Electronic Supporting Material

Supporting Methods

We collated data from peer-reviewed literature on microhabitat and macrohabitat temperatures

from the Earth’s tropical regions. We used the following search term to locate articles: habitat

type (i.e., tropical rainforest, forest, savanna) and microhabitat* and buffer* and ambient* and

temperature* and climate* in ISI Web of Science and Google Scholar. We used all studies that

sampled both microhabitat (e.g., within or under a fall tree trunk) and ambient temperatures

adjacent to the microhabitat (hereafter referred to as macro habitat). In total, we reviewed 36

studies from 1957 to 2013 from 25 countries. Of these studies, fourteen were from Central

America and South America, seven were from Southeast Asia, four were Australian, one

Oceanian, and nine were from Africa.

For each study we recorded the mean, standard deviation and variance in temperatures for

both microhabitats and macrohabitat. If graphs were provided instead of summary statistics, we

used the graph digitizing software Digitizeit (http://www.digitizeit.de) to extract temperature

data from the graphs (See Supporting methods for more details). DigitizeIt works by defining

each axes system and scaling the axes to relevant and correct values. We then digitized each

figure by manually extracting raw data along each curve. We only chose papers that had a paired

design (micro : macro habitat temperatures). Due to high variability in figure types and formats,

adopting a standardized means for extracting data was not possible. Instead, we ensured that our

data extractions were comparable between microhabitats and paired macrohabitat samples within

each study.

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Table S1. A list of 36 studies used for reviewing microhabitat buffering across the tropics (in

order by date). See corresponding reference list below. Mean temperature and maximum

temperature columns indicate whether authors considered mean and/or maximum temperatures

in their study.

Study Number Study Province

MeanTemp

.Maximum

Temp.1 Chang 1957 Indomalayan X2 Denslow 1980 (Shultz 1960, therein) Neotropical X3 Denslow 1980 (Grubb and Whitmore 1966, therein) Neotropical X4 Denslow 1980 (Lawson et al 1970, therein) Afrotropical X5 Hopkins and Jenkin Afrotropical6 Lawson et al Afrotropical X7 Johansson 1974 (Cachan 1963, therein) Afrotropical X8 Johansson 1974 (Evans 1939, therein) Afrotropical X9 Feder 1982 Neotropical X

10 Fetcher et al 1985 Neotropical X11 Belsky et al 1989 Afrotropical X12 Navas 1996 Neotropical X13 Jose et al 1996 Indomalayan X14 Korb and Linsenmair 1998 Afrotropical X15 Vitt et al 1998 Neotropical X16 Yanoviak 1999 Neotropical X17 Sluiter and Smit 1999 Neotropical X18 Arunachalam and Arunachalam 2000 Indomalayan X19 Freiberg 2001 Neotropical X X20 Seebacher and Alford 2002 Australian X21 Stuntz et al 2002 Neotropical X22 Chacko and Renuka 2002 Indomalayan X23 Daussmann et al 2004 Afrotropical X X24 Asbjornsen et al 2004 Neotropical X25 Cardelus and Chazdon 2005 Neotropical X26 Akpo et al 2005 Afrotropical X27 Turner and Foster 2006 Indomalayan X28 Isaac et al 2008 Australian X X29 Brower et al 2009 Neotropical X X30 Sporn et al 2010 Indomalayan X X31 Shoo et al 2010 Australian X X32 Mlambo and Mwenje 2010 Afrotropical X33 Charruau and Hénaut 2012 Neotropical X

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34 Ibanez et al 2012 Oceanian X35 Scheffers et al 2013 Indomalayan X36 Ewers and Banks-Leite 2013 Neotropical X X

*Corresponding Reference list for Table 1.

1. Chang J. 1957. World patterns of monthly soil temperature distribution. Annals of the Association of American Geographers. 47, 241-249.

2. Denslow JS. 1980. Gap partitioning among tropical rainforest trees. Biotropica 12, 47-55

3. Hopkins B, Jenkin RN. 1962. Vegetation of the Olokermeji Forest Reserve, Nigeria: I. General features of the reserve and the research sites. Journal of Ecology 50, 559-598.

4. Lawson GW, Armstrong-Mensah KO, Hall JB. 1970. A catena in tropical moist semi-deciduous forest near Kade, Ghana. Journal of Ecology 58, 371-398.

