Patterns of ferns community assemblages in some Malaysian and Nigerian tropical forests

Research on fern ecology has gained attention in the last decade, yet there is a paucity of information on the comparison of ferns communities across continents. This study focused on comparing the ferns community assemblages in some tropical forests of Malaysia and Nigeria, thereby assessing the patterns of species richness (SR) and phylogenetic diversity (PD) in relation to the bioclimatic drivers across the continents. The diversity and taxonomic compositions of ferns were assessed using 180 plots of 10 m × 10 m in each country. The species richness and other diversity indices were determined using the combined forests data for each country and for the individual forests. Also, the phylogenetic diversity of the ferns was assessed using the genus‐based molecular sequences downloaded from the GeneBank. The patterns of the ferns SR and PD in the two countries as driven by some bioclimatic factors were evaluated using the regression analysis. The observed and rarefied–extrapolated fern species richness is significantly higher in Malaysian forests than in Nigerian forests. Also, the other diversity indices are significantly higher in Malaysian forests except for the Shannon index which showed no significant difference between the two biogeographic regions. There is a very low similarity (7.41%) in the taxonomic composition of ferns between the two biogeographic areas, although the similarity in composition increased with increasing taxonomic levels (species: 7.41%, genus: 12.77%, family: 70.96%). Terrestrial and epiphytic ferns are more dominant than the other life forms in the two countries. The precipitation variables drive the phylogenetic structure of ferns in Nigeria, whereas both precipitation and temperature variables drive the phylogenetic structure of ferns in Malaysia. This indicates that ferns assemblages in Nigeria and Malaysia are driven by both climatic variables. Besides, we also hypothesize that these observed differences could be due to other historical and evolutionary processes.     

Termite diversity in Neotropical dry forests of Colombia and the potential role of rainfall in structuring termite diversity

Termites are ecosystem engineers that play an important role in the biotransformation and re‐distribution of nutrients in soil. The dry forests are endemic repositories, but at same time, they are most threatened by extensive livestock and crop farming, fires, and climate change. In Colombia, the best‐protected dry forests are located in the north. The termite fauna of dry forests are poorly known. The aim was to identify the termite species occurring in tropical dry forests of the Colombian Caribbean coast in relation to diet and precipitation, temperature, elevation, and soil properties. A total of 32 species in 1,103 occurrences were found. Termitidae accounted for 78% of the species richness with the Anoplotermes‐group, Microcerotermes, and Nasutitermes being the dominant genera. Differences in species composition and abundance were found across sites. These differences may be linked to anthropogenic disturbance and polygyny and polydomy. Strikingly, our highest elevation site (334 m) had the highest species richness much higher than the two lower elevation sites. This implies an inversion of the common elevation‐diversity gradient, also found for termites which can be explained by increasing precipitation with elevation in the dry forest. An analysis of termite species richness at the global scale confirms that termite species richness correlates positively with rainfall. Hence, rainfall seems to positively affect termite diversity. In line, the studied Colombian tropical dry forests had low diversity compared to rain forests. A decline of species‐rich soil‐feeding termites with increasing aridity may explain why the highest termite diversity occurs in humid tropical rain forests. Abstract in Spanish is available with online material.     

Bugs beneath the surface： the functional significance of soil macroinvertebrates to landscape health in Australia＇s tropical savannas

Soil macroinvertebrates play an important role in sustaining production and biodiversity in Australia＇ s tropical savannas. For example, termites, through their foraging and nesting activities, recycle nutrients and carbon and produce soil pores that facilitate water infiltration. The challenge ahead is to quantitatively understand the relationships and processes that drive this. What roles do different species and functional groups of macroinvertebrates play in various landscape processes？ What are the effects of different land management practices （e.g., domestic cattle grazing, fire） on these relationships, and the consequences for landscape health？ This paper presents preliminary results from studies in northern Australia, that examine the effects of land condition and domestic cattle grazing on soil macroinvertebrates, and the potential for termites to be used as a tool to restore soil function in degraded areas. In northern Australia, increased degradation seems to be associated with declines in the diversity and activity of macroinvertebrates. Termites appear to be one of the most resilient groups, with some species capable of maintaining activity in degraded landscapes.     

