ライフサイエンスコーパス: savanna

1 al regions) and precipitation (e.g. tropical savannas).

2 ed set of LMH exclosures in semi-arid Kenyan savanna.

3 ss an aridity gradient in a semiarid African savanna.

4 d at the landscape scale, as forest replaces savanna.

5 the West African forest and the West African savanna.

6 er than in other neotropical biomes, such as savanna.

7 alian herbivores in a semi-arid East African savanna.

8 a ants) animal species in a semi-arid Kenyan savanna.

9 (six wild, one domestic) in semiarid African savanna.

10 l dung balls along straight paths across the savanna.

11 o determine tree distributions in an African savanna.

12 and woody thickening in a warm-temperate oak savanna.

13 e rates of tree growth and canopy closure in savanna.

14 fire-free intervals, which are rare in mesic savanna.

15 more appropriate to seasonal forest than to savanna.

16 als on an ant-Acacia mutualism in an African savanna.

17 pe-scale productivity gradient in an African savanna.

18 r determining the distribution of forest and savanna.

19 precipitation variability and was largest in savannas.

20 ease two and a half times that of Australian savannas.

21 ense precipitation change, especially within savannas.

22 ill accelerate the expansion of forests into savannas.

23 n the stability of tree-grass coexistence in savannas.

24 e coexistence of woody plants and grasses in savannas.

25 erwise displacing grasses, at least in mesic savannas.

26 critical transitions between grasslands and savannas.

27 anna environments, as well as in present-day savannas.

28 tion of burned areas, in particular in xeric savannas.

29 re-adapted and sensitive fungal taxa in pine savannas.

30 ance trends over time in rural West Africa's savannas.

31 Are trees in savannas a 'slow' variable?

32 ng several tropical rainforests into derived savannas, a phenomenon known as "savannization." Yet, we

33 ed woody cover and homogenized vegetation in savannas across the planet.

34 present knowledge of diversity across other savanna-adapted species, as well as with palaeoclimate a

35 me from multiple locations across forest and savanna Africa.

36 al resolution of 56 cm throughout 1640 ha of savanna after 6-, 22-, 35-, and 41-year exclusions of he

37 dynamics in frequently burned longleaf pine savannas along a gradient of soil moisture availability

38 ons, generally decreased, both in forest and savanna, although the directionality of changes varied l

39 can be used to differentiate between forest, savanna and admixed isolates, which has not previously b

40 l variations in evaporative water use by the savanna and annual grassland were relatively decoupled f

41 ally, fire-tree cover feedbacks can maintain savanna and forest as alternative stable states.

42 the climate-carbon-fire feedback in tropical savanna and forest biomes.

43 t with fire to determine the distribution of savanna and forest by influencing the time needed to rea

44 und traits resulted in clusters representing savanna and forest species, with low and high shoot inve

45 Global change will likely affect savanna and forest structure and distributions, with imp

46 Fire shapes the distribution of savanna and forest through complex interactions involvin

47 imodal, and only fire differentiates between savanna and forest.

48 ssy ecosystem structure worldwide, such that savanna and grassland states determined by fire or grazi

49 ants were not from deep rainforests but from savanna and mixed habitats.

50 arbon dioxide exchange over and under an oak savanna and over an annual grassland in the Mediterranea

51 k (NLCB 334 Mg C km(-2) year(-1) ), and that savanna and wetland areas contributed 84% and 16% to thi

52 d pattern of woody vegetation expansion into savannas and densification within forests and savannas f

53 s, sedges, and succulents common in tropical savannas and deserts) likely represents a significant ec

54 Fire regimes in savannas and forests are changing over much of the world

55 adaptation in frequently burned areas across savannas and forests in both temperate and tropical regi

56 vity of ecosystem carbon across 180 plots in savannas and forests throughout the 2.2-million km(2) Ce

57 supported more diverse AMF communities than savannas and grassland.

