Anthropic Sites Research Articles

An Invasive Ecological Study on the Flora of Soil Seed Bank and Standing Vegetation Across Diverse Anthropo-ecosystems in Indian Dry Tropics

Plant invasions in tropical ecosystems are being increasingly realized particularly in highly dynamic but fragile dry tropical ecosystems, where there is generally little ecological information on invasions in subterranean vegetation. The present study was carried out to understand the floristic composition of both seed bank and standing vegetation across a range of five diverse anthropo-ecosystems in an urban region in Indian dry tropics. A total of one hundred soil samples (each of size of 25cm×25cm from 0-5 cm and 5-10 cm depth) from five anthropic sites (vegetation of University campus, polluted Kali River bank, Brick kiln, Waste land and Road side) were analyzed for their taxonomic position, life form and bio-geographic origin of the seedling emergents in relation to the flora in standing vegetation. A total of 221 plant species (58% aliens, 34% of aliens of American origin, 75% weedy herbs) in standing vegetation spread over 54 families were recorded in standing vegetation of the study sites with more than 55% representation from eight dominant families led by Fabaceae, Poaceae and Asteraceae followed by Malvaceae, Amaranthaceae and Solanaceae. In contrast, a total of 81 seed bank flora (10 unidentified, 62% aliens, 43% of American origin, 87% herbs) distributed over 32 angiospermic families were recorded. While none of the seed bank vegetation at any site showed significant similarity with its standing vegetation indicating the minor role of seed bank flora in the regeneration of the standing plant communities above ground. However, a considerable similarity among seed banks and standing vegetation at other sites indicated a significant possible role of anthropogenic activities in the urban regions of Indian dry tropics, evinced by the largest proportion of grasses and herbs dominated by exotics, especially of American origin. These aliens through successful naturalization via seed banks may cause homogenization of floristic structure. In conclusion, the present study revealed a heavy scale of intrusion by the alien plants dominated by American elements into not only standing vegetation but also in seed banks across the anthropic sites in urban regions in Indian dry tropics which is likely to alter the standing vegetation floristic structure with a larger abundance of alien flora.

Plastic ingestion and dispersion by vultures may produce plastic islands in natural areas

Rubbish dumps can become an important environmental source of plastic. Several species feed on organic waste from these sites, but at the same time are exposed to non-organic materials. Species that can gather food in these sites might at the same time disperse waste consumed, but this has rarely been evaluated. We compare the occurrence of plastic debris in regurgitated pellets of three sympatric vultures from northwest Patagonia, Andean condors (Vultur gryphus), black vultures (Coragyps atratus) and turkey vultures (Cathartes aura), foraging in different degrees of humanized sites. We also evaluate the influence of rubbish dumps in the presence of plastic debris in pellets of the studied species and their potential role in spreading plastic to the environment. Most synthetic material present in pellets was plastic. Pellets of Andean condors, which avoid disturbed anthropic sites in this area, showed almost no plastic debris compared with the other sympatric vulture species, suggesting an influence of the foraging habits on plastic ingestion. For black and turkey vultures, we found that rubbish dumps may be an important source of plastic. The occurrence of plastic debris in pellets of black vultures sampled in 2010 and 2020 increased, probably associated with the increase in urbanization and waste production in the study area. Avian scavengers were exposed to and are able to transport plastic to distant communal roosts generating “plastic islands”. It is necessary to reduce plastic generation and better waste management practices to avoid species and environments to be affected by this pollutant.

The effects of cattle ranching on the communities of necrophagous flies (Diptera: Calliphoridae, Mesembrinellidae and Sarcophagidae) in Northeastern Brazil

