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Dynamics of juvenile woody plant communities on termite mounds in a West African savanna landscape
(2014)
Termites are keystone species in savanna ecology, and their mounds are thought to be an important source of habitat heterogeneity and structural complexity of the savanna. Macrotermes termitaria have been shown to allow woody plant colonisation of landscapes otherwise dominated by C4 grasses. In this study, we assess how resource-rich Macrotermes mounds affect juvenile woody plant and non-woody plant species diversity, community composition, biomass and population dynamics. We repeatedly sampled paired termite mound and savanna plots in Pendjari National Park (Sudanian vegetation zone, North Benin, West Africa) over the course of two years. Despite considerable overlap in their species pools, plant communities of mound and savanna plots were clearly separated in ordinations. Species richness and diversity of juvenile woody plants was consistently higher on termite mounds, while no differences could be detected for non-woody plants. Evenness of juvenile woody plants was generally lower on mounds, whereas density and basal area were higher on mounds. In contrast, we did not detect any influence of the mound microhabitat on colonisation, mortality and turnover of woody juveniles. Therefore, we suggest that differences in the communities on and off mounds should be strongly influenced by directed diaspore dispersal through zoochory.
Flächenbezogene Artenzahlen sind besonders im Kontext von Monitoringprojekten grundlegend für die Beurteilung von Veränderungen der Biodiversität. Diese Studie vergleicht die von neun Bearbeitern (5 Einzelbearbeiter, 2 Zweierteams) erfasste Zahl an Gefäßpflanzenarten bei Vegetationserhebungen auf markierten Flächen von 4, 100 und 400 m2 Größe in einem artenreichen Kalkbuchenwald im Göttinger Stadtwald. Dabei wurden Bearbeiter- und Zeiteffekte untersucht, sowie artspezifische Übersehensraten, Fehlbestimmungsraten und Ungenauigkeiten bei der Zuordnung von Pflanzenindividuen zur jeweiligen Aufnahmefläche (Fehlzuordnungsraten) abgeschätzt.
Protokollierte Fragen ließen keine systematischen Unterschiede bei der Vertrautheit der Bearbeiter mit der Vegetation vor Ort erkennen, so dass Ausbildung und Erfahrung für gefundene Unterschiede ausschlaggebend sein dürften. Bei den 4 m2 großen Erhebungseinheiten ergaben sich bei der Artenzahl relative Abweichungen der Bearbeiter vom Erwartungswert von 8 bis 26 % (1 bis 4 Arten absolut). Diese waren bei den 100 m2 großen Erhebungseinheiten mit 9 bis 27 % (2 bis 6 Arten absolut) höher. Mit zunehmender Flächengröße nahm der Flächenidentitätseffekt tendenziell ab und der Bearbeitereffekt signifikant zu. Bei den 100 m2 großen Flächen hatte eine längere Bearbeitungszeit einen positiven Effekt auf die Artenzahl.
Mit Hilfe artbezogener Auswertungen wurden Übersehens-, Fehlbestimmungs- und Fehlzuordnungsraten ermittelt. Nicht eine Art wurde von allen Bearbeitern auf allen Flächen gefunden, auf denen sie jeweils auftrat. Schwer differenzierbare Arten sowie Arten in ungünstigen Entwicklungsstadien wiesen höhere Übersehens-, aber auch höhere Fehlbestimmungsraten auf. Bei morphologisch gut charakterisierten Arten wurde bei Einzelfunden von einer Fehlzuordnung zur Erhebungseinheit ausgegangen.
Die erzielten Ergebnisse sind auch für andere Projekte zur Erfassung der Biodiversität relevant und Bemühungen zur Reduzierung entsprechender Bearbeitereffekte sollten unternommen werden. Eine organisatorische Einbindung entsprechender Bemühungen wird vorgeschlagen.
Results of an Odonata survey carried out in the peatlands of Central Kalimantan, Indonesia, in 2012
(2014)
The results of a survey of Odonata (dragonflies and damselflies) in the peat lands of Central Kalimantan, Indonesia, in 2012 are presented. Fifty four species of Odonata found in the area in June-July 2012 are listed, along with brief notes and the locations in which they were found. Of the species found, twelve had not been recorded in Central Kalimantan previously, and of these at least four are completely new to science. Six species, originally described from Central Kalimantan and not recorded any- where since 1953, were rediscovered. At least sixteen of the species found during the survey are considered to be of conservation concern. The discovery of at least four new species to science in a relatively short survey indicates a high probability of occurrence of many more species that are awaiting discovery, and that many un-discovered species may be lost or highly threatened because of the rapid demise of peat swamp forest habitats. A checklist of the Odonata known from Central Kalimantan is provided in an appendix.
The study of the Portuguese marine ichthyofauna has a long historical tradition, rooted back in the 18th Century. Here we present an annotated checklist of the marine fishes from Portuguese waters, including the area encompassed by the proposed extension of the Portuguese continental shelf and the Economic Exclusive Zone (EEZ). The list is based on historical literature records and taxon occurrence data obtained from natural history collections, together with new revisions and occurrences. It comprises a total of 1191 species, distributed among 3 superclasses, 4 classes, 42 orders, 212 families and 617 genera. If considering only the EEZ and present territorial waters, this list represents an increase of 230 species (27.8%) and of 238 species (29.0%), when compared to the information available in FishBase (2012) and in the last checklist of marine and estuarine fishes of Portugal (1993), respectively. The order Perciformes shows the highest diversity, with 54 families, 162 genera and 299 species. Stomiidae (80 species), Myctophidae (71 species) and Macrouridae (37 species) are the richest families. From the listed species, 734 are present off mainland Portugal, 857 off the Azores and 766 off Madeira. Within the limits of the examined area, three species are reported for the first time in mainland Portugal and twenty-nine records are identified as doubtful. A total of 133 species have been recorded from the extended Portuguese continental shelf (2 off mainland Portugal, 117 off the Azores and 14 off Madeira), two of which are common to the Azores and Madeira extensions. Biogeographically, the Atlantic group is the most important (548 species – 46.01%), followed by the Lusitanian group (256 species – 21.49%), the African group (71 species – 5.96%), the Boreal group (34 species – 2.85%), the Mediterranean group (31 species – 2.60%), the Macaronesian group (21 species – 1.76%), the Atlantic/African group (19 species – 1.60%) and the Mediterranean/African and the Arctic groups, each with only 1 species (0.08%). Regarding the preferences for vertical habitat, the demersal fishes are the most important group (305 species – 25.61%), followed by the mesopelagic group (228 species – 19.14%), the bathypelagic group (164 species – 13.77%), the benthopelagic group (147 species – 12.34%), the bathydemersal group (115 species – 9.66%), the reef-associated group (88 species – 7.39%), the pelagic group (74 species – 6.21%), the epipelagic group (58 species – 4.87%) and 1 species (0.08%) of the benthic group. The oceanic habitat is the best represented group comprising 446 species (37.45%), followed by the shelf group (199 species – 16.71%), the slope group (164 species – 13.77%), the inner shelf group (89 species – 7.47%), the coastal group (70 species – 5.88%), the outer shelf group (29 species – 2.43%) and the oceanic/shelf group (7 species – 0.59%).