Heat poses an urgent threat to public health in cities, as the urban heat island (UHI) effect can amplify exposures, contributing to high heat-related mortality and morbidity. Urban trees have the ...potential to mitigate heat by providing substantial cooling, as well as co-benefits such as reductions in energy consumption. The City of Boston has attempted to expand its urban canopy, yet maintenance costs and high tree mortality have hindered successful canopy expansion. Here, we present an interactive web application called Right Place, Right Tree-Boston that aims to support informed decision-making for planting new trees. To highlight priority regions for canopy expansion, we developed a Boston-specific Heat Vulnerability Index (HVI) and present this alongside maps of summer daytime land surface temperatures. We also provide information about tree pests and diseases, suitability of species for various conditions, land ownership, maintenance tips, and alternatives to tree planting. This web application is designed to support decision-making at multiple spatial scales, to assist city officials as well as residents who are interested in expanding or maintaining Boston's urban forest.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Siberia has undergone dramatic climatic changes due to global warming in recent decades. Yet, the ecological responses to these climatic changes are still poorly understood due to a lack of data. ...Here, we use a unique data set from the Russian ‘Chronicles of Nature’ network to analyse the long‐term (1976–2018) phenological shifts in leaf out, flowering, fruiting and senescence of 67 common Siberian plant species. We find that Siberian boreal forest plants advanced their early season (leaf out and flowering) and mid‐season (fruiting) phenology by −2.2, −0.7 and −1.6 days/decade, and delayed the onset of senescence by 1.6 days/decade during this period. These mean values, however, are subject to substantial intraspecific variability, which is partly explained by the plants' growth forms. Trees and shrubs advanced leaf out and flowering (−3.1 and −3.3. days/decade) faster than herbs (−1 day/decade), presumably due to the more direct exposure of leaf and flower buds to ambient air for the woody vegetation. For senescence, we detected a reverse pattern: stronger delays in herbs (2.1 days/decade) than in woody plants (1.0–1.2 days/decade), presumably due to the stronger effects of autumn frosts on the leaves of herbs. Interestingly, the timing of fruiting in all four growth forms advanced at similar paces, from 1.4 days/decade in shrubs to 1.7 days/decade in trees and herbs. Our findings point to a strong, yet heterogeneous, response of Siberian plant phenology to recent global warming. Furthermore, the results highlight that species‐ and growth form‐specific differences among study species could be used to identify plants particularly at risk of decline due to their low adaptive capacity or a loss of synchronization with important interaction partners.
Siberia has undergone dramatic climatic changes due to global warming in recent decades. Yet, the ecological responses to these climatic changes are still poorly understood due to a lack of data. Using a large data set of phenological records (>15,000 observations) collected at the Barguzin Nature Reserve in Siberia, we analysed long‐term (1976–2018) phenological shifts in leaf out, flowering, fruiting and senescence of 67 common Siberian plant species. We find a strong, yet heterogeneous, response of Siberian plant phenology to recent global warming, which can be partly explained by the plants' growth forms
Temperate understory plant species are at risk from climate change and anthropogenic threats that include increased deer herbivory, habitat loss, pollinator declines and mismatch, and nutrient ...pollution. Recent work suggests that spring ephemeral wildflowers may be at additional risk due to phenological mismatch with deciduous canopy trees. The study of this dynamic, commonly referred to as "phenological escape", and its sensitivity to spring temperature is limited to eastern North America. Here, we use herbarium specimens to show that phenological sensitivity to spring temperature is remarkably conserved for understory wildflowers across North America, Europe, and Asia, but that canopy trees in North America are significantly more sensitive to spring temperature compared to in Asia and Europe. We predict that advancing tree phenology will lead to decreasing spring light windows in North America while spring light windows will be maintained or even increase in Asia and Europe in response to projected climate warming.
abstract
Ecologists are increasingly combining historical observations made by naturalists with modern observations to detect the ecological effects of climate change. This use of historical ...observations raises the following question: How do we know that historical data are appropriate to use to answer current ecological questions? In the present article, we address this question for environmental philosopher Henry David Thoreau, author of Walden. Should we trust his observations? We qualitatively and quantitatively evaluate Thoreau's observations using a three-step framework: We assess the rigor, accuracy, and utility of his observations to investigate changes in plants and animals over time. We conclude that Thoreau was an accurate observer of nature and a reliable scientist. More importantly, we describe how this simple three-step approach could be used to assess the accuracy of other scientists and naturalists.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
5.
Generating ecological insights from historical data Primack, Richard B; Miller, Tara K; Miller‐Rushing, Abraham J
Frontiers in ecology and the environment,
June 2023, 2023-06-00, 20230601, Letnik:
21, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Ecologists worldwide are searching for historical datasets that can provide insight into how ecosystems and species are responding to climate change, often with a focus on changes in species' ...phenology, distribution, and abundance. Once confined to libraries, museums, attics, and overlooked file cabinets, physical or offline records are increasingly being digitized, made available online, and used by ecologists in innovative ways. In many cases, these records provide detailed descriptions of changes that occurred in particular places. Resurveying the records of ecologist Joseph Grinnell from the Sierra Nevada Mountains is yielding information about bird species' range shifts and helping to identify climate-change refugia. Revisiting amateur naturalist David Bertelsen's observations of the Santa Catalina Mountains has generated insights into community-level changes in phenology in an arid ecosystem. Likewise, our own work with the records of the environmental philosopher Henry David Thoreau, and less well-known naturalists like Alfred Hosmer, from Concord, Massachusetts, has provided evidence of changes in phenology and abundance in plant communities and across trophic levels.
