Tropical insectivorous birds comprise a diverse group that has a distinct response to habitat degradation. However, knowledge on birds’ ecological functions and their large-scale functional responses to human impacts across various habitats is scarce. We sampled 22 1-km-radius buffer landscapes within the Cantareira-Mantiqueira region (south-east Brazil), including native forests, pastures and marshes, to assess how landscape and habitat characteristics might affect insectivorous birds within the Brazilian Atlantic Forest. We studied whether bird species and functional diversity might respond to habitat turnover and nestedness and to native forest cover using generalized linear mixed models. We found negative effects of increased native forest cover on functional diversity indices. Bird communities in pastures show more nestedness, whereas marsh areas exhibit higher turnover. Forest areas receive a balanced contribution from both nestedness and turnover. These results are attributable to the predominantly secondary growth and early successional stages of the native forest fragments in the region, emphasizing the connection between landscape characteristics, habitat types and bird functional diversity in the Brazilian Atlantic Forest.

Globe artichoke [Cynara cardunculus L. var. scolymus (L.) Fiori] is one of the most important crops across the Mediterranean basin, where weeds are an important biotic constraint limiting crop yields. However, the effects of globe artichoke–cropping systems on weeds have been rarely tested. Following the demand for eco-friendly weed management practices, a multi-location trial (13 farms) was carried out, measuring weed seedbanks and aboveground communities within four globe artichoke–cropping systems: globe artichoke monoculture (ART), past cultivation of globe artichoke (8 to 10 yr ago) (past-ART), a globe artichoke–durum wheat (Triticum durum Desf.) rotation (ART-WHEAT), and a control where globe artichoke was never grown. Both below- and aboveground weed communities were dominated by annual therophytes, but a low correspondence was found between both types of communities. Averaged over farms, ART highly reduced both the weed soil seedbank (1,600 seeds m−2 on average) and the aboveground weed biomass (only 3.4 g dry weight m−2) compared with the control, with a decrease of 72% in the soil seedbank and 99% in the aboveground flora. Moreover, on the farms where globe artichoke was previously grown, a very low aboveground weed biomass (77% less than control) was found. In addition, ART contributed to the preservation of high levels of weed diversity (except for aboveground communities) and therefore avoided the creation of a specialized weed flora. In conclusion, we suggest the inclusion of globe artichoke into crop rotation schemes in Mediterranean agroecosystems as a sustainable tool for reducing both the soil weed seedbank and aboveground weeds, thus reducing the requirement of direct weed control methods and preserving the environment.

Biological invasions are a threat to protected areas globally; however, the relative lack of studies quantifying the ecological impacts impairs informed decision-making. We selected three annual alien plants, widespread in the riparian habitats of the Kruger National Park, South Africa: Datura innoxia, Parthenium hysterophorus, and Xanthium strumarium, to examine their potential impacts on riparian plant communities. We identified 12–13 populations for each and placed a pair of invaded and uninvaded plots in each population. Species richness, Shannon diversity, and Pielou evenness were compared between the invaded and uninvaded plots using LMM models, and species composition was compared using ordination. The invaded vegetation showed lower species richness compared to the uninvaded, with the strongest effect observed for P. hysterophorus. The invaded plots also showed lower Shannon diversity and Pielou evenness due to the presence of alien dominants. For all three invaders, the invasion resulted in changes in the composition of native vegetation. Some native plants were more frequent and abundant in the invaded vegetation, possibly due to the habitats created in sandy river beds. The native species richness decreased with increasing invader cover, but the species richness of aliens accompanying the invasive dominants was not negatively affected by their cover. Our results confirmed the negative impact of invasive aliens on native plant diversity, with the most pronounced effect by Parthenium hysterophorus invasions.

Itaipu Hydroelectric Power Plant initiated a large reforestation programme after the expropriation of the areas destined for the formation of the reservoir. This study aimed to evaluate the effectiveness of forest restoration of the Seasonal Semideciduous Forest in the Upper Paraná Atlantic Forest ecoregion, Brazil, using epigaeic ant assemblages as bioindicators, by comparing ant species richness and composition in the Reservoir Protection Strip with adjacent areas, such as the primary forest of the Iguaçu National Park and the Permanent Preservation Area located on a rural property and agricultural areas. In total, 171 ant species were identified. Ant species richness was higher in forest than in agricultural areas and did not differ among forest areas. However, ant species composition in forest areas, regardless of the restoration technique used, was not similar to the primary forest, possibly due to variation in forest recovery time. This study highlights the great value of the Iguaçu National Park as a conservation unit. Also, it reveals that the efforts for the creation and maintenance of the Reservoir Protection Strip, which remains without anthropic interventions for years, might indeed lead to a complete recovery of the ant species composition over time, reinforcing their great importance for biodiversity conservation.

