Large-Scale Controls on the Leaf Economic Spectrum of the Overstory Tree Species <i>Metrosideros polymorpha</i>
The role of intraspecific trait variation in functional ecology has gained traction in recent years as many papers have observed its importance in driving community diversity and ecology. Yet much of the work in this field relies on field-based trait surveys. Here, we used continuous canopy trait in...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-09-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/15/19/4707 |
| _version_ | 1797575223320510464 |
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| author | Megan M. Seeley Gregory P. Asner |
| author_facet | Megan M. Seeley Gregory P. Asner |
| author_sort | Megan M. Seeley |
| collection | DOAJ |
| description | The role of intraspecific trait variation in functional ecology has gained traction in recent years as many papers have observed its importance in driving community diversity and ecology. Yet much of the work in this field relies on field-based trait surveys. Here, we used continuous canopy trait information derived from remote sensing data of a highly polymorphic tree species, <i>Metrosideros polymorpha</i>, to quantify environmental controls on intraspecific trait variation. <i>M. polymorpha</i>, an endemic, keystone tree species in Hawai’i, varies morphologically, chemically, and genetically across broad elevation and soil substrate age gradients, making it an ideal model organism to explore large-scale environmental drivers of intraspecific trait variation. <i>M. polymorpha</i> canopy reflectance (visible to shortwave infrared; 380–2510 nm) and light detection and ranging (LiDAR) data collected by the Global Airborne Observatory were modeled to canopy trait estimates of leaf mass per area, chlorophyll a and b, carotenoids, total carbon, nitrogen, phosphorus, phenols, cellulose, and top of canopy height using previously developed leaf chemometric equations. We explored how these derived traits varied across environmental gradients by extracting elevation, slope, aspect, precipitation, and soil substrate age data at canopy locations. We then obtained the feature importance values of the environmental factors in predicting each leaf trait by training random forest models to predict leaf traits individually. Of these environmental factors, elevation was the most important predictor for all canopy traits. Elevation not only affected canopy traits directly but also indirectly by influencing the relationships between soil substrate age and canopy traits as well as between nitrogen and other traits, as indicated by the change in slope between the variables at different elevation ranges. In conclusion, intraspecific variation in <i>M. polymorpha</i> traits derived from remote sensing adheres to known leaf economic spectrum (LES) patterns as well as interspecific LES traits previously mapped using imaging spectroscopy. |
| first_indexed | 2024-03-10T21:36:42Z |
| format | Article |
| id | doaj.art-4fb41307c9074d45b599d1d0a66215b0 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-10T21:36:42Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-4fb41307c9074d45b599d1d0a66215b02023-11-19T14:58:51ZengMDPI AGRemote Sensing2072-42922023-09-011519470710.3390/rs15194707Large-Scale Controls on the Leaf Economic Spectrum of the Overstory Tree Species <i>Metrosideros polymorpha</i>Megan M. Seeley0Gregory P. Asner1Center for Global Discovery and Conservation Science, Arizona State University, Tempe, AZ 85281, USACenter for Global Discovery and Conservation Science, Arizona State University, Tempe, AZ 85281, USAThe role of intraspecific trait variation in functional ecology has gained traction in recent years as many papers have observed its importance in driving community diversity and ecology. Yet much of the work in this field relies on field-based trait surveys. Here, we used continuous canopy trait information derived from remote sensing data of a highly polymorphic tree species, <i>Metrosideros polymorpha</i>, to quantify environmental controls on intraspecific trait variation. <i>M. polymorpha</i>, an endemic, keystone tree species in Hawai’i, varies morphologically, chemically, and genetically across broad elevation and soil substrate age gradients, making it an ideal model organism to explore large-scale environmental drivers of intraspecific trait variation. <i>M. polymorpha</i> canopy reflectance (visible to shortwave infrared; 380–2510 nm) and light detection and ranging (LiDAR) data collected by the Global Airborne Observatory were modeled to canopy trait estimates of leaf mass per area, chlorophyll a and b, carotenoids, total carbon, nitrogen, phosphorus, phenols, cellulose, and top of canopy height using previously developed leaf chemometric equations. We explored how these derived traits varied across environmental gradients by extracting elevation, slope, aspect, precipitation, and soil substrate age data at canopy locations. We then obtained the feature importance values of the environmental factors in predicting each leaf trait by training random forest models to predict leaf traits individually. Of these environmental factors, elevation was the most important predictor for all canopy traits. Elevation not only affected canopy traits directly but also indirectly by influencing the relationships between soil substrate age and canopy traits as well as between nitrogen and other traits, as indicated by the change in slope between the variables at different elevation ranges. In conclusion, intraspecific variation in <i>M. polymorpha</i> traits derived from remote sensing adheres to known leaf economic spectrum (LES) patterns as well as interspecific LES traits previously mapped using imaging spectroscopy.https://www.mdpi.com/2072-4292/15/19/4707imaging spectroscopyleaf economic spectrumintraspecific trait variation<i>Metrosideros polymorpha</i>Hawai’i |
| spellingShingle | Megan M. Seeley Gregory P. Asner Large-Scale Controls on the Leaf Economic Spectrum of the Overstory Tree Species <i>Metrosideros polymorpha</i> Remote Sensing imaging spectroscopy leaf economic spectrum intraspecific trait variation <i>Metrosideros polymorpha</i> Hawai’i |
| title | Large-Scale Controls on the Leaf Economic Spectrum of the Overstory Tree Species <i>Metrosideros polymorpha</i> |
| title_full | Large-Scale Controls on the Leaf Economic Spectrum of the Overstory Tree Species <i>Metrosideros polymorpha</i> |
| title_fullStr | Large-Scale Controls on the Leaf Economic Spectrum of the Overstory Tree Species <i>Metrosideros polymorpha</i> |
| title_full_unstemmed | Large-Scale Controls on the Leaf Economic Spectrum of the Overstory Tree Species <i>Metrosideros polymorpha</i> |
| title_short | Large-Scale Controls on the Leaf Economic Spectrum of the Overstory Tree Species <i>Metrosideros polymorpha</i> |
| title_sort | large scale controls on the leaf economic spectrum of the overstory tree species i metrosideros polymorpha i |
| topic | imaging spectroscopy leaf economic spectrum intraspecific trait variation <i>Metrosideros polymorpha</i> Hawai’i |
| url | https://www.mdpi.com/2072-4292/15/19/4707 |
| work_keys_str_mv | AT meganmseeley largescalecontrolsontheleafeconomicspectrumoftheoverstorytreespeciesimetrosiderospolymorphai AT gregorypasner largescalecontrolsontheleafeconomicspectrumoftheoverstorytreespeciesimetrosiderospolymorphai |