October research news from the Ecological Society of America

November 7, 2024
For Immediate Release

Contact: Mayda Nathan, gro.asenull@adyam

The Ecological Society of America (ESA) presents a roundup of five research articles recently published across its esteemed journals. Widely recognized for fostering innovation and advancing ecological knowledge, ESA’s journals consistently feature illuminating and impactful studies. This compilation of papers pokes holes in the “tens rule” of invasion ecology, reports that environmental reviews increasingly rely on crowdsourced science, uses artificial intelligence to identify individual animals, examines a counterintuitive outcome of reduced nitrogen pollution and uncovers how fungal partners limit trees’ ability to respond to climate change.

From Ecological Applications:

A recent Ecological Applications study found that non-native plants (like this yellow star-thistle, which humans have transported worldwide) can have much higher odds of becoming invasive than previously thought.
Image credit: Wikipedia user Javier Martin | Public Domain

Invasive rule of thumb given the thumbs down
Author contact: William G. Pfadenhauer (ude.ssamunull@reuahnedafpw)

The “tens rule” is a longstanding edict in invasion ecology stating that approximately 10% of introduced plant species will gain a toehold in their new range, and approximately 10% of those established species will become invasive. However, this rule of thumb is an unreliable indicator of real-world invasion rates, according to new research. Analysis of an extensive global database of thousands of non-native plants revealed that the rate at which established species went on to become invasive was in fact highly variable, ranging from 7.2% to 33.8%, and dependent on such factors as geographical scale and the natural characteristics of the invaded area. Islands, for instance, experienced higher invasion rates than mainland sites. What’s more, tropical regions were found to be far more susceptible to invasion than previously believed. The authors urge that the tens rule should be discarded and recommend instead that invasion estimates be based on the setting under consideration.

Read the article: Quantifying vulnerability to plant invasion across global ecosystems

From Frontiers in Ecology and the Environment:

Environmental assessments increasingly rely on crowdsourced science
Author contact: Corey T. Callaghan (ude.lfunull@nahgallac.c)    

Planning to build a skyscraper, dig a mine or expand a residential area but need to know what the environmental impact will be? You might start by considering crowdsourced data, sometimes referred to as citizen science, suggest the authors of this study. Scrutiny of 1,300 environmental impact statements (EISs) mandated for new development projects by the U.S. National Environmental Policy Act revealed a sharp increase in the inclusion or mention of citizen science data in EISs over the past decade, surging from a mere 3% of reviews in 2012 to over 40% in 2022. Although the vast databases amassed by members of the public on platforms like eBird and iNaturalist represent a potential treasure trove of information, the authors caution that their use for environmental reviews comes with ethical and analytical challenges, like bias toward recording more charismatic organisms. The authors recommend that clear guidelines be developed to standardize the use of citizen science in IESs, ensuring that its potential is harnessed while maintaining rigorous scientific standards.

Read the article: Citizen science as a valuable tool for environmental review

From Ecosphere:

A study in Ecosphere demonstrates a new artificial intelligence-based tool that recognizes individual western leopard toads (as well as humpback whales, bottlenose dolphins and harbor seals) through matching pairs of images.
Image credit: ToadNUTS, from Kabuga et al., 2024

Can’t tell one seal or toad from another? Leave it to AI
Author contact: Emmanuel Kabuga (az.ca.smianull@agubak)

Animals of the same species often look alike, making it difficult to distinguish individuals even when they are caught on camera. This is where deep learning — a form of artificial intelligence (AI) machine learning — can come in handy, propose the authors of a recent study. Manual identification of individuals from photographs can be time-, labor- and cost-intensive, and requires a practiced eye; to overcome these limitations, the researchers developed a similarity learning network to determine whether pairs of images show the same or two different individuals. Surveying photos of bottlenose dolphins, harbor seals, leopard toads and humpback whales obtained from existing databases, models using this automated approach successfully identified individuals 83–96% of the time, even when photos of the same individual spanned multiple years. Application of deep learning can thus improve population size estimates, ultimately improving conservation and management strategies.

Read the article: Similarity learning networks uniquely identify individuals of four marine and terrestrial species

From Ecology:

Battling air pollution may contribute to climate change
Author contact: Zachary B. Freedman (ude.csiwnull@namdeerfz)

Decades-old policies aimed at improving air quality may also be accelerating global climate change, warns a new study. For generations, nitrogen pollution in the air has worked its way into ecosystems in a process called deposition, leading to greater carbon stores in soils around the world (among many other consequences). Since the 1970s, however, rates of nitrogen deposition have fallen as multinational agreements targeting air pollution took effect. Now, nearly 30 years of data from a long-running nitrogen deposition experiment in Michigan suggest that the improvements in air quality are rapidly reversing carbon gains in soils. With less nitrogen pollution coming from the atmosphere, soil microbial activity is picking up, ramping up decomposition and decreasing the amount of carbon retained and stored in soils. This reduction in soils’ capacity to serve as carbon sinks could compromise efforts to mitigate climate warming, say the authors, especially if similar patterns are repeated in forest systems across the planet.

Read the article: Gains in soil carbon storage under anthropogenic nitrogen deposition are rapidly lost following its cessation

From Ecological Monographs:

A study published in Ecological Monographs experimentally transplanted soil and seedlings (seen here) to reveal that beneficial soil fungi are missing outside of some trees’ current ranges, limiting the trees’ ability to shift their distributions in response to climate change.
Image credit: Jordon Tourville, from Tourville et al., 2024

Missing mycorrhizae a barrier to tree migration in a warming climate
Author contact: Jordan C. Tourville (gro.sroodtuonull@ellivruotj)

Organisms throughout the world are on the march due to a rapidly changing climate, but the results of a new study indicate that trees’ ability to track changing conditions may be determined by an unlikely ally. In an effort to test whether trees will be able to shift their distributions upslope as temperatures warm, the research team established a series of greenhouse and field experiments on mountainsides across Vermont, transplanting seedlings and soils among sites. The experiments revealed that survival and growth of sugar maple and American beech seedlings were generally lower when the seedlings were raised in soils taken from beyond the trees’ current range. The authors attribute this difference to the absence of beneficial fungi called mycorrhizae — fungal partners that facilitate nutrient absorption by tree roots in exchange for carbon — in soils outside the trees’ historical home range. The study highlights the crucial role of species interactions, like those between trees and mycorrhizal fungi, in determining how species will shift their distributions as climate change reshapes ecosystems.

Read the article: Mycorrhizal fungi as critical biotic filters for tree seedling establishment during species range expansions

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The Ecological Society of America, founded in 1915, is the world’s largest community of professional ecologists and a trusted source of ecological knowledge, committed to advancing the understanding of life on Earth. The 8,000 member Society publishes seven journals including a membership bulletin and broadly shares ecological information through policy, media outreach and education initiatives. Visit the ESA website at https://ecologicalsocietyofamerica.org 

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