Parasites directly and indirectly influence the important interactions among hosts such as competition and predation through modifications of behaviour, reproduction and survival. Such impacts can affect local biodiversity, relative abundance of host species and structuring of communities and ecosystems. Despite having a firm theoretical basis for the potential effects of parasites on ecosystems, there is a scarcity of experimental data to validate these hypotheses, making our inferences about this topic more circumstantial. To quantitatively test parasites' role in structuring host communities, we set up a controlled, multigenerational mesocosm experiment involving four sympatric freshwater crustacean species that share up to four parasite species. Mesocosms were assigned to either of two different treatments, low or high parasite exposure. We found that the trematode Maritrema poulini differentially influenced the population dynamics of these hosts. For example, survival and recruitment of the amphipod Paracalliope fluviatilis were dramatically reduced compared to other host species, suggesting that parasites may affect their long-term persistence in the community. Relative abundances of crustacean species were influenced by parasites, demonstrating their role in host community structure. As parasites are ubiquitous across all communities and ecosystems, we suggest that the asymmetrical effects we observed are likely widespread structuring forces.

Tropical coastal areas are amongst the most diverse ecosystems in the world. However, there are quite a few coasts that have rarely been studied for their macro-benthic diversity. The Indian coastline presents one such gap area. Two sub-parallel coastlines of India have a wide latitudinal span (8–23°N) and strikingly different physiographic environments. While the east coast receives a high siliciclastic input from large river systems flowing to the Bay of Bengal with fluctuating salinity, the west coast has a large shelf area and high productivity of the Arabian Sea. Such difference enables us to evaluate the effect of regional environmental parameters on marine molluscan diversity and distribution in an intra-tropical setting. Because of the wide latitudinal range, it is also possible to assess if spatial difference in species richness in such a regional scale follows the large-scale biodiversity pattern such as Latitudinal Biodiversity Gradient (LBG) despite inherent environmental variation. We used species distribution of marine bivalves, compiled using bioSearch and the Ocean Productivity database, to address this question. Our results show that intra-tropical species richness of marine bivalves is guided primarily by regional environmental parameters. Even with identical latitudinal extent, higher nutrient availability and larger shelf area, the west coast has significantly lower richness than the east coast; among environmental variables, productivity, salinity and coastline length emerged as significant predictors of species diversity. Moreover, a positive influence of a South Asian biodiversity hotspot on east coast fauna and a negative impact of the oxygen-depleted condition of Arabian Sea on west coast fauna, may have a significant contribution in developing such coastal variation in species richness. The latitudinal variation in species richness did not follow LBG. In contrast to the coast-specific diversity difference, species composition is not found to be dictated by coastal affiliation. The composition corresponds primarily to physiographic conditions. We identified three distinct eco-regions (north-western, southern, north-eastern) with characteristic species composition corresponding to unique physiography and productivity mechanism. The NW region has low siliciclastic input and high productivity associated with upwelling during winter cooling. The NE region has a distinctly high riverine input and salinity fluctuation. The southern region, in contrast, has well developed reefal system with moderate variation in salinity. Such correspondence underscores the importance of the regional environment in dictating the species diversity and distribution in the shallow marine realm.

