Mountain Slopes Research Articles

Application of cohesive soil flow limit and slope critical flow angle

To investigate the relationship between moisture content in cohesive soils during spontaneous liquefaction and their corresponding critical slope failure angles. This study modified the liquid limit test apparatus originally developed by A. Atterberg in 1911, adapting it into a liquid-flow limit test apparatus. On-site soils from three actual cases of slope failures in Xiaolin Village, Jiasian District, Kaohsiung City, as well as soils from slope failures along the banks of Meilong River and Zengwun River were used for experiments involving different soil moisture content and slope failure angles. Based on the experimental findings, the moisture content which cohesive soils undergo spontaneous liquefaction was designated as the Flow Limit (FL), corresponding to the downslope angle at which circular failure occurs. This value represents the critical sliding angle at which spontaneous liquefaction occurs as a results of soil saturation. It also represents the maximum slope angle for exposed mudrock or clay slopes, and establishes the critical slope angle for vegetated slopes. Beyond this critical FL angle, all vegetation is susceptible to loss due to soil liquefaction. Furthermore, this study conducted FL tests on soils from thirteen tree holes in Kaohsiung City, two mountain slopes in Fengshan District, and the silty clay responsible for property damage and injuries during a landslide in Yanchao District on September 29, 2016, as a means of validation. The consistent test results observed reaffirm that different soils exhibit similar spontaneous liquefaction angles and flow limit behavior. These FL test results demonstrate a consistent pattern, reinforcing the notion of distinct curve characteristics that can be replicated across diverse soil compositions.

PENGEMBANGAN BIBIT PORANG DARI BEBERAPA SUMBER DENGAN BERBAGAI MEDIA TUMBUH MELALUI TEKNIK POTTING MIX PADA TANAH ENTISOL

Porang plants (Amorphophallus muelleri Blume) are herbaceous plants that are commonly found growing wild in forested areas, under bamboo clumps, along riverbanks, on mountain slopes, amidst dense and humid vegetation. Porang propagation from corms and cormels requires a considerable amount of time, around 7-9 months. Therefore, there is a need for the development of porang seedlings through easy vegetative propagation methods that can be implemented at the farmer level. This research utilized Entisol soil originating from Andalan Village, Bayan Subdistrict, North Lombok Regency. The research was conducted using an experimental method. The treatments were arranged using a Completely Randomized Design (CRD) involving 4 seed sources (porang cormels/bulbils, split corms, porang leaves, and porang stems) with 3 treatments, namely no treatment, biochar, liquid organic fertilizer, PGPR, and Trubus plant growth regulator. The analysis of variance results showed that the application of various growing media (biochar, liquid organic fertilizer, and PGPR) influenced changes in soil properties and the growth of porang seedlings. The growth of porang seedlings was influenced in the split corm and cormel techniques. Further tests indicated that the cormel technique, specifically in terms of plant height and stem diameter, was affected by the addition of organic materials compared to the absence of organic material application

Biomorphological features and antioxidant activity of mint species of non-hybrid origin growing in the North Caucasus region

Introduction. Modern researchers note the role of antioxidants in the correction of fat and carbohydrate metabolism, so the search for new raw materials for obtaining substances with antioxidant activity is relevant. Polyphenolic compounds are considered the most powerful natural antioxidants. Our attention was drawn to non-hybrid mint species growing in the North Caucasus region. Objective. Study of biomorphological features and economically valuable characteristics of the species Mentha L. (Lamiaceae), their phytochemical characteristics based on the content of essential oil and some phenolic compounds, determination of antioxidant activity to substantiate the prospects for use in medicine and pharmacy. Material and methods. The studies were carried out according to the methods of the State Pharmacopoeia (SP) XIV and XV editions. Samples of raw mint (M. arvensis L.), watermint (M. aquatica L.), longleaf mint (M. longifolia (L.) Huds.), flea mint (M. pulegium L.), m spicata (M. spicata L.), harvested in forest-steppe and steppe zones, as well as on mountain slopes, damp places, sometimes in wastelands, in North Ossetia – Alania, Karachay-Cherkessia, Kabardino-Balkaria and the Stavropol Territory in their natural places of growth (end of July–August 2021–2023). Objects were dried using the air-shadow method. Antioxidant activity was determined by amperometric and titrimetric methods. Results. Non-hybrid mint species growing in the North Caucasus contain essential oils, hydroxycinnamic and triterpene acids, flavonoids and polyphenolic compounds. The established antioxidant properties of hydroalcoholic extracts of mint species, in addition to the traditionally known choleretic and antispasmodic effects, can be considered significant for reducing body weight. Conclusion. The content of essential oil and polyphenolic compounds in various types of mint, as well as the established antioxidant properties of aqueous-alcoholic extracts, in addition to the traditionally known choleretic and antispasmodic effects, can be considered significant for weight loss.