Deciduous trees, shrubs and forest wildflowers may be advancing their leaf‐out phenology at different rates in response to a warming climate. A mismatch between understory and overstory phenology may ...lead to a reduction of understory light levels in the early spring, which is a critical period when many spring‐blooming wildflowers achieve highest photosynthetic rates. However, the extent of this phenomenon beyond a single site or region is largely unknown.
Using 3083 herbarium specimens collected between 1870 and 2019 across eastern North America, we assessed leaf‐out and flowering times of 10 tree species (6 native, 4 non‐native), 4 shrub species (2 native, 2 non‐native) and 7 wildflower species (6 native, 1 non‐native). We paired phenological data with historical climate data to quantify differences in phenological sensitivity to spring temperature across canopy strata, across species' geographical ranges and between native and non‐native species.
Predicted phenological mismatches between native trees and wildflowers differed across large spatial scales, with wildflower populations in warmer regions of North America more likely to be affected. Overall, native tree species leafed out 3.6 days earlier per °C spring warming, while native wildflower species advanced their flowering times by 3.2 days per °C, resulting in phenological mismatch as wildflowers experience fewer days before tree leaf‐out at warmer temperatures. Native trees and wildflowers in the warmer, southern part of their ranges advanced their spring phenology 2 and 1.5 times faster, respectively, than those in colder, northern locations. The phenological sensitivity of non‐native plants was less variable across their ranges. Non‐native trees and shrubs exhibited greater phenological sensitivity than native wildflowers. Notably, phenological sensitivities differed substantially among wildflower species, suggesting that certain species are more likely to be affected by phenological mismatch as climate warming progresses.
Synthesis: Our results provide new insight into novel phenological responses within and among species across a wide geographical range and the potential impact of competition and interactions with non‐native invasive species. This research highlights the value of newly‐available digitized museum collections in phenological research to cover longer time periods, wider spatial areas and a greater diversity of species than otherwise possible.
Our results provide new insight into phenological responses within and among species across a wide geographical range and the potential impact of competition and interactions with non‐native invasive species. This research highlights the value of newly‐available digitized museum collections in phenological research to cover longer time periods, wider spatial areas and a greater diversity of species than otherwise possible.
Fruiting remains under-represented in long-term phenology records, relative to leaf and flower phenology. Herbarium specimens and historical field notes can fill this gap, but selecting and ...synthesizing these records for modern-day comparison requires an understanding of whether different historical data sources contain similar information, and whether similar, but not equivalent, fruiting metrics are comparable with one another.
For 67 fleshy-fruited plant species, we compared observations of fruiting phenology made by Henry David Thoreau in Concord, Massachusetts (1850s), with phenology data gathered from herbarium specimens collected across New England (mid-1800s to 2000s). To identify whether fruiting times and the order of fruiting among species are similar between datasets, we compared dates of first, peak and last observed fruiting (recorded by Thoreau), and earliest, mean and latest specimen (collected from herbarium records), as well as fruiting durations.
On average, earliest herbarium specimen dates were earlier than first fruiting dates observed by Thoreau; mean specimen dates were similar to Thoreau's peak fruiting dates; latest specimen dates were later than Thoreau's last fruiting dates; and durations of fruiting captured by herbarium specimens were longer than durations of fruiting observed by Thoreau. All metrics of fruiting phenology except duration were significantly, positively correlated within (r: 0.69-0.88) and between (r: 0.59-0.85) datasets.
Strong correlations in fruiting phenology between Thoreau's observations and data from herbaria suggest that field and herbarium methods capture similar broad-scale phenological information, including relative fruiting times among plant species in New England. Differences in the timing of first, last and duration of fruiting suggest that historical datasets collected with different methods, scales and metrics may not be comparable when exact timing is important. Researchers should strongly consider matching methodology when selecting historical records of fruiting phenology for present-day comparisons.
Questions
Which environmental variables are most important in determining plant species composition in subarctic springs? Do observed patterns differ between typical wetland and general ...matrix‐derived species?
Location
Helocrenic (seepage) springs, Northern Norway.
Methods
We sampled 49 helocrenic spring sites, measuring environmental variables (water temperature, water pH, electrical conductivity, discharge volume, geographic position) and recording all species present. We performed a partial canonical correspondence analysis (pCCA) to determine the relative importance of water quality, spatial, and climatic variables for patterns in species composition and to compare the differences in these patterns between wetland and matrix‐derived species.
