Bioacoustic assessment of the taxonomic status of pool frog populations (Rana lessonae) with reference to a topotypical population

Six structural and temporal features of the mating calls of pool frogs recorded at eight localities in Italy, Germany, Yugoslavia and Albania were compared with those of the calls of topotypical Rana lessonae in northern Italy. All populations shared three out of six characters studied: call duration, intercall interval and call period. The pool frogs of three localities in peninsular Italy significantly differed in three characters from those of the other six localities, including the northern Italian one: pulses per pulse group, pulse groups per call, and pulse groups per second. This study demonstrates the existence of Rana bergeri , a pool frog species different from R. lessonae in peninsular Italy, but does not support the species status of the chemotaxonomically established R. shqiperica , which is considered as a synonym of R. lessonae .     

Female frog auditory sensitivity,male calls,and background noise: potential influences on the evolution of a peculiar matched filter

The matched filter hypothesis proposes that the tuning of females' auditory sensitivity matches the spectral energy distribution of males' signals. Such correspondence is expected to arise over evolutionary time, as it promotes conspecific information transfer and reduces interference from other sound sources. Our main objective was to determine the correspondence between the acoustic sensitivity of female frogs of Eupsophus roseus and the spectral characteristics of advertisement vocalizations produced by conspecific males. We also aimed to determine how auditory sensitivity is related to the characteristics of background noise. We analysed data on the auditory sensitivity of E. roseus females, and recordings of conspecific male vocalizations and of the acoustic environment during the breeding period of this species. Our results indicate a concordance between the auditory sensitivity of females and call spectra that would provide an appropriate detection of these signals. In addition, this matching is large relative to the correspondence between auditory sensitivity with the spectra of the abiotic and biotic background noise, with the last component being associated with calls of the related species Eupsophus vertebralis. This may be an adaptation of receivers confronting sound interference, which improves the capability of E. roseus to communicate sexually by means of acoustic signals. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110 , 814–827.     

Intrinsic and extrinsic factors acting on the reproductive process in alpine‐snowbed plants: roles of phenology,biological interaction,and breeding system

Pollinator activity and competition for pollinators lead to quantitative and qualitative pollen limitations on seed production and affect the reproductive success of plant species, depending on their breeding system (e.g., self‐compatibility and heterospecific compatibility) and genetic load (e.g., inbreeding depression and hybrid inviability). In alpine ecosystems, snowmelt regimes determine the distribution and phenology of plant communities. Plant species growing widely along a snowmelt gradient often grow with different species among local populations. Their pollinators also vary in their abundance, activity, and behavior during the season. These variations may modify plant–pollinator and plant–plant interactions. We integrated a series of our studies on the alpine dwarf shrub, Phyllodoce aleutica (Ericaceae), to elucidate the full set of intrinsic (species‐specific breeding system) and extrinsic factors (snow condition, pollinator activity, and interspecific competition) acting on their reproductive process. Seasonality of pollinator activity led to quantitative pollen limitation in the early‐blooming populations, whereas in the late‐blooming populations, high pollinator activity ensured pollination service, but interspecific competition for pollinators led to qualitative and quantitative pollen limitation in less competitive species. However, negative effects of illegitimate pollen receipt on seed‐set success might be reduced when cryptic incompatibility systems (i.e., outcross pollen grains took priority over self‐ and heterospecific pollen grains) could effectively prevent ovule and seed discounting. Our studies highlight the importance of species‐specific responses of plant reproduction to changing pollinator availability along environmental gradients to understand the general features of pollination networks in alpine ecosystems.     

Individual variation in the booming calls of captive Horned Guans (Oreophasis derbianus): an endangered Neotropical mountain bird

The Horned Guan (Oreophasis derbianus) is a cracid restricted to cloud forests in the Sierra Madre of Chiapas in Mexico and the western-central Mountains in Guatemala. It is an endangered species and urgent conservation measures are required, such as non-invasive monitoring techniques. Here, we study individual features in the boom calls of Horned Guans. Boom calls are acoustic signals used by males during courtship and territorial displays. This call is made of seven notes, divided into two parts: an introductory section characterized by low-amplitude notes and a body section characterized by high-amplitude notes. We recorded 10 males during the breeding seasons of 2010 and 2011 in two captive populations and measured 22 acoustic variables of the calls. We used a combination of statistical analyses to test individuality in Horned Guan vocalizations. Our results showed that time-related variables – but not frequency-related traits – varied between individuals, and that individual calls showed no variation between years. Our results suggest that Horned Guan individuals can be distinguished using fine structural characteristics of their calls and that calls remain stable across years. We argue that such vocal signature could be used to track wild populations as a non-invasive technique in order to improve census data in the short and long term.     