Eksplorasi Teks Budaya Hindu di Lereng Gunung Rahung Kabupaten Banyuwangi Kajian Antropolinguistik

One of the ethnic groups that has a long cultural history is the Javanese ethnic group that inhabits on a Mountain Slopes - Raung in the Banyuwangi Regency, East Java. The Javanese ethnic group on the slopes of Mountain Raung is considered that have already known yulis reading since Majapahit kingdom, and therefore this Javanese ethnic group has cultural remained in the form of writing which were known as Cultural texts. The analysis used a qualitative descriptive research. Researchers used an anthropolinguistic perspective or theoretical framework which viewed that text was a cultural phenomenon which was an activityof the language use, language is the main focus of study, which was always connected to the cultural context. The results of the research were the text forms that preferred were (1) oral text forms, (2) written text forms, and (3) symbolic text forms. Noun category, namely Attributive Noun Phrases which had the structure Noun (N1) + Noun (N2). Then, written text was text written on a certain media such as signboards and nomenclature. Then, simbolic text was text that stored in cultural artifacts or sites such as temples, padmasana, and statues.

Species Composition of Bryophytic Flora along Altitudinal Gradient in Mt. Musuan, Bukidnon, Philippines

A floristic assessment was conducted in Mt. Musuan Bukidnon, the Philippines – an isolated, low grass-covered andesitic lava dome and tuff cone. Two 50-m transect lines were established in each of the altitudinal gradients (350–400, 401–451, 452–502, 503–553, 554–604, and 605 + masl) in the mountain slope to sample the bryophyte communities. The study compared the bryophyte populations between six altitudinal gradients and analyzed their altitudinal distribution. Results revealed a total of 56 species of bryophytes belonging to 39 genera and 21 families. Of these, 39 are moss species with 29 genera and 16 families. Sixteen (16) species are liverworts with nine genera and four families. One hornwort was encountered. The greatest number of bryophytes were documented between 452–502 masl, whereas the fewest number occurred between 350–400 and 605 masl and near the summit. The two most abundant bryophyte species were Octoblepharum albidum Hedw. and Hyophila involuta (Hook.) A. Jaeger, which are widely distributed in all altitudinal gradients. The findings from this research will offer valuable insights that can promote the implementation of efficient management strategies and initiatives for conserving biodiversity across different altitudinal gradients. This is particularly vital because bryophytes are known to be highly susceptible to human- induced threats and the influences of changing environmental conditions.