58 en up by the mid-continent aridification and savannas and grasslands expanded into the interior of th

59 encroachment in both Australian and African savannas and grasslands may present similar threats to b

60 ct the spread of woody vegetation in African savannas and grasslands under future climate scenarios,

61 ween forested areas and periodically flooded savannas and grasslands.

62 010-11 carbon sink was primarily ascribed to savannas and grasslands.

63 c N(2) fixers in phosphorus-limited tropical savannas and lowland tropical forests.

64 several million years before fire-maintained savannas and probably, in different environmental condit

65 provide insights into the nature of African savannas and suggest that future changes in precipitatio

66 abundance to climate variations in tropical savannas and suggest that projected increases in rainfal

67 rresponding displacement of native woodland, savanna, and shrubland.

68 predict will be frequent in rain forest and savanna, and which represent excellent case studies of i

69 nate tropical and subtropical grasslands and savannas, and C(3) grasses dominate the world's cooler t

70 . used spatial data to show that grasslands, savannas, and forests represent opposing stable states.

71 y hotspot comprised of dry forests, woodland savannas, and grasslands.

72 tning strikes were more frequent in forests, savannas, and urban areas than in grasslands, shrublands

73 al model with two components: (1) forest and savanna are alternative stable states, maintained by tre

74 The idea that tropical forest and savanna are alternative states is crucial to how we mana

75 Above a MAP of approximately 650 mm, savannas are 'unstable' systems in which MAP is sufficie

76 Tropical savannas are a globally extensive biome prone to rapid v

77 hment over the next century and that African savannas are at high risk of widespread vegetation chang

78 Tree clusters in savannas are commonly found in sizes that follow power l

79 Savannas are globally important ecosystems of great sign

80 lusions 55 Acknowledgements 55 References 56 Savannas are highly variable systems, and predicting var

81 lly vulnerable, whereas seasonal forests and savannas are more robust.

82 Dimensions of tree root systems in savannas are poorly understood, despite being essential

83 e range of environmental conditions in which savannas are stable are still lacking.

84 e range of environmental conditions in which savannas are stable.

85 A large fraction of the world grasslands and savannas are undergoing a rapid shift from herbaceous to

86 African savannas are undergoing management intensification, and

87 s biodiversity hotspot shows that forest and savanna area both declined, by 74% (2.8 million ha) and

88 carbon-diversity trade-offs on the amount of savanna area remaining requires land managers to careful

89 es in seasonal floodplains in Bolivia's Beni savannas as vestiges of pre-European earthen fish weirs,

90 eastern African australopith diet to include savanna-based foods represents a shift to use of plant f

91 ist and that by about 1.8 million years ago, savanna-based foods such as grasses or sedges or animals

92 initial tropical or subtropical expansion of savanna between 10 and 15 Ma, which then extended to hig

93 rica and between the West African forest and savanna bioclimes, with evidence of unidirectional gene

94 use in the context of climate-driven forest-savanna biome shifts through the mid-to-late Holocene.

95 Forest and savanna biomes dominate the tropics, yet factors control

96 oss the Rainforest, Succulent, Temperate and Savanna Biomes.

97 ates of the origin and latitudinal spread of savannas broadly correspond with isotopic age estimates

98 Recurrent backcrossing of female hybrids to savanna bulls replaced the forest nuclear genome.

99 se results show that climatic impacts on dry-savanna burning are heterogeneous through time, with imp

100 middle Holocene, the relative importance of savanna burning in the region varied primarily in respon

101 Savanna burning shifted the catchment to a net C source

102 ial native vegetation (forest, grassland, or savanna) but strongly dependent on the characteristics o

103 the distributions of tropical woodlands and savannas, but our understanding of these processes is li

104 Herbivores cause treefalls in African savannas, but rates are unknown at large scales required

105 ack understanding of how cyclic fire affects savanna carbon dynamics.

