Anthropic Landscape Research Articles

Worldwide impacts of landscape anthropization on mosquito abundance and diversity: A meta-analysis.

In recent decades, the emergence and resurgence of vector-borne diseases have been well documented worldwide, especially in tropical regions where protection and defense tools for human populations are still very limited. In this context, the dynamics of pathogens are influenced by landscape anthropization (i.e., urbanization, deforestation, and agricultural development), and one of the mechanisms through which this occurs is a change in the abundance and/or diversity of the vectors. An increasing number of empirical studies have described heterogeneous effects of landscape anthropization on vector communities; therefore, it is difficult to have an overall picture of these effects on a global scale. Here, we performed a meta-analysis to quantify the impacts of landscape anthropization on a global scale on the presence/abundance and diversity of mosquitoes, the most important arthropods affecting human health. We obtained 338 effect sizes on 132 mosquito species, compiled from 107 studies in 52 countries that covered almost every part of the world. The results of the meta-analysis showed an overall decline of mosquito presence/abundance and diversity in response to urbanization, deforestation, and agricultural development, except for a few mosquito species that have been able to exploit landscape anthropization well. Our results highlighted that these few favored mosquito species are those of global concern. They, thus, provide a better understanding of the overall effect of landscape anthropization on vector communities and, more importantly, suggest a greater risk of emergence and transmission of vector-borne diseases in human-modified landscapes.

PRACTICES RELATED TO PHYSICAL-NATURAL THEMES IN GEOGRAPHIC EDUCATION USING VIRTUAL GLOBES

The article addresses Information and Communication Technologies as a resource for mediating the learning process in pandemic times. The objective is to present Google company tools (Earth Pro, Maps, MyMaps) and their potential for teaching geography regarding physical-natural themes. The work commences with an analysis of the document named “Base Nacional Comum Curricular para o Ensino Fundamental”, focusing on the organic and progressive set of essential learning that geography must develop throughout Basic Education. It is followed by some references in the matter of geotechnologies contributions to the learning process. Subsequently, it presents some propositions created and tested using geotechnologies as a stimulus to spatial thinking applied to some units that cover and structure the school of Geography: World and work (Transformation of natural and anthropic landscapes); Forms of representation and spatial thinking; Nature, environments and quality of life. It is concluded that in the period of adaptation of the learning process experienced during the COVID-19 Pandemic, these tools were a strategic resource in the training process of geography teachers.

Vultures feeding on the dark side: current sanitary regulations may not be enough

SummaryIt is widely acknowledged that the conservation of vultures, a group of birds threatened worldwide, requires the management of safe, high-quality human subsidies, free of potentially harmful toxic compounds. Additionally, in Europe, the supply of livestock carcasses is subject to current sanitary regulations. It is largely unknown how vultures use sources of food of different abundance, predictability, or different legal status and how individual features shape these preferences. To answer these questions, we took advantage of information yielded by 35 GPS-tagged adult Eurasian Griffon Vultures Gyps fulvus living in a region of northern Spain, which hosts one of the most important European populations. Our results indicated that vultures preferably used predictable feeding sites, such as carcass dumping sites, intensive farms and landfills which together account for the 62% of the observed feeding sites. Less than 10% of all observed sites had permission of authorities for the disposal of the carcasses. Interestingly, sites with large accumulations of carcasses were less used that those with intermediate amounts of food probably because of high intraspecific competition. In addition, sex and breeding status also played a role with males and breeding birds being more prone to visit the studied intensively managed feeding places. This vulture population is heavily dependent on food sources which are not under legal control where the birds could be at risk of intoxication and pathogen acquisition. Hence, current legal scenario allowing farmers to abandon carcasses in their exploitations seems insufficient. The future of vultures in highly anthropized regions is uncertain if interdictory regulations on the abandonment of carcasses of intensive livestock are applied. Additionally, conservation scenarios based on food subsidization must consider the effects of environmental and individual variability. We need science-based strategies ensuring the long-term viability of avian scavenger populations within a scenario of anthropized landscapes and livestock farming intensification.

