Monoon liukiuense (Annonaceae) is an endangered tree species distributed in Iriomote Island and Hateruma Island in the Ryukyu (Nansei) Islands, Japan, and in Orchid Island (Lanyu) in Taiwan. While its habitat is confined to small areas surrounded by human-altered landscapes, the matured trees bear abundant fruits, and many offspring grow under the mother trees. M. liukiuense is hypothesised to have lost effective seed dispersers. To test this hypothesis, fate of its seeds and the behaviour of frugivores were observed using time-lapse photography during three fruiting seasons from June 2015 to August 2016 in Iriomote Island, Japan. Although several animal taxa were observed to consume the fruit pulp, only two volant animals, namely the Yaeyama flying fox and large-billed crow, were proposed as seed dispersal agents for M. liukiuense. The present study shows that an average of 82% of the fruits in the canopies fell directly beneath the fruiting trees and an average of 90% of the seeds on the forest floor remained in their original positions. These results suggest that M. liukiuense has lost most of its seed dispersal agents and the chance to expand its distribution.

The genus Lysmata Risso, 1816 includes five species in the Mediterranean Sea, namely two well-known species with an Atlantic–Mediterranean distribution, L. seticaudata (Risso, 1816) and L. nilita Dohrn & Holthuis, 1950, and three additional species only known from single records. These are L. kempi Chace, 1997 and L. vittata (Stimpson, 1860), alien species native to the Indo-Pacific region, and L. olavoi Fransen, 1991, a poorly known species originally described from the Azores (Atlantic Ocean) and only reported three decades ago from the eastern parts of the basin. Based on an integrative taxonomic approach, we report the first finding of an ovigerous female of L. olavoi from Italy (Gulf of Naples, Tyrrhenian Sea) and the entire western Mediterranean, thus confirming the presence of this species in the basin and filling a wide gap in its published distribution. It is possible that this taxon was present in the Mediterranean for centuries but went overlooked or undetected due to cryptic habits, occupancy of still unexplored habitats, or misidentification with the highly similar L. seticaudata. Results of phylogenetic analyses confirm the exclusion of L. olavoi by the major lysmatid groups and underline the necessity of multilocus approaches to disentangle its correct phylogenetic position. As the species is still surrounded by a number of unsolved ecological and phylogenetic questions, further field and laboratory work is required to shed light on them.

Begonia jocelinoi Brade (Begoniaceae) is a threatened species, endemic to a small locality in the Brazilian Atlantic Forest. The species was formerly listed as Wanted in the Red List of Endemic Flora of the state of Rio de Janeiro because it had not been recorded since 1953. After evaluating herbarium collections and conducting fieldwork during May 2019–February 2020, we report the rediscovery of a single population of 65 reproductive individuals of B. jocelinoi, along with numerous seedlings, besides a trail in Itatiaia National Park. This Park is an IUCN category II protected area that permits some tourism activities. Some individuals of B. jocelinoi showed signs of pruning following the maintenance of the trail. We recommend strategies for in situ and ex situ conservation of this narrowly endemic species, including provision of advice to tourists regarding the occurrence of threatened species, and diversion of the trail where the species occurs.

Bactrospora dryina is an epiphytic lichen-forming fungus specifically related to old-growth floodplain forests, which have dramatically declined in Europe over the past centuries. In order to promote conservation management of such forest remnants, we aimed to study population genetics of this rare and threatened lichen. The newly developed 16 microsatellite markers are specific for the mycobiont of B. dryina and reliably amplify either single fruiting bodies or a sterile thallus. This allows the use of these markers for the identification of sterile crusts and for quantification of recent dispersal of the species into restored habitats. We tested the markers in 264 samples collected from 10 pedunculate oak trees growing in three localities in north-eastern Switzerland. All markers were polymorphic and showed two to five alleles per locus, and unbiased gene diversity varied from 0·06 to 0·71 over three populations. The relatively low number of alleles in B. dryina is possibly the consequence of colonization of secondary habitats created by forest management. Although oaks were largely covered with a single, continuous B. dryina colony, the microsatellite markers identified single or complex multi-genotype colonizations per tree. For future population genetic studies, we recommend collection of 5–15 specimens from one tree which would enable detection of 60–80% of the multilocus genotypes present. Hierarchical AMOVA revealed high variation (70%) on host trees, and a relatively high differentiation (12%) among the three locations in NE Switzerland indicated limited gene flow between those regions. Thus, the newly developed markers showed their applicability in population genetics at different spatial scales. They will play an important role in monitoring habitat restoration for the conservation of B. dryina and associated forests and riverscapes.