金沙江干热河谷滇榄仁开花物候与繁育系统

通过野外定点观测,并利用套袋实验、解剖实验以及花粉形态特征观察与活力检测、柱头可受性检测、花粉/胚珠比以及异交指数等,研究了金沙江干热河谷滇榄仁自然群体花部形态特征与开花进程、繁育系统特征以及传粉媒介与环境的适应性等内容。结果表明,滇榄仁始花期在每年4月上旬,群体花期持续时间为30d左右,开花同步性高,呈典型的"集中开花模式"。单花开放时,柱头先伸长和膨大,约4d后雄蕊伸出,具有雌雄异熟的特征,一定程度上避免了自交的发生。单花开放进程可划分为花蕾期、柱头伸长期、雄蕊始露期、盛开期、盛开后期、花谢期等6个时期。除了花蕾期外,整个开花期的花粉均具有活力。花粉活力与柱头可受性之间避开了最适授粉期,但也有部分重叠。滇榄仁可能同时具有风媒和虫媒传粉。繁育系统以异交为主,部分自交亲和,需要传粉者。滇榄仁花部特征、开花物候和繁育系统为其适应干热河谷恶劣气候环境提供了一定的生殖保障和进化潜力。良好的群落环境有助于促进滇榄仁异花传粉,产生更多有效的种子,从而促进林下自然更新。     

Reproductive ecology of the endangered Alpine species Eryngium alpinum L. (Apiaceae): phenology, gene dispersal and reproductive success

BACKGROUND AND AIMS: Eryngium alpinum (Apiaceae) is an endangered perennial, characteristic of the Alpine flora. Because the breeding system influences both demographic (reproductive success) and genetic (inbreeding depression, evolutionary potential) parameters that are crucial for population maintenance, the reproductive ecology of E. alpinum was investigated. Specifically, the aims of the study were (1) to determine the factors (resources and/or pollen) limiting plant fitness; and (2) to assess the potential for gene flow within a plant, within a patch of plants, and across a whole valley where the species is abundant. METHODS: Field experiments were performed at two sites in the Fournel valley, France, over three consecutive years. Studies included a phenological survey, observations of pollinators (visitation rates and flight distances), dispersal of a fluorescent powder used as a pollen analogue, the use of seed traps, determination of the pollen/ovule ratio, and an experiment to test whether seed production is limited by pollen and/or by resources. KEY RESULTS: E. alpinum is pollinated by generalist pollinators, visitation rates are very high and seed set is resource- rather than pollen-limited. The short flights of honeybees indicate a high potential for geitonogamy, and low pollen and seed dispersals suggest strong genetic structure over short distances. These results are interpreted in the light of previous molecular markers studies, which, in contrast, showed complete outcrossing and high genetic homogeneity. CONCLUSION:S. The study highlights the usefulness of adopting several complementary approaches to understanding the dynamic processes at work in natural populations, and the conservation implications for E. alpinum are emphasized. Although the studied populations do not seem threatened in the near future, long-term monitoring appears necessary to assess the impact of habitat fragmentation. Moreover, this study provides useful baseline data for future investigations in smaller and more isolated populations.     

国家尺度自然保护地生态系统联网监测指标体系构建与应用研究

自然保护地是维护国家生态安全, 提升生物多样性保护成效的重要载体, 对保护地生态系统进行实时、高频、多尺度的监测是认知其动态变化的有效手段, 也是实现自然保护地生态系统健康管理的基石。由于目前我国没有形成自然保护地生态系统监测网络, 缺少统一的联网监测指标体系, 导致多数自然保护地生态系统组成家底不清、动态不明, 应对生物多样性保护新问题的能力不足, 并且在国家尺度上的自然保护地生态系统健康状况及保护成效评估缺乏联网监测数据支撑。因此, 亟需构建国家尺度的自然保护地生态系统组成和动态监测网络, 以及一套科学、系统、规范的自然保护地生态系统联网监测指标体系。该文针对自然保护地生物多样性和生态系统监测的目标和内容, 参考国内外现有的生态系统监测网络的指标体系, 确定了自然保护地生态系统联网监测指标体系建立和选取的基本原则, 建立了一套适用于国家尺度的自然保护地生态系统联网监测指标体系, 并在6个国家级自然保护区进行示范。构建的指标体系针对构成生态系统的6类关键要素(生境要素、生物要素、气象要素、土壤要素、大气和水环境要素、景观要素)制定了30个监测指标, 有效应用于森林、草地、荒漠、湿地等生态系统类型的自然保护地, 能够实现对不同类型自然保护地生态系统组分和结构的现状和演变特征进行长期、动态化监测, 并可为自然保护地保护成效评估和健康管理提供规范化、标准化的基础数据。     