Relationships among climate,latitude and migration: Australian butterflies are not temperate-zone birds

We examined the distribution of butterflies over the mostly arid and semi-arid continent of Australia and analyzed the proportion of migrant species and species diversity with respect to an array of climatic and geographic variables. On a continent-wide scale, latitude explained virtually no variance in either proportion of migrants (r ²=0.01) or species diversity (r ²=0.03) in Australian butterflies. These results are in marked contrast to those for temperate-zone birds from three continents where latitude explained between 82 and 98% of the variance in frequency of migrants and also accounted for much of the variance in bird species diversity. In eastern Australia where rainfall regimes are similar to those in temperate Europe and North and South America, latitude explains 78% of the variance in frequency of butterfly migrants. In both eastern and central Australia, latitude also accounts for relatively high proportions of the variance in species diversity. Rainfall patterns and especially soil moisture are negatively associated with migration frequency in Australian butterfly faunas, both alone and in combination with other climate variables. Where moisture levels are relatively high, as in eastern Australia, measures of temperature are associated with migration frequency, a result consistent with findings for temperate-zone birds, suggesting latitude is a surrogate for temperature. The ultimate causes of migration in temperate-zone birds and Australian butterflies are the uneven temporal, and in Australia also spatial, distribution of resources. Uneven distribution is brought about primarily by temperature in temperate regions and by erratic rainfall over much of arid Australia. As a key determinant of productivity, especially in the tropics and subtropics, aridity is likely to be an important determinant of the global distributions of migrants. Received: 14 July 1999 / Accepted: 12 January 2000     

Global Spread of Human Chromoblastomycosis Is Driven by Recombinant Cladophialophora carrionii and Predominantly Clonal Fonsecaea Species

Global distribution patterns of Cladophialophora carrionii, agent of human chromoblastomycosis in arid climates of Africa, Asia, Australia, Central-and South-America, were compared with similar data of the vicarious Fonsecaea spp., agents of the disease in tropical rain forests. Population diversities among 73 C. carrionii strains and 60 strains of three Fonsecaea species were analyzed for rDNA ITS, partial β-tubulin, and amplified fragment-length polymorphism (AFLP) fingerprints. Populations differed significantly between continents. Lowest haplotype diversity was found in South American populations, while African strains were the most diverse. Gene flow was noted between the African population and all other continents. The general pattern of Fonsecaea agents of chromoblastomycosis differed significantly from that of C. carrionii and revealed deeper divergence among three differentiated species with smaller numbers of haplotypes, indicating a longer evolutionary history.     

Comparative responses of termite functional and taxonomic diversity to land‐use change

1. While it is clear that land‐use change significantly impacts the taxonomic dimension of soil biodiversity, how the functional dimension responds to land‐use change is less well understood. 2. This study examined how the transformation of primary forests into rubber tree monocultures impacts individual termite species and how this change is reflected in termite taxonomic and functional α‐diversity (within site) and β‐diversity (among sites). 3. Overall, individual species responded strongly to land‐use change, whereby only 11 of the 27 species found were able to tolerate both habitats. These differences caused a 27% reduction in termite taxonomic richness and reduced taxonomic β‐diversity in rubber plantations compared with primary forests. The study also revealed that the forest conversion led to a shift in some termite species with smaller body size, shorter legs and smaller mandibular traits. Primary forests exhibited higher functional richness and functional β‐diversity of termite species, indicating that functional traits of termite species in rubber plantations are more evenly distributed. 4. The present study suggests that forest conversion does not merely decrease taxonomic diversity of termites, but also exerts functional trait filtering within some termite species. The results affirm the need for biodiversity assessments that combine taxonomic and functional indicators when monitoring the impact of land‐use change.     