5. Johansson D. 1974. Ecology of vascular epiphytes in West African rain forest. Acta Phytogeographica Suecica 59, 1-124

6. Feder EM. 1982. Thermal ecology of neotropical lungless salamanders (Amphibia: Plethodontidae): Environmental temperatures and behavioral responses. Ecology 63, 1665-1674.

7. Fetcher N, Oberbauer SF, Strain BR. 1985. Vegetation effects on microclimate in lowland tropical forest in Costa Rica. International Journal of Biometeorology 29, 145-155

8. Belsky AJ, Amundson RG, Duxbury JM, Riha SJ, Ali AR, Mwonga SM. 1989. The effects of trees on their physical, chemical and biological environments in a Semi-arid Savanna in Kenya. Journal of Applied Ecology 26, 1005-1024.

9. Navas CA. 1996. Implications of microhabitat selection and patterns of activity on the thermal ecology of high elevation Neotropical anurans. Oecologia 108, 617-626.

10. Jose S, Gillespie AR, George SJ, Kumar BM. 1996. Vegetation responses along edge-to-inte-rior gradients in a high altitude tropical forest in peninsular India. Forest Ecology and Manage-ment 87, 51-62

11. Korb J, Linsenmair KE. 1998. The effects of temperature on the architecture and distribution of Macrotermes bellicosus (Isoptera, Macrotermitinae) mounds in different habitats of a West African Guinea savanna. Insectes Sociaux 45, 51-65.

12. Yanoviak SP. 1999. Community structure in water-filled tree holes of Panama: effects of hole height and size. Selbyana 20, 106-115

13. Sluiter R, Smit N. 1999. Gap study in mixed tropical rainforest. Guyana. 1998 MSc thesis. Dept. of Physical Geography, Utrecht University. Tropenbos Guyana-Programme, Georgetown, Guyana.

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14. Arunachalam A, Arunachalam K. 2000. Influence of gap size and soil properties on micro-bial biomass in a subtropical humid forest of north-east India. Plant and Soil 223, 185-193.

15. Vitt LJ. Avila-Pires TCS, Caldwell JP, Oliveria VRL. 1998. The impact of individual tree harvesting on thermal environments of lizards in Amazonian rain forest. Conservation Biology12, 654-664.

16. Freiberg M. 2001. The influence of epiphyte cover on branch temperature in a tropical tree. Plant Ecology 153, 241-250

17. Seebacher F, Alford RA. 2002. Shelter microhabitats determine body temperature and dehy-dration rates of a terrestrial amphibian (Bufo marinus). Journal of Herpetology 36, 69-75

18. Stuntz S, Simon U, Zotz G. 2002. Rainforest air-conditioning: the moderating influence of epiphytes on the microclimate in tropical tree crowns. International Journal of Biometeorology 46, 53-59.

19. Chacko TP, Renuka G. 2002. Temperature mapping, thermal diffusivity and subsoil heat flux at Kariavattom of Kerala. Proceedings of the Indian Academy of Science 111, 79-85

20. Dausmann KH, Glos J, Ganzhorn JU, Heldmaier G. 2004. Hibernation in a tropical primate. Nature 429, 825-826.

21. Asbjornsen H, Ashton MS, Vogt DJ, Palacios S. 2004. Effects of habitat fragmentation on the buffering capacity of edge environments in a seasonally dry tropical oak forest ecosystem in Oaxaca, Mexico. Agriculture, Ecosystems and Environment 103, 481-495.

22. Cardelús CL, Chazdon RL. 2005. Inner-crown microenvironments of two emergent tree species in a lowland wet forest. Biotropica 37, 238-244.

23. Akpo LE, Goudiaby VA, Grouzis M, Le Houerou HN. 2005. Tree shade effects on soils and environmental factors in a Savanna in Senegal. West African Journal of Applied Ecology 7, 41-52.

24. Turner E, Foster WA. 2006. Assessing the influence of Bird’s Nest Ferns (Asplenium spp.) on the local microclimate across a range of habitat disturbances in Sabah, Malaysia. Selbyana 27, 195-200.

25. Isaac JL, Vanderwal J, Johnson CN, Williams SE. 2009. Resistance and resilience: quantifying relative extinction risk at a diverse assemblage of Australian tropical rainforest vertebrates. Diversity and Distribution 15, 280-288.