Mosquitoes transmit a variety of diseases to humans. Their abundance and distribution are related to the characteristics of larval habitats. Mosquito larvae were collected from 120 natural and artificial habitats in 30 villages of 16 counties using standard 350 ml dippers and pipette, on a monthly basis from May–December 2014 in Mazandaran Province, northern Iran. Larval habitat characteristics were recorded separately, based on the conditions of the habitats (permanent or temporary, stagnant or running), type of habitats (natural or artificial), vegetation, exposure to sun, type of bed, water condition (clear or turbid), expanse (m), depth (cm, m) and temperature (°C) of habitats. The relationship between larval density and environmental variables was assessed by Chi-square tests. Totally, 19,840 larvae from three genera and 16 species were collected and identified. Anopheles maculipennis s.l. and Culex pipiens were the dominant species and collected with the highest density in plain areas. The highest number of larvae were collected from natural habitats (60.34%), including; river edge, marsh, pit and wetlands; with temporary and stagnant water, expanse of 0–5 m, depth of 1–25 cm, without plant, shadow-sun, muddy floor, turbid water, temperature 20–25°C and in sunny conditions. River edge and rice fields for An. maculipennis s.l and, wetlands and discarded tires for Cx. pipiens were the main larval habitats in the province. Statistical analysis revealed significant relation between occurrence of An. maculipennis s.l., Cx. pipiens, Culex torrentium, Culex mimeticus and Cs. annulata with each of the environmental variables (P < 0.001). These findings are essential in expanding our knowledge of the vectors ecology specially the type of habitat preference and will be beneficial in larval control programs.

Understanding the ecological characteristics of areas invaded and not invaded by exotic plants is a priority for invasive plant science and management. Buffelgrass is an invasive perennial species that managers view as a major threat to indigenous ecosystems of conservation lands in Australia, Mexico, the United States, and other locations where the species is not native. At 14 sites in Saguaro National Park in the Arizona Uplands of the Sonoran Desert, we compared the soil, vegetation, and soil seed bank of patches invaded and not invaded by buffelgrass. Abiotic variables, such as slope aspect and soil texture, did not differ between buffelgrass patches and patches without buffelgrass. In contrast, variables under primarily biotic control differed between patch types. Soil nutrients, such as organic C and NO3–N, were approximately twofold greater in buffelgrass compared with nonbuffelgrass patches. Average native species richness was identical (14 species 100 m−2) between patch types, but native plant cover was 43% lower in buffelgrass patches. Unexpectedly, native seed-bank densities did not differ significantly between patch types and were 40% greater than buffelgrass seed density below buffelgrass canopies. Results suggest that (1) soil nutrient status should not be unfavorable for native plant colonization at buffelgrass sites if buffelgrass is treated; (2) at least in the early stages of buffelgrass patch formation (studied patches were about 10 yr old), native vegetation species were not excluded, but rather, their cover was reduced; and (3) native soil seed banks were not reduced in buffelgrass patches.

Plant communities and ecosystem processes in seres at multiple altitudes in the tropical montane forest zone of northern Borneo were studied to understand the patterns and mechanisms of the secondary succession after shifting cultivation. A total of 25 stands (and additional three stands) were sampled with stand ages ranging from 2 to 55 y after slash and burn at altitudes between 900 and 1400 m asl. Plant species composition, above-ground biomass (AGB), chemical properties of soils, litter and foliar samples were investigated in each stand. A TWINSPAN analysis classified five plant communities primarily as a sere but with two altitudinal communities in the later successional phase. AGB accumulated steadily at the rate of 2.42 Mg ha−1 y−1 during the succession for the first 55 y due to the ontogenetic development of plants as well as plant community shifts. At the onset of secondary succession, pool of soil NO3-N and soil total P was high probably because burning caused flushes of minerals originating from the burnt plant materials. Pool of soil NO3-N and soil total P decreased with increasing stand age during the succession. Leaf-litter N:P ratios of dominant species significantly increased with increasing stand age suggesting disproportionately greater P deficiency than N deficiency in the later successional phase. It is suggested that tree species shifted to those of greater P-use efficiency during succession in response to decreasing soil P availability. We conclude that the interaction of altitude with the reduction of soil N and P availability was related to the altitudinal split of plant communities in the later phase, while pioneer communities were wide-ranging across altitudes reflecting richer soil nutrients.