Contrasting the distribution of butterflies and termites in plantations and tropical forests

In the tropics vast areas of natural forests are being converted into plantations. The magnitude of the resulting loss in arthropod biodiversity and associated ecosystem services represents a significant topic of research. In this study we contrasted the abundance, species richness and faunal turnover of butterflies, resident butterflies (i.e., whose host plants were ascertained to occur in the habitats studied) and termites between small (average 4.3 ha) 20+ year old exotic plantations (teak and Terminalia), native plantations (Cedro espino), and an old growth forest in Panama. We used Pollard walks and manual search to quantify the abundance or occurrence of butterflies and termites, respectively. In 2014 we observed 4610 butterflies representing 266 species and 108 termite encounters (out of 160 quadrats) representing 15 species. Butterflies were more abundant and diverse in plantations than in the forest, whereas this pattern was opposite for resident butterflies and termites. There was marked faunal turnover between plantations and forest. We conclude that (a) the magnitude of faunal changes between forest and plantations is less drastic for termites than for butterflies; (b) resident butterfly species are more impacted by the conversion of forest to plantations than all butterflies, including transient species; and (c) species richness does not necessarily decrease in the series forest > native > exotic plantations. Whereas there are advantages of studying more tractable taxa such as butterflies, the responses of such taxa can be highly unrepresentative of other invertebrate groups responsible for different ecological services.     

Road-associated edge effects in Amazonia change termite community composition by modifying environmental conditions

Roads and road-building are among the most important environmental impacts on forests near urban areas, but their effects on ecosystem processes and species distributions remain poorly known. Termites are the primary decomposer organisms in tropical forests and their spatial distribution is strongly affected by vegetation and soil structure. We studied the impacts of road construction on termite community structure in an Amazonian forest fragment near Manaus, Brazil. One leading question was whether the fragment under study was large enough to maintain the termite species pool present in nearby continuous forests. We also asked how soil moisture and canopy openness varied with proximity to roads, and whether these changes were associated with changes in termite species richness and composition in the fragment. While the forest fragment had a termite composition very similar to that of continuous forests, roads caused important changes in soil moisture and canopy openness, especially when close to forest edges. At distances of up to 81 m from roads, changes in soil moisture were significantly related to changes in termite species composition, but there was no correlation between canopy openness and species richness or composition. These results suggest that fragmentation caused by roads impacts termites in a different and less damaging manner than fragmentation caused by other kinds of degradation, and that even fragments bisected by roads can support very diverse communities and even undescribed taxa of termites. We conclude that a buffer zone should be established for conservation purposes in the reserves surrounded by roads.     

A statistical approach to estimate soil ciliate diversity and distribution based on data from five continents

A total of 359 soil samples collected from five continents (Africa, Asia, Australia, Europe and South America) were investigated for the presence/absence of soil ciliate species. Merging records by species identity, we have compiled a master data list (species by sample matrix). In the list, a total of 964 soil ciliate species (644 described and 320 undescribed) are recorded. The species distributions within the 359 samples and across the five continents are examined. The frequency distribution of the species over samples is used for global diversity estimation. A statistical ACE (abundance‐based coverage estimation) model which links observed data to unseen species is applied to assess regional and global soil ciliate species richness. The model, whose reliability was tested by its power to predict the number of new species in additional samples from Africa, may resolve the controversial issue on global species diversity of soil ciliates. Although an accurate point estimate is not feasible due to severe undersampling, the statistical model enables us to obtain a minimum regional diversity and global species diversity. A consistent finding over all five continents is that at least half of the species diversity is still undiscovered. Our model also yields a global soil ciliate diversity of at least 1900 species, that is, doubles the number of currently known species, and thus diversity is relatively high. This is consistent with the finding of Foissner, who used a probability‐based method. Soil ciliate distributions between continent pairs are analyzed by adjusted abundance‐based similarity/overlap indices. These new indices account for the effect of unseen species and also reduce the bias generated by undersampling. The adjusted abundance‐based Jaccard (or Sørensen) index shows that there is about 30% (18% for Sørensen) dis‐similarity between any two continents, supporting the moderate endemicity model. The results are discussed with respect to protist species distribution, that is, whether they are cosmopolitan or of restricted distribution.     

