News & Publications

Authors of a new study using Nature's Notebook data found that in cold regions, urbanization leads to earlier leaf-out and flowering in plants. However, in warmer temperate and sub-tropical regions, urbanization delays leafing and flowering. The authors speculate several reasons for this difference, including a lack of winter chilling that some plants require, heat stress, or a greater influence of other aspects of urbanization besides heat. Phenology can serve as the “canary in the coal mine” for climate change impacts on our environment, so keep those Nature’s Notebook observations coming!

Urban growers need information about how best to manage pests, for example, knowing when to apply a pesticide to have the least likelihood of impacting a beneficial pollinator. Data resulting from citizen science programs like Nature’s Notebook, iNaturalist, and eButterfly can support urban growers’ efforts to increase the presence of pollinators and other beneficial insects and decrease insect pests. Growers can use these platforms to support insect identification, store their data in a standardized format, compare their data to those from other farms, and predict when pests will be most vulnerable to treatment.

The timing of phytoplankton blooms is critical to the survival of fish including haddock, herring, and salmon. The authors looked at the impact of a high-emissions climate warming scenario on two groups of fishes that live in the surface layer of the ocean and spawn in springtime. Fish species that rely on geographic features such as rivers are predicted to change their spawning timing twice as fast as phytoplankton bloom timing, resulting in spawning occurring earlier than phytoplankton bloom across 86% of the area studied. Mismatches in this ecosystem could cause population declines with cascading effects on global carbon cycles.

The number of early springs followed by late freeze events, called false springs, is predicted to increase due to climate change. To determine the likelihood of damage from a late spring freeze in temperate forests, the authors evaluated several datasets that reflect the start of spring including the USA-NPN’s spring leaf index. Many factors play a role in the susceptibility of plants to damage from false springs, including the plant’s life stage, functional group, morphology, and phenological traits such as whether the plant puts on buds early. A clearer understanding of how to estimate the risk of false springs for various species/functional types improves estimates of the future frequency of false springs under different climate change scenarios and can help improve models of species range shifts, carbon budgets and even feedback loops between climate shifts and forest composition.

Integrating herbarium data with contemporary phenology data requires standardized terminology, definitions, and principles. The authors of a new study in Applications in Plant Sciences describe the Plant Phenology Ontology, an effort to integrate herbarium and field data. They demonstrate the use of this framework by combining herbarium data and observations from Nature’s Notebook to show that in North America, flowering time for black cherry (Prunus serotina) has been steadily accelerating since 1873.

Nature’s Notebook data were used to evaluate how common milkweed flowering is responding to changes in climate. With each degree of maximum temperature increase, the mean flowering date for milkweed shifted nearly four days earlier. The shift occurred across first, last, and mean flowering dates but did not extend to initial growth or fruit ripening. The shift became more significant over the period of 2011 to 2016. These findings will help managers develop conservation plans for this species and its pollinators.

Researchers at UC Santa Barbara combined herbarium records with observations contributed by Nature’s Notebook participants to assess the impact of climate variables on timing of flowering in 2,500 species of plants. The authors found that maximum temperature, the number of frost-free days, and the quantity of precipitation as snow were the best predictors of flowering time for both herbarium and observed data. A better understanding of the climate variables that drive flowering phenology can help us anticipate how future changes in climate might impact flowering.

In order to better understand precision and accuracy in phenology data collection and how that varies by training level, researchers at Acadia National Park’s Schoodic Institute compared data from three different observer types – expert professional scientists, trained citizen scientists, and untrained citizen scientists. The authors found that untrained citizen scientists recorded data that was as precise and sometimes more accurate than trained citizen scientists, likely due to a misinterpretation of materials presented at trainings. The authors recommend that informative datasheets, mid-season assessments and calibration trainings may help to ensure high-quality data.

In a new study, researchers at Oregon State University sought to quantify the role bears in Alaska play in dispersing seeds. The authors estimated that brown and black bears disperse over 200,000 seeds per hour per square km while foraging for fleshy fruits and then excreting them on the landscape. Brown bears disperse more seeds than black bears overall, and at different times of the year. Because bears disperse a large percentage of the seeds of fleshy-fruit bearing species, they have a great influence on the species composition of plants in their ecosystems. If populations of bears are reduced, the number of fleshy-fruited shrubs may also decline and be replaced by wind-dispersed plants.

To better link phenology data from time-lapse cameras and on-the-ground observations, authors of a new study in Ecosphere compared digital images of tree foliage color from spring to autumn to observations made using the USA-NPN protocols. The authors also found that chill and minimum temperature in autumn, drought stress in autumn, and heat stress in summer are all important factors to the timing of peak fall foliage color.