1
2
Electronic Supporting Material
3
4
Supporting Methods
5
We collated data from peer-reviewed literature on microhabitat and macrohabitat temperatures
6
from the Earth’s tropical regions. We used the following search term to locate articles: habitat
7
type (i.e., tropical rainforest, forest, savanna) and microhabitat* and buffer* and ambient* and
8
temperature* and climate* in ISI Web of Science and Google Scholar. We used all studies that
9
sampled both microhabitat (e.g., within or under a fall tree trunk) and ambient temperatures
10
adjacent to the microhabitat (hereafter referred to as macro habitat). In total, we reviewed 36
11
studies from 1957 to 2013 from 25 countries. Of these studies, fourteen were from Central
12
America and South America, seven were from Southeast Asia, four were Australian, one
13
Oceanian, and nine were from Africa.
14
For each study we recorded the mean, standard deviation and variance in temperatures for
15
both microhabitats and macrohabitat. If graphs were provided instead of summary statistics, we
16
used the graph digitizing software Digitizeit (http://www.digitizeit.de) to extract temperature
17
data from the graphs (See Supporting methods for more details). DigitizeIt works by defining
18
each axes system and scaling the axes to relevant and correct values. We then digitized each
19
figure by manually extracting raw data along each curve. We only chose papers that had a paired
20
design (micro : macro habitat temperatures). Due to high variability in figure types and formats,
21
adopting a standardized means for extracting data was not possible. Instead, we ensured that our
22
data extractions were comparable between microhabitats and paired macrohabitat samples within
23
each study.
24
25
Table S1. A list of 36 studies used for reviewing microhabitat buffering across the tropics (in
26
order by date). See corresponding reference list below. Mean temperature and maximum
27
temperature columns indicate whether authors considered mean and/or maximum temperatures
28
in their study.
Study
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
Mean Maximum
Province
Temp.
Temp.
Chang 1957
Indomalayan
X
Denslow 1980 (Shultz 1960, therein)
Neotropical
X
Denslow 1980 (Grubb and Whitmore 1966, therein) Neotropical
X
Denslow 1980 (Lawson et al 1970, therein)
Afrotropical
X
Hopkins and Jenkin
Afrotropical
Lawson et al
Afrotropical
X
Johansson 1974 (Cachan 1963, therein)
Afrotropical
X
Johansson 1974 (Evans 1939, therein)
Afrotropical
X
Feder 1982
Neotropical
X
Fetcher et al 1985
Neotropical
X
Belsky et al 1989
Afrotropical
X
Navas 1996
Neotropical
X
Jose et al 1996
Indomalayan
X
Korb and Linsenmair 1998
Afrotropical
X
Vitt et al 1998
Neotropical
X
Yanoviak 1999
Neotropical
X
Sluiter and Smit 1999
Neotropical
X
Arunachalam and Arunachalam 2000
Indomalayan
X
Freiberg 2001
Neotropical
X
X
Seebacher and Alford 2002
Australian
X
Stuntz et al 2002
Neotropical
X
Chacko and Renuka 2002
Indomalayan
X
Daussmann et al 2004
Afrotropical
X
X
Asbjornsen et al 2004
Neotropical
X
Cardelus and Chazdon 2005
Neotropical
X
Akpo et al 2005
Afrotropical
X
Turner and Foster 2006
Indomalayan
X
Isaac et al 2008
Australian
X
X
Brower et al 2009
Neotropical
X
X
Sporn et al 2010
Indomalayan
X
X
Shoo et al 2010
Australian
X
X
Mlambo and Mwenje 2010
Afrotropical
X
Charruau and Hénaut 2012
Neotropical
X
Study
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
34 Ibanez et al 2012
35 Scheffers et al 2013
36 Ewers and Banks-Leite 2013
*Corresponding Reference list for Table 1.
Oceanian
Indomalayan
Neotropical
X
X
X
X
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 semideciduous 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-tointerior gradients in a high altitude tropical forest in peninsular India. Forest Ecology and
Management 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.
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
14. Arunachalam A, Arunachalam K. 2000. Influence of gap size and soil properties on
microbial 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
dehydration 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, 4152.
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.
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
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.
140
141
142
143
144
145
146
147
148
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.
149
150
151
152
153
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).
154
155
156
157
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.
158
159
160
161
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).
162
163
164
165
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).
166
167
168
169
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).
170