Peracarid crustaceans are an important component of the vagile fauna associated with coralline algal beds, which often characterize the infralittoral fringe of tropical rocky shores. Among other variables affecting faunal assemblages, sedimentation, food supply and oxygen concentration within mats or turfs of coralline algae may greatly depend on the exposure to waves. In this study, peracarid assemblages were compared at replicated rocky shores within different levels of wave exposure, along a coastline in south-eastern Brazil. Overall amphipod diversity (11 species) was much higher than tanaidacean diversity (two species). Correlation analyses did not support any biological interactions between amphipods and tanaidaceans. Habitat complexity, while apparently limiting amphipod populations, did not affect tanaidaceans at a local scale. Amphipod abundance, not assemblage structure, was positively affected by wave exposure, probably improving oxygen concentration levels and renewal of food resources. Rather than abundance, which remains fairly stable, exposure to waves determined species identity in tanaidaceans, with Zeuxo coralensis found at exposed shores and Leptochelia aff. dubia found at sheltered shores, except for two L. aff. dubia individuals found at one of the exposed sites. Differences in the supply of sediment and the ability of these species in manipulating grains for tube building may explain such a striking pattern.

This study determined variation in liana diversity, composition and community structure in different topographic habitats, as well as the environmental factors associated with them in the Atewa Range Forest Reserve, Ghana. The above-mentioned liana assemblage attributes were examined in thirty 40 × 40-m plots, randomly demarcated within three topographic habitats at different average altitudes (hill bottom: 85.6 m asl, hill slope: 343 m asl, plateau: 641 m asl). Soil properties, altitude and slope angle were determined for the plots. Using multiple stepwise regression, non-metric multidimensional scaling analysis, and analysis of similarity, environmental factors that influenced the above-mentioned attributes of liana assemblages were determined. The findings revealed significant variation in liana diversity, composition and community structure among the topographic habitats. Liana species composition related with soil P, Mg and moisture, and altitude. Soil Mg and P associated positively with species composition in the hill-bottom habitat while altitude and soil moisture related negatively with it. A reverse trend occurred in the other habitats. Five environmental factors related significantly with liana diversity and community structure as follows – species richness: soil Ca and Mg, altitude; Shannon diversity: soil Ca, altitude; abundance: soil moisture and P, altitude; basal area: soil moisture, P.

Mass-flowering plant species are often pollinated by social bees that are able to use the abundant resource by recruiting workers from their colonies. In this study we surveyed pollinators on the mass-flowering perennial crop coffee (Coffea arabica) in its native range in Ethiopia. Previous studies in areas where coffee is introduced often find the social honeybee, Apis mellifera, to be the dominant pollinator. In those areas, the bee-species composition visiting coffee varies with a higher bee diversity closer to forest or in less modified habitats. We surveyed pollinators of coffee under different shade-tree structures, by collecting hoverflies and bees landing on coffee flowers in 19 sites in south-west Ethiopia. We found the native honeybee (A. mellifera) to be the dominant visitor of coffee flowers in all sites. Honeybee abundance was not affected by the local shade-tree structure, but was positively affected by the amount of coffee flower resources. Other pollinators were positively affected by complex shade-tree structures. To conclude, the honeybee is clearly the dominant pollinator of coffee in Ethiopia along the whole shade-tree structure gradient. Its high abundance could be a consequence of the provision of traditional bee hives in the landscape, which are colonized by wild swarming honeybees.

A twelve-month investigation was undertaken on how copepod community structure varied in relation to environmental factors in the Coleroon estuary, south-east India. Sampling was monthly, from Station 1 in the sea to Station 4 in the Vettar backwaters. Canonical correspondence analysis (CCA) was applied to elucidate the environmental factors affecting the copepod community. A total of 104 copepod species in 38 genera and 26 families were recorded, with the Calanoids, Acartia erythraea and Oithona brevicornis being the most dominant. At all four stations, both these species loaded near the intercept of CCA axes 1 and 2, perhaps reflecting that they were autochthonous. Most species occurred in distinct seasonal patterns. Abundances ranged from 13 × 103 to 215 × 103 (ind. m−3). Coleroon waters showed high diversity (bits/ind.), from 5.29 at Station 3 to 4.97 at Station 4. Abundance correlated positively with temperature and salinity and negatively with rainfall, dissolved oxygen concentration (DO) and pH. Species diversity correlated strongly with abundance (P < 0.01). Abundance and diversity were highest during the summer, and both correlated positively with salinity. Temperatures (air and water), salinity, pH and DO varied in the ranges 26–36°C, 25–34.2°C, 9–38, 7.0–8.7 and 3.0–6.8 ml l-1, respectively. Nitrate, nitrite, phosphate and silicate (µM) varied in the ranges: 4.7–64.5, 0.4–14.1, 0.2–12.9 and 9.3–148, respectively.