Dispersal constrains the biotic connectivity of mountain assemblages

AbstractAimClimate warming is shifting the bioclimatic optima of species towards mountaintops, but the ability of organisms to track these changes also depends on their dispersal skills. Here, we assessed the role of dispersal over niche‐driven processes in connecting assemblages along mountain slopes and between mountain massifs.LocationCantabrian Mountains, Spain.TaxonBirds (Animalia; Aves) and Lichens (Fungi; Ascomycota, Basidiomycota).MethodsWe examined the change with elevation of community‐level traits that are dispersal proxies (wing shape in birds and type of dispersing propagule in lichens) and ecological niche proxies (micro‐habitat, substrate, and foraging features). We then permutate species composition within sites and massifs to create models of species distribution constrained by dispersal and niche processes. These models were compared with observed species distribution to disclose the relative contribution of dispersal and niche‐based processes in the biotic interchange along mountain slopes (vertical connectivity) and between isolated summits (horizontal connectivity).ResultsBoth bird and lichen communities were formed by species with traits that enhance dispersal at high elevations. These groups also showed similarities in the elevational patterns of niche diversity, which dropped at high elevations. Dispersal was by far the dominant assembly mechanism in both taxa. Pairwise community comparisons among elevation belts showed weak vertical connectivity, with predominant dispersal limitations but also niche barriers between the extremes of the gradient. Among massifs, horizontal connectivity was higher among high mountain assemblages than those from lower elevations.Main ConclusionDispersal was found to be the dominant assembly mechanism in mountain systems, even in taxa with high dispersal potential. Highland assemblages had low functional diversity but their species had high mobility. This permits biotic interchange between isolated summits and, potentially, colonization of other summits as climate warms. Our framework combining traits and occurrence‐permutation models improve the understanding of community assembly mechanisms along elevation gradients and points to dispersal limitations, especially at low‐middle elevations.

Rockfall from an increasingly unstable mountain slope driven by climate warming

Rockfall in high-mountain regions is thought to be changing due to accelerating climate warming and permafrost degradation, possibly resulting in enhanced activity and larger volumes involved in individual falls. Yet the systematic lack of long-term observations of rockfall largely hampers an in-depth assessment of how activity may have been altered by a warming climate. Here we compile a continuous time series from 1920 to 2020 of periglacial rockfall activity using growth-ring records from 375 trees damaged by past rockfall at Täschgufer (Swiss Alps). We show that the ongoing warming favours the release of rockfall and that changes in activity correlate significantly with summer air temperatures at interannual and decadal timescales. An initial increase in rockfall occurred in the late 1940s to early 1950s following early twentieth century warming. From the mid-1980s, activity reached new and hitherto unprecedented levels. This long-term record of rockfall activity can help to inform the design of vital mitigation and risk reduction measures in inhabited mountain environments.

Adaptation Strategy And of Topo Da’a Remote Indigenous Communities Survivability to Climate Change in Their Settlement Environment (Case Study: Lekatu Da’a Topo Settlement in Central Sulawesi Province)

Topo Da’a is one of sub-ethnic of Kaili tribe in Central Sulawesi, Indonesia. This Isolated Traditional Community or Komunitas Adat Terpencil (KAT) originally is nomadic people who live in Kamalisi mountain forest area. Generally, this society live in mountain area either in highland area, mountain slope, or lowland area. Topo Da’a Lekatu settlement is the only settlement of Topo Da’a that located in Palu city administrative region. This settlement is in lowland area that near from central area of Palu city. Aim of this study is to know how adaptation strategy and community survival ability against climate change environment around their living area from inside the mountain forest area with low temperature then live in lowland area the near the center of the city with high temperature. Qualitative method with phenomenological approach applied in this research. Data collection is purposive sampling with snowball sampling technique. Data analysis is inductive with three steps of selection or reduction, which are phenomenological reduction, eidetic reduction, and transcendental reduction. The research results found that the main factors of survival were economic factors and customs. Apart from that, the settlement location is close to schools and markets. Meanwhile, the adaptation strategy is to adjust to different climates, by creating relaxing or gathering space outside their house and sometimes they sleep in the farm that located on the mountain.