106 The discovery that savanna chimpanzees use tools to obtain USOs contradicts

107 Determining whether savanna chimpanzees, who face much more extreme environm

108 Here, we show that savanna chimpanzees, who live in ecologically marginal h

109 mary agent of treefall across widely varying savanna conditions, and a large-scale 'elephant trap' pr

110 ive data of tree distributions in an African savanna, derived from airborne Light Detection and Rangi

111 riving forest expansion and densification of savannas directly (i.e., increasing precipitation) and i

112 We identified forest:savanna-discriminatory genomic regions and report a set

113 developed a long-term analysis of forest and savanna distribution across the Amazon-Cerrado transitio

114 Resolving the drivers of forest and savanna distribution has moved beyond simple correlative

115 herbarium records, we mapped the forest and savanna distributions across Africa and quantified their

116 arpest trade-offs between carbon storage and savanna diversity occurred at the early stages of carbon

117 Juniperus virginiana was the only savanna dominant in which neither survival nor final abo

118 expanse of presumed anthropogenic grassland savanna, dominated by the Family Poaceae, that blankets

119 our clusters representing dry savanna, humid savanna, dry forest and moist forest, characterized by a

120 structure of AMF communities in grasslands, savannas, dry forests and miombo in a protected area und

121 erestimate the bistability of grasslands and savannas due to limitations of substituting space for ti

122 biome distributions, whether at the cost of savanna (due to fragmentation) or forest (due to climate

123 The role of savannas during the course of early human evolution has

124 e distribution of 349 species of forest- and savanna-dwelling mammal species across South America.

125 (i.e., prior to human disturbance) of forest-savanna dynamics.

126 ntral Asia (16%) and decline in many African savannas (e.g., -18% in sub-Saharan western Africa).

127 transect largely contained within the Sudan-Savanna ecoclimatic zone, we analyzed chromosomal invers

128 itude and direction of changes in forest and savanna ecosystem cover.

129 perimentally excluding large wildlife from a savanna ecosystem in East Africa, and examining changes

130 iving in a temporally and spatially variable savanna ecosystem, I found that variance in reproductive

131 beest, zebra and buffalo-dominant species in savanna ecosystems - to be replaced by smaller, less wat

132 Tree cover in savanna ecosystems is usually regarded as unstable, vary

133 suggest that although woody encroachment in savanna ecosystems may provide substantial carbon benefi

134 Fire regulates the structure and function of savanna ecosystems, yet we lack understanding of how cyc

135 play in driving tree growth and survival in savannas, ecosystems of global economic and ecological i

136 Male African savanna elephants (Loxodona africana) provide a telling

137 African forest and savanna elephants are distinct species separated by a hy

138 was not consequent to regional decimation of savanna elephants for their ivory in the 19(th) and 20(t

139 Contrastingly to savanna elephants, forest elephants' impact on ecosystem

140 er, we show that the ivory was entirely from savanna elephants, most probably originating from a narr

141 s deep genetic separation between forest and savanna elephants.

142 Within African savannas, elephants often damage individual trees to the

143 y encroachment may reduce plant diversity of savanna endemics, even as the diversity of encroaching f

144 n expansion and fragmentation in the African savanna environment, similar to the processes that acted

145 t of woody plant species adapted to the open savanna environment.

146 lumbian tropical forest and Central American savanna environments, as well as in present-day savannas

147 Meanwhile, savannas, especially where they immediately bordered for

148 s low-resource sites are likely to remain as savanna even if fire is infrequent.

149 Our findings suggest that herbivore-adapted savannas evolved several million years before fire-maint

150 Tree abundance in tropical savannas exhibits large and unexplained spatial variabil

151 ether mammals could also have contributed to savanna expansion by using spinescence as a marker of ma

152 on and reignite the debate on the drivers of savanna expansion.

153 A savanna fire analysis identified fire frequencies of 3-4

154 principal sources of disturbance in African savannas, fire and elephants, and measured their indepen

155 Savannas first began to spread across Africa during the

156 avannas and densification within forests and savannas for at least the past ~1,600 years.

