Achieving Target 2 of the Global Strategy for Plant Conservation: building a preliminary assessment of vascular plant species using data from herbarium specimens

The Global Strategy for Plant Conservation calls for a preliminary assessment of the conservation status of all known plant species by the year 2010. To date insufficient progress has been made on meeting this target. New efforts to develop a preliminary list beyond using the full IUCN criteria in plant assessments are needed. Here we present an algorithm that provides a preliminary assessment of the conservation status of plant species using data from herbarium specimens. We use Hawaiian specimen data from the United States National Herbarium to calibrate the parameters of the algorithm and then use specimen data from the Arecaceae, Commelinaceae, Gesneriaceae and Heliconiaceae as examples of the application of the algorithm. The algorithm was calibrated to insure 95% accuracy in placing the Hawaiian plant species into previously and independently determined threatened categories. Our results indicate that 28% of the Hawaiian taxa, 27% of the species of Arecaceae, 45% of the species of Commelinaceae, 32% of the species of Gesneriaceae, and 35% of the species of Heliconiaceae are Not Threatened and will not need any further evaluation for the preliminary assessment. Species identified here as Potentially Extinct and Potentially Threatened can be further assessed by additional herbarium material and/or conservation specialists for final evaluation using other assessment strategies (e.g., regional and national lists, taxonomic expert assessment, etc.).     

The use of specimen information influences the outcomes of Red List assessments: the case of southern African plant specimens

Information contained on specimen labels of natural history collections is often the most reliable and available source of information to guide conservation decisions. When used for making IUCN Red List assessments, the inherent limitations associated with specimen information affect the assignment of Red List categories, and the case of the southern African plant Red Lists reflects this. Red List assessments that are based on specimen information can result in predictable outcomes, namely the tendency to assign the following categories: Data Deficient, Lower Risk-least concern, Vulnerable D2 or a threatened category using Criterion B. The reason for this is that specimen information satisfies distribution parameters of the IUCN system more readily than demographic parameters.     

Diversity and genetic structure of the endangered cycad Dioon sonorense (Zamiaceae) from Sonora, Mexico: Evolutionary and conservation implications

The diversity and genetic structure of the cycad Dioon sonorense (De Luca, Sabato & Vázq. Torres) Chemnick, T.J. Greg. & S. Salas-Mor. were evaluated from the four known populations in tropical dry forests of Sonora, Mexico. The estimates of genetic diversity in the 19 loci analysed were: mean number of alleles per locus (A = 2.0), percentage of polymorphic loci (P = 81.6) and expected heterozygosity (H_E = 0.314). The subpopulations were found to be in Hardy–Weinberg equilibrium at the local level (F_is), even though we found a global excess of homozygotes (F_it = 0.13). Genetic variation attributed to differences among populations was 15%. Our results indicate that the geographical isolation caused by the historical effects of the Pleistocene among populations has probably generated clinal variation of the allelic frequencies at two loci, in relation to their latitudinal distribution. We compare our results with the long-lived southern hemisphere trees Fitzroya and Nothofagus in relationship to the Pleistocene glaciations. We also infer that the populations have become fragmented recently due to increasing pressure of habitat conversion, disturbance and illegal extraction of plants and seeds for the international horticultural trade. We therefore recommend three aspects: (i) propagation of this species for reintroduction, (ii) declare the localities of its northern distribution as a protected area, and (iii) an amendment of the current International Union for Conservation of Nature Red List categorisation for this species to ‘Critically Endangered’.     

