat from roads and buildings, but unlike larger parks, these medium-sized forests lack the cooling capacity of many trees.\u00a0<\/p>\n

Smaller \u201cpocket parks\u201d are \u200balready dominated by their surroundings, so their response to climate change in time is less distinct, while larger parks can better resist heat due to their cooling capacity.<\/p>\n

In addition to climate change, trees are under a constant barrage of invasive insects, pathogens, plants and animals due to the increase and expansion of development, said Mark Ashton ENV \u201985 \u201990, senior associate dean of The Forest School at the Yale School of the Environment.<\/p>\n

\u201cTaken together, trees and forests have never before been under such dire compounded and interacting impacts as today,\u201d Ashton said.<\/p>\n

In addition to affecting seasonal allergies, delayed seasons also means that trees will have less carbon intake, as a result of being less foliated. For trees, this reduces carbon uptake and growth. For people, it reduces early-spring cooling and shading benefits, and shifts pollen release, which can affect allergies.\u00a0<\/p>\n

\u201cFor ecosystems, delayed leaf-out can disrupt the timing of pollinators, migratory birds, and other species that depend on trees, altering ecological balances,\u201d Kong said. \u201cThese shifts could reshape biodiversity and ecosystem health within urban parks.\u201d<\/p>\n

Kong said that successful future initiatives should include \u201ccareful consideration of park size, species selection, tree planting and long-term conservation planning.\u201d<\/p>\n

New Haven\u2019s drinking water runs through 26,000 acres of natural forest.<\/p>\n

MICHELLE SO <\/p>\n

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\n Michelle So is a beat reporter for the SciTech desk, covering climate change and the School of the Environment. Originally from Los Angeles, California, she is a sophomore in Timothy Dwight College majoring in Ecology and Evolutionary Biology. <\/p>\n