Mathematical conservation ecology: A one-predator-two-prey system as case study

A method is presented to analyse the long-term stochastic dynamics of a biological population that is at risk of extinction. From the full ecosystem the method extracts the minimal information to describe the long-term dynamics of that population by a stochastic logistic system. The method is applied to a one-predator-two-prey model. The choice of this example is motivated by a study on the near-extinction of a porcupine population by mountain lions whose presence is facilitated by mule deer taking advantage of a change in land use. The risk of extinction is quantified by the expected time of extinction of the population.     

Long-term ecological study (palaeoecology) to chronicle habitat degradation and inform conservation ecology: an exemplar from the Brecon Beacons, South Wales

For ecosystems perceived as degraded, but for which the causal factors or timescales for the degradation are disputed or not known, long-term (palaeo-)ecological records may aid understanding and lead to more meaningful conservation approaches. To help ‘bridge the gap’ between (very) long-term ecology and contemporary ecology for practical application, there have been calls for working relationships to be established between palaeoecologists and conservation ecologists. One environment in which this has been attempted is blanket mire. Many blanket mires in Europe are degraded and contain few sphagna. In South Wales, almost all exhibit symptoms of degradation, with dominance by purple moor grass (Molinia caerulea) widespread. We used palaeoecological techniques on three peat profiles in the Brecon Beacons to investigate vegetation history of high-altitude blanket mire to help assess the relative contribution of various factors in mire degradation and to inform strategies for mire conservation and restoration management. We found that declines in sphagna preceded the rise to dominance of monocotyledons. Macrofossil records showed that although Molinia was already present on the Beacons before the start of the industrial revolution, its major rise to dominance in one profile was within the 20th Century, coincident with evidence for local fire. In another profile, it was out-competed by Eriophorum vaginatum after the start of the industrial revolution; there is circumstantial evidence to suggest that a reduction in burning contributed to the rise in E. vaginatum. Conservation management to reduce the current local dominance of both Eriophorum and Molinia is supported by the palaeoecological data, but severe erosion and hagging of peat will constrain practical methods for achieving this on the Beacons until the peat is stabilised. We suggest that palaeoecological techniques have wider applicability in conservation.     

Tropical African cedars (Widdringtonia, Cupressaceae): systematics, ecology and conservation status

Phenetic analyses of 24 morphological characters, collected in the field for 150 trees of Widdringtonia in Malawi, Zimbabwe, Mozambique and northern South Africa, show two distinct clusters. One can be identified as W. whytei , a tall, wide-crowned forest tree endemic to Mt Mulanje in Malawi, while the other is W. nodi/bra , a multi-stemmed shrub or narrow-crowned tree, which is common on Mulanje and widespread in southern Africa. These two sympatric species are distinct on phenetic, phylogenetic, ecological and biological grounds. The distinguishing characters of the two species are analysed and discussed and the differences are related to different responses to fire. Widdringtonia whytei is a forest pioneer with limited fire survival ability, while W. nodiflora coppices after fire and is common in fire-prone heathlands. To date it has been assumed that there is a single species of Widdringtonia on Mt Mulanje, and this has led to faulty management and exploitation decisions. Extensive plantations of the economically useless W. nodiflora have been established, in the belief that they are the economically desirable Mulanje cedar, W. whytei , which is now in danger of extinction.     

On the fauna and ecology of mosquitoes (Diptera: Culicidae) in forest-steppe and steppe regions of Western Siberia

Fauna and ecology of the mosquitoes from the southern forest-steppe (Chany Lake) and the northern steppe (Karasuksky lakes) have been investigated during 2004-2006. Species composition, dominant species, biotopical and seasonal distribution are examined. Detailed data on the biotopical and seasonal distribution, sex ratio and terms of development for the dominant species Coquillettidia richiardii (Ficalbi, 1889) are reported.     

Seasonal development of the lacewing Chrysopa dorsalis Burmeister (Neuroptera, Chrysopidae) in the forest-steppe zone of Russia

Seasonal adaptations of Chrysopa dorsalis Burmeister were studied in Belgorod Province of Russia (50°N, 36°E). It was found that in the forest-steppe zone two generations may be produced, but from 76 to 100% of the prepupae of the first generation entered diapause, about 40% of them having an obligate diapause. In the rest of the population, seasonal development was controlled by photoperiod and temperature. The critical day length was about 17 h at 20°C. Some prepupae were found to require two or three years to complete the diapause. This prolonged diapause seems to be a permanent element of the life cycle of the studied species. The proportion of the prepupae that remain in diapause after the first winter positively correlated with the percentage of diapausing prepupae of the first generation in the previous season (r = 0.8). The offspring from eggs laid by females simultaneously collected under the natural conditions emerged in successive years, and the tendency to enter a long-term diapause was not inherited. The rate of the larvae development and the prepupae weight were not different in individuals which had one-year-long and prolonged diapause. However, the weight loss due to dehydration and respiration during the first winter was slightly lower in the prepupae with the prolonged diapause. The expression of the prolonged diapause was independent of the photoperiod during the diapause induction, but it was increased at a high temperature (28°C). Probably, the prolonged diapause increases polymorphism of local Ch. dorsalis populations, ensuring their survival under unpredictable conditions.     