157 These parallel savanna-forest alternate states, which likewise have myr

158 Fire spread in savanna-forest mosaics is not as deterministic as often

159 e wet-dry transition season and northward to savanna-forest transition and tropical seasonal forest r

160 s structure alone cannot separate out wetter savannas from drier forests for example, and there are a

161 ws litter decomposition, thereby influencing savanna fuel dynamics.

162 netic and functional--in C4-dominanted mesic savanna grassland sites with similar structure and physi

163 es of up to ca. 20-30% were simulated within savanna, grassland, and shrubland vegetation types.

164 ion density in places previously occupied by savanna-grassland mosaics) favouring some species at the

165 rbon and nitrogen losses were substantial in savanna grasslands and broadleaf forests, but not in tem

166 e carbon sink capacity of frequently burning savanna grasslands and broadleaf forests.

167 Here we analyse data from 48 sites in savanna grasslands, broadleaf forests and needleleaf for

168 In the context of the expansion of savanna grasslands, our results represent a resource-ric

169 changes in soil carbon, especially in drier savanna grasslands.

170 sponses to altered fire regimes in two mesic savanna grasslands.

171 elevations, and considered afforestation of savannas, grasslands, and shrublands to be restoration.

172 an additional tool for dating the spread of savanna habitat.

173 ositively associated with living in semiarid savanna habitats and with temporal variability in rainfa

174 Savanna habitats are not only highly seasonal, but also

175 the management of biodiversity and carbon in savanna habitats, but has rarely been evaluated empirica

176 roles in the initial hominin colonization of savanna habitats, the development of the distinctive sku

177 frican forest elephants currently range into savanna habitats;(11-13) our findings suggest that this

178 rge herbivores (ungulates) in grasslands and savannas has fascinated ecologists for decades.

179 articularly in the vast deserts and tropical savannas) has been in areas that are remote from human p

180 When accounting for land use, African savannas have a mean rate annual woody cover increase tw

181 Earth's ancient grasslands and savannas-hereafter old-growth grasslands-have long been

182 In savannas, however, the situation is more complex.

183 s resulted in four clusters representing dry savanna, humid savanna, dry forest and moist forest, cha

184 Though controversial, the savanna hypothesis continues to motivate research into t

185 Our results are consistent with the savanna hypothesis of early hominin evolution and reigni

186 Climate is clearly important, but extensive savannas in some high rainfall areas suggest a decouplin

187 ion by the ants stabilizes tree cover across savannas in what is otherwise a highly dynamic biome.

188 nderpin a variety of ecological processes in savannas, including responses to climate change.

189 condary contact with its close relative--the savanna-inhabiting Silver-backed Butcherbird--whose cont

190 of elephants, tree encroachment may convert savannas into closed-canopy woodlands; when elephants in

191 intensified browsing pressure can transform savannas into open grasslands.

192 e coexistence of woody plants and grasses in savannas is determined by a complex set of interacting f

193 haping ecosystems, especially grasslands and savannas, it is important to understand its broader impa

194 tives on an emerging alternative approach to savanna land use and conservation that can help reduce c

195 t the inhabitants exploited a naturally open savanna landscape that they maintained around their sett

196 uctural diversity of vegetation across large savanna landscapes.

197 ons of cooperatively breeding vertebrates in savanna-like habitats and other temporally variable envi

198 al habitat, clustered open and closed areas (savanna-like), where the advantage of planning peaks.

199 ican forest (Loxodonta cyclotis) rather than savanna (Loxodonta africana) elephants.