Most of the ongoing decline in biodiversity, worldwide, is due to human activities, in particular, the expansion of agriculture. In this context, we highlight the need for studies of the taxonomic groups that can provide insights into the dynamics of the ecological communities facing anthropogenic impacts. For this, we evaluated the effects of the environmental changes caused by cattle ranching on five phytophysiognomies (Cerrado Savanna, Amazon Forest, Palm Forest, Marshland, and Mangrove) in the state of Maranhao, Brazil. We tested the hypothesis that the species composition, abundance, and richness of the families Calliphoridae, Mesembrinellidae, and Sarcophagidae (Diptera) are affected by ranching in each of the phytophysiognomies. Specimens were collected at 90 sites, including 45 anthropic sites (cattle ranches) and 45 preserved habitats, using traps baited with bovine lung. We collected 15,023 calliphorids (11 species), 10,772 sarcophagids (52 species), and 241 mesembrinellids (one species). The results indicated significant differences between anthropic and preserved habitats in the species composition, abundance, and richness of sarcophagids, in particular in the Amazon Forest, where the highest species richness was recorded in the anthropic environments. In the case of the calliphorids and mesembrinellids, by contrast, significant differences were found in species composition and abundance in only in four of the five phytophysiognomies analyzed (excluding the Cerrado Savanna), while species richness only varied in the palm forest and marshland. In all cases, lower values were recorded in the anthropic environments. These results indicate that the insects of the families Sarcophagidae, Calliphoridae, and Mesembrinellidae respond differentially to the anthropic activity (cattle ranching) and can be used to evaluate this type of anthropogenic impact systematically. In addition, the Amazon Forest was the phytophysiognomy most impacted by this activity in the Brazilian state of Maranhao.

Distribution of Heavy Metals and Minerals in the Various Size Fractions of Soil from Copșa Mică, România

The Copsa Mică area is one of the most polluted anthropic sites in Romania. Because higher heavy metal concentrations occur in finer fractions, this research focuses on the size fraction < 500 μm. Two kilograms soil sample was sieved on the 500-μm sieve and was air classified into size fractions down to the low micrometer range. The size fraction’s composition was investigated by ICP-OES IC, XRD, and FTIR spectrometry. Approximately 80 and 62% of the material was smaller than 2 mm and < 500 μm, respectively. The predominant size fraction had a mass median diameter (MMD) of approximately 75 μm. The smallest size fraction with a MMD of 2.2 μm had a share of 3.6% and contained the highest amount of heavy metals. The concentrations of Pb, Zn, Cd, Cu, Sb, and As exceeded the legally regulated values for soils according to Romanian legislation. The respective concentrations were 26,900, 27,600, 415, 2130, 466, and 915 mg·kg−1. In the coarser size fractions 5, 4, and 3, the predominant minerals were quartz and alkaline feldspar, while in the finer size fractions 1 and 2, the clay minerals and total carbon (TC) were predominant. Illites and montmorillonites in the fine fraction composition retain heavy metals due to the high levels of cation exchange capacity. Black carbon accumulated in soil acts as a heavy metal adsorbent due to its porosity and high specific surface area. The good correlation between heavy metals and TC in the top soil can be an indicator of the level of heavy metal pollution.

Abundance, density and habitat use of lowland paca (Cuniculus paca, Rodentia: Cuniculidae) in the Lacandon Rainforest, Chiapas, Mexico

In this study, the effect of relevant variables (availability of food and cavities, competition, predation, and hunting pressure) on the relative abundance and population density of the spotted lowland paca (Cuniculus paca) was assessed. In addition, habitat use of this species at three sites with different land use regime (Montes Azules Biosphere Reserve, community reserves, and anthropic sites) in the Lacandon Rainforest, Chiapas, Mexico was analysed. From the perspective of the source-sink systems, it was predicted that pacas selectively would use the habitat with higher food and cavity availability (source habitats), where higher densities were expected. Twelve transects were located in three sites with different land use regimes, where food availability and potential cavities used by pacas were assessed. Along these transects, 4 camera-traps were deployed every 200 meters to estimate the relative abundance of pacas and their potential competitors and predators. Photo-captured individuals were identified to estimate population density and seasonal variation in habitat use. Generalized linear models (GLM) were constructed to analyse the effects of several variables on paca abundance and density. A relative abundance of 0.05 and 0.08 paca photographs/100 camera-days were recorded in the dry and the rainy season, respectively. A density of 54 pacas/km2 was estimated in both seasons. The availability of cavities was the only variable that showed a significant effect on paca density (P = 0.04 for the dry season, and P = 0.006 for the rainy season). Community reserves were used in the dry season more than expected from their availability in the study area (x2 = 28.8; P = 0.0001). In the rainy season, all three sites were used by paca in proportion to their availability. Our results suggest that the cavities used as refuges by pacas drive their population dynamics, and constitute a key habitat resource for them in the study area. We propose that the Ejidal Reserve and Montes Azules Biosphere Reserve may be source habitats supporting higher paca densities and greater availability of adequate cavities to protect adults and their offspring. On the other hand, areas transformed into croplands and grasslands for livestock production would represent sink habitats with lower paca densities, less availability of adequate cavities, and absence of offspring. The long-term conservation and habitat management of pacas in transformed landscapes will probably rely on the distribution and connectivity between and within the different habitat types available in the study area.