ADAPTATION STRATEGY AND OF TOPO DA’A REMOTE INDIGENOUS COMMUNITIES SURVIVABILITY TO CLIMATE CHANGE IN THEIR SETTLEMENT ENVIRONMENT (CASE STUDY: LEKATU DA’A TOPO SETTLEMENT IN CENTRAL SULAWESI PROVINCE)

Topo Da’a is one of sub-ethnic of Kaili tribe in Central Sulawesi, Indonesia. This Isolated Traditional Community or Komunitas Adat Terpencil (KAT) originally is nomadic people who live in Kamalisi mountain forest area. Generally, this society live in mountain area either in highland area, mountain slope, or lowland area. Topo Da’a Lekatu settlement is the only settlement of Topo Da’a that located in Palu city administrative region. This settlement is in lowland area that near from central area of Palu city. Aim of this study is to know how adaptation strategy and community survival ability against climate change environment around their living area from inside the mountain forest area with low temperature then live in lowland area the near the center of the city with high temperature. Qualitative method with phenomenological approach applied in this research. Data collection is purposive sampling with snowball sampling technique. Data analysis is inductive with three steps of selection or reduction, which are phenomenological reduction, eidetic reduction, and transcendental reduction. The research results found that the main factors of survival were economic factors and customs. Apart from that, the settlement location is close to schools and markets. Meanwhile, the adaptation strategy is to adjust to different climates, by creating relaxing or gathering space outside their house and sometimes they sleep in the farm that located on the mountain.

Selection and chemical composition of plant species consumed by goats under drought conditions in three microregions of the Comarca Lagunera, Mexico

Objective: To evaluate the plant selection of the diet of goats during the dry season and the chemical composition of the said plants in three microregions of the Comarca Lagunera, Mexico.
 Design/Methodology/Approach: Three microregions were identified within the Comarca Lagunera: 1) mountain slope, 2) plain, and 3) cultivation areas. The selection of the goat diet, the availability of forage, and the nutritional composition (CP, EE, DNF, AFD, NFC, TDN, and NEl) of plant species and strata were evaluated in the three microregions.
 Results: The shrubs and herbaceous in the Comarca Lagunera had the highest forage availability and a better nutritional profile during winter. On the one hand, these plant strata had an adequate protein content. On the other hand, the overall energy content reached <1 Mcal kg-1 DM.
 Study Limitations/Implications: The plant strata have an adequate protein content; however, the energy content is not enough and limits growth. Consequently, supplementation programs for grazing dairy goats in the Comarca Lagunera must include sources of energy.
 Findings/Conclusions: Regardless of the microregion, the energy content of the species consumed by grazing dairy goats in the Comarca Lagunera is low.

Linking the future likelihood of large fires to occur on mountain slopes with fuel connectivity and topography

AbstractIn the long run, ongoing climate change is expected to alter fuel production as well as the frequency and severity of fire weather, which may result in an unprecedented frequency of extreme fire events. In this paper we propose a simplified and spatially explicit method to assess the probability of experiencing large fires, based on topography (slope length) as well as extent and aggregation of the forested area (fuel connectivity). We considered 21 homogeneous pyroregions covering entire Switzerland as a study case and computed the length of the upslope paths within the forested areas, simulating ignition points on a systematic 100 × 100 m square grid. We then compared the obtained path lengths for each pyroregion with selected historical large forest fire statistics (e.g., mean area of the largest 5% of fires, maximum burnt area per fire) collected over the course of the last 30 years. This resulted in rather high R2 values, ranging from 0.558 to 0.651. The proposed approach was shown to allow for an easy identification and geo-localization of potential hotspots in terms of the likelihood for large fires to occur in mountainous regions, which is a prerequisite for a targeted planning of fire management measures aimed at preventing large fires and related post-fire gravitative natural hazards.

Convective Properties and Lightning Activity in Different Categories of Thunderstorms over the Beijing Area during Five Warm Seasons

Based on comprehensive observations, including total lightning, Doppler radar, precipitation, and other meteorological data, the variations in thunderstorm properties and lightning activity of different categories for thunderstorms over the Beijing area during five warm seasons were investigated. According to the morphology of radar echo, thunderstorms were classified into five categories, including single convective cells, multi-cells, linear mesoscale convective system (MCS), nonlinear MCS, and weak convective precipitation system (WCPS). The diurnal variability of lightning, thunderstorm occurrence, and precipitation showed late-afternoon maxima, with the peak time of lightning frequency occurring before that of precipitation. Despite WCPS having the lowest lightning frequency, the percentage of +CG/CG was the highest with large peak currents. The convective available potential energy (CAPE) of linear MCS, multi-cells, nonlinear MCS, single cells, and WCPS categories followed a pattern from largest to smallest. Meanwhile, warm cloud depth (WCD) exhibited a smaller value in the well-organized thunderstorm categories and a larger value in the WCPS. The topographic forcing mechanism and large wind gradient along mountain slopes facilitated convection occurrence and enhancement, further promoting lightning production. Meanwhile, the nocturnal convection mechanism significantly impacted the activity of nonlinear MCS and WCPS.