A transcontinental comparison of the diversity and composition of tropical forest understory herb assemblages

Although tropical forests are renowned for their high plant diversity, to date there has been no global quantitative evaluation of the local species richness of terrestrial forest herbs in tropical forests. In this paper, richness and composition of terrestrial herb assemblages is compared in tropical forests of America, Africa and South East Asia. We established 86 non-continuous transects of 445 m each. Herb species richness was analysed and compared to six environmental parameters using minimal adequate regression models and simultaneous autoregressive models. At the global scale, we found a close relationship between herb species richness and temperature parameters, with no differences between continents. The subdivision into three main taxonomic groups (ferns, monocots, dicots) showed that each group has distinct relations to environmental factors and differences in richness between continents. Most of the 72 families found have pantropical distributions but 12, 11, and 16 families were significantly over-represented in America, Africa, and Asia, respectively. Although total species richness was closely related to climatic factors, ferns, monocots and dicots were represented by distinct sets of families with varying species richness on each continent. Which species are found at a given site may thus reflect group-specific evolutionary and historical factors.     

5. Biogeography of desmids

Compared with other groups of unicellular freshwater algae, desmids lend themselves well to biogeographical studies since, at species level, identification is often relatively easy, whereas high ecological demands use to curtain their geographical distribution. Considering some ten desmid floral regions as distinguished in the beginning of this century, Indo-Malaysia/Northern Australia, tropical America, and equatorial Africa come to the fore as most pronounced. Also well typified are Eastern Asia, New Zealand/Southern Australia, and North America. Less endemic species are met with in Southern Africa and extratropical South America, whereas temperate Eurasia, with respect to the other continents, is mainly negatively characterized. The so-called arctic-alpine desmid flora may be encountered on all continents, provided that adequate minimum temperatures occur. Its distribution seems to be determined microclimatologically rather than macroclimatologically. Arguments for a tropical origin of the desmids as an algal group are adduced.     

Vertical stratification of the termite assemblage in a neotropical rainforest

The importance of termites as decomposers in tropical forests has long been recognized. Studies on the richness and diversity of termite species and their ecological function have flourished in more recent times, but these have been mostly conducted in a thin stratum within a standing man’s reach. Our aims were to evaluate the specific richness and composition of the termite assemblage in the canopy of a tropical rainforest and to determine its originality with respect to the sympatric ground-level fauna. We conducted systematic searches for canopy termites, together with conventional sampling of the sympatric ground-level fauna, in the San Lorenzo forest, Panama. We hypothesized that (1) the canopy accommodates two categories of wood-feeding termites (long-distance foragers and small-colony “one-piece” species) and possibly soil-feeders in suspended soil-like habitats; (2) due to the abundance of soil-feeders, the overall diversity of the ground fauna is higher than that of the canopy; (3) differences in microclimate and resource accessibility favour vertical stratification among wood-feeders. Sixty-three canopy samples yielded ten species of termites, all wood-feeders. Five of these were not found at ground level, although a total of 243 ground samples were collected, representing 29 species. In addition to long-distance foragers (Microcerotermes and Nasutitermes spp.) and small-colony termites (mostly Kalotermitidae), the canopy fauna included Termes hispaniolae, a wood-feeding Termitidae from an allegedly soil-feeding genus, living in large dead branches. Soil-feeders were absent from the canopy, probably because large epiphytes were scarce. As predicted, the ground fauna was much richer than that of the canopy, but the species richness of both habitats was similar when only wood-feeders were considered. Vertical stratification was strongly marked among wood-feeders, as all common species, apart from the arboreal-nesting Microcerotermes arboreus, could unequivocally be assigned to either a ground or a canopy group. The canopy, therefore, contributes significantly to the total species richness of the termite assemblage, and the diversity, abundance and ecological importance of canopy termites in tropical rainforests may be higher than previously recognized.Electronic Supplementary Material Supplementary material is available to authorized users in the online version of this article at .     