Las prácticas de paisaje El prodigio ecológico de un acontecimiento cultural

&lt;p&gt;La historia del paisajismo indica que se ha implementado privilegiadamente sobre sitios antrópicos. A su vez, su paradigma histórico ha sido fruto de los diferentes consensos en torno a la respuesta sobre los conflictos ambientales y sociales en la ciudad industrial. Desde la perspectiva del riesgo ambiental y social en la megalópolis contemporánea, la vegetación urbana protagoniza una estrategia ambiental que converge hacia la invención creativa de la ciudad posindustrial en una alianza entre la biología y la construcción social del paisaje.&lt;/p&gt;

Mosquitoes in degraded and preserved areas of the Atlantic Forest and potential for vector-borne disease risk in the municipality of São Paulo, Brazil

In order to assess the epidemiological potential of the Culicidae species in remaining areas of the Brazilian Atlantic Forest, specimens of this family were collected in wild and anthropic environments. A total of 9,403 adult mosquitoes was collected from May, 2009 to June, 2010. The most prevalent among species collected in the wild environment were Anopheles (Kerteszia) cruzii, the Melanoconion section of Culex (Melanoconion), and Aedes serratus, while the most common in the anthropic site were Coquillettidia chrysonotum/albifera, Culex (Culex) Coronator group, and An. (Ker.) cruzii. Mosquito richness was similar between environments, although the abundance of individuals from different species varied. When comparing diversity patterns between environments, anthropic sites exhibited higher richness and evenness, suggesting that environmental stress increased the number of favorable niches for culicids, promoting diversity. Increased abundance of opportunistic species in the anthropic environment enhances contact with culicids that transmit vector-borne diseases.

Mecistocephalus guildingii Newport, 1843, a tropical centipede with amphi-Atlantic distribution (Chilopoda: Geophilomorpha)

Mecistocephalus guildingii Newport, 1843 (Chilopoda: Geophilomorpha: Mecistocephalidae) is redescribed, and its geographical distribution revised and updated, after examination of 28 specimens from different localities together with critical assessment of published accounts and records. Mecistocephalus guildingii Newport, 1843 (= Mecistocephalus punctilabratus Newport, 1845, n. syn.; = Lamnonyx leonensis Cook, 1896, n. syn.; = Mecistocephalus maxillaris guadeloupensis Demange and Pereira, 1985, n. syn.) is distinguished from other Mecistocephalus species, with which it has been often confused, mainly in head elongation and some features of the clypeus. M. guildingii has been reported hitherto from less than two dozen sites on the eastern side of tropical Americas, however it is actually established in islands and coastal sites on both sides of the tropical part of the Atlantic ocean: on the American side from Bermuda through the Antilles to southern Brazil; on the African side in the Cape Verde archipelago and from Gambia to Liberia. It is also established in a locality on the Pacific coast of Mexico, and has been found occasionally inland in Brazil and in European hothouses and other disturbed anthropic sites.

Applying dynamics and comparing life tables for Pleistocene Equidae in anthropic (Bau de l'Aubesier, Combe-Grenal) and carnivore (Fouvent) contexts with modern feral horse populations (Akagera, Pryor Mountain)

In this study, we propose a method based on life tables currently used in population dynamics and ecology to compare the mortality curves of Equidae from anthropic and carnivore fossil assemblages with those from modern populations. The combined analysis of frequency ( f x ) with various ecological parameters such as mortality rate ( q x ), survival rate ( l x ), fecundity rate ( m x ), and killing factor ( k x ), established for each age class, allows us to characterize the stability of fossil populations. These ecological parameters, developed in demography, correspond to many curves and constitute a complementary approach to interpret the two main mortality models, attritional and catastrophic, often evoked in zooarchaeology. The age structures of fossil horses from the anthropic sites of Bau de l'Aubesier (Vaucluse, France) and Combe-Grenal (Dordogne, France) and the hyena den of Fouvent (Haute-Saône, France) are compared to typical catastrophic modern populations of Equidae from the National Park of Akagera (Rwanda). We also used data collected by the Bureau of Land Management for present day feral horses from Pryor Mountain (Montana, USA) which constitutes a reliable referential of a stable living population. The characterization of age structures in those different contexts is discussed as well as the impact of Neanderthals and hyenas on fossil assemblages.