26. Brower LP, Williams EH, Slayback DA, Fink LS, Ramírez MI, Zubieta RR, Garcia MIL, Gier P, Lear JA, Hook TV. 2009. Oyamel fir forest trunks provide thermal advantages for overwintering monarch butterflies in Mexico. Insect Conservation and Management 2, 163-175.

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27. Sporn SG, Bos MM, Kessler M, Gradstein SR. 2010. Vertical distribution of epiphytic bryophytes in an Indonesian rainforest. Biodiversity Conservation 19: 745-760.

28. Mlambo D, Mwenje E. 2010. Influence of Colphospermum mopane canopy cover on litter decomposition and nutrient dynamics in a semi-arid African savannah. African Journal of Ecology 48, 1021-1029.

29. Charruau P, Hénaut Y. 2012. Nest attendance and hatchling care in wild American crocodiles (Crocodylus acutus) in Quintana Roo, Mexico. Animal Biology 62, 29-51.

30. Ibanez T, Hély C, Gaucherel C. 2012. Sharp transitions in microclimate conditions between savanna and forest in New Caledonia: Insights into the vulnerability of forest edges to fire. Austral Ecology 38, 680-687.

31. Scheffers BR, Brunner RM, Ramirez SD, Shoo LP, Diesmos A, Williams SE. 2013. Thermal buffering of microhabitats is a critical factor mediating warming vulnerability of frogs in the Philippine biodiversity hotspot. Biotropica 45, 628-635

32. Ewers RM, Banks-Leite C. 2013. Fragmentation impairs the microclimate buffering effects of tropical forests. Plos ONE 8: e58093.

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Figure S1. Map of 36 study sites by biogeographical provinces and by study location. The vertical strata of a rainforest and the various microhabitats within (photos A, B, D), all collectively buffer temperature and serve as critical habitat for rainforest fauna. Logs and buttress roots of canopy trees provide ground refuges for animals (photo A) whereas large basket ferns (Drynaria spp.) (photo D) provide space and significantly reduce maximum temperatures in rainforest canopies. Some species are highly dependent on canopy microhabitats. For example, Platymantis luzonensis (photo C) is highly dependent on Asplenium bird’s nest ferns (photo B) as breeding habitat as well as diurnal thermal refuges (see main manuscript reference [19] for more information). Photos courtesy of BR Scheffers and R Brunner.

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Figure S2. Temperature buffering by microhabitats for three elevation bands (0-500 m, 500-1500 m, and > 1500 m) across the Earth’s tropical regions. Mean thermal buffering was lowest in the lowlands and relatively similar at mid and high elevations whereas thermal buffering of maximum temperatures was highest in the lowlands and decreased towards the uplands. Data below zero indicates thermal buffering (i.e., microhabitats were cooler than macrohabitat temperatures).

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Figure S3. Variance in temperature for micro and macrohabitats across three elevation bands (0-500 m (N=32), 500-1500 m (N=10), and > 1500 m (N=16)) across the Earth’s tropical regions. Variance in temperature at the microhabitat scale decreased from low to high elevations. Temperatures across elevation bands were highly variable at the macrohabitat scale.

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Figure S4. Distribution of mean temperature buffering by macrohabitats. Macrohabitat classification are: Boulder-boulder field (N=0), Conifer-conifer forest (N=2), Grass-grassland (N=5), Plantation – plantation (N=1), Shrub- shrubland (N=4), TD- tropical deciduous forest (N=6), TR- tropical rainforest (N=46), and TS- tropical savanna forest (N=9).

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Figure S5. Distribution of temperature buffering of maximum temperatures by macrohabitats. Macrohabitat classification are: Boulder-boulder field (N=4), Conifer-conifer forest (N=4), Grass-grassland (N=0), Plantation – plantation (N=0), Shrub- shrubland (N=0), TD- tropical deciduous forest (N=4), TR- tropical rainforest (N=14), and TS- tropical savanna forest (N=3).

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Figure S6. Distribution of temperature variance by macrohabitats. Macrohabitat classification are: Boulder-boulder field (N=0), Conifer-conifer forest (N=2), Grass-grassland (N=5), Plantation – plantation (N=1), Shrub- shrubland (N=4), TD- tropical deciduous forest (N=6), TR- tropical rainforest (N=32), and TS- tropical savanna forest (N=8).

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