Epiphytic ferns and bryophytes of Tasmanian tree‐ferns: A comparison of diversity and composition between two host species

Abstract Ferns, bryophytes and lichens are the most diverse groups of plants in wet forests in south‐eastern Australia. However, management of this diversity is limited by a lack of ecological knowledge of these groups and the difficulty in identifying species for non‐experts. These problems may be alleviated by the identification and characterization of suitable proxies for this diversity. Epiphytic substrates are potential proxies. To evaluate the significance of some epiphytic substrates, fern and bryophyte assemblages on a common tree‐fern species, Dicksonia antarctica (soft tree‐fern), were compared with those on a rare species, Cyathea cunninghamii (slender tree‐fern), in eastern Tasmania, Australia. A total of 97 fern and bryophyte species were recorded on D. antarctica from 120 trunks at 10 sites, and 64 species on C. cunninghamii from 39 trunks at four of these sites. The trunks of C. cunninghamii generally supported fewer species than D. antarctica, but two mosses (particularly Hymenodon pilifer) and one liverwort showed significant associations with this host. Several other bryophytes and epiphytic ferns showed an affinity for the trunks of D. antarctica. Species assemblages differed significantly between both sites and hosts, and the differences between hosts varied significantly among sites. The exceptionally high epiphytic diversity associated with D. antarctica suggests that it plays an important ecological role in Tasmanian forests. Evidently C. cunninghamii also supports a diverse suite of epiphytes, including at least one specialist species.     

Termite Diversity along an Amazon–Andes Elevation Gradient,Peru

Through their role as ‘ecosystem engineers’, termites provide a range of ecosystem services including decomposition, and carbon and nitrogen cycling. Although termite diversity levels differ between regions as a result of variation in regional species pool size, in general, termite diversity is thought to decline with elevation. This study (1) investigated how termite species density, abundance, functional group diversity and termite attack on dead wood vary with altitude along an Amazon–Andes altitudinal gradient in Peru; (2) identified likely environmental causes of this pattern; and (3) explored the implications of termite presence for ecosystem functioning (notably for decomposition). Termites were sampled with a standardized 100 × 2 m straight‐belt transect at five undisturbed forest sites along a gradient 190 to 3025 m, as were environmental variables and termite and fungus attack on dead wood. Termite diversity was similar to that found at comparable sites in South America, and there was little turnover of assemblage composition with elevation suggesting that montane specialists are not present. Termite diversity declined with increased elevation, though the upper distribution limit for termites was at a lower elevation than anticipated. We suggest that key drivers of this elevation pattern are reduced temperature with altitude and mid‐elevation peaks in soil water content. Also, attack on dead wood diminished with decreasing termite indirect absolute abundance, while the depth of the soil humic layer increased. We hypothesize that termite abundance is a major accelerant of decomposition rates (and associated mineralization) in Amazonian forests.     

Species poor but distinct: bird assemblages in white sand vegetation in Jaú National Park, Brazilian Amazon

There have been few studies of the fauna of the distinctive vegetation that grows on sandy soil in Amazonia. Leached and nutrient-poor sandy soil is associated with a vegetation type that varies in structure from open fields (campinas) to low canopy forests (campinaranas). During a bird inventory in sandy soil vegetation at Jaú National Park (JNP), I recorded 128 bird species, with 55 in campina and 94 in campinarana. Estimates suggested only 150 bird species should be expected to occur in these habitats, a reduced species diversity compared with other vegetation types in the Amazon region. This low species diversity is probably linked to the low productivity of this habitat and its relatively simple vegetation structure. Despite the relatively low diversity, at least 14 bird species (3% of the entire avifauna) appear to be restricted to white sand vegetation in JNP. In Amazonia as a whole, some 37 bird species are associated with vegetation in sandy soils. Biological inventories of other taxa are needed to understand the contribution of white sandy vegetation to the faunal distribution in Amazonia.     