Quantification and Simulation of Landscape Anthropization around the Mining Agglomerations of Southeastern Katanga (DR Congo) between 1979 and 2090

In Southeastern Katanga, mining activities are (in)directly responsible for deforestation, ecosystem degradation and unplanned building densification. However, little is known about these dynamics at the local level. First, we quantify the landscape anthropization around four agglomerations of Southeastern Katanga (Lubumbashi, Likasi, Fungurume and Kolwezi) in order to assess the applicability of the Nature–Agriculture-Urbanization model based on the fact that natural landscapes are replaced by anthropogenic landscapes, first dominated by agricultural production, and then built-up areas. Secondly, we predict evolutionary trends of landscape anthropization by 2090 through the first-order Markov chain. Mapping coupled with landscape ecology analysis tools revealed that the natural cover that dominated the landscape in 1979 lost more than 60% of its area in 41 years (1979–2020) around these agglomerations in favor of agricultural and energy production, the new landscape matrix in 2020, but also built-up areas. These disturbances, amplified between 2010 and 2020, are more significant around Lubumbashi and Kolwezi agglomerations. Built-up areas which spread progressively will become the dominant process by 2060 in Lubumbashi and by 2075 in Kolwezi. Our results confirm the applicability of the Nature–Agriculture-Urbanization model to the tropical context and underline the urgency to put in place a territorial development plan and alternatives regarding the use of charcoal as a main energy source in order to decrease the pressure on natural ecosystems, particularly in peri-urban areas.

DNA metabarcoding unveils the effects of habitat fragmentation on pollinator diversity, plant-pollinator interactions, and pollination efficiency in Maldive islands.

Habitat fragmentation affects biodiversity, but with unclear effects on pollinators and their interactions with plants in anthropized landscapes. Islands could serve as open air laboratories, suitable to disentangle how land-use alteration impacts pollination ecology. In Maldive islands we investigated how pollinator richness, plant-pollinator interactions and pollination efficiency are influenced by the green area fragmentation (i.e., gardens and semi-natural patches). Moreover, we considered the mediating role of pollinator body size and the plant trait of being invasive in shaping interactions. To do this, we surveyed pollinator insects from 11 islands representing a gradient of green area fragmentation. A DNA metabarcoding approach was adopted to identify the pollen transported by pollinators and characterize the plant-pollinator interactions. We found that intermediate levels of green area fragmentation characterized pollinator communities and increased their species richness, while decreasing interaction network complexity. Invasive plants were more frequently found on pollinator bodies than native or exotic noninvasive ones, indicating a concerningly higher potential for pollen dispersal and reproduction of the former ones. Intriguingly, pollinator body size mediated the effect of landscape alteration on interactions, as only the largest bees expanded the foraging diet in terms of plant richness in the transported pollen at increasing fragmentation. In parallel, the pollination efficiency increased with pollinator species richness in two sentinel plants. This study shows that moderate landscape fragmentation of green areas shapes many aspects of the pollination ecosystem service, where despite interactions being less complex and mediated by pollinator body size, pollinator insect biodiversity and potential plant reproduction are supported.

Arboreal elements of the agricultural matrix as structural connecting devices in fragmented landscapes – A case study in the Los Tuxtlas Biosphere Reserve

Agriculture is one of the main drivers of deforestation worldwide, generating highly fragmented landscapes that severely limit the mobility of forest species. Knowledge of the state of previously forested landscapes, taking into account all of its arboreal elements (including isolated trees, living fences, riparian corridors, and others) is a necessary first step to gaining a better understanding of the ecological dynamics of anthropic landscapes, and for designing conservation and management plans that enhance functional connectivity within these landscapes. We used high-resolution images (2.5 m/pixel) to identify all of the arboreal elements—from single tree crowns up to large forest fragments—for 40,000 ha of the Los Tuxtlas Biosphere Reserve. We included isolated trees, usually ignored in most inventories of fragmented landscapes, but which together with the other arboreal elements play an important role as landscape connectors and extra habitat for many species. Using a graph theory approach, we assessed landscape connectivity at six inter-patch distances across open areas (from 50 to 500 m), and propose two strategies for improving landscape connectivity: the creation of woodland islets and the widening of forested riparian corridors in the agricultural matrix. The main arboreal elements that influenced connectivity were old-growth forest fragments and widespread treed living fences, each increasing connectivity by up to 57% (depending on the threshold distance), while riparian corridors and isolated trees contributed 38% and 6%, respectively. Isolated trees in pastures substantially increased the number of effective connections at all distances (>85%). The GIS-simulated restoration proposals to establish circular woodland islets (10 m radius) in the middle of open agricultural areas increased connectivity by 26%, while widening riparian corridors by up to 10 m per riverside increased it by 11%. Increasing the number of arboreal elements within the agricultural matrix at key sites would enhance landscape connectivity considerably, benefiting the organisms that live in forest remnants in the study area without the need to stop agricultural activities.