A novel species of nematode belonging to the rare genus Psammonema Verschelde & Vincx, 1995 is described from the continental margin of the north-eastern Arabian Sea (214 m). Psammonema kuriani sp. nov. shows a different position of the lateral alae compared with the original genus diagnosis, hence an emended genus diagnosis is given. The genus Psammonema was previously described from the estuarine sediments of Indian Ocean region and the present study reports the genus from the deep sea for the first time.

The “whitefin” gudgeon Romanogobio cf. belingi was recorded in the Nida River, a large lowland tributary of the upper Vistula (Southeastern Poland), for the first time in 2009. Since then, it has been caught during the periodical (three times per year) monitoring only sporadically. Conversely, in October and November 2012 R. cf. belingi was recorded frequently along an ∼60-km lowermost stretch of the Nida River. The abundance of this fish gradually increased downstream. This paper provides details of that phenomenon and discusses it in the context of the currently known distribution of this species.

Pannaria howeana and P. streimannii are described here as new to science. Both species are restricted to the isolated Lord Howe Island in Australia. The former is known only from one collection and the latter from two sites. Pannaria howeana is a primarily fertile species, with rather broad lobes and few rhizines restricted to the central part of the lower side of the thallus. The lower sides of the lobes have a pattern of characteristic radiating hyphae and narrowly recurved margins similar to the New Zealand lichen P. araneosa (C. Bab.) Hue, which is considered to be its closest relative. Pannaria streimannii is a phyllidiate counterpart of P. howeana. Both species share a new chemosyndrome consisting of porphyrilic acid in combination with vicanicin and leprolomin. Local endemic species are uncommon among tripartite Pannaria species, and the coarse vegetative propagules of both species appear to be an adaptation to local dispersal on a small, isolated island.

Many mires of high conservation value occur in Bulgaria. These mires acted as refugia during the dry phases of ice ages and therefore contain a high number of rare and disjunct species. The mires harbour specific ecotypes and genotypes of plants and animals, and thus provide an opportunity to test biogeographical hypotheses, and they also contain important information about the history of European mires. In this study we ranked all known mire and spring complexes in Bulgaria according to the occurrence of rare and threatened plant and mollusc species. This analysis shows a conspicuous concentration of rare species at several sites, and no correspondence between the importance of individual mires for biodiversity and their legal protection. Of the 10 mire complexes of highest priority only one is effectively protected. The remaining unprotected mires have either been destroyed or are threatened by ongoing development. Having joined the European Union, Bulgaria has built a Natura 2000 network that could provide an opportunity for mire conservation. However, destruction of mire habitats proceeds faster than the approval of Natura 2000 sites. There is thus a possibility that unique Bulgarian mires will be lost before the Natura 2000 system begins to perform its role. Only effective and timely protection of the mire remnants, together with appropriate management, will ensure the future of these unique habitats.

The Farasan Archipelago in Saudi Arabia is an Important Plant Area (IPA) in the Arabian Peninsula. This paper describes the flora of the Farasan Islands and provides an up-to-date botanical checklist together with background information on the geology and fauna of the islands. It designates the locality as an IPA due to the presence of nationally and regionally rare species and the presence of good examples of mangrove vegetation, which is both regionally and globally threatened. In addition to conservation assessments, this study also examines conservation planning concerns, particularly the colonisation of the main island Farasan Al-Kabir by the invasive species Prosopis juliflora. Suggestions for conservation action are provided. A new combination is made for Tetraena boulosii.