Aegilops (Poaceae) in Italy: taxonomy,geographical distribution,ecology, vulnerability and conservation

ABSTRACT

Aegilops L. includes wild species from which, over millennia, man has cultivated forms of Triticum L. Ten species of Aegilops occur in Italy. Three species are allochthonous and eight out of ten species are recorded in the Apulia region. Five out of the ten species have been included in Red Lists. Each taxon is presented and discussed, citing old and new sites of occurrence, by examining specimens from many different herbaria, and describing their ecology and habitats, according to the Directive 92/43 EEC. A new taxonomic key, for the identification of all Aegilops species growing in Italy, is provided. The occurrence of Aegilops caudata L., A. peregrina (Hack. in J. Fraser) Maire & Weiller and A. speltoides Tausch in Italy is doubtful.     

Allopatric distribution,ecology and conservation status of the Pilosella alpicola group (Asteraceae)

The Pilosella alpicola group comprises four morphologically distinct and geographically vicariant alpine taxa. We performed a thorough herbarium revision and literature survey to infer their distributional pattern(s). Pilosella alpicola s.s. occurs in the Alps in two disjunct areas: the Swiss Valais Alps and the Italian Dolomites. Historical records come also from the Austrian Alps (Gurktaler Alps and Hohe Tauern) and from one site from the Alpes Maritimes (Col de Larche), but the localities have not been recently confirmed. Pilosella rhodopea, a Balkan subendemic taxon, is quite widespread in Bulgaria (Stara planina Mts, Rila Mts and Pirin Mts), but is more rare in Albania, Greece and Macedonia. Interestingly, this species has also been recorded at two isolated sites in the Romanian southern Carpathians (the C?p??înii and Cozia Mts). This occurrence underlines the floristic affinities of this part of the Carpathians to the Balkan flora. Only two localities of P. serbica, based on voucher specimens, have been recorded so far; Kopaonik Mts in Serbia and the Prokletije Mts in Montenegro. The records from other ranges are related to P. rhodopea. Pilosella ullepitschii, the detailed distribution of which has already been published, is a Carpathian endemic with its core area of distribution in the western Carpathians (Slovakia and Poland). Three isolated localities are also known in the eastern Carpathians (Nemira Mts) and one locality in the southern Carpathians (Bucegi Mts). The possible causes of disjunctions between and within species ranges are briefly discussed. Based on the distributional data, population sizes and ecology, we evaluate the conservation status of the P. alpicola taxa and propose their inclusion in national Red Lists.     

The biology, ecology, and harmfulness of the flea-beetle Chaetocnema aridula Gill (Coleoptera, Chrysomelidae) in the forest-steppe of the middle Volga Area

In the forest-steppe of Samara Province, Chaetocnema aridula Gill. dominates among all the species of Chaetocnema Steph. found in cereal crops. The species develops mainly on winter wheat, and, to a lesser extent, on spring wheat and barley. In autumn, adult beetles aggregate on millet for pre-hibernation feeding. The highest population density of Ch. aridula was observed in the humid and warm 1997 and the lowest one, in the extremely dry 1998. In late April-the first third of May, adults begin oviposition after wintering. Larvae appear in winter and spring wheat in mid-May and in late May-early June, respectively. Larvae pupate in winter wheat, beginning from mid-June; in spring crops, pupation begins in mid-June. Adults of a new generation emerge between the middle of June and the middle of July. In spring crops, development of Ch. aridula finishes 2–3 weeks later than in winter crops. Larvae penetrate shoots in the upper soil level in the tillering zone. 50–80% of wheat and barley plants are damaged by larvae. In damaged plants, the number of shoots increases by 1.2–5.8 times, and the number of productive shoots decreases to 17–68%. In plants damaged by flea-beetles, harvest losses constitute 62–90% and 5–20% in winter and spring wheat crops, respectively, and the total harvest loss constitutes 0.3–3.9 and 1–15%, respectively.     

