The structure of Leguminosae-Detarioideae dominant rain forest in Korup National Park, Cameroon

Background and aims – We studied a cluster of trees in the Leguminosae subfamily Detarioideae, to: (1) determine the size, structure, and tree species composition of this cluster; (2) map the size, shape, and structure of groups of individual Detarioideae tree species in the cluster.Location – Lowland rain forest in southern Korup National Park, in the Southwest Region of Cameroon.Material and methods – Trees in permanent plots were recorded using standard plot enumeration techniques. Outside plots, single-species tree groups were recorded by a rapid technique. From this data, detailed maps of groups of trees were prepared.Key results – Detarioideae tree species occur co-dominant in a cluster of at least 32 km2 with an irregular shape. The cluster contained at least 42 Detarioideae tree species; at least 29 of these occurred in groups ranging in size from 50 to 4000 m across, depending on the species. Groups usually had circular shapes, caused by ballistic seed dispersal. In a group, trees were always mixed with trees of several other Detarioideae species. Every area within the cluster contained a specific set of Detarioideae species. The percentage of Detarioideae trees ≥ 60 cm stem diameter on 50 ha was up to 76% in Detarioideae-rich forest, to 6% in Detarioideae-poor forest. Of all trees in the centre of the cluster, 2.8% belonged to pioneer forest species, which indicates that disturbance levels were low during the past generations of trees.Discussion – The forests in the Detarioideae cluster have not been subject to substantial human and natural impacts in historic or prehistoric times. Such forests are exceptional in Africa. Detarioideae clusters may indicate glacial age forest refuges, especially clusters that contain both many different Detarioideae species and some Detarioideae species endemic to the cluster.

The genus Cola (Malvaceae) in Cameroon’s Korup National Park, with two novelties

Background and aims – Cola, the second largest genus of the Malvaceae-Sterculioideae comprises 100–135 small to large tree species confined in nature to African forests, though cultivated elsewhere. Current species distribution ranges show that the genus is highly diverse in the seasonally wet forests along the Nigeria-Cameroon border, including the Korup National Park (KNP). In this paper we examine the diversity and abundance of Cola in KNP compared to other forests for which comparable data are available. We also describe two novelties in the genus.Methods – We used inventory data from a 50-ha permanent plot in southern KNP where all Cola trees and saplings down to 1 cm in diameter were tagged, mapped and identified. Additional collections of the genus came from the 11 km trail leading to the plot. Classic herbarium techniques and field observations were used for the morphological identification and description of specimens at MO and YA and from our personal collections. Cola species richness and abundance was estimated from the plot data and compared to other African forest sites for which comparable data are available. The evaluation of the conservation status of the two new species described in this paper followed the IUCN Red List Categories and Criteria. Key results – Twenty-five species of Cola were identified in the southern part of the KNP, including four undescribed species, raising the total number of Cola species in Cameroon to 46. The abundance of the genus in KNP was three orders of magnitude higher than in the Rabi forest in southwestern Gabon or in the Ituri forest in eastern D.R. Congo. This high species richness and abundance suggests that KNP is part of the center of diversity of the genus. Two new species, Cola zemagoana Kenfack & D.W.Thomas and C. mamboana Kenfack & Sainge are described and illustrated. Both species are only known from the lowland rainforest of southwestern Cameroon. Cola zemagoana is narrow endemic of southern KNP and its conservation status is assessed as Endangered. Cola mamboana is confined to the lowland forests of southwestern Cameroon, is locally very abundant in protected areas and is also assigned the conservation status Endangered.

New taxa of oribatid mites from Korup National Park (Cameroon). The genus Pergalumna (Acari, Oribatida, Galumnidae), with description of three new species and a key to known species from the Ethiopian region

Three new species of oribatid mites of the genus Pergalumna (Oribatida, Galumnidae) are described from litter and soil in the Korup National Park (Cameroon). Pergalumna jenoi sp. nov. differs from P. margaritata Mahunka, 1989 and P. pseudomargaritata Mahunka, 1994 by the presence of simple dorsosejugal suture, dentate anterior margin of the ventral plate, distinct reticulate pattern on the pteromorphs and dense stria on the genital plates, the localization of setal alveoli la posterior to porose areas Aa, and the absence of a median pore. Pergalumna tuberclesejugalis sp. nov. differs from P. margaritata and P. pseudomargaritata by the larger body size, the localization of porose areas Aa closer to lm than la, and setal alveoli h3 close and lateral to A2, the presence of sejugal porose areas, and the absence of a median pore and stria on the genital plates. Pergalumna grebennikovi sp. nov. differs from P. bifissurata Hammer, 1972 by the larger body size, the presence of smooth bothridial setae, well-developed interlamellar setae, reticulate anterior margin of pteromorphs, comparatively long prodorsal median ridge and a median pore, and the localization of setal alveoli la and porose areas Aa. An identification key to the known species of the genus Pergalumna from the Ethiopian region is presented.

Oribatid mites (Acari, Oribatida) from Korup National Park (Cameroon): list of taxa, new findings, descriptions of two new species

The present study is based on oribatid mite material (Acari, Oribatida) collected from the Cameroonian Korup National Park in 2016. A list of identified taxa, including 51 species from 33 genera and 19 families, is presented; of these, 28 species, 16 genera and 6 families are recorded in Cameroon for the first time. Two new species belonging to the genera Lasiobelba and Haplozetes are described: Lasiobelba camerunica sp. nov. differs from Lasiobelba decui (Vasiliu & Ivan, 1995) by the presence of eight pairs of notogastral setae (c represented by alveoli, h3 and their alveoli absent), spindle-form bothridial setae with distinct thin apex and longer notogastral setae la, lm and lp; Haplozetes paracancellatus sp. nov. differs from Haplozetes cancellatus Beck, 1964 by the presence of long interlamellar setae and foveolate anogenital region.

Contribution to the knowledge of the oribatid mite genus Cavernocepheus (Acari, Oribatida, Otocepheidae)

A new subgenus, with two new species, of the genus Cavernocepheus (Oribatida, Otocepheidae) are described from soil and litter of Korup National Park in Cameroon. Cavernocepheus (Paracavernocepheus) subgen. nov. differs from the nominative subgenus by the presence of four pairs of genital setae. Revised generic and subgeneric diagnoses and an identification key to the known taxa of the genus Cavernocepheus are presented.