Genetic variation in time and space: the use of herbarium specimens to reconstruct patterns of genetic variation in the endangered orchid Anacamptis palustris

Habitat alteration, fragmentation and destruction as a consequence of human impact are a global phenomenon. Here we document changes in genetic variation in the marsh orchid Anacamptis palustris as a consequence of such habitat changes. We examined historical specimens that were collected during the nineteenth and early twentieth centuries, prior to the most recent massive habitat changes affecting this species. Sequences of a hypervariable region in the plastid DNA, located in the tRNA^LEU intron, from herbarium vouchers were compared with those from a near-exhaustive survey of the extant A. palustris populations on the Italian peninsula. It was found that private haplotypes and alleles found in small, extant populations were once widespread and more common in historic populations and that alleles, once present in historic populations, have gone extinct. In addition, genetic differentiation among populations has increased over time and haplotype frequencies significantly differ among historic and extant populations. These results document that human induced habitat changes have reduced genetic diversity and increased the importance of random genetic drift in this species. It is concluded that the analysis of herbarium specimens may provide important insights into changes of genetic diversity over time and may be critical for correct inference of the evolutionary history of rare and endangered species.     

Shell strength and primate seed predation of nontoxic species in eastern and southern Africa

The large African primates that eat fruit destroy the seeds of a number of fruiting species. This paper addresses several questions about seed-eating: What is the nature of the dietary niche provided by the nonpoisonous seeds of eastern and southern Africa? How well are these seeds mechanically protected? What other means of reducing seed predation are employed by the plants? and is the niche ecologically stable? Measurements of seed shell strength on 37 species from 17 families reveal a range of values, from <100-kg (numerous species) to over 2000-kg (palm nuts) breaking load. Primates crack open with their teeth seed shells from species exhibiting test strengths less than 600 kg. Variation in shell strength appears to increase dramatically for average species strengths above 100 kg. Plant species are not characterized by specific shell strengths but instead, display envelopes of shell strength overlapping broadly with other species. Taking this into account, adult male baboons (Papio spp.) appear to be dentally capable of preying upon most of the seed species of eastern and southern Africa. The possibility for predation of nonpoisonous seeds exists primarily because the plants periodically produce large crops in synchrony and the hard-shelled seeds are effectively dispersed, sometimes explosively but more often by means of edible fruits. The concomitant primate seed predation is a facultative specialization, of little apparent threat to the community of plants that support it.     

<Emphasis Type="Italic">Tabebuia karsoana</Emphasis> (Bignoniaceae), a new species from the northern karst of Puerto Rico

Summary   Tabebuia karsoana is a shrub or small tree species from the northern karst of Puerto Rico, where it is confined to ridges and hilltops. Its habit and general flower appearance are similar to those of T. haemantha (Bertero ex Spreng.) A. DC. However, T. karsoana is distinguished by leaflets densely covered with white peltate scales on both sides, the corolla fuchsia with a white microscopically papillose throat, the stamens with arcuate filaments, and the anthers divaricate and connivent, among other features. In addition, the two species’ distributions do not overlap and their habitats are contrasting. According to IUCN criteria, the new species can be defined as “endangered” and consequently needs legal protection.

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Resumen   Tabebuia karsoana es una especie de arbusto o árbol peque?o del karso norte?o de Puerto Rico, donde crece sobre riscos y cimas. Es similar a Tabebuia haemantha (Bertero ex Spreng.) A. DC., en la forma de crecimiento y en la apariencia general de las flores. Sin embargo, T. karsoana es distinguible por sus hojuelas densamente cubiertas de escamas blancas y peltadas, sus corolas fucsia con la garganta blanca y microscópicamente papilosa, sus estambres con filamentos arqueados, y sus anteras divaricadas y coniventes, entre otras características. Además, las áreas de distribución de las dos especies no se traslapan y sus hábitats son contrastantes. Con base en los criterios de la UICN, la nueva especie puede definirse como “en peligro”, y consecuentemente amerita protección legal.