This paper reports on the phytoplankton community, its composition, structure and distribution in Changjiang estuary from February 1999 to March 2000. Two hundred and eight species were identified in the dry and flood periods. Diatoms, with 143 species observed, was the most abundant phytoplankton group, accounting for 68.75% of the total phytoplankton species number. Skeletonema costatum was dominant among all the species. The phytoplankton of Changjiang estuary in China was divided into five ecological categories: freshwater species, estuary brackish water species, inshore low salinity species, inshore widespread species and off-sea high salinity species. During the dry period, the major phytoplankton populations in the surface layer were estuary inshore and offshore populations, distinguished from the composition of the bottom layer. The community structure was similar in the two layers during the flood period. The phytoplankton species diversity was calculated for Simpson, Shannon–Weaver diversity and evenness indices, and found to be higher in the dry period, due to the simple dominant species and low spatial heterogeneity in the flood period. Higher phytoplankton abundance was observed in the surface layer during the flood period. The phytoplankton species distribution, coinciding with the dominant species distribution, varied with salinity, and their abundance correlated significantly with nutrients and light.

Spatial and temporal variation of tropical insect communities has rarely been studied, although such variation influences estimates of global species richness. Therefore, we compared spatial and temporal variation of herbivorous insect communities on Neoboutonia macrocalyx trees among seven sites over 1 y in a primary tropical rain forest in Kibale National Park, Uganda. The distance between the study sites varied from 4.8 to 31.2 km and altitudinal differences ranged from 20 to 242 m. Permutational multivariate analysis of variance (PERMANOVA) revealed significant spatial changes in community composition of the herbivorous insects and study sites differed also in insect abundance (6.9–26.2 individuals m−2 of leaf area). This is likely to be caused by differences in vegetation, altitude and microclimate among the study sites. The similarity of insect species composition was negatively correlated with geographic and altitudinal distances among sites and positively correlated with the similarity of tree community composition. Species richness varied significantly between sampling dates, ranging from 33 to 41 species. Also community compositions changed between sampling dates, which likely follows from marked seasonal changes in climate and the phenology of other host plants used by the generalist insect species also living on Neoboutonia macrocalyx. In general our study supports the idea of high variability of herbivorous insect communities in primary rain forests even at a small spatial scale. This should be considered when estimations of insect biodiversity are made.

To determine species composition of fruit flies on six cultivated varieties of citrus (Late Valencia orange, Pineapple orange, Ovaleto, Mediterranean sweet lemon, Satsuma tangerine and Ortanique orange), a study was conducted at the Agricultural Research Centre, Kade, Ghana. Improvised Lynfield baited traps (methyl eugenol (ME) and citrus juice (CJ)) and McPhail baited traps (trimedlure (TML)) were used. Ripe infested fruits from the selected varieties were also collected and incubated. Tephritid fruit fly species from trapping were identified as Bactrocerainvadens Drew, Tsuruta & White, Bactroceracucurbitae (Coquillet), Ceratitisditissima Munro, C. anonae Graham, C. capitata (Wiedemann), C. bremii Guerin-Meneville, Dacusbivittatus (Bigot), D. punctatifrons Karsch and Trirhithrum Bezzi. A total of 35,247 fruit flies were collected from the traps, with densities of 10.38, 1.00 and 0.27 flies/trap/day for ME, CJ and TML traps, respectively. All incubated fruit varieties showed co-habitation of three different species (C. ditissima, C. anonae and B. invadens) in each of them. In addition, one Dacus vertebratus was obtained from dropped Late Valencia fruits. Moreover, three individual Fopius caudatus (Szèpligeti) parasitoids were recorded from the infested incubated fruits. Ranking of the different fruit fly species from infested incubated host fruits was as follows: C. ditissima (476) >C. anonae (74) > B. invadens (71) and D. vertebratus (1). Competitive ability among the invasive flies in their process to infest the six citrus varieties was observed. These findings could serve as a useful starting point for the development of a reliable catalogue of host diversity, fruit fly species diversity and associated natural enemy records in Ghana.