Bolete diversity in two relict forests of the Mexican beech (Fagus grandifolia var. mexicana; Fagaceae)

The current distribution of the endangered Mexican beech [Fagus grandifolia var. mexicana (Martinez) Little] is restricted to relict isolated populations in small remnants of montane cloud forest in northeastern Mexico, and little is known about its associated biota. We sampled bolete diversity in two of these monospecific forests in the state of Hidalgo, Mexico. We compared alpha diversity, including species richness and ensemble structure, and analyzed beta diversity (dissimilarity in species composition) between forests. We found 26 bolete species, five of which are probably new. Species diversity and evenness were similar between forests. Beta diversity was low, and the similarities of bolete samples from within and between forests were not significantly different. These results support the idea that the two forests share a single bolete ensemble with a common history. In contrast, cumulative species richness differed between the forests, implying that factors other than the mere presence of the host species have contributed to shaping the biodiversity of ectomycorrhizal fungi in relict Mexican beech forests.     

Spatial variation in egg polymorphism among cuckoo hosts across 4 continents

Although egg color polymorphism has evolved as an effective defensive adaptation to brood parasitism, spatial variations in egg color polymorphism remain poorly characterized. Here, we investigated egg polymorphism in 647 host species (68 families and 231 genera) parasitized by 41 species of Old Word cuckoos (1 family and 11 genera) across Asia, Europe, Africa, and Australia. The diversity of parasitic cuckoos differs among continents, reflecting the continent-specific intensities of parasitic selection pressure on hosts. Therefore, host egg polymorphism is expected to evolve more frequently on continents with higher cuckoo diversity. We identified egg polymorphism in 24.1% of all host species and 47.6% of all host families. The common cuckoo Cuculus canorus utilized 184 hosts (28.4% of all host species). Hosts of the common cuckoo and of Chrysococcyx species were more likely to have polymorphic eggs than hosts parasitized by other cuckoos. Both the number of host species and the host families targeted by the cuckoo species were positively correlated with the frequency of host egg polymorphism. Most host species and most hosts exhibiting egg color polymorphism were located in Asia and Africa. Host egg polymorphism was observed less frequently in Australia and Europe. Our results also suggested that egg polymorphism tends to occur more frequently in hosts that are utilized by several cuckoo species or by generalist cuckoo species. We suggest that selection pressure on hosts from a given continent increases proportionally to the number of cuckoo species, and that this selection pressure may, in turn, favor the evolution of host egg polymorphism.     

Termites facilitate and ungulates limit savanna tree regeneration

Both large herbivores and termites are key functional groups in savanna ecosystems, and in many savanna areas, large termite mounds (termitaria) are associated with distinct woody clusters. Studies on the effect of large mammals on tree regeneration are few, and the results are conflicting. Large herbivores have been found to be important seedling predators in some areas, but facilitate tree regeneration by outcompeting small mammals and reducing grass cover in other areas. Through the use of the experimental fencing of termite mounds and adjacent savanna areas in this study, we investigated how termites and large herbivores influence tree regeneration. Termite mounds had a higher number of seedlings, more species richness, more alpha diversity (OD) and lower evenness (E) than savanna plots. Large herbivores did not significantly affect overall seedling density, species richness, OD or E. Beta diversity was higher in savanna areas than on termitaria, and beta diversity decreased in savanna areas when herbivores were excluded. Herbivore exclusion increased the density of the 12 (40 %) most common seedling species, representing 79 % of all seedlings, and fenced plots had relatively taller seedlings than open plots. Thus, termites were the main determinants of tree regeneration in our study area, but large mammals regulated the most common species. Although our study confirms previous work suggesting that large herbivores affect tree regeneration, we found that termites were an even more important determinant. Termite impacts on tree regeneration deserve increased attention by savanna ecologists.     

Contrasts in the large herbivore faunas of the southern continents in the late Pleistocene and the ecological implications for human origins

Aim

Africa is renowned for the current abundance and diversity of its large mammals. The aim of this study was to assess distinctions evident in the functional composition of continental large herbivore faunas during the late Pleistocene before extinctions depleted the megafauna outside Africa.

