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991.
Heterocarpy is described for Thymelaea velutina (Thymelaeaceae), an evergreen dioecious shrub endemic to the Balearic Islands (Spain). It consists of dry and fleshy fruits (the latter, less numerous, have not been reported previously). The phenomenon could possibly have originated by different ripening processes in the pericarp, the main factor responsible for the difference between the types of fruit. We believe it shows an incomplete transition from fleshy to dry fruits, since the latter would have a high adaptative value in a xeric environment- The close relationship between the genera Daphne and Thymelaea is verified and a theory is put forward to explain differentiation under selective environmental pressures.  相似文献   
992.
Fosshagen  Audun  Iliffe  Thomas M. 《Hydrobiologia》1994,294(1):17-22
The insects of a small and cold aestival stream in northern Sweden were studied from semiquantitative kick-samples taken every ten days throughout the ice-free season in 1987. The stream froze solid at least in some sections in some winters. In addition to dipterans that were only identified to the family level, five ephemeropteran, four plecopteran, 11 coleopteran (Dytiscidae), and four trichopteran (Limnephilidae) species were found. Baetis bundyae Lemkuhl, Heptagenia orbiticola Kluge (Ephemeroptera), Nemoura cinerea (Retzius) (Plecoptera), Hydroporus palustris (L), Agabus setulosus (J. Sahlberg) (Coleoptera), Anabolia concentrica (Zetterstedt), Limnephilus coenosus Curtis, and Micopterna sequax McLachlan (Trichoptera) were all common. Malaise trap data are given for Plecoptera. The two ephemeropteran species Heptagenia orbiticola and Metretopus alter Bengtsson, and the plecopteran species Nemoura viki Lillehammer were recorded for the first time in Sweden. The remarkable species composition was attributed to the harsh abiotic and poorly studied environment. We predicted that the larval composition of this stream was representative for aestival streams in northernmost Fennoscandia.  相似文献   
993.
Macaca fascicularis is broadly distributed in Southeast Asia across 30° of latitude and 35° of longitude (Indochinese Peninsula, Isthmus of Kra, Malay Peninsula, Greater and Lesser Sunda Islands, Philippine Islands, and numerous small, neighboring islands). The range is divisible into 1) a core area comprised of mainland Southeast Asia, Borneo, Sumatra, and Java (large land masses interconnected during the last glacial maximum, 18,000 B. P.); 2) shallow-water fringing islands, which are smaller islands connected to the core area during the last glacial maximum; and 3) deep-water fringing islands, which are peripheral islands not connected to the core area during the last glacial maximum. Skull length was used to study effects of latitude and insularity on patterns of size variation. The data are from 802 adult M. fascicularis specimens from 140 core-area localities, 63 shallow-water islands, and 29 deep-water islands. Sex-specific polynomial regressions of skull length on latitude were used to describe skull length variation in the core area. These regressions served as standards for evaluating variation among samples from shallow-water and deep-water islands. The core area exhibits Bergmannian latitudinal size clines through most of the species range. Thus, skull length decreases from about 8°S (Java) to the equator (Sumatra and Borneo), then increases as far north as about 13°N (Isthmus of Kra). Farther north, to the northernmost Indochinese localities at about 17°N, skull length in M. fascicularis decreases with increasing latitude, contrary to Bergmann's rule. Latitudinal size variation in shallow-water fringing islands generally parallels that in the core area. However, skull length tends to be smaller than in the core area at similar latitudes. Deep-water fringing islands are markedly more variable, with relatively small specimens in the Lesser Sunda Islands and relatively large specimens in the Nicobar Islands. These analyses illustrate how a primate species may vary in response to latitudinal temperature variation and to isolation. © 1993 Wiley-Liss, Inc.  相似文献   
994.
ABSTRACT. The ultrasound-sensitive ears found in several families of moths are believed to be part of a predator (bat) specific defence strategy; the moth's evasive responses, elicited by the calls of bats, reduce its chances of being caught. Bats have never been found on the Faeroe Islands, whereas moths migrated there before the last Ice Age, and have since been isolated from areas with bats. For this reason, the hearing characteristics of moths from the Faeroes are investigated in this study. All noctuid moths caught there have functional ears sensitive to ultrasound. Audiograms are determined for thirty-two individuals of four noctuid species: Cerapteryx gramminis L., Apamea crenata Hūfn., Apamea maillardi Gey. and Diarsia mendica F. The auditory characteristics of the moths from the Faeroes resemble those of moths from other temperate zones where bats are abundant. The audiograms revealed best frequencies between 20 and 45 kHz, relatively broad turnings (Q10dB around 1), and thresholds of 35–50 dB SPL at the best frequency. The fact that the moths on the Faeroes possess such sensitive ears is explained by the large time spans which might be required for reduction of a character which is not directly opposed by a selection pressure.  相似文献   
995.