Diet selection in the green ringtail possum (Pseudochirops archeri): A specialist folivore in a diverse forest

Abstract This study investigated the feeding ecology of the green ringtail possum, Pseudochirops archeri (Pseudocheiridae) in a tropical rainforest with 94 plant species in the canopy. Over 50% of tree use was from only four tree species, Aleurites rockinghamensis, Ficus fraseri, Arytera divaricata and Ficus copiosa. These species were used significantly more frequently than would be expected if tree species were selected randomly in proportion to their relative abundance in the forest. Conversely, 88 other tree species present were used less frequently than expected. Possums also favoured particular individual trees within some of the preferred tree species. In 91% of feeding observations, possums consumed mature leaves only. The availability of young leaves, flowers and fruit varied throughout the year, with a peak in availability of these resources during the early wet season. By primarily selecting mature leaves, green ringtail possums reduce their dependence on seasonally variable resources. We suggest that green ringtail possums should be considered as specialist folivores, focusing on only a few of the tree species available, possibly due to advantages associated with limiting the number of plant secondary metabolites in their diet. Furthermore, they favour certain individual trees within species, perhaps due to intraspecific variation in plant secondary metabolites or nutrient content, behaviour that has been well established in eucalypt folivores. We conclude that green ringtail possums are highly specialized in their feeding ecology, limiting their diet to a small number of continuously available food items.     

Mating system of Carapa procera (Meliaceae) in the french guiana tropical forest

The mating system of the tropical rainforest tree Carapa procera was studied for a population located within a sylvicultural trial in French Guiana. We used the mixed-mating model with the genotypes of 47 open-pollinated progenies at ten polymorphic loci, obtained through isozyme analysis. Seeds were collected on both logged and unlogged (control) plots, which were interspersed. A high multilocus outcrossing rate (0.78) was found for the global population. and there was indirect evidence for nonrandom mating for outcrosses. It is argued that this may be due to some kind of positive assortative mating, probably biparental inbreeding. Correlation of selfing between sibs was not significantly different from zero. and the proportion of full-sibs among outcrossed sib-pairs was significant but low (0.16). We found significant differences between outcrossing rates when computing separate estimates for the 14 trees located on logged plots (tm = 0.63) and the 33 trees located on undisturbed plots (tm = 0.85). It is argued that the decrease in density is probably not the only cause of the decrease in outcrossing rate on logged plots. Lastly, several points concerning the reliability of the estimation are outlined. In particular. the downward bias due to ignoring null alleles during genetic interpretations of zymograms is quantified in a few cases by simulating artificial populations.     

Life history differences of Psilotreta locumtenens (Trichoptera: Odontoceridae) in two reaches of a mountain stream in Korea

The life history traits of the caddisfly, Psilotreta locumtenens Botosaneanu (Odontoceridae), were studied in two stream reaches with different thermal ranges (main and branch streams) of the Gapyeong Stream, a typical mountain stream located in the central Korean Peninsula. Psilotreta locumtenens larvae were quantitatively sampled monthly from November 2008 to July 2010, and biweekly during the emergence period (late April to early July), using a Surber sampler (30 × 30 cm). Adults were quantitatively sampled with a sweep net. Larval density in the main stream (324.21 ± 38.59 m^?2) was higher than that in the branch stream (60.48 ± 10.86 m^?2). The larvae hatched in the early summer and overwintered as 5th and 3rd instars in the main and branch streams, respectively. The emergence peak at the main stream was approximately 2 weeks earlier. The sex ratio at both sites was approximately 0.3. The life history in both streams was univoltine. Secondary production in the main stream was much higher than in the branch stream, owing to high larval densities, and the P/B ratios at the two sites were similar. This study demonstrated remarkable differences in larval growth patterns and emergence peaks in P. locumtenens between the two stream reaches due to differences in accumulated degree days (230.30 DD) and other phenological cues such as daily mean threshold water temperature (9°C) during the ascending phase, despite their relatively small mean annual water temperature difference of 0.58°C.     