Location

The African large herbivore fauna was compared with that formerly inhabiting South America, Australia, North America, Eurasia and tropical Asia during the late Pleistocene.

Methods

Pleistocene faunas were reconstructed from the literature in terms of their relative body size composition, grazer/browser contributions and taxonomic representations, omitting forest and island species.

Results

Although the three southern continents were closely similar in the overall species richness of large herbivores that they supported during the late Pleistocene, South America had a predominance of very large herbivores, while most of Australia's mammalian herbivores were relatively small and those of Africa were intermediate. Africa had many more grazers, especially in the size range 100–1000 kg, than other continents. The South American pattern resembled that in North America and Eurasia, while Africa and Australia diverged in different ways.

Main conclusions

Neither the total extent of savannas in each continent nor the morphological features enabling bovid radiation seemed adequate on their own to explain the greater richness of macrograzers in Africa. Africa is characterized by the widespread occurrence of arid/eutrophic savannas, which are unrepresented in other continents. The prevalence of savanna is partly attributable to the high elevation of interior eastern and southern Africa, associated with relatively low rainfall, and to the comparatively high soil fertility, related to volcanic influences. This promoted an abundance and diversity of medium‐sized grazing ruminants unrivalled elsewhere. Indigenous grasses in South America and Australia are less well adapted to withstand severe grazing than the African grasses introduced to support livestock. The locally high abundance of African ungulates presented conditions that facilitated the adaptive transition by early hominins from plant‐gatherers to meat‐scavengers.     

Ecology of Australia: the effects of nutrient-poor soils and intense fires

Australia, the flattest, driest, and geologically oldest vegetated continent, has a uniquely high proportion of nutrient-poor soils. We develop a "Nutrient-Poverty/Intense-Fire Theory," which postulates that most anomalous features of organisms and ecosystems of Australia are the evolutionary consequences of adaptations to nutrient poverty, compounded by intense fire that tends to occur as a result of nutrient poverty. The fundamental tenet of the theory is that plants growing in environments with plentiful light and periodic adequate moisture, but on soils poor in phosphorus, zinc, and other indispensible nutrients, can synthesize carbohydrates in excess of the amount that can be combined with, or catalyzed by, these nutrients for metabolism and production of nutrient-rich foliage and reproductive tissues. They use this "expendable energy" to produce well-defended foliage, large quantities of lignified tissues, and readily digestible exudates. Rapid accumulation of nutrient-poor biomass, a result of low rates of herbivory, provides fuel for intense fire. Intense fire exacerbates nutrient poverty by volatilizing certain micronutrients critical for animals. Anomalous features of organisms of Australia that can be explained by this theory, rather than by climate or phylogenetic history alone, include the following: most woody plants have long-lived, durable foliage; plants defend their tissues primarily with carbon-rich but nutrient-poor compounds; an unusually high proportion of plants protects seeds from fire and granivores in sturdy, woody capsules or follicles; plants allocate unusually large amounts of expendable energy to production of carbon-based exudates, such as nectar and gums; an unusually high proportion of plant species is pollinated by vertebrates that average larger size than pollinators on other continents; herbivores are small and have slow metabolism; there are no ruminants, mammals that eat mainly subterranean plant matter, or fungus-culturing termites and ants; vegetation dominated by leaf-spinescent plants is more extensive than vegetation dominated by stem-spinescent plants; nitrogen-fixing plants are major components of most vegetation types; there is a higher proportion of myrmecochorous plant species than on any other continent; there are hardly any stem-succulent and few leaf-succulent, perennial, non-halophytic plant species; and an unusually high proportion of bird species breeds cooperatively. Although the Nutrient-Poverty/Intense-Fire Theory can provide plausible explanations for these anomalous features, some puzzles remain, among them the great success of introduced herbivores, the lack of grazers on extensive grasslands on cracking clays, the apparently low productivity of ants, and the prominence of the parasitic plants of Australia. By examining the ratios of available energy to nutrients, particularly scarce nutrients, ecologists may identify processes not previously recognized as important for life forms or biotic adaptation on other continents.