     

The relative importance of photoperiod and temperature as cues for seasonal acclimation of thermoregulation in pouched mice (Saccostomus campestris: Cricetidae) from southern Africa

Summary The effect of short photoperiod and cold on metabolism and thermoregulation was investigated in pouched mice (Saccostomus campestris: Cricetidae) from three localities in southern Africa which experience contrasting climatic conditions. Mice were initially acclimated to long photoperiod (14L: 10D) at 25°C, followed first by a decline in photoperiod (to 10L: 14D) and then by a fall in temperature (to 10°C). Minimum observed metabolic rate (basal metabolic rate) was unaffected by the decline in photoperiod but increased significantly following cold acclimation. Because minimal thermal conductance remained constant throughout the study the increase in minimum observed metabolic rate caused a decline in lower critical temperature to around 26°C. In contrast to minimum observed metabolic rate, regulatory non-shivering thermogenesis improved significantly following the decline in both photoperiod and temperature. However, pouched mice from the warmest locality were significantly less responsive to photoperiod than those from the other two localities whose survival might depend upon their ability to accurately predict seasonal changes in temperature. Neither photoperiod nor temperature had any effect on body mass, yet pouched mice from the most arid locality, where food supply might be unpredictable, were significantly smaller and had lower total energy requirements than those from areas experiencing higher annual rainfall. These results indicate that S. campestris displays considerable geographical variation in energy requirements together with differences in the use of photoperiod as an anticipatory cue for predicting the onset of winter. These differences appear to be related to the availability of energy and the relative severity of climatic conditions in each locality.Abbreviations ANOVA analysis of variance - BMR basal metabolic rate - C _m minimal thermal conductance - M _b body mass - MOMR minimum observed metabolic rate - MWU Mann-Whitney U-test - NA noradrenaline - NST non-shivering thermogenesis - RMR resting metabolic rate - RQ respiratory quotient - T _a ambient temperature - T _b body temperature - T _1c lower critical temperature - oxygen consumption - maximum - following NA injection     

Origins and genetic conservation of tropical trees in agroforestry systems: a case study from the Peruvian Amazon

Hundreds of native tree species are currently found in extensive agroforestry ecosystems in the Peruvian Amazon, forming an important reservoir of biodiversity. To further promote conservation, farmers are encouraged to supplement intra-specific genetic diversity in these populations with seed collected from local forests. For some tree species, however, this approach may be inappropriate, as stands of these taxa already found on-farm may not be of local origin. Despite this issue being of importance for conservation, little information is available on the history of cultivated trees in the region, a situation that we here rectify for the important fruit tree Inga edulis. Based on nuclear SSR and chloroplast DHPLC analyses of closely geographically matched natural and planted stands at five sites, it appears that cultivated material of I. edulis is primarily of non-local origin, indicating that conservation based on new wide-scale infusions from local wild stands into farms may be inappropriate in the region. Although nuclear and chloroplast diversity were both lower in planted stands, values were still relatively high (∼80 and 70% of natural stands, respectively), indicating that when farmers plant trees, good collection practice of seed from already cultivated I. edulis should be an effective means for ensuring long-term conservation on farms.     

TheMoegistorhynchus longirostris (Diptera: Nemestrinidae) pollination guild: long-tubed flowers and a specialized long-proboscid fly pollination system in southern Africa

A guild of 20 late spring- and early summer-flowering species ofIridaceae, Geraniaceae andOrchidaceae is pollinated partly or exclusively by the long-proboscid flyMoegistorhynchus longirostris (Nemestrinidae). This large-bodied fly, active in late spring and early summer, has mouthparts 40–70 (90) mm long and forages for nectar from a variety of species. These plants share a suite of convergent floral features including a straight or weakly curved floral tube usually 50–70 mm long but sometimes to 90 mm, relatively short petals or tepal lobes coloured white, cream or salmon with reddish nectar guides, and often violet or red anthers and pollen. Flowers of most species with these characteristics are zygomorphic with the stamens either arcuate (mostIridaceae) or declinate (Geraniaceae and someIridaceae). The flowers are odourless and typically secrete large amounts of nectar of relatively constant sugar concentration, mostly 24–29%, with a high sucrose:hexose ratio. Guild members utilize five separate sites of pollen deposition on the body of the fly, typically utilizing different deposition sites when two or more co-occur, indicating strong selection to aviod pollen contamination.M. longirostris is restricted to the west coast of southern Africa and at least 8 species appear to depend exclusively on the insect for pollination. The remaining species in the guild are pollinated by one or both of the long-proboscid fliesPhiloliche gulosa andP. rostrata (Tabanidae) over other parts of their range. Species and races pollinated entirely byM. longirostris have longer floral tubes which makes nectar unavailable to other insects, including other species of long-proboscid fly. The only insect with mouthparts long enough to forage effectively on these long-tubed flowers isM. longirostris and this fly must be considered a keystone species in the ecosystems in which it occurs.Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday     

