Role of vegetation characteristics on the distribution of three hornbill species in and around Pakke Tiger Reserve, Arunachal Pradesh, India

The relationship between various vegetation characteristics and the relative abundance of three hornbill species [Great Pied Hornbill (Buceros bicornis), Wreathed Hornbill (Rhyticeros undulatus) and Oriental Pied Hornbill (Anthracoceros albirostris)] was studied in and around Pakke Tiger Reserve, Arunachal Pradesh. We walked transects (n=11; 22 walks) in three study sites to detect hornbills. Vegetation sampling was done using circular plots (n=33; 10 m radius) at every 400m interval along each transect. Encounter rate (1.5/km) of Great Pied Hornbill (Buceros bicornis) was highest in the protected and undisturbed forest area where food and roosting tree density were also high (114/ha). Oriental Pied Hornbill was common in both the sites within Pakke Tiger reserve near riverine forests (0.75/km) and also in the dense undisturbed forest (0.875/km). Multivariate analysis revealed that tree density, presence of fruiting trees (utilized by hornbills), canopy cover, and tree diversity in a particular area are the major factors responsible for the assemblage of more than one species of hornbills. The study shows that protection of the forest patches to keep the diversity and density of the tree species intact is crucial for the survival and distribution of the hornbills in the landscape.

Comparative assessment of the ecological state of Timiryazevsky district forest park zones in Moscow

The article presents the results of a comparative environmental assessment of the quality of the environment in the central and outlying zones of two forest parks, contrasting in area, types and magnitude of anthropogenic load, - the Experimental Forest Station and the Dubki Culture and Recreation Park, located in the Timiryazevsky district of Moscow. The quality of the environment in the undisturbed forest biocenosis in the center of the Experimental Forest Station corresponded to the quality of the environment in the rural areas of the Moscow Region, while the environmental situation in the outlying zones of both forest parks bordering various urban infrastructure facilities deviated to varying degrees from the conditional norm. The worst indicators of the environmental quality and forest stand conditions were noted in the recreational zones located at the III-IV stage of digression, as well as in the zones bordering the roads, within which the degree of fluctuating asymmetry of birch leaves was suspended and the cellulolytic activity of the soil was 1.5-2.5 times lower than the background. The combination of recreational and transport loads reduced the quality of the environment in the Dubki park to a critical level. Keywords: CITY FOREST, BORDERLAND, ANTHROPOGENIC LOAD, POLLUTION, RECREATION, DEGRADATION, FLUCTUATING ASYMMETRY, CELLULOLYTIC ACTIVITY, APPLICATION METHOD, AIRBORNE POLLUTION, SNOW COVER

Patterns of Bat Diversity in an Undisturbed Forest and Forest Mosaic Habitats of the Afromontane Forest Biome of Western Cameroon

Anthropogenic activities continue to degrade natural montane ecosystems globally. Bats communities are altered by these changes. We analyzed how bats are affected by human-induced habitat changes by comparing the bat species diversity and functional diversity in undisturbed forest habitats and disturbed forest habitats of the Afromontane biome of Cameroon. We recorded 244 individuals from 13 species in the undisturbed forest, while 233 individuals from 16 species were recorded in the disturbed forest. Bat diversity was higher in disturbed habitats (D = 0.84) than undisturbed habitats (D = 0.67). Jackknife 1 species richness estimator suggests 21.53 species for the disturbed forest and 19.30 in the undisturbed forest. Closed-space forager insectivorous bats made up nearly half of the species in the undisturbed forest, but this dropped to 25% in the disturbed forest, meanwhile, edge-space foragers increased in the disturbed forest. Bat community analyses by ordination revealed a distinct bat community composition between the two forest types, demonstrated as a significant difference in diversity between the two forest types. The distribution of Rousettus aegyptiacus, Myonycteris angolensis, Hipposideros cf. ruber, and Micropteropus pusillus contribute the most to the difference in bat community composition between the two forest types. Edge and open-space species were likely to benefit from additional resources provided by the disturbed area, by expanding their range and distribution. However, this may not compensate for the decline in the population of forest species caused by the loss of pristine forests, thus measures to conserve montane forest remnants should be of utmost significance.