Distribution Regularities of Tree Species of the Rosaceae Family in Shrubs in River Valleys and a Streak in the Flora of the Nakhchivan Autonomous Republic

The presented article provides information about the shrub vegetation of the river basins and valleys of the woody species of the Rosaceae family in the flora of the Nakhchivan. The river basins of Arpachay, Nakhchivanchay, Alinchachay, Havushchay, Gilanchay and river basins of the Sharur, Shahbuz, Julfa and Ordubad districts were studied as the research object. The conducted research allows to determine the important features characteristic of the woody species of the Rosaceae family spreading in the river valleys and riverbanks. In the structure of the steppe complex, shrub plants, especially woody species of the Rosaceae family, occupy an important place. They are part of the bush steppes, form independent groups and form unique formations. Both the sandy areas of the banks of rivers and streams, as well as the bushes found on the mountain slopes on the right and left banks of the rivers, differ sharply in terms of their species composition. In the studied vegetation class, 6 formations, 13 associations and 1 sub-association were determined by us for the first time and a phytocoenological classification of vegetation was given. In formation 1, 2 associations dominated by Rosa canina are found along the river valleys mentioned above. In the 2nd formation, 2 associations are identified, dominated by the species Crataegus meyeri. Prunus fenzliana, P. divaricata, and P. nairica species are also widely spread in this grouping. In the 3rd formation, 3 associations with a significant abundance of almond bushes and 1 sub-association identified by us for the first time. Prunus fenzliana is the dominant species in the subassociation. At the same time, Rosa canina and R. buschianaspecies are noticeably widespread in the grouping. The composition of the 4th formation includes 3 associations dominated by Crataegus meyeri, C. caucasica, C. monogyna, Sorbus graeca, and S. persica species. The 5th formation contains 2 associations dominated by Cotoneaster melanocarpus, C. integerrimus, Rosa canina, R. hracziana species, and the 6th formation contains 1 association dominated by Prunus microcarpaspecies.

Study of experimental and numerical simulation on the influence of gravel on the interflow of slope land.

The formation of interflow is of great significance for the stability of mountain slopes and soil erosion. Hillsides are often covered with a certain amount of gravel, and research on interflow of slope land with different gravel ratios needs to be carried out. This article is based on indoor experiments and numerical models to study the formation law of interflow in hillside soil under different gravel coverage ratios. It was found that the interflow in the soil rapidly increased in the early stage and began to decrease after briefly reaching equilibrium. The formation of interflow is a complex process that is related to slope, soil characteristics, and rainfall intensity, but the correlation is not high when viewed separately. The lattice Boltzmann model can effectively simulate such problems and achieve high simulation accuracy. The [Formula: see text] of the simulated data and measured data ranged from 0.5217 to 0.7403, and [Formula: see text] of the simulated data and measured data ranged from 0.4051 to 0.5711.

Spatial exploration of rural capital contributing to quality of life and urban-to-rural migration decisions: a case study of Hokuto City, Japan