Over the last three decades, vegetation surveys in southwest Arabia have documented the existence of a small number of valley forest patches. A well-known area is in Wadi Rijaf, Jabal Bura, a protected area which has recently been surveyed by the current authors. The other valley forest sites in southwest Arabia have not been surveyed for over 15 years. This paper presents a descriptive study of five of these important valley forest localities. To provide an assessment of conservation value, field studies recorded the extent, quality and composition of the vegetation and the presence of regionally rare species. The significance of these remaining patches of Arabian forest, and the immediate threats to their survival, are also discussed.

Despite several works that have documented patterns of diversity in deep sea organisms, trends of diversity and the processes responsible for such trends still remain unclear. To date very few studies have documented the effects of variables such as latitude and longitude in deep-sea organisms in the Antarctic region. We explored the spatial patterns of diversity of benthic gastropods and bivalves in an extensive region about 2200 km long and 500 km wide from the South Shetland Islands to the Bellingshausen Sea in West Antarctica. A total of 134 species from 54 sites was recorded. Alpha diversity and beta diversity (measured as Whittaker’s and Bray-Curtis similarity indices) were highly variable among areas. None of the species richness estimators measured as Sobs, Chao2, Jacknife1 and Jacknife2, stabilized towards asymptotic values in any area. The number of rare species was large with almost half of species represented by 1 or 2 individuals (41%) and most species (62%) restricted to 1 or 2 sites. The partial Mantel test revealed that similarity between sites increased with the decrease of depth differences, but not with horizontal separation.

The isolated massif Jabal Bura (Yemen) is home to the largest area of ‘valley forest’ in southwest Arabia's western escarpment mountains. This study surveys the composition of this very rare forest and records the diversity of vascular plant species. It notes the valley forest as the home of several regionally rare species and records new locations for these taxa. A brief analysis of the canopy layer is provided, enabling comparisons with similar vegetation in northeast Africa. The paper discusses the importance of this regionally rare vegetation as well as threats to its conservation.

In the European Alps, subalpine forests are important for lichen diversity conservation at multiple levels. However, the potential role of coarse woody debris (CWD) has been only marginally considered in the previous literature. The aims of this case study are (i) to provide a first evaluation of the effects of different types of CWD (stumps, logs, and snags) and wood decay on lichen diversity in Pinus-Larix forests in the Italian Alps, and (ii) to increase the knowledge of the lichen biota on CWD in Italy. Seventy-eight species were found, including 12 nationally rare and 10 calicioid species; Placynthiella hyporhoda is new to Italy. Different types of CWD in different decay stages had significantly different lichen communities. Snags seem to be particularly effective for conservation, since they host the highest number of nationally rare species. Our survey suggests that CWD could be an important substratum for several nationally rare species, indicating that further surveys at a regional scale are urgently required in order to evaluate the role of CWD for lichen diversity conservation in the Alps.

Detailed studies on the lichen genus Porina in Macaronesia have led to a reappraisal of the genuine identity of Porina atlantica (Erichsen) P. M. Jørg., a characteristic species that has previously been confused with P. guaranitica, P. heterospora, P. nucula, P. mastoidea or P. rhodostoma in the literature, and is here reported from Madeira, the Canary Islands, Ireland, France and Portugal. Two new species are described: P. effilata Brand & Sérus. sp. nov. (known from Madeira, the Canary Islands, Great Britain, Ireland and Portugal) and P. ocoteae Brand & Sérus. sp. nov. (restricted to La Palma, Canary Islands, and São Jorge in the Azores). Porina leptospora Nyl. is recognized at the species level, and P. isidiata Kalb & Hafellner is reduced into synonymy with P. atlantica. A key to all known species of Porina in Macaronesia is provided.