Indicators of Rainforest Recovery from Disturbance

Recovery of forest after logging can be tested in many ways: the presence of particular species of fauna or flora, the similarity of the biodiversity of the recovering forest to that on neighbouring areas of undisturbed forest; or the characteristics of soils and streams whose conditions may have drastically changed during logging. Three cases of rainforest recovery after logging and clearance from Australia and Borneo exhibit different starting and different goals for recovery. Faunal indicators of recovery vary with size and with species dependence of the rainforest. Endemic forest species may have difficulty in recovering. Tree species richness and abundance may recover in two decades, but canopy closure takes longer. Compacted soils may retain low infiltration capacities for many decades. This diversity in recovery rates is confirmed when compared with those used elsewhere. Because the starting points for recovery vary, from damage by tropical cyclones and landslides, to clearance for shifting cultivation, pasture or agriculture, to post-logging conditions, universal indicators may be inappropriate. The desired endpoints of recovery also range from a “wilderness” state to a National Park for human enjoyment, biodiversity preservation, safeguarding rights of traditional forest-dwelling peoples, or a second round of selective logging.

Impatiens parviflora (small balsam).

I. parviflora is an exceptionally successful invader of many European countries. Its spread has been rapid, it is abundant in many parts of its exotic range and is one of few plants to successfully invade undisturbed forest vegetation. It is consequently regarded as undesirable by some, though there is little evidence of negative economic, social or environmental impacts. Further spread in central Europe is not likely as the species is already very abundant. In North America, on the other hand, it is still very localized. Even without clear evidence for impacts, a further spread there should not be encouraged by deliberate or careless transport of the species.

Disturbed Amazonian forests support diminished breeding bird communities

Twenty percent of the Brazilian Amazon has now been deforested, and deforestation rates are increasing. This compels us to evaluate the conservation potential of human-modified landscapes; yet the ecological value of regenerating and fragmented Amazonian forests remains poorly understood. To date, most faunal studies in disturbed forests have examined metrics derived from presence or abundance. Although valuable, these data cannot tell us how old-growth species are using disturbed forests. In this study, we complement presence data with breeding observations to assess more comprehensively the habitat quality of disturbed forests in central Amazonia. We synthesized breeding evidence from standardized passive mist-netting, mixed-species flock-following, and opportunistic nest-searching across a full annual cycle in 30–35-year-old secondary forest, 10-ha fragments, and undisturbed forest. We then used multistate occupancy models to estimate the number of undetected breeding species in each forest type, which illustrated that fewer species bred in secondary forest (–43%) and 10-ha fragments (–17%) than in undisturbed forest. Both these losses are larger than the associated decrease in species richness alone (–17% and –10%, respectively). Notably, we confirmed breeding by only three terrestrial and near-ground insectivores in fragments and secondary forest combined (of the 9 species found in undisturbed forest). Disturbed forests also supported fewer breeding individuals (–35% to –50%) and, in secondary forest, fewer successful breeding attempts (–24%). Encouragingly, however, some forest-dependent birds are breeding and producing fledglings in disturbed forests, including representatives from almost every guild. This was especially apparent for mixed-species flocks and army-ant followers, two guilds that have historically been considered vulnerable to anthropogenic disturbance. Therefore, despite a loss of breeding habitat in disturbed forests, these data suggest that landscapes composed of regenerating forest and small fragments have conservation potential for forest bird populations.

Field surveys along habitat gradients revealed differences in herpetofauna assemblage in Margalla Hills National Park, Islamabad, Pakistan