Biology, ecology and conservation of the Mobulidae

The Mobulidae are zooplanktivorous elasmobranchs comprising two recognized species of manta rays (Manta spp.) and nine recognized species of devil rays (Mobula spp.). They are found circumglobally in tropical, subtropical and temperate coastal waters. Although mobulids have been recorded for over 400 years, critical knowledge gaps still compromise the ability to assess the status of these species. On the basis of a review of 263 publications, a comparative synthesis of the biology and ecology of mobulids was conducted to examine their evolution, taxonomy, distribution, population trends, movements and aggregation, reproduction, growth and longevity, feeding, natural mortality and direct and indirect anthropogenic threats. There has been a marked increase in the number of published studies on mobulids since c. 1990, particularly for the genus Manta, although the genus Mobula remains poorly understood. Mobulid species have many common biological characteristics although their ecologies appear to be species-specific, and sometimes region-specific. Movement studies suggest that mobulids are highly mobile and have the potential to rapidly travel large distances. Fishing pressure is the major threat to many mobulid populations, with current levels of exploitation in target fisheries unlikely to be sustainable. Advances in the fields of population genetics, acoustic and satellite tracking, and stable-isotope and fatty-acid analyses will provide new insights into the biology and ecology of these species. Future research should focus on the uncertain taxonomy of mobulid species, the degree of overlap between their large-scale movement and human activities such as fisheries and pollution, and the need for management of inter-jurisdictional fisheries in developing nations to ensure their long-term sustainability. Closer collaboration among researchers worldwide is necessary to ensure standardized sampling and modelling methodologies to underpin global population estimates and status.     

Long-term dynamics of the species composition of herpetobiont and hortobiont beetles (Coleoptera) in the Galichya Gora Nature Reserve

A long-term study of the species composition of adult beetles (Coleoptera) was performed in the Morozova Gora locality (the Galichya Gora Nature Reserve, Lipetsk Province, Russia). From 1995 to 2005, a total of 23 683 ind. of 545 species from 57 families were captured in the migration trap, i.e., a system of 10 pitfall traps connected by guide barriers. Net-sweeping of the herbage in the steppe, oak grove, and meadow yielded 9048 ind. of 383 species from 33 families. The species composition of herpetobiont beetles was shown to change gradually in time, while that of inhabitants of the herbage layer changed sharply from year to year. The abundance dynamics patterns varied greatly between species and habitats.     

The structure of the fauna and life cycles of black flies (Diptera,Simuliidae) in streams of the forest-steppe in central Russia

The paper deals with the species composition, life cycles, structure of the fauna, and biodiversity of black flies (Diptera, Simuliidae) in different types of streams in the central Russian forest-steppe. Complexes of black flies in different types of streams are rather similar but faunas differ in the dominance structure.     

Long-term ecology of euglossine orchid-bees (Apidae: Euglossini) in Panama

Summary Abundance patterns during 6–7 years and orchid visitation were determined for 51 species of the 57 local euglossine bees. Male bees were counted at 3 chemical attractants presented in the same manner each month. Sites were separated by 75 km but included wet Atlantic forest at 500 m elevation, moist forest at 180 m near Barro Colorado Island, and cloud forest at 900 m near the Pacific ocean. 1. From 15 to 30 euglossine species of 4 genera were active in each month and site; monthly species number and general bee abundance were positively correlated. Many species had 3 annual abundance peaks (range 1–4) and were active throughout the year, but peak annual abundances rarely occurred during late wet or early dry seasons. In contrast, Eufriesea generally were present as adults only 1–2 months in a year. 2. Euglossine populations were exceptionally stable. Species at each site were more stable than any known insect population, and stability and abundance were positively associated. However, year-to-year population stability and the degree of seasonality were not correlated. Among the three sites, the more diverse (species rich) bee assemblages displayed lower stability; these were the wetter and upland sites. 3. The most abundant bees visited more orchid species. Eg. and El. each visited and average of 4 orchid species (range 0–13); Ex. and Ef. visited 0–3. Stable populations did not visit more or fewer orchid species than did unstable populations. 4. Less than 68% of species at each site visited orchid flowers; less than a few dozen of the 100–800 bees counted in a day carried orchid pollinaria. Over 20% of the euglossine species never were seen with pollinaria at any site and probably seldom visit orchids in central Panama. 5. Most bee species visited 1 or no fragrance orchids in a given habitat. Orchids tended to utilize common pollinators that seldom included more than 1 species, and they utilized stable or unstable, seasonal or aseasonal bees. However, the most stable and abundant bee, Eg. imperialis, rarely pollinated orchids; fewer than 10 of ca. 20000 bees carried pollinaria. 6. Orchids may interact primarily with discrete seasonal bee population peaks-probably the emerging adults. Although specialized orchid preferences are implicated for species that visit few or no local orchids but pollinate other species and carry pollinaria in other areas, euglossine bees do not need orchids to survive or reproduce.     