The conservation of high-altitude medicinal plants is of concern throughout the Himalayan region, because they are important for traditional health care and in large-scale collection for trade. Because little is known regarding their conservation status in relation to the diversity of land-use patterns and habitats, this paper explores patterns of species composition and diversity of medicinal plants in five different pasture types in a traditionally-managed high-altitude landscape in northwest Nepal. Environmental variables, including human activities, strongly affected species composition, diversity and cover-abundance of medicinal plant species. Species richness of rare and commercially threatened medicinal plants (CTMP) showed patterns similar to overall medicinal plant species richness. Sub-alpine meadows, which have intermediate levels of human pressure related to grazing and relatively high levels of resource availability in terms of rainfall and soil nutrients, were richer in medicinal-plant species than alpine meadows. The coexistence of various plant communities under different human management regimes also enhanced landscape-level species diversity by maintaining some species restricted to particular habitat or pasture types. A number of medicinal plant species reported to be resistant to grazing were most abundant in heavily grazed sites. This pattern suggests that medicinal plant species may be positively influenced, to a certain extent, by human activities (mainly grazing). The combination of grazing and high levels of harvesting, however, had a negative impact on diversity and cover-abundance of rare and CTMP species. Maintenance of medicinal plant diversity and cover-abundance is critically dependent on managing grazing and resource harvesting to maintain levels that are both ecologically and economically sustainable. Forage for livestock and medicinal plants for local health care cannot be managed independently; a systems approach is needed, incorporating social management to accommodate the needs of different users. This could be achieved by maintenance of a mosaic landscape, in which different use patterns and pressures, reflecting the values attached to resources by different users and favouring different types of biodiversity, co-exist.

The need for a better understanding of the role of biodiversity in the functioning of aquatic ecosystems has been raised recently by several authors. If the question is not entirely new, its formulation is. It is therefore the opportunity to re-examine the pool of data already available in order to discuss some results that may be relevant for that purpose, while some major ecological questions have been identified. The top-down view argues that the effects of fish predation cascade down the trophic chain and are responsible for controlling the state of the entire ecosystem. The influence of fish predation on prey assemblages (prey selection, ontogenic shift) has been fairly well documented by various studies of African fish. They are also challenging subjects for studies of resource partitioning, a well documented example being given by zooplanktivores in Lake Turkana. The principle of cascading trophic interactions has been documented in Lake Victoria, after the introduction of a top predator, Lates niloticus. Another striking example is thatof Lake Nakuru where the introduction of a tilapiine resulted in a substantial increase of bird diversity, by the extension of the food chain to fish-eating birds. This introduced tilapiine may be considered as a keystone species, but this concept is questioned. A possible origin of fish biodiversity is adaptive radiation, that is to say the differentiation of species in morphology and resource use through competition. The cichlid flocks of the African Great Lakes where hundreds of rather similar species coexist, provide one of the best known examples of adaptive radiation. The question of niche overlap and functional redundancy has been raised and various studies have been conducted in the East African Lakes. The role of rare species has also been questioned. They may provide an insurance of ecosystem stability, which means that the more stable ecosystems in terms of key functions are those richest in species. In fact, in many large Nilo-Sudan river basins, there are apparently several groups of species which are able to replace the current assemblage when it experiences new ecological situations. Finally, the question has been raised as to what extent patterns of biodiversity are important for ecosystem productivity. The cornparison of data for four African lakes shows no relationship between fish diversity and fishery production, and speciesrichness does not appear to be a major determinant of basic production trends. At present we have only anecdotal, sometimes controversial, evidence of the role of fish diversity on the functioning of African freshwater ecosystems. We need to improve this knowledge on the importance of biodiversity in order to convince decision-makers that fish biodiversity needs protection.