Dispersal and settling of translocated populations: a general study and a New Zealand amphibian case study

Translocations are widely used to reintroduce threatened species to areas where they have disappeared. A continuum multi-species model framework describing dispersal and settling of translocated animals is developed. A variety of different dispersal and settling mechanisms, which may depend on local population density and/or a pheromone produced by the population, are considered. Steady state solutions are obtained using numerical techniques for each combination of dispersal and settling mechanism and for both single and double translocations at the same location. Each combination results in a different steady state population distribution and the distinguishing features are identified. In addition, for the case of a single translocation, a relationship between the radius of the settled region and the population size is determined, in some cases analytically. Finally, the model is applied to a case study of a double translocation of the Maud Island frog, Leiopelma pakeka. The models suggest that settling occurs at a constant rate, with repulsion evidently playing a significant role. Mathematical modelling of translocations is useful in suggesting design and monitoring strategies for future translocations, and as an aid in understanding observed behaviour.      

Defining and identifying sustainable harvests of resources: Archaeological examples of pinniped harvests in the eastern North Pacific

Archaeologists and resource managers are starting to recognize the value of studying ancient cultures for examples of how resources have, and have not, been sustainably utilized in the past as a way of understanding current trends in environmental degradation. These studies do not provide sweeping generalizations about aboriginal resource use but, rather, identify the range of conditions under which sustainable harvests may be possible. The hypothesis of sustainable harvests must be tested using variables that can be measured equally well in ancient (e.g., archaeological) and modern contexts.These factors are carefully considered in this analysis of pinniped (seal and sea lion) remains from two archaeological sites on the eastern North Pacific (ENP) coast, where pinnipeds have been hunted for millennia. Reconstruction of the age composition, or harvest profile, of Callorhinus ursinus at the Ozette Village Site, Washington, shows that males and females of all ages were harvested, and supports the hypothesis that it was done so sustainably for over 500 years. After this period of apparent stability, C. ursinus abandoned local breeding colonies in the early historic period. In contrast, harvests of this species at the Moss Landing Hill Site, California, primarily targeted young of the year, and sub-adult and adult females. While this harvest is also inferred to have targeted a local breeding colony, C. ursinus appear to have been extirpated nearly 2000 years earlier at Moss Landing than at Ozette.The causes of these extirpations are not known, but the timing does not correspond well with known climatic changes, suggesting that subsistence, and perhaps commercial, hunting may have played a role. These examples underscore the need to recognize that patterns of resource use are highly variable – different cultures have had varying levels of effects on economically important species, and these effects have varied temporally, spatially, and taxonomically.     