Estimating water infiltration rate in oxisols under pasture and agriculture management in the Brazilian Savanna with support of a Drone-RGB onboard sensor

Methods for evaluating physical water data are being increasingly supported by modern and practical tools that have become indispensable for field surveys. Among these tools, unmanned aerial vehicles (UAV) equipped with optical, multispectral, and thermal sensors allow carrying out interventions, monitoring, and strategic data collection with significant cost and time reductions. In this research we used a fixed wing UAV (Swinglet CAM, Sensefly) with RGB camera for creating a precise Digital Terrain Model (DTM) aiming to support an assessment of soil water infiltration in areas under pasture and agricultural management, using the Kostiakov model with concentric rings. Thus, we produced a centimetric-resolution DTM for identifying geomorphological features intrinsically linked to the soil water dynamics and and the accurate insertion of the concentric rings in the slopes. Water velocity and infiltration rates were estimated from descriptive statistics of the data obtained with the Kostiakov model. In this way, the application of the potential equation (Kostiakov) made it possible to mathematically construct the determinants of accumulated infiltration and instantaneous velocity, which can then be replicated and updated at various times, changing only the input data that were logarithmized. The results showed a higher infiltration (54%) in the pasture area, while the unmanned aerial vehicle was considered as an essential tool for obtaining a detailed synoptic representation of the natural and anthropic landscape.

SEROSURVEY FOR SELECTED PARASITIC AND BACTERIAL PATHOGENS IN DARWIN'S FOX (LYCALOPEX FULVIPES): NOT ONLY DOG DISEASES ARE A THREAT.

The Darwin's fox (Lycalopex fulvipes) is one of the most endangered carnivores worldwide, with the risk of disease spillover from domestic dogs being a major conservation threat. However, lack of epidemiologic information about generalist, non-dog-transmission-dependent protozoal and bacterial pathogens may be a barrier for disease prevention and management. To determine the exposure of some of these agents in Darwin's fox populations, 54 serum samples were collected from 47 Darwin's foxes in Southern Chile during 2013-18 and assessed for the presence of antibodies against Brucella abortus, Brucella canis, Coxiella burnetii, pathogenic Leptospira (serovars Grippotyphosa, Pomona, Canicola, Hardjo, and Copehageni), Toxoplasma gondii, and Neospora caninum. The highest seroprevalence was detected for T. gondii (78%), followed by pathogenic Leptospira (14%). All the studied Leptospira serovars were confirmed in at least one animal. Two foxes seroconverted to Leptospira and one to T. gondii during the study period. No seroconversions were observed for the other pathogens. No risk factors, either intrinsic (sex, age) or extrinsic (season, year, and degree of landscape anthropization), were associated with the probability of being exposed to T. gondii. Our results indicate that T. gondii exposure is widespread in the Darwin's fox population, including in areas with minimal anthropization, and that T. gondii and pathogenic Leptospira might be neglected threats to the species. Further studies identifying the causes of morbidity and mortality in Darwin's fox are needed to determine if these or other pathogens are having individual or population-wide effects in this species.