Globally, urbanization constitutes one of the major underlying drivers of global ecological degradation. Hence, deurbanization, i.e., demographic shift from urban to distant rural areas in a way that increases quality of life (QoL), can be one of the key pathways to address this global challenge. In this study, we investigated the contribution of nature and other types of rural capital to QoL and to people’s decision to migrate from urban to rural areas by studying residents in Hokuto City, a popular urban-to-rural migration destination in Japan. An integrated analysis of the 414 responses to a questionnaire survey and open and commercial geospatial datasets representing natural, built, human, cultural, and financial capital revealed the contributions of specific elements of rural capital to people’s QoL. These included natural capital (farmland, symbolic natural sites, mountain peak view, lower temperature, and tranquility), built capital (highways, railway stations, shops, and restaurants), and financial capital (employment). Many of these are related to the reasons that migrants, including return and one-way migrants, chose their present home location in Hokuto City, indicating their intention to increase QoL by migration. Particularly, one-way migrant homes were located predominantly on higher up mountain slopes with lower temperatures, higher forest cover, near natural parks, and symbolic natural sites, and yet with easier access to railway stations and employment. These results provide a valuable evidence base for rural spatial planning for increased QoL and attracting migrants that considers ecological–social feedbacks, and hence supports deurbanization.

DETERMINATION OF SAND MINING PROSPECTIVE ZONES BASED ON SEDIMENT THICKNESS ANALYSIS USING HVSR MICROTREMOR AND GRAVITY METHODS: A CASE STUDY IN CANGKRINGAN, SLEMAN, DAERAH ISTIMEWA YOGYAKARTA

Mount Merapi is the most active type A volcano, especially on the island of Java. It produces sediment products totaling 140 million m3 located at the peak of Mount Merapi, descending through the mountain slopes to rivers originating from Mount Merapi. This sediment is subsequently utilized as a sand mining area. Therefore, it is necessary to determine prospect zones for sand mining that align with environmental, economic, and mitigation aspects in the Cangkringan area, Sleman, Yogyakarta Special Region. Seventeen microtremor measurement points were used with the Horizontal to Vertical Spectral Ratio (HVSR) method to determine sediment thickness, constituent lithology, and mining zones suitable for safety and mitigation aspects. Additionally, the gravity method was employed with 247 measurement stations obtained from GGM Plus to determine rock density and estimated thickness based on 2.5D modeling. The study resulted in the distribution of dominant soil frequencies ranging from 0.5 Hz to 7.5 Hz. High frequencies indicate old rocks, while medium frequencies suggest alluvial rocks with a thickness of ± 5 m. Low frequencies indicate alluvial rocks with a thickness exceeding ± 30 meters. Based on gravity results, the average depth is ±90-200 m with a density of 2.6 g/cm3, reflecting the depth of the bedrock in the study area, composed of andesitic volcanic rock. Soil vulnerability analysis in the study area classified into three categories, with values of 4.2-5.4 being highly vulnerable to surface deformation, values of 1.8-3.8 indicating moderate vulnerability, and values of -0.2-1.4 representing low vulnerability. Furthermore, the Peak Ground Acceleration (PGA) ranges from 500-1200 gal with intensity X. Ground Shaking Spectrum (GSS) data indicates that the study area experiences vibration phenomena with elastic soil dynamics. Therefore, the exploitation of sand resources in the Cangkringan area can be conducted in the southern region of Mount Merapi, approximately 2 km away from the mountain center. This is because the southern part of the research area has suitable mitigation measures. Moreover, based on the analysis, sediment thickness in this area ranges from ± 5-30 meters.

MENUMBUH KECINTAAN PEKERJAAN PERTANIAN BAGI GENERASI Z (GEN-Z) PADA LAHAN TERASIRING DENGAN SMART MACHINE PORTABEL MULTIFUNCTION

Education has shifted the work mindset of Generation Z (Gen-Z) in mountainous areas. A fairly good education, for example a high school/vocational school graduate, has shifted the desire to become a worker in the non-agricultural industrial sector, leaving behind the agricultural work that his parents started. From the preliminary survey, the main reason is actually the hard work of being a rice farmer on mountain slopes or terraced land. Many agricultural machines (agricultural tools) that have been created, starting from plows, rice harvesters and rice threshers, are still dominated for agricultural land in flat areas. This can be seen from the size of the existing machines which are very large and very difficult to use on terraced land. The application of smart machine technology is to make the rice harvesting process easier. The aim of this service is to foster a love of agricultural work for Gen-Z and to create food self-sufficiency. This service methodology starts from designing, manufacturing rice cutting and threshing machines, simulating and practicing. Then they will be taken to the service location to socialize on the use of the machine and the benefits that will be obtained by farmers. At the time of this service implementation, the service location in Tlahab Lor Village, Karangreja District, Purbalingga Regency, did not yet have rice ready to be harvested, therefore the service implementation only showed how the machine worked. It is said to be a smart machine because this machine has 3 (three) functions, namely cutting rice stalks, threshing rice and its main function is cutting grass. This machine is also portable because it only weighs less than 15 kg so it can be carried by itself to the harvest location in a terraced rice field model