Cannibalism and Interspecific Predation in a Phytoseiid Predator Guild from Cassava Fields in Africa: Evidence from the Laboratory

Interspecific predation and cannibalism are common types of interaction in phytoseiid predator guilds, but the extent and nature of these interactions have not been determined yet in phytoseiid guilds composed of African native and neotropical exotic phytoseiid predators found in cassava habitat in southern Africa. We determined in laboratory experiments the level of cannibalism and interspecific predation among the three phytoseiid mite species Euseius fustis, Iphiseius degenerans, and Typhlodromalus aripo in the absence of food and in the presence of limited or abundant quantities of two food types – Mononychellus tanajoa and maize pollen – commonly found on cassava in Africa. When confined without food, only two T. aripo females laid each two eggs within 5 days, and this species survived longer than I. degenerans and E. fustis. In the presence of con- or hetero-specific larvae or protonymphs, the three species fed more on the former than on the latter, and more on hetero-specifics than on con-specifics. Oviposition rates of the three species did not exceed 0.7 egg/female/day on con- and hetero-specific immatures. Typhlodromalus aripo and E. fustis survived longer on con-specific and hetero-specific larvae and on hetero-specific protonymphs than in the absence of any food, while T. aripo survived longer than the two other species on the same diets. Provision of limited quantity of food decreased interspecific predation rate by I. degenerans and T. aripo, but not by E. fustis, and increased oviposition rate and longevity of all three species. Provision of abundant food, however, eliminated cannibalism by all three species and further reduced interspecific predation rates, but their oviposition and longevity remained relatively unchanged compared with limited food provision. Potential consequences of cannibalism and interspecific predation among phytoseiid mites on cassava for the biological control of M. tanajoa are discussed.     

The role of taste in food selection by African apes: implications for niche separation and overlap in tropical forests

Ripe fruit eating shapes the behavior of most of the apes. Gorillas (Gorilla gorilla) and chimpanzees (Pan troglodytes) are very different sizes and, consequently, have been traditionally viewed as ecologically distinct, but few studies have explored the behavioral and physiological foundations of their diets. Debate continues on the extent that large-bodied gorillas may be less selective and more opportunistic fruit eaters than chimpanzees. Taste responses have been predicted to relate to body size and digestive strategies. This study employs laboratory research on taste perception and discrimination among captive zoo-housed chimpanzees and relates it to previous work on gorillas to better characterize diets and niche separation among these apes. During the captive trials, differences were recorded in consumption patterns of water and varying concentrations of dilute aqueous fructose (sweet) and tannic acid solutions (astringent), compounds commonly found in wild foods. The chimpanzees exhibited similar preference thresholds for fructose (50 mM) to other primates studied. They exhibited slightly lower inhibition thresholds for tannic acid solutions than gorillas, but higher than smaller primates studied to date. These preliminary findings suggest that tannin tolerance may well be mediated by body size, though possible species differences in salivary proteins or other sensory differences remain to be explored. This research furthers our efforts to understand the roles of body size and physiological adaptations in shaping diet and niche separation of chimpanzees and gorillas.     

Forest fragmentation and plant reproductive success: a case study in four perennial herbs

We assessed the effects of habitat fragmentation on reproductive success in natural populations of four forest herbs with differing life-history traits and whose distribution patterns appeared to be negatively affected by decreased habitat size and/or increased isolation: Carex sylvatica, Galium odoratum, Sanicula europaea and Veronica montana. Our aims were to test (1) whether habitat size and isolation are positively correlated with population size and isolation, respectively, (2) whether plant reproductive success, a major component of plant fitness, is reduced in small and/or isolated populations when also accounting for differences in habitat quality (edaphic conditions, light intensity) and the effects of plant size, and (3) whether species with different life histories are affected differently. There were significant positive relationships between habitat and population size and between habitat and population isolation in some, but not all of the species. We mostly found no negative effects of small population size or isolation on reproduction. However, reproductive success was reduced in small populations of Sanicula, and this effect was independent of differences in plant size and environmental conditions. The reduced fecundity in small populations may be a consequence of the Allee-effect, a possible mechanism being pollen limitation. Furthermore, the proportion of flowering ramets was reduced in small and isolated populations of Galium, which may have been caused by changes in population structure. Lastly, we found some evidence for largely outcrossing, non-clonal species to be more sensitive to reductions in population size, at least in terms of their reproductive success.     