This study was conducted to see whether herpetofaunal assemblage differed amongst hiking trails, undisturbed forest and urban areas within the Margalla Hills National Park, Islamabad Capital Territory, Pakistan. Circular plot area-constrained searches (45 plots in each habitat, each plot with an area of 25 m2) were used from March 2018 to July 2019. We recorded seven amphibian species, nine lizard species and six snake species. The species richness of amphibians and lizards was the same in the studied strata, while the detection and encounter rate of snakes was lower in the undisturbed forest and urban areas. The encounter rate of amphibians differed significantly between urban areas and hiking trails/undisturbed forest. The encounter rate and population density of lizards differed significantly between undisturbed forest and urban areas. The most frequently encountered amphibian species along the hiking trail and urban areas was Duttaphrynus stomaticus, with Hoplobatrachus tigerinus in undisturbed forest. The most common and frequently encountered lizard species along the hiking trail and urban areas was Hemidactylus brookii, while the Ophisops jerdonii was the most frequently seen in undisturbed forest. The most common and frequently encountered snake species along the hiking trail and undisturbed forest was the Indotyphlops braminus, while Ptyas mucosa was the most common in urban areas. The subsequent bio-assessment, based on herpetofauna, of the Park revealed good to excellent biotic integrity The Park faces threats including livestock grazing, alien invasive vegetation and human disturbance due to settlements, restaurants and tourism-related activities. While several of these threats have been mitigated since the establishment of the Islamabad Wildlife Management Board, the Park still requires improved management, especially regarding regulating tourism.

Rubus ellipticus (yellow Himalayan raspberry).

The invasiveness of the thorny shrub R. ellipticus has been most thoroughly documented on the island of Hawaii. Since the first report of its escape from cultivation in 1961, this species has become established in mid-elevation forest and pastureland, forming tall, dense thickets. Seeds are sufficiently viable following passage through the digestive systems of birds and mammals to readily germinate in pastureland and undisturbed forest sites where they are deposited. Several introduced frugivorous birds and feral mammals, are capable of dissemination of seeds via ingestion of the succulent fruit and birds in particular, are able to carry seeds to adjacent sites. It can also spread by suckers and resprouts vigorously after fire. The ability to colonize undisturbed native forests and displace native species is cause for alarm among resource managers of Hawaii Volcanoes National Park and other natural reserves of Hawaii, comprised of highly ecologically sensitive systems. It has been listed as one of the world's 100 worst invasive alien species (Lower et al., 2000), and is a prohibited species in South Africa (NEMBA Category 1a).

The effect of different logging regimes on the ecomorphological structure of stream fish assemblages in the Brazilian Amazon

We evaluated the effects of changes in habitat structure resulting from conventional logging (CL) and reduced-impact logging (RIL) on the ecomorphological structure of stream fish assemblages in the eastern Brazilian Amazon, investigating (1) which habitat characteristics are influenced by different logging methods, (2) the differences in the ecomorphological structure of fish assemblages between two logging methods and undisturbed forest (UF), and (3) the relationships between ecomorphological traits of fish assemblages and habitat variables. We measured 13 habitat variables and characterized 11 ecomorphological traits of 55 fish species collected in 34 sampling sites (stream stretches) located in CL, RIL, and UF. In logged areas, the streams present a fine sediment increase and reduced vegetation cover, while in the UF a greater amount of natural shelter and more cover vegetation were observed. These environmental changes selected ecomorphological traits of stream fish assemblages, recording a greater relative width of the mouth in UF, higher ventral flattening index in RIL, or greater relative head length, and higher caudal peduncle compression index in CL. In this sense, we recommend that logging practices, including RIL, should be reviewed as a means of adopting better strategies to minimize human disturbances in streams.

Contrary to vertebrates, less aggressive and more consistent individuals are common in disturbed habitats in the colonial spider Metabus gravidus (Araneae: Araneidae)

Habitat disturbance may affect average behavioural types and consistency/plasticity of behaviour. Studies with solitary vertebrates suggest that human-modified habitats may favour bolder, more aggressive and more plastic individuals. We evaluated whether wild colonial spiders, Metabus gravidus, vary in the magnitude, consistency and plasticity of boldness and aggressiveness between an undisturbed forest and an adjacent urban area in Monteverde, Costa Rica. Repeatability of aggressiveness was high at the disturbed site but moderate at the undisturbed site; repeatability of boldness was low at both sites. Individual and population plasticity was similar between sites for both behaviours. Aggressiveness decreases with increasing colony size at the disturbed site; this trend was not observed at the undisturbed site. Boldness did not change with colony size. In contrast to solitary animals, our results indicate that less aggressive and more consistent colonies may have an advantage living in human-disturbed habitats.