Changes in oxygen and nitrate in Bahia Darwin between July 1968 and March 1969 indicate that denitrification occurred in the deeper waters of this tropical, intermittently anoxic basin. Assuming constant rates of oxidation of organic matter in equally spaced depth intervals below the pycnocline depth, the rate of denitrification was estimated to be about 62.0 µg-atom NO3-N/liter/year. This rate is attributable to denitrification in the water column because a smaller rate was estimated for strata closer to the sediment water interface.Contribution No. 3193 from the Woods Hole Oceanographic Institution. Woods Hole, Massachusetts 02543. This study was supported in part by the National Science Foundation Grants GA 29303 and GB 6870. Reprints should be requested from the second author.  相似文献   
996.
The Oceania region is home to some of the world's most restrictive abortion laws, and there is evidence of Pacific Island women's reproductive oppression across several aspects of their reproductive lives, including in relation to contraceptive decision-making, birthing, and fertility. In this paper we analyse documents from court cases in the Pacific Islands regarding the illegal procurement of abortion. We undertook inductive thematic analysis of documents from eighteen illegal abortion court cases from Pacific Island countries. Using the lens of reproductive justice, we discuss the methods of abortion, the reported context of these abortions, and the ways in which these women and abortion were constructed in judges' summing up, judgements, or sentencing. Our analysis of these cases reveals layers of sexual and reproductive oppression experienced by these women that are related to colonialism, women's socioeconomic disadvantage, gendered violence, limited reproductive control, and the punitive consequences related to not performing gender appropriately.  相似文献   
997.
Oceanic islands are renowned for their unique flora and high levels of endemism. Native island plants, however, are imperilled by non-native species that can become invasive by outcompeting natives. The threat of native island assemblages generally increases with isolation and the number of endemics featured, but also with human-associated disturbance and land use. Based on this, the Canary Island native plant systems should be highly threatened by invasives, similar to other oceanic islands globally. However, Canarian native plant systems are only weakly infiltrated and are rarely directly threatened by invasive plants. Further, highly disturbed areas, usually among the first colonized by invasives on islands, are recolonized here by natives. Based on this, we postulate four hypotheses (climatic filter, well-preservation status, human legacy and permanent colonization) for explaining this unusual behaviour of plant systems on the Canary Islands, providing an opportunity to understand the drivers and processes behind invasion into plant communities on islands.  相似文献   
998.
Summary

Non-native species form a significant, but under-recorded, component of the Falkland Islands vascular flora. With this in mind a comprehensive re vie w of the non-native flora of the Falkland Islands was undertaken for the first time since the publication of the definitive Flora in 1968. We have recorded 175 non-native taxa, from 46 families, from the Falkland Islands which are listed with accompanying notes on habitat, status and distribution. Twenty-nine of these are likely to be commonly encountered, though only Aira praecox, Cerastium fontanum, Rumex acetosella and Sagina procumbens are near ubiquitous throughout. The origins of much of the non-native flora are obscure, however most species seem to be of European descent, and a significant proportion of taxa seem to have become established after introductions for agricultural and horticultural purposes.  相似文献   
999.
Predators are an essential component of past and present ecosystems and trophic networks. In addition, their role as bone bio-accumulators may at least partly determine the richness of fossil sites. Prior to human arrival, terrestrial mammals were absent from the Pityusic Archipelago (Eivissa and Formentera islands, Western Mediterranean Sea), a feature that represents an ecological singularity in the Mediterranean islands. The diurnal and nocturnal predatory bird guild from the Upper Pleistocene and Holocene of the Eivissa Island is approached here through the study of Accipitridae, Falconidae and Strigidae from Es Pouàs, an extraordinarily rich fossil site that provided more than two thousand bones of birds belonging to these three families. The importance of each species as bio-accumulator and a comparison with current fauna are outlined.  相似文献   
1000.
Background and AimsSeveral biogeographical models have been proposed to explain the colonization and diversification patterns of Macaronesian lineages. In this study, we calculated the diversification rates and explored what model best explains the current distribution of the 15 species endemic to the Canary Islands belonging to Helianthemum sect. Helianthemum (Cistaceae).MethodsWe performed robust phylogenetic reconstructions based on genotyping-by-sequencing data and analysed the timing, biogeographical history and ecological niche conservatism of this endemic Canarian clade.Key ResultsOur phylogenetic analyses provided strong support for the monophyly of this clade, and retrieved five lineages not currently restricted to a single island. The pristine colonization event took place in the Pleistocene (~1.82 Ma) via dispersal to Tenerife by a Mediterranean ancestor.ConclusionsThe rapid and abundant diversification (0.75–1.85 species per million years) undergone by this Canarian clade seems the result of complex inter-island dispersal events followed by allopatric speciation driven mostly by niche conservatism, i.e. inter-island dispersal towards niches featuring similar environmental conditions. Nevertheless, significant instances of ecological niche shifts have also been observed in some lineages, making an important contribution to the overall diversification history of this clade.  相似文献   
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