200 of hybridization between forest females and savanna males, which are larger and reproductively domin

201 at pre-Columbian farmers practiced fire-free savanna management calls into question the widely held a

202 In the dry tropics, including African savannas, many trees grow new leaves during the dry seas

203 The access of groundwater by the oak savanna may make these ecosystems more robust in a warme

204 These arid and semi-arid savannas may be considered 'stable' systems in which wat

205 rest extensions into the Arctic and semiarid savannas; more frequent wildfire in Amazonia, the far no

206 bility, the other in the northern rainforest-savanna mosaic, with species of greater hunting potentia

207 Savanna must become an explicit policy priority in the f

208 Of studies done in Amazonian savannas, none has the temporal resolution needed to det

209 Although grassland and savanna occupy only a quarter of the world's vegetation,

210 nutrient-rich soils, whereas fire-maintained savannas occur in wetter climates on nutrient-poor soils

211 l data indicate that fire in the dry lowland savanna of southeastern Kenya was not fuel-limited durin

212 ss (Schizachyrium scoparium) in southern oak savanna of the United States were evaluated under four c

213 Fires burning the vast grasslands and savannas of Africa significantly influence the global ca

214 ls on fire occurrence in the grass-dominated savannas of eastern equatorial Africa.

215 ted to rocky habitats within the Neotropical savannas of eastern South America.

216 at extensive fires in the seasonally flooded savannas of French Guiana are a post-Columbian phenomeno

217 sing most rapidly in the remaining uncleared savannas of South America, most likely due to fire suppr

218 ology is ubiquitous across the woodlands and savannas of southern tropical Africa.

219 Forest Code governs the fate of forests and savannas on Brazil's 394 Mha of privately owned lands.

220 Converting rainforests, peatlands, savannas, or grasslands to produce food crop-based biofu

221 r the range of rainfall observed in semiarid savannas; patterns of soil moisture display islands whos

222 forces reconsideration of how pre-Columbian savanna peoples practiced raised-field agriculture and h

223 In savannas, predicting how vegetation varies is a longstan

224 In contrast, 38% of Malagasy savanna primates will experience less pronounced warming

225 me are frequent and that biome shifts to the Savanna, Rainforest and Temperate Biomes are infrequent

226 iomass burning associated with pre-A.D. 1492 savanna raised-field agriculture and a sharp increase in

227 Are trees in savannas really more heterogeneous?

228 s across Africa, that maximum woody cover in savannas receiving a mean annual precipitation (MAP) of

229 The savanna region underneath the Sahel in West Africa appea

230 ropical America, especially in the Brazilian Savanna region.

231 0% for certain latitudinal bands, and 17% in savanna regions.

232 We find the strongest impacts of fire in savanna regions.

233 ver, pre-Columbian human impact in Amazonian savannas remains poorly understood.

234 s, even in disturbance-dependent biomes like savanna, remains poorly understood.

235 nteract to determine vegetation structure in savannas represents a challenge.

236 raits should be a priority for understanding savanna responses to changing climate and disturbances.

237 stand how vegetation structure in an African savanna shaped the perceived predation risk of small mam

238 - and branch-level data harvested from three savanna sites across a rainfall gradient in Mali, West A

239 ts gathered for a large number of forest and savanna sites distributed across the continent.

240 sing field observations from several African savanna sites.

241 Are trees in savannas spatially patterned?

242 ed us to classify tree species as forest vs. savanna specialists, with some generalist species that s

243 We found that the distribution of savanna species is likely to increase by 11%-30% and spr

244 of forest encroachment, and beyond a point, savanna species losses outpace forest species gains with

245 Furthermore, the loss of savanna species quickens in the final stages of forest e

246 merica will be increasingly replaced by open savanna species, a phenomenon we name "faunal savannizat

247 celerate the transition between a forest and savanna state.

248 int, that separates regions where forest and savanna states are naturally selected.

249 on which of these are the primary drivers of savanna structure.

250 National Park, Zimbabwe, a semi-arid African savanna structured by artificial waterholes.

251 milarly high lightning frequency in tropical savannas suggests that lightning also influences savanna

252 irm extensive climatic overlap of forest and savanna, supporting the alternative stable states hypoth

253 hed quickly, increasing the probability that savanna switches to forest, whereas low-resource sites a

254 In a Kenyan savanna system, replicate plots dominated by the tree Ac

255 metric Similarity, and Stress Similarity) in savanna systems.