Interaction network between frugivorous birds and zoochorous plants in cloud forest riparian strips immersed in anthropic landscapes

Worldwide, tropical montane cloud forest is one of the most important and biodiverse ecosystems; however, it is also one of those most threatened by anthropic activities. These activities lead to a fragmented, deforested landscape with narrow riparian forest strips immersed in an agricultural matrix dominated by pastures. Here, we characterize the interaction network between frugivorous birds and zoochorous plants in riparian strips of cloud forest in deforested landscapes of Central Veracruz, Mexico. To characterize the network of this mutualistic interaction, we estimated network- and species-level metrics using the Bipartite R package. Nestedness, modularity and robustness were used to describe network structure. Centrality measures of degree, closeness, betweenness centrality and their relative contribution to nestedness were used to determine the importance of each bird/plant species to the network’s structure. This interaction network has 24 species of birds and 30 species of plants, with low connectance (0.11), low nestedness (11.53), and intermediate but not significant modularity (0.49). The bird species most important to network stability were Chlorospingus flavopectus, Myadestes occidentalis, and Catharus mexicanus. The most important plants were Conostegia xalapensis, C. arborea, and Rubus ulmifolius. Network robustness varied from 0.36 to 0.86 and its stability is compromised when species of birds or plants with the highest values of centrality are removed, with plant removal more detrimental. Riparian strips of cloud forest crossing deforested areas maintain a relatively rich set of birds that disperse the seeds of many forest plants, thus they are crucial to the preservation of this mutualistic network in anthropic landscapes. Network stability is severely undermined by the loss of any of the few species — whether birds or plants — with high centrality values. The most important plants for this stability are pioneer tree and shrub species that provide food for several bird species, and they are also crucial to cloud forest regeneration. A worrisome finding is that some of the bird species most important to network stability are also among the most sought-after as ornamental birds by illegal collectors in the region.

Molecular evidence, risk factors analysis, and hematological alterations associated with Theileria spp. spillover in captive wild mouflon sheep in Punjab, Pakistan.

Landscape anthropization and interaction between domestic and wild animals are the major contributing factors involved in the emergence of new pathogens in wild animals. Theileriosis is an emerging issue of wild ungulates, especially in the tropical and subtropical areas of the globe. The current study investigated the mouflon sheep for Theileria infection using molecular methods and hematological analysis. This study was conducted on a total of 103 captive wild mouflon sheep present in eight different recreational zoos, and wildlife parks in Punjab, Pakistan to investigate the genotypic prevalence of Theileria spp. by targeting 18S rRNA and molecular evidence for Theileria spillover between domestic and wild mouflon sheep by phylogenetic analysis. The association of assumed risk factors and the effect of Theileria spp. on various hematological parameters were also assessed. The results depicted that Theileria spp. was prevalent in 8 (7.77%, CI 95%: 3.99-14.59%), and 11 (10.68%, CI 95%: 06.07-18.12%) animals based on microscopy, and PCR, respectively. The phylogenetic analysis of the 18S rRNA gene of Theileria spp. from mouflon revealed a close resemblance with T. annulata from domestic animals. The risk factor analysis revealed that tick infestation, enclosure hygiene, previous tick infestation history, and the presence of wooden logs in the enclosure were significantly (P<0.05) associated with the occurrence of Theileria spp. infection in the captive mouflon sheep of Pakistan. Furthermore, a significant reduction in blood parameters like PCV, RBCs count, Hb, and platelets was observed in Theileria-positive animals. This study is the first evidence at the molecular level to characterize the spillover of Theileria spp. between the captive wild mouflon sheep and domestic animals of Pakistan, and it will be useful in developing control strategies for emerging theileriosis in captive wild animals.

Laelia anceps Lindl. (Orchidaceae) adaptation on phorophytes within an anthropized landscape, Amatlán de los Reyes, Veracruz, Mexico

Objective: To determine the best phorophyte species for the adaptation of the Laelia anceps Lindl orchid. (Orchidaceae) in an anthropized landscape. Design/methodology/approach: A completely randomized experimental design with four treatments (phorophytes) was used: Swietenia macrophylla King., Fraxinus sp., Persea schiedeana Nees. and Tecoma stans. (L.) Juss. ex Kunth), with five repetitions per phorophyte and with three L. anceps orchid plants in each phorophyte. The following variables were measured: day to emergence, root length and thickness, and survival at 28 weeks after tying them in phorophytes.&#x0D; Results: Root emergence of L. anceps occurred in less time in S. macrophylla and in Fraxinus sp. at 52 and 54 days respectively; the longest root length (19.11 cm) and number of roots (32.45) were observed in S. macrophylla. However, the root thickness was greater in Fraxinus sp. (0.28 cm). After 28 weeks of establishing the L. anceps plants; 100% survival was obtained in the phorophytes S. macrophylla and Fraxinus sp., 77% in P. schiedeana and 33% in T. stans.&#x0D; Study limitations/implications: The amount of light received by L. anceps in each phorophyte was not measured.&#x0D; Findings/Conclusions: The best phorophytes for the establishment of L. anceps were S. macrophylla and Fraxinus sp. observed, the best development and strength of the roots and 100% survival at 28 weeks.