Blocking-baffle mechanism of vegetation to rock avalanche on the forested slope of the east Sichuan-Tibet Mountains

Blocking-baffle mechanism of vegetation to rock avalanche on the forested slope of the east Sichuan-Tibet Mountains

Regional‐scale effects of deer‐induced forest degradation on river ecosystem dynamics

AbstractAlmost all ecosystems are open systems, meaning that significant changes in one ecosystem can lead to unexpected changes in others. Deer overabundance has become a problem worldwide, leading to forest degradation that has impacts on not only terrestrial, but also aquatic ecosystems. This study aims to investigate the regional‐scale importance of large herbivores in inter‐ecosystem interactions by examining the effects of deer‐induced forest degradation on fish populations. We selected similar‐scale catchments from river systems in Hyogo, Japan, that differed in the time since deer‐induced forest degradation. Conventional surveys for fish densities and microhabitat environments were conducted in 23 catchments, and surveys using quantitative eDNA metabarcoding were conducted in 95 catchments. We examined the relationships between fish population densities, microhabitats, and time since forest degradation, considering confounding effects. Data from 8 and 17 fish taxa detected by snorkeling and eDNA methods, respectively, were available for statistical analysis. Snorkeling‐counts (Individuals/1 m transect) and eDNA concentrations (Copies/L) in river water were strongly correlated. Fine sediments on riverbeds were increased in the 3–15 years following forest degradation and decreased after 16 years. Population densities of sand‐preferring fishes, as inferred from both eDNA and snorkeling, reasonably followed this pattern. These patterns may be caused by the depletion of fine sediments on mountain slopes. The results of this study suggest that deer‐induced worldwide alternation may also occur in aquatic ecosystems.

Holocene process-based hydroclimate evolution coupled with human behaviours in Dian Lake basin, Southwest China

Lakes are considered excellent archives for the reconstruction of sedimentary processes and related hydroclimatic variations. Dian Lake in south-western China was selected to demonstrate the impacts of Indian summer monsoon-induced water and sediment availabilities on land surface changes and human behaviours. A new sediment core from Dian Lake in the vicinity of Hebosuo village was analyzed by grain size composition, geochemical content, and minerals to detect land-lake processes that responded to hydroclimatic variations and human impacts through the Holocene. Our data suggest that Dian Lake levels during the last 9.8 cal. ka BP were controlled by the variations of the Indian summer monsoon moisture supply according to the displacements of the Intertropical Convergence Zone. A low lake level stage of ∼ 4 m lower than present was determined between 3.1 and 1.73 cal. ka BP, allowing the residents of the Dian culture to occupy the low terrains for settlement and farmland cultivation. With lake level rise at around 1.73 cal. ka BP (220 CE) the high input of clay-fine silt-sized sediments rich in rubidium and barium indicates intensified soil erosion in the Dian Lake basin. Former paddy farmlands and mountain slopes were drained by artificial and natural channels towards the lake in response to strengthened rainfalls covering low terrains by coarse and red alluvial sediments that fostered the residents to abandon the lowlands in the southern basin until 1368 CE. However, the surface erosion process during this period promoted the elevation of the south-eastern delta so that it could be re-occupied since Ming Dynasty. The Indian summer monsoon influence comparable to the modern pattern was responsible for lake level rise to the present level since then but also triggered high seasonality in flood and drought events to foster manual regulation of flood discharge during the last centuries.