Species composition,abundance and emergence phenology of midges (Deiptera: Chironomidae) in a brown-water stream of West-Central Alberta,Canada

Sixteen floating, box type emergence traps, each covering 0.1 m², were placed along 150 m of a third-order stretch of the Bigoray River, a slow-flowing, vegetation-choked, brown-water muskeg stream. Effects of trap design, trap shading, length of sampling interval, and stream velocity on the number of midges caught was examined. Of the 112 species of Chironomidae caught, 32 species made up 90% of the catch and their emergence phenology is described in detail. There were more rare species than expected from Preston's lognormal distribution. Percentage of Bigoray species belonging to Tanypodinae, Orthocladiinae, Chironomini and Tanytarsini was 18%, 43%, 20%, and 19%, and was compared with 27 other studies on lotic chironomids. During the 140-day emergence period an average of 19.3 × 10³ chironomids emerged per square meter of stream. Based on changes in male:female ratios throughout a species emergence period, it was postulated that 30% of the Bigoray chironomid species were univoltine, 50% were bivoltine, and 20% were trivoltine.     

Zygotic dormancy underlies prolonged seed development in Franklinia alatamaha (Theaceae): a most unusual case of reproductive phenology in angiosperms

In Franklinia alatamaha (Theaceae) an extended period of dormancy, associated with winter, separates pollination in the late summer and autumn from observable fruit growth, which occurs during the subsequent summer season. Here, ovule and early seed development were examined to decipher the timing of reproductive events that underlie this unusual phenological pattern. Female gametophytes were found to be mature before pollination. Evidence for double fertilization was observed soon after pollination. Early endosperm development progresses for up to 3 months after fertilization but comes to a standstill at the onset of winter. The zygote becomes dormant shortly after fertilization and does not divide during the autumn or winter. At the start of the following growing season, endosperm development is reinitiated and the first events associated with the formation of an embryo occur. Seed development is completed roughly at the same time as new flowers are opening, a full year after pollination and fertilization. Dehiscence of fruits does not occur until later in autumn. The prolonged zygotic dormancy in Franklinia is exceedingly rare among angiosperms and differs markedly from patterns of delayed fertilization that typically underlie extended periods between pollination and seed maturation in other temperate, perennial species.     

Cockroach pollination and breeding system of Uvaria elmeri (Annonaceae) in a lowland mixed-dipterocarp forest in Sarawak

Tropical forest plants are known to be pollinated by a diverse array of animals. Here we report on the pollination of a woody climber species, Uvaria elmeri (Annonaceae), by cockroaches in a lowland mixed-dipterocarp forest in Sarawak, Malaysia. To the best of our knowledge, this is the first report of pollination by cockroaches. The cauliflorous flowers in the understory are protogynous and bloomed for 50 h. An odor similar to decayed wood or a mushroom was secreted by flowers and was stronger during the male stage. Pollinators were cockroaches (Blattellidae) and drosophilid flies (Drosophilidae). Cockroaches, the main pollinators, visited flowers during both female and male stages at night, feeding on stigmatic exudate and pollen. Drosophilids, the secondary pollinators. mainly visited female-stage flowers during daytime, fed on stigmatic exudate. and laid eggs on stigmas. Neither autogamy nor self-compatibility was observed. Fruit production appeared to be pollen-limited. The fruit set, which was 2% of flowers in natural condition, was significantly lower than the 30% fruit set obtained by artificial cross-pollination. We discuss the traits of cockroaches as pollinators and the breeding system of U. elmeri.     

Using structural sustainability for forest health monitoring and triage: Case study of a mountain pine beetle (Dendroctonus ponderosae)-impacted landscape

Heavy disturbance-induced mortality can negatively impact forest biota, functions, and services by drastically altering the forest structures that create stable environmental conditions. Disturbance impacts on forest structure can be assessed using structural sustainability⿿the degree of balance between living and dead portions of a tree population⿿s size-class distribution⿿which is the basis of baseline mortality analysis. This analysis uses a conditionally calibrated reference level (i.e., baseline mortality) against which to detect significant mortality deviations without need for historical references. Recently, a structural sustainability index was developed by parameterizing results of this analysis to allow spatial and temporal comparisons within or among forested landscapes. The utility of this index as a tool for forest health monitoring programs and triage decisions has not been examined. Here, we investigated this utility by retrospectively analyzing the structural sustainability of a mountain pine beetle (Dendroctonus ponderosae)-impacted, lodgepole pine (Pinus contorta)-dominated landscape annually from 2000 to 2006 as well as among watersheds. We show that temporal patterns of structural sustainability at the landscape-level reflect accumulating beetle-induced mortality as well as beetle-lodgepole pine ecology. At the watershed-level, this sustainability spatially varied with 2006 beetle-induced mortality. Further, structural sustainability satisfies key criteria for effective indicators of ecosystem change. We conclude that structural sustainability is a viable tool upon which to base or supplement forest health monitoring and triage programs, and could potentially increase the efficacy of such programs under current and future climate change-associated disturbance patterns.     

