Птицы озерных котловин южной части хребта Черского.

New data and analysis of the avifauna and bird species abundance are given for the lake systems of the southern part of the Chersky mountain ridge. In August - October of 2018 and in June and August of 2021, bird studies of lake basins of Ui, Momontay, Malyk, Darpir and Urultun lakes, situated at altitudes of 818-1234 meters above the sea level, were performed. 81 bird species were registered, of which 69 were recorded during breeding season, including 56 species referred to breeding and 13, to summering species. In comparison to the bird fauna of neighboring mountain areas, the avifauna of the studied lake systems is characterized by low species diversity, low percentage of widely-distributed species, and high percentage of boreal-hypoartcic and hypoarctic types of zonal- landscape distribution with clearly dominating species of the Siberian origin. Species content of the studied area is similar to that of the subalpine belt of Yakutia's northern mountains in the presence of Long-toed Stint, Red-throated Pipit and Pallas' Reed Bunting as well as, contrary to the subalpine belt of the Kolyma Highland, in the absence such species as Pine Grosbeak, Siberian Rubythroat, Pallas' Leaf Warbler, and Arctic Warbler on these elevations. On the other hand, the presence of such species as Ringed Plover and Dusky Warbler and the absence of Bluethroat is similar to the bird fauna of the Kolyma Highland subalpine belt. High abundance of both Beringian and Green-headed Yellow Wagtails sharing their habitats appeared to be a unique feature of the studied area. Confirmed breeding of Fieldfare on the elevations over 1000 m above the sea level significantly increases the knowledge on the distribution and ecology of this species.

Effects of Long-Term Land Use and Land Cover Changes on Ecosystem Service Values: An Example from the Central Rift Valley, Ethiopia

Changes in land use and land cover (LULC) are the leading contributors to the decline and loss of ecosystem services in the world. The present study covered the Central Rift Valley lakes basin in Ethiopia, focusing on the valley floor and the East and West escarpments, to analyze changes in LULC and to estimate associated losses in ecosystem service values (ESVs). Covering both upstream and downstream areas in the basin, the study addressed major gaps in existing studies by connecting the sources and sinks of material (e.g., sediment and water) in source-to-lake systems. Additionally, the study facilitated the identification of critical areas for conserving natural resources and reversing the decline of associated ESVs in the Central Rift Valley. A post-classification comparison approach was used to detect LULC changes between 1973 and 2020 using four Landsat images from 1973, 1990, 2005 and 2020. The value transfer valuation method was used to estimate the changes in ESVs due to LULC changes. Among the seven major identified LULC classes, farmlands, settlements, and bare lands showed positive changes, while forestlands, grasslands, shrublands and waterbodies showed negative changes over the last 47 years. The expansion of farmlands, for example, has occurred at the expense of grasslands, forestlands and shrublands. The changes in LULC over a period of 47 years resulted in a total loss of US $62,110.4 × 106 in ESVs. The contributors to the overall loss of ESVs in decreasing order are provisioning services (US $33,795.1 × 106), cultural services (US $28,981.5 × 106) and regulating services (US $652.9 × 106). The results imply that addressing the degradation of land and water resources is crucial to reversing the loss of ecosystem services and achieving the national Sustainable Development Goals (SDGs) related to food and water security (SDGs 2 and 6) and life on land (SDG 15).

Role of River–Lake System Sediments and Microbial Activity in the Hyporheic Zone

The effect of river–lake systems on the surface water self-purification process is a significant and not fully recognised scientific issue. The conditions prevailing in the hyporheic zone of these ecosystems are of great importance in the process of component exchange between water and sediments. The aim of this study was to investigate the influence of the type of sediments located at the bottom of the riverbed being part of a river–lake system on microbial activity in the hyporheic zone. An ex situ experiment was used to study the microbiological activity and the transformation of components in the collected river sediments. It was found that the specific properties of sediments varied depending on their location in the riverbed between the lakes comprising the system and that the prevailing meteorological conditions can also have an effect on microbial activity in the hyporheic zone, e.g., aerobic conditions. These conditions determined the intensity of component conversion in the sediments due to microbial metabolism. A closer understanding of the processes occurring in the hyporheic zone may allow the processes of water self-purification within river–lake systems to be supported in the future, which will contribute to the improvement of surface water quality.

Improving age-depth correlations by using the LANDO model ensemble

Age-depth correlations are the key elements in paleoenvironmental studies to place proxy measurements into a temporal context. However, potential influencing factors of the available radiocarbon data and the associated modeling process can cause serious divergences of age-depth correlations from true chronologies, which is particularly challenging for paleolimnological studies in Arctic regions. This paper provides geoscientists with a tool-assisted approach to compare outputs from age-depth modeling systems and to strengthen the robustness of age-depth correlations. We primarily focused in the development on age determination data from a data collection of high latitude lake systems (50° N to 90° N, 62 sediment cores, and a total of 661 dating points). Our approach used five age-depth modeling systems (Bacon, Bchron, clam