Modelling Climate Using Leaves of Nothofagus cunninghamii—Overcoming Confounding Factors
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Species
- The species and its close relatives are found in Quaternary deposits through southeastern Australia, where paleoclimates are currently unresolved. Thus, determining the responses of N. cunninghamii to current climates can assist in hindcasting paleoclimatic conditions and understanding the species response to past climate change.
- Living Nothofagus cunninghamii occurs over a relatively large latitudinal and elevation gradient (Figure 1; elevation range = 112–1240 m), and the species has been found to be able to grow within a mean annual temperature range of 5 °C. This capacity to persist in a wide range of temperature environments makes N. cunninghamii ideal for modelling climate responses [14,15,16].
- The leaves of N. cunninghamii are evenly covered with stomata (including all veins except the mid-vein), and the stomata and epidermal cells are easily identified and counted, allowing their density to be measured relatively quickly and with accuracy. This is an important consideration, particularly when using fossil leaves for paleoclimatic reconstructions. In contrast, other species in the genus have stomata distributed in areoles that impact measures such as stomatal and epidermal cell density, especially in fragmentary fossil leaf material.
- The Cenozoic macrofossil record in eastern Australia contains many examples of leaves that appear to be intermediate in morphology between the living species N. cunninghamii and N. moorei, which is distributed further north in Australia, around the New South Wales and Queensland border [17,18]. This offers the potential to extend the range over which leaf anatomical data can be extended back into the Cenozoic.
2.2. Measurements and Field Collection
2.3. Modelling
3. Results
4. Discussion
Author Contributions
Funding
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Variable | Sun | Shade |
---|---|---|
Stomatal density (stomata mm−2) | 396 ± 1 | 281 ± 9 |
Epidermal cell density (epidermal cells mm−2) | 5788.6 ± 1255.4 | 4537.6 ± 1036.8 |
Epidermal cell area (µm2) | 197.5 ± 94.8 | 286.1 ± 142.0 |
Epidermal cell perimeter (µm) | 63.3 ± 22.7 | 86.8 ± 32.7 |
Undulation index | 1.3 ± 0.2 | 1.5 ± 0.2 |
Leaf area (mm2) | 108.6 ± 43.3 | 114.5 ± 42.2 |
Stomatal index (%) | 6.4 ± 1.4 | 5.8 ± 1.4 |
Variable | Maximum Spring Temperature (°C) | Minimum Spring Temperature (°C) | Total Summer Rainfall (mm) |
---|---|---|---|
Leaf area (mm2) | 1 | 1 | 1 |
Epidermal cell density (epidermal cells mm−2) | 0.29 | 0.31 | 0.16 |
Epidermal cell area (µm2) | 0.29 | 0.26 | 0.13 |
Stomatal index (%) | 0.20 | 0.31 | 0.21 |
Stomatal density (stomata mm−2) | 0.16 | 0.15 | 0.11 |
Sun or shade leaf | 0.14 | 0.08 | 0.32 |
Undulation index | 0.06 | 0.09 | 0.07 |
Epidermal cell perimeter (µm) | 0 | 0 | 0 |
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Hill, K.E.; Brown, S.C.; Jones, A.; Fordham, D.; Hill, R.S. Modelling Climate Using Leaves of Nothofagus cunninghamii—Overcoming Confounding Factors. Sustainability 2023, 15, 7603. https://doi.org/10.3390/su15097603
Hill KE, Brown SC, Jones A, Fordham D, Hill RS. Modelling Climate Using Leaves of Nothofagus cunninghamii—Overcoming Confounding Factors. Sustainability. 2023; 15(9):7603. https://doi.org/10.3390/su15097603
Chicago/Turabian StyleHill, Kathryn E., Stuart C. Brown, Alice Jones, Damien Fordham, and Robert S. Hill. 2023. "Modelling Climate Using Leaves of Nothofagus cunninghamii—Overcoming Confounding Factors" Sustainability 15, no. 9: 7603. https://doi.org/10.3390/su15097603
APA StyleHill, K. E., Brown, S. C., Jones, A., Fordham, D., & Hill, R. S. (2023). Modelling Climate Using Leaves of Nothofagus cunninghamii—Overcoming Confounding Factors. Sustainability, 15(9), 7603. https://doi.org/10.3390/su15097603