The damselfishes (Pisces: Osteichthyes: Pomacentridae) of Peninsular Malaysia and Singapore: systematics,ecology and conservation

Damselfishes (Pomacentridae) are among the most common of reef fishes in tropical seas, comprising 320 species in all, with 268 species alone in the Indo-West Pacific regions. 15 genera (Abudefduf, Amblyglyphidodon, Amphiprion, Chelioprion, Chromis, Chrysiptera, Dascyllus, Pristotis, Dischistodus, Hemiglyphidodon, Neoglyphidodon, Neopomacentrus, Plectroglyphidodon, Pomacentrus, Stegastes) and at least 39 species inhabit the waters of Peninsular Malaysia and Singapore. They are important ecologically because many species are extremely abundant in reefs, and also economically, as several are collected in large numbers for the lucrative aquarium trade. This demand has led to some fishermen using destructive methods in obtaining the fishes, to the point that original standing populations may not be recoverable. This threat poses a need for conservation of the reefs. The present study based primarily on fishes collected from the waters of Singapore and specimens from the Zoological Reference Collection at the National University of Singapore, will serve the dual purpose of establishing a current species list for Malaysia and Singapore, and to update and clarify the local taxonomy of the group. An annotated list (with localities) is provided of the known or reported species to aid studies on reefs.     

New data on the fauna,taxonomy and ecology of praying mantises (Dictyoptera,Mantodea) from Russia

Two little-known species of praying mantises, Severinia turcomaniae (Saussure, 1872) and Rivetina nana Mistshenko, 1967, are reported for the faunas of Russia and Europe for the first time based on the material collected in Astrakhan Province of Russia. New data on the morphology, ecology, and distribution of these species are given. The male genitalia of S. turcomaniae and the female of R. nana are described for the first time. The lectotype of Oxythespis turcomaniae Saussure, 1872 is designated and deposited in the collection of the Zoological Museum of the Moscow University. The synonymy of O. turcomaniae and Mantis wagneri Kittary, 1849 is shown to be insufficiently justified; M. wagneri is provisionally placed in the genus Severinia Finot, 1902. Since R. nana Lindt, 1968 is most probably not a synonym of R. nana Mistshenko, 1967 but a separate species, a substitute name R. pseudonana Shcherbakov nom. n. is proposed for the former. Some characters traditionally used for the identification of Rivetina species are shown to be significantly variable and thus unreliable. A key to 11 praying mantis species of the Russian fauna is provided. The recent discovery of S. turcomaniae and R. nana in the northern Caspian Sea region is assumed to reflect the expansion of the natural ranges of thermophilic species caused by increasing aridity of the climate.     

Distribution,ecology and conservation survey on Trifolium michelianum Savi (Fabaceae) in Sicily (Italy)

We report the identification of four residual stations for Trifolium michelianum Savi (Fabaceae) in Sicily, whereas the species was documented to be extinct at the Gorgo Cerro station (western Sicily), the only locality previously reported in the literature. In addition to an update on the distribution of the species, a survey on the new Sicilian populations led to their biological, ecological and phytosociological characterization, as well as to an assessment of the risk factors. The species, here relegated to the limit of its distribution area, occurs in particularly sensitive and vulnerable environments, such as the “Mediterranean temporary ponds”, considered “priority” by the Council Directive 92/43/EEC. Moreover, a new Sicilian association (Trifolio micheliani–Glycerietumspicatae ass. nova), framed in the alliance Glycerio-Sparganion (class Phragmito-Magnocaricetea), is described.     

Status,conservation and ecology of the exceptionally rare metallophyte Cornish Path-moss (Ditrichum cornubicum Paton)

Cornish Path-moss is one of the world’s rarest bryophytes, presently known from just three sites, former copper mines in the UK and Ireland. Covering the two UK sites, for the first time this study provides a set of location coordinates (x-, y- and z-axis) that is comprehensive, accurate and precise, in addition to investigating aspects of its ecology and assessing the success of trial habitat management plots. The species is shown to be rare, with a total population occupying 490 Ordnance Survey (OS) 10?cm grid cells, 77% at Phoenix United Mine and the remainder at South Caradon Mine, confined to bare patches of metalliferous soil that are especially high in the phytotoxins arsenic, cobalt and copper. Whilst the hostile chemical environment limits competition, various tolerant and larger bryophytes, lichens and vascular plants are shown to occupy the same niche, so that competitive exclusion is a constant threat. Turf-stripping of trial habitat management plots using a mechanical excavator at Phoenix United Mine, re-exposing bare metalliferous ground, is shown to be remarkably successful, providing a 20-fold increase in the population, presently making it the most important site for the plant in the world. Priorities for future survey and research are considered.