Geissospermum argenteum (Angiosperma: Apocynaceae): a reservoir of parasitoids of fruit flies (Diptera: Tephritidae) in an upland forest in the Brazilian Amazon

1. This work aimed to assess the potential of Geissospermum argenteum Woodson (Apocynaceae) as a reservoir of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) in an upland forest in Brazil.
2. The study was conducted in a remnant of primary upland forest, in which were distributed 10 plots (0.5 ha each). All individuals of G. argenteum with diameters greater than 5 cm at a height of 1.3 m were inventoried. Two trees per plot were selected to assess the total production of fruit. Collectors were installed under the canopy projection of each tree. The fruits were counted and weighed in the field and were transported to the laboratory, to determine the dry mass. Samples of fruits were collected to investigate their infestation by fruit flies and percentage of parasitism.
3. A total of 394 specimens of G. argenteum were identified in the 5 ha investigated area, of which only 126 produced fruits during the 12 months of the assessment. Production ranged from 59 to 2478 fruits per plant (0.59 and 19.73 kg of fresh mass, respectively). Fifty-nine fruit samples were collected from 44 plants, from which 7703 puparia were obtained. Only Anastrepha atrigona Hendel emerged from the puparia. The mean infestation rate was 554.9 puparia/kg of fruit (0.4–1628.6 puparia/kg). Four species of parasitoids were obtained, with mean percentage of parasitism of 2.27% (0.23–9.01%).
4. Our results show that G. argenteum is a reservoir of fruit fly parasitoids, highlighting the importance of its conservation in native habitats, as well as its multiplication in areas close to commercial orchards.

     

Abundance and life cycle of Zonocerus variegatus (Orthoptera: Pyrgomorphidae) in the humid forest zone of southern Cameroon

Weekly captures from January 2000 to January 2002 enabled us to study the abundance and life cycle of the variegated grasshopper, Zonocerus variegatus (Orthoptera: Pyrgomorphidae), in the humid forest zone of Southern Cameroon. We found that Z. variegatus was present throughout the year in the forest reserve and the human‐influenced zones of Yaounde and Mbalmayo in two univoltine populations, which had unequal abundance and durations. The separation of the two populations was clearer in the Yaounde and Mbalmayo developed zones than in the Mbalmayo forest reserve (undeveloped zone). The abundance of Z. variegatus varied according to the post‐embryonic stage, sex, year and season. Hatching and coupling took place during the dry and rainy seasons, whereas oviposition occurred only in the rainy season. In Cameroon, the type of life cycle of Z. variegatus observed in the humid forest zone of the south is different from that of the “Sudanian and Sahelian” zones.     

Life cycle,phenology and economic importance of the walnut husk fly Rhagoletis completa Cresson (Diptera: Tephritidae) in northern Italy

The walnut husk fly Rhagoletis completa Cresson, a pest originating from North-America, was detected for the first time in Europe in 1991. The life cycle and phenology of R. completa were studied, during two successive seasons, in two commercial orchards located in northern Italy. The pest develops one generation per year. Fly emergence lasted from early July to the second half of August. Oviposition was detected from late July to early September, with peaks between August 5 and 18. First instar larvae were recorded from early August and mature larvae left husks from late August onwards to pupate in the soil. The seasonal patterns of nuts infestation showed rapid growths in August following oviposition peaks. Nuts infestation levels in the untreated plots of the two orchards, ranged from 74–91% in the first year to 89–91% in the following season. Relatively dark shell surfaces were linked to a weight reduction in nuts and kernels and to an increase in darkened and mouldy kernels. Observations made in an untreated orchard for additional 3 years confirmed these trends. Baited Pherocon AM were effective in monitoring flies but catches on woody green spheres were better correlated with the first relevant oviposition phases. When pesticides were sprayed with the correct timing, i.e. against eggs or first instar larvae, infestation was kept to acceptable levels with a single application. Considering average yields, nuts prices and costs for insecticide use, 1–2 insecticide treatments are economically viable. Other Implications are discussed.