Diversity of small terrestrial mammals under different organic farming management in Mediterranean and Continental agriculture ecosystems

Diversity of small terrestrial mammals under different organic farming management in Mediterranean and Continental agriculture ecosystems

Partitioning beta diversity to untangle mechanisms underlying the assembly of bird communities in Mediterranean olive groves

AbstractAimWe investigated taxonomic and functional beta diversity of bird communities inhabiting Mediterranean olive groves subject to either intensive or low‐intensity management of the ground cover and located in landscapes with different degrees of complexity.LocationAndalusia, southern Spain.MethodsWe partitioned taxonomic and functional beta diversity into its two additive components, turnover and nestedness. We also explored the contributions of single sites to overall beta diversity (LCBD) and separated the effects of species replacement (turnover) and richness difference (nestedness) in order to identify ecologically unique sites—keystone communities—within the metacommunity. In a further step, we employed abundance‐ and functional‐based indicator species analyses to characterize bird assemblages.ResultsTaxonomic beta diversity increased with landscape complexity. Although both taxonomic and functional differences among assemblages were driven mainly by species replacement (regardless of management or landscape type), the contribution of trait replacement to the total functional beta diversity was much lower, suggesting that species performing similar functions replace each other between sites. There were no differences in LCBD between management types or categories of landscape complexity, but the contributions of sites to beta diversity decreased as the percentage cover of olive groves increased. Species richness was also important in explaining variation in LCBD as species‐poor sites tended to contribute the most to the local‐to‐regional beta diversity. However, some farms displayed high values of LCBD due to the existence of a high replacement component, indicating that some species recorded in these sites were scarce elsewhere. The indicator species analyses revealed that the woodchat shrike Lanius senator may constitute an excellent indicator of biodiversity in this agro‐forestry system.Main conclusionsOur results show that agricultural expansion promotes biotic homogenization and exemplify how the identification of both keystone species and communities can represent a powerful tool for the management of anthropized landscapes.

Landscape Anthropization Affects Mosquito Diversity in a Deciduous Forest in Southeastern Mexico.

Mosquitoes (Diptera: Culicidae) are considered the group of insects that most impacts human health. Land use change, conversion of conserved sites into agricultural environments, urbanization, defaunation, and introduction of domestic animals can affect mosquito diversity positively or negatively, increasing the risk of transmission of zoonotic diseases. Here, we describe the diversity of adult mosquitoes in two environments (deciduous forest and anthropized zone) over 2 yr (2014-2016), using eight CDC traps at each site in three climatic seasons (rainy, cold, and dry). We captured 795 individuals belonging to 22 species. We constructed rank-abundance curves to determine spatial and temporal changes in the mosquito communities. We measured alpha diversity using the Shannon index (H'), Shannon exponential (eH) and Simpson dominance (Ds), and beta diversity using Jaccard's coefficient of similarity (Ij). The most abundant species were Culex quinquefasciatus (40.5%), Culex coronator (18.3%), and Anopheles pseudopunctipennis (12.4%). The highest mosquito diversity was in the deciduous forest during the rainy season. Beta diversity analysis showed that species overlap varied among climatic seasons, with the sites sharing 65% species during the rainy season, but only 33% of species during the dry season. We found differences in the diversity of mosquitoes at the two sites, and the mosquito assemblage of the anthropized zone was significantly different from that of the deciduous forest.