Estimation de l'effet réservoir 14C marin en mer d'Arabie

Measurements of the marine reservoir effect in the Arabian Sea, from the present to 8685 cal ВС, make it possible to discuss the 14C calibration of marine biomineralisations (shells, otoliths, bioapatite). From the present to 4560 cal ВС, the ΔR (210 ± 15) remains constant in the north-west of Arabian Sea allowing us to insert the 14C dates of many anthropic sites from the coast of the gulf of Oman into classical chronologies. During the early to mid-Holocene, the high amplitude in sea surface temperature variation linked to intensified upwelling activity lead to higher values of the marine reservoir effect of up to 700 years from 6475 to 7305 cal ВС.

Trace metals in the soil and in Quercus ilex L. leaves at anthropic and remote sites of the Campania Region of Italy

The concentrations of Cd, Cr, Cu and Pb were measured in leaves of Quercus ilex L. and in the soils collected from 15 sites of the Campania Region of Italy of two different typologies (anthropic and remote), in order to evaluate: (1) the effect of translocation and/or direct deposition from air on leaf element concentrations; and (2) the suitability of the studied matrices as pollution monitors. The available fractions of the studied elements in the soils were also measured. The accumulation factor (anthropic/remote sites) was calculated to evaluate the element accumulation, both in leaves and soils, at the anthropic sites compared to the remote sites. The concentration factor (leaf/soil) was used to investigate the translocation of the element from soil to leaves. Cd and Cr soil contents at the remote sites were higher than at the anthropic ones; in contrast, at the latter, Cd and Cr leaf concentrations were higher than at the remote sites. Cu and Pb concentrations were greater both in the soils and in the leaves of the anthropic sites as compared to the remote ones. The differences between the two site typologies were statistically different with the exception of Cu soil contents. The concentrations of Cu and Pb in the leaves and in the soils were significantly correlated. Available Cd, Cu and Pb fractions were significantly correlated to the total soil contents. Moreover, available Cu in the soil was significantly correlated to Cu leaf concentrations. All the studied elements appear to be taken up in relevant measure directly from the air at the anthropic sites. The translocation from roots to leaves could be relevant only for Cu. Q. ilex leaves appear better biomonitors than soil in the investigated area. The soil background contents of all the studied elements hid the input of trace elements from the air. In addition, soil contents reflect a mixture of past and recent inputs, whereas leaf contents reflect the element inputs for a known exposure time.

Black rats (Rattus rattus) from medieval Mertola (Baixo Alentejo, Portugal)

This paper is about the analysis and interpretation of micromammal samples from archaeological sites while reporting on a black rat assemblage from XIIIth century Muslim levels in the city of Mertola. Questions concerning skeletal representation, size plus age estimations and bone fragmentation are discussed from a taphonomic standpoint. It is concluded that the tendency to interpret rodent accumulations in anthropic sites as evidence of preybird activities might be an oversimplification in need of substantial revision.

Polyploidy and habitat differentiation in Dactylis glomerata L. from Galicia (Spain).

The microdistribution of diploid and tetraploid plants of Dactylis glomerata L. was examined and related to their immediate environment in several sites in central Galicia, where morphologically indistinguishable individuals of both ploidies grow in sympatry. The two related cytotypes differed in habitat preference. Diploids were mainly confined to the low-density forest-floor habitat in woodlands of mostly ancient origin, whereas tetraploids were widespread in varied habitats but clearly predominant in open areas, particularly in disturbed anthropic sites. The in situ comparison of plant performance showed that where plants of each ploidy were more common they produced more tillers, panicles and seeds. This habitat preference closely reflected differences in life-history characteristics. The tetraploids had an early and short flowering time almost always completed before the aestival drought, whereas the diploids began to flower several weeks later and flowered throughout the drought. Comparisons along artificial gradients of soil water availability and light transmittance indicated that the cytotypes had distinct physiological requirements which probably originated in metabolic and more general genetic differentiation and could be directly attributable to ploidy. Habitat differentiation increases the species' colonizing ability. It also amplifies divergence in reproductive strategy between diploids and tetraploids, which reduces ineffective crossing between cytotypes and thereby permits them to coexist in sympatry. The effect of hybridization at the polyploid level on the differentiation between cytotypes was assessed from the recent introduction of a foreign tetraploid entity into the study area. Hybridization between the two distinct tetraploids was found to increase habitat differentiation between the diploids and the tetraploids, but the major part of this differentiation is probably attributable to ploidy itself.