Extinction threat evaluation of endemic fig trees of New Caledonia: Priority assessment for taxonomy and conservation with herbarium collections

This article focuses on the relationship between priority-setting in conservation and in taxonomy. A simple and generally applicable scheme is presented based on prior quantitative extinction threat evaluation. In the main part of the study we describe the assessment of the herbarium voucher collection date time series of 21 endemic fig tree species of Ficus sect. Oreosycea (Moraceae). The fig tree assessment is then compared with the available IUCN Red List data and with the collection information on two other groups of endemic tree radiations in New Caledonia: ebonies of Diospyros sect. Maba (Ebenaceae) and the Iguanura palm lineage (Arecaceae). We find a remarkably low level of extinction threat evident in Ficus but a pronounced need to differentiate between true species rarity and putative rarity of potential taxonomic artifacts. To this end it is proposed how such numerical evaluations can be used to set future priorities for the assessment or validation of the taxonomic and conservation status of taxa. The limitations and implications of the evaluation are discussed and relevant criteria for a meaningful analysis of collection records are listed. Finally, putting our results on woody plants into perspective, we briefly review the general conservation situation and outlook of New Caledonia, acknowledging both its high conservation priority and potential. Abbreviations: Note that different IUCN threat category classifications have been in use during the last decade and that some of the cited categories and their abbreviations have changed (IUCN 1994, 2001).     

Adaptation and niche construction in human prehistory: a case study from the southern Scandinavian Late Glacial

The niche construction model postulates that human bio-social evolution is composed of three inheritance domains, genetic, cultural and ecological, linked by feedback selection. This paper argues that many kinds of archaeological data can serve as proxies for human niche construction processes, and presents a method for investigating specific niche construction hypotheses. To illustrate this method, the repeated emergence of specialized reindeer (Rangifer tarandus) hunting/herding economies during the Late Palaeolithic (ca 14.7-11.5 kyr BP) in southern Scandinavia is analysed from a niche construction/triple-inheritance perspective. This economic relationship resulted in the eventual domestication of Rangifer. The hypothesis of whether domestication was achieved as early as the Late Palaeolithic, and whether this required the use of domesticated dogs (Canis familiaris) as hunting, herding or transport aids, is tested via a comparative analysis using material culture-based phylogenies and ecological datasets in relation to demographic/genetic proxies. Only weak evidence for sustained niche construction behaviours by prehistoric hunter-gatherer in southern Scandinavia is found, but this study nonetheless provides interesting insights into the likely processes of dog and reindeer domestication, and into processes of adaptation in Late Glacial foragers.     

Three genetically divergent lineages of the Oryx in eastern Africa: Evidence for an ancient introgressive hybridization

Phylogeographic and population genetic studies using sequence information are frequently used to infer species boundaries and history; and to assess hybridization and population level processes. In this study, partial mitochondrial DNA (mtDNA) control region (423 bp) and cytochrome b sequences (666 bp) of Oryx beisa sampled from five isolated localities in its entire current range in Africa were analyzed to investigate the extent of genetic variation and differentiation between populations. We observed high nucleotide diversity at the control region in the total sample (6.3%) but within populations, it varied considerably ranging from 1.6% to 8.1%. Population pairwise genetic differentiation was generally significantly high (ranging from F _ST = 0.15, P<0.01 to F _ST = 0.54, P<0.001). In the total sample, 29 and 12 haplotypes were observed in the control region and the cytochrome b data sets respectively. For both data sets, the haplotypes cluster into three distinct clades (sequence divergence ranged from 6.0%–12.9% to 0.8%–1.0% for the control region and cytochrome b sequences, respectively) that do not correspond to sampling locations. Two of these clades are found in the same localities (Samburu and Marsabit), which represent the O.beisa beisa subspecies, whereas the last clade represents the fringe-eared oryx (O. beisa callotis). We interpret these findings in terms of an ancient hybridization and introgression between two formerly isolated taxa of Oryx beisa.