256 rest environments and into tropical woodland/savanna systems.

257 logical record from a French Guianan coastal savanna that forces reconsideration of how pre-Columbian

258 een mosaic, consisting of a matrix of wooded savanna that formed a transitional zone between the extr

259 tent with scenarios of hominin adaptation to savannas, these data come from Ugalla (Tanzania), one of

260 e will differentially alter the structure of savannas through hydrological changes to the seasonally

261 th evidence of unidirectional gene flow from savanna to forest strains.

262 h fire exclusion often causing a switch from savanna to forest.

263 e African vegetation types, varying from dry savanna to moist forest, in a glasshouse for 6 months, a

264 ed tree rooting patterns in Southern African savannas to ask: how tree rooting strategies affected sp

265 gh the process of hydraulic lift could allow savannas to persist stably in mesic regions that would o

266 We use the rainforest-savanna transition region in Brazil to show differences

267 ate assemblages in ecotone regions of forest-savanna transitions from South America will be increasin

268 nnas suggests that lightning also influences savanna tree mortality rates and ecosystem processes.

269 Savanna tree-grass interactions may be particularly sens

270 nal Park, South Africa, to assess sources of savanna treefall across nested gradients of climate, top

271 raits influence both thresholds; saplings of savanna trees accumulate bark thickness more quickly tha

272 We hypothesize savanna trees have greater length-scaling exponents than

273 lephant trap' predominantly removes maturing savanna trees in the 5-9 m height range.

274 trees accumulate leaf area more rapidly than savanna trees, thereby accelerating the transition to fo

275 Here, using the evolutionary ages of African savanna trees, we suggest an initial tropical or subtrop

276 pth systematically structures the ecology of savanna trees.

277 f all sampled profiles) were associated with savannas under dry conditions.

278 the trajectory of juniper encroachment into savannas, under these anticipated climatic conditions.

279 nt in the southeastern region where tropical savannas undergo long seasonally dry periods.

280 contribute to a predictive understanding of savanna vegetation heterogeneity.

281 sturbances to identify what determines local savanna vegetation heterogeneity.

282 Savanna vegetation is variable, and predicting how water

283 Savanna vegetation structure was reasonably predictable,

284 ess for impala escaping from cheetah in open savanna versus acacia thicket habitat, though escape suc

285 Area of converted Cerrado savannas was nearly 2.5 times that of Amazon forests, an

286 mine climate-vegetation-fire linkages in dry savanna, we conducted macroscopic and microscopic charco

287 In a pine savanna, we established patches near and away from pines

288 ed in 83 different locations for forests and savannas, we developed interpolation maps to assess the

289 the human footprint, and proximity to woody savanna were each strongly associated with HeV spillover

290 , 6 domesticated) in a semiarid East African savanna, which enabled high-resolution assessment of sea

291 Pyrogenic savannas with a tree-grassland 'matrix' experience frequ

292 Spiny savannas with abundant mammal herbivores occur in drier

293 African savannas with extensive versus minimal woody cover often

294 hat is commonly referred to as tree- or bush-savanna, with 25% or less woody canopy cover.

295 ved in a river-margin forest in an otherwise savanna (wooded grassland) landscape at Aramis, Ethiopia

296 the two main landscape components, that is, savanna woodland and seasonal wetlands.

297 n basin, in the Paraguayan Chaco, and in the savanna woodlands of the Sahel and East Africa).

298 s expected, but that the richness of endemic savanna woody plant species declines with carbon storage

299 Via a meta-analysis, we quantified savanna woody vegetation change spanning the last centur

300 -deciduous (SDF), dry forests (DF) and woody savanna (WS), we find that (i) climate is more closely r