Results
We found that climatic and water quality variables were almost equally important in determining species composition in subarctic springs, with climatic variables explaining 26.62% of variation in species composition and water quality variables explaining 26.14%. Spatial variables explained the least variation (21.53%). When looking at the variables individually, altitude (10.93%) and mean summer temperature (9.25%) explained the most variation. The trend was the same for matrix‐derived species and wetland species, with climatic variables explaining the most variation (matrix‐derived: 27.26%; wetland: 24.42%), followed by water quality (matrix‐derived: 26.40%; wetland: 24.13%) and spatial variables (matrix‐derived: 24.87%; wetland: 16.27%). The main difference between matrix‐derived species and typical wetland species was that the spatial variables explained less variation for wetland species.
Conclusions
The close relationship of species composition (total vegetation as well as separated into wetland and matrix‐derived species) with climatic and water quality conditions indicates a sensitivity of subarctic springs to future climate change. In combination with altitude, which was found to be the most important individual variable, it is likely that the future distribution of spring species tracking climate change will be limited by the occurrence of suitable spring habitats, especially at high altitudes.
We studied the influence of climatic, water quality, and spatial variables on plant species composition in subarctic springs in northern Norway, examining both general matrix‐derived and typical wetland species. It is likely that the future distribution of spring species tracking climate change will be limited by suitable spring habitats, especially at high altitudes.
Recent evidence suggests that community science and herbarium datasets yield similar estimates of species' phenological sensitivities to temperature. Despite this, two recent studies by Alecrim ...et al. (2023) and Miller et al. (2022) found very different results when using different data sources (community science and herbarium specimens, respectively) to investigate whether warming threatens wildflowers with phenological mismatch in relation to shading by deciduous trees.
Here, we investigated whether differences between the two studies' results could be reconciled by testing four hypotheses related to model design, species, spatiotemporal data extent and phenophase.
Hybrid model structures brought results from the two datasets closer together but did not fully reconcile the differences between the studies. Neither the species nor the phenophase selected for analysis seemed to be responsible for differences in results. Cropping the datasets to match spatial and temporal extents appeared to reconcile most differences but only at the cost of much higher uncertainty associated with reduced sample size.
Synthesis: Our analysis suggests that although species‐level estimates of phenological sensitivity may be similar between community science and herbarium datasets, inherent differences in the types and extent of data may lead to contradictory inference about complex biotic interactions. We conclude that, until community science data repositories expand to match the range of climate conditions present in herbarium collections or until herbarium collections match the spatial extent and temporal frequency of community science repositories, ecological studies should ideally be evaluated using both datasets to test the possibility of biased results from either.
Résumé
Des preuves récentes suggèrent que les ensembles de données de la science communautaire et des herbiers produisent des estimations similaires des sensibilités phénologiques des espèces à la température. Malgré cela, deux études récentes menées par Alecrim et al. (2023) et Miller et al. (2022) ont obtenu des résultats très différents en utilisant des sources de données différentes (science communautaire et spécimens d'herbier, respectivement) pour déterminer si le réchauffement menace les fleurs sauvages avec un décalage phénologique par rapport à l'ombrage des arbres à feuilles caduques.
Ici, nous avons cherché à savoir si les différences entre les résultats des deux études pouvaient être conciliées en testant quatre hypothèses liées à la conception du modèle, aux espèces, à l'étendue spatio‐temporelle des données et à la phénophase.
Les structures de modèles hybrides ont rapproché les résultats des deux ensembles de données, mais n'ont pas permis de réconcilier complètement les différences entre les études. Ni les espèces ni la phénophase sélectionnées pour l'analyse ne semblent être responsables des différences de résultats. Le recadrage des ensembles de données pour faire correspondre les étendues spatiales et temporelles a semblé concilier la plupart des différences, mais seulement au prix d'une incertitude beaucoup plus élevée associée à la taille réduite de l'échantillon.
Synthèse : Notre analyse suggère que, bien que les estimations de la sensibilité phénologique au niveau des espèces puissent être similaires entre les ensembles de données de la science communautaire et des herbiers, les différences inhérentes aux types et à l'étendue des données peuvent conduire à des déductions contradictoires sur des interactions biotiques complexes. Nous concluons que, jusqu'à ce que les banques de données de la science communautaire s'étendent pour correspondre à la gamme des conditions climatiques présentes dans les collections d'herbiers ou jusqu'à ce que les collections d'herbiers correspondent à l'étendue spatiale et à la fréquence temporelle des dépôts de données de la science communautaire, les études écologiques devraient idéalement être évaluées en utilisant les deux ensembles de données pour tester la possibilité de résultats biaisés de l'un ou de l'autre.
This analysis suggests that although species‐level estimates of phenological sensitivity may be similar between community science and herbarium datasets, inherent differences in the types and extent of data may lead to contradictory inference about complex biotic interactions. The authors conclude that, until community science data repositories expand to match the range of climate conditions present in herbarium collections or until herbarium collections match the spatial extent and temporal frequency of community science repositories, ecological studies should ideally be evaluated using both datasets to test the possibility of biased results from either.
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