A total of twenty-seven species of marine-living coccolithophores were recorded from seawater samples that were collected during two spring cruises along the shelf regions of the Yellow Sea (YS) and the East China Sea (ECS). They were classified into ten families and four orders, with some additional species incertae sedis. Most of these species were heterococcolithophores, and no holococcolithophores were examined from the YS waters. Six species were recorded for the first time from the coastal waters of the China Seas and their morphological characteristics are described and photographically illustrated in this paper. They were Cyrtosphaera lecaliae, Syracosphaera histrica, Syracosphaera marginaporata, Pappomonas cf. sp. type 3, Calyptrolithophora papillifera and Corisphaera strigilis. Three types of Emiliania huxleyi, type A, type B/C and type C, were examined. Species of the genus Syracosphaera, in addition to E. huxleyi and Gephyrocapsa oceanica, frequently occurred at the surveyed sites. The coccolithophore assemblages in the offshore waters of the ECS were characterized by high species diversity—fourteen species in one sample. This finding indicated that the shelf waters adjacent to the Kuroshio path were ideal habitats for living coccolithophores. The variation in taxonomic composition of these algae could be associated with differences in their preferred habitats.

The impact of Elodea canadensis on aquatic macrophyte biodiversity in (Lake) Steinsfjord has been studied through extensive lake-wide surveys and photographic sampling. E. canadensis greatly expanded in Steinsfjord since its appearance in 1978 and still dominated the macrophyte community in 2004. The areal distribution of E. canadensis peaked within 6 years from invasion and has remained relatively stable since; however, stands no longer reach the water surface. E. canadensis significantly increased its depth range, but the cover-weighted mean depth remained unchanged, suggesting that 3–4 m is its optimal depth in Steinsfjord. Species richness has not changed significantly since the earliest survey in 1936–38. However, species composition has changed remarkably, from isoetid dominance in 1936–38 to a diverse community dominated by Najas flexilis in 1979–80 to a less diverse community dominated by E. canadensis in 2004, with Potamogeton berchtoldii and Myriophyllum alterniflorum as lake-wide subdominants. Regardless of their abundance at the onset of the E. canadensis invasion, taxa whose cover-weighted mean depth overlapped with E. canadensis's in 1979–80 greatly reduced their abundance in 2004, shifted to deeper or shallow water or disappeared from sampling stations. Our survey indicates that E. canadensis may be the reason for the decrease of N. flexilis, likely through depletion of CO2 in the water column and reduced nutrients in sediments. The abilities to survive and grow in periodically exposed shallow areas, combined with minor herbivory by waterfowl, are likely important factors for the increase of M. alterniflorum in Steinsfjord's shallow waters.

This study constitutes a first contribution to the knowledge of the ecology of the decapod crustaceans in waters off Guinea-Bissau. Samples were collected during a survey undertaken between October and November 2008. A total of 122 species of decapod crustaceans were identified. Results showed an increase of decapod biomass and abundance with depth, reaching maxima values in the 200–500 m depth stratum but decreasing at depths over 500 m. Average diversity by strata increased with depth, with maximum over the deep slope. Seven main assemblages were identified: five primarily associated with depth—coastal shelf (<60 m), shelf (60–200 m), upper slope (200–300 m), middle slope (300–500 m), deep slope (500–1000 m)—and two other northern shelf assemblages affected by sediment type—coastal shelf-north (<50 m) and shelf-north (50–100 m). Species of each assemblage are typified. This study provides new information about composition, distribution, abundance and assemblage structure of decapod crustaceans in Guinea-Bissau that may be useful for future assessment of the effect of trawling pressure in the area.

Bird species assemblages in isolated Neotropical highland mountains have been moulded by the drastic climatic changes that occurred in late Pleistocene. Palynological evidence indicates that after the Pleistocene the highlands of Costa Rica and western Panama became isolated as climate turned gradually more tropical and highland vegetation retreated to the upper elevations of high mountains, forming highland islands. We surveyed birds at 10 representative sites throughout the Costa Rican highlands in order to determine the species composition of highland endemic assemblages. The area of available highland habitat explains 77% of the variance in species richness of the 36 highland endemics across highland islands, and the composition of these species assemblages have a nested distribution, rather than being independent sets of species on each island. The observed nested pattern is more consistent with a differential extinction model of species assemblages, and less likely to be explained by differential migration. We conclude that the reduction of highland vegetation and the avifauna associated with it, and its subsequent confinement to the summit of high mountains, is a possible explanation for the current distribution of highland endemic species in Costa Rican highland islands.