A unique Pyrenean varved record provides a detailed reconstruction of Mediterranean vegetation and land-use dynamics over the last three millennia

The Pyrenean Lake Montcortès sediments hold the longest continuous and absolutely varve-dated record of the Mediterranean region, encompassing the last three millennia, from the Late Bronze Age to the present. The reconstruction of vegetation and landscape dynamics during this time period has advanced gradually, following the progress of absolute dating by varve counting, and has been progressively published and updated in a number of papers dealing with specific time intervals at different temporal resolutions. This paper synthesizes all these studies in a single composite paleoecological sequence constrained by a single age-depth varve model. The final resolution of this reconstruction is bidecadal, on average, but some periods have been resolved at quasidecadal (Middle Ages) and subdecadal (Modern Age to present) resolutions. The study is focused on the timing of anthropization and the further development of vegetation under climatic and anthropogenic drivers until the shaping of present landscapes. An additional advantage of Montcortès is that the local history of the Pallars region, where the lake is located, is well documented and can be easily correlated with the paleoecological record. Contrary to former interpretations of general landscape anthropization of the Pyrenees during the Middle Ages, the Montcortès catchment was irreversibly transformed by anthropic activities at the beginning of the Iron Age (ca. 750-650 BCE). From this point, the catchment underwent successive transformations due to varied human uses (fire, grazing, cereal cultivation, weed/ruderal plant expansions, hemp cultivation/retting), which have been related to the different cultural phases and sociopolitical changes documented in the local historical records. The regional forests, dominated by Pinus and Quercus, experienced four main clearance events (RD) during the Iron Age (RD1; ca. 300 BCE), the Roman Period (RD2; ca. 300 CE), the Middle Ages (RD3; ca. 1000 CE) and the Modern Age (RD4; ca. 1800 CE). The detailed trends of the last two deforestation events and their causes could be studied at a decadal resolution, which significantly improved interpretation quality in ecological terms. The potential effects of climatic changes and the eventual interactions with human activities on catchment vegetation and regional forests throughout the record have also been discussed. The Montcortès record has been compared with other records at local (Pyrenees), regional (Iberian Peninsula) and biome (Mediterranean) scales. Locally and regionally, anthropization times and further ecological trends showed significant heterogeneity according to elevation, biogeographical patterns and cultural trends. The most significant coincidence is an intensification of human pressure, as noted in forest clearing and extensive land use, during several phases of the Middle Ages. At the Mediterranean level, the Montcortès record emerges as a unique sequence for the western sector of this biome that should be complemented with similar archives from the central and eastern Mediterranean. The most promising candidates for such sequences are discussed on the basis of available Mediterranean varved records.

The role that nature conservation can play to mitigate the spread of future infectious diseases

The emergence of infectious diseases is reviewed highlighting the potential role played by main environmental anthropogenic disturbances as, deforestation, land-use change, human-induced climate change, biodiversity loss and the illegal wildlife trade. Ultimately, it is plausible that the human impact on the biosphere could be the root cause of these emerging diseases, and that economic globalization, population growth and landscape anthropization might increase the likelihood of the emergence of novel zoonoses. This pattern bears similarities to phenomena that occurred during the Neolithic period with the emergence of agriculture and cattle domestication. Still today such phenomena could be accelerated by the vastly increased traffic of people and goods. Finally, we argue in favour of strong policies and actions aiming to mitigate the human impact on natural ecosystems as a key strategy to prevent future zoonoses.

Lethal interactions among forest-grouse predators are numerous, motivated by hunger and carcasses, and their impacts determined by the demographic value of the victims.

New vertebrate communities are emerging in Europe following the recovery of multiple native predators to highly anthropized landscapes where predator control is still prevalent. While the lack of reference points for these communities creates novel challenges for conservationists and wildlife managers, they also provide opportunities to further our understanding of species interactions. Despite a growing body of evidence, many aspects of interactions among predators remain poorly understood, impairing our ability to anticipate the effects of such changes in predator communities. Through a systematic literature review, we gathered all the available evidence concerning the existence, strength, and demographic impacts of lethal predator interactions among forest‐grouse predators in Europe. We found a highly interconnected predator community, with 44 pairwise lethal interactions among 12 taxa. Three of these resulted in some degree of population suppression of the victim, while another three did not. However, most interactions (38) have not been evaluated for population suppression. Additionally, we highlight how predators interact simultaneously with a large range of other predators and identified at least two further taxa possibly suppressed through the combined impacts of multiple predators. We propose that interactions causing demographic suppression are characterized by impacts on individuals with high survival elasticity and that they are motivated by food limitation and additionally, in mammals, by competition for carcasses. Predator interactions, and our still poor understanding of them, introduce large uncertainties to conservation actions based on the management of predator abundances, which should be carefully evaluated.

Bronze Age to Medieval vegetation dynamics and landscape anthropization in the southern-central Pyrenees

The varved sediments of Lake Montcortès (central pre-Pyrenees) have provided a continuous high-resolution record of the last ca. 3000 years. Previous chronological and sedimentological studies of this record have furnished detailed paleoenvironmental reconstructions. However, palynological studies are only available for the last millennium, when the landscape around the lake had already been transformed by humans. Therefore, the earlier vegetation of Montcortès and the history of its anthropogenic transformations remain unknown. This paper presents a palynological analysis of the interval between the Late Bronze Age and the Early Medieval period, aimed at recording preanthropic conditions, anthropization onset and the further landscape transformations. During the Late Bronze Age (ca. 1100 BCE to 770 BCE), the vegetation did not show any evidence of human impact. The decisive anthropogenic transformation of the Montcortès catchment vegetation and landscape started at the beginning of the Iron Age (770 BCE) and continued during Roman and Medieval times in the form of recurrent burning, grazing, cultivation, silviculture and hemp retting. Some intervals of lower human pressure were recorded, but the original vegetation never returned. The anthropization that took place during the Iron Age did not cause notable changes in the sediment yield to the lake, but a significant limnological shift occurred, as manifested in the initiation of varve formation, a process that has been continuous until today. Climatic shifts seem to have played a secondary role in influencing vegetation and landscape changes. These results contrast with previous inferences of low anthropogenic impact until the Medieval Period, at a regional level. Similar studies may be developed on other mountain ranges to verify whether landscape anthropization occurred earlier than previously thought, and to verify the potential occurrence of elevational gradients in the anthropization of mountain landscapes.

Hidden in plain sight: detectability and habitat selection of the central plateau dusky rattlesnake in anthropized landscapes

Human activities have caused several changes in biotic communities all over the world. Some species maintain viable populations in altered environments through different adaptations, however, knowledge in this regard is scarce for certaintaxa, including reptiles. We analysed the detectability and habitat selection of the rattlesnake Crotalus triseriatus to contribute to our knowledge about how this species responds to anthropogenic landscape change. Rattlesnakes were monitored for two years in two anthropized landscapes using visual encounter surveys. We analysed detectability in relation to climatic factors and human activity, and habitat selection was analysed in native and non-native vegetation. Our study shows that detectability of C. triseriatus is differentially affected in anthropized landscapes; human activity may be determinant in landscapes such as agricultural fields, whilst climatic factors may be determinant in landscapes where people are less active such as the protected areas within urban parks. The analyses of habitat selection shows that native vegetation is crucial for the persistence of C. triseriatus in the studied landscapes. Several strategies may allow rattlesnakes to persist in different anthropized landscapes; nonetheless, native habitat remnants should be protected in anthropized areas to conserve wildlife.

A spatiotemporal gradient in the anthropization of Pyrenean landscapes. Preliminary report

A preliminary analysis of the timing of landscape anthropization in the southern-central Pyrenees shows the occurrence of an elevational gradient from the Bronze Age (basal belts) to the Middle Ages (alpine belts). This relationship is statistically significant and suggests an average anthropization rate of 40 m in elevation per century. The elevational gradient is most clear between the Bronze Age and the Roman occupation, suggesting a progressive upward anthropization trend from the south with the likely involvement of Iberian cultures. During the Middle Ages, a massive anthropization pattern of subalpine/alpine areas is observed; this pattern is chronologically consistent with the incursion of northern cultures crossing the Pyrenees and the development of extensive high-mountain pastoralism and horizontal transhumance. In general, the progression of upward anthropization has occurred during warm climatic phases. Further work is needed to confirm these observations, especially in areas with few available paleoecological studies, notably the basal and montane belts. It could be interesting to develop similar studies of other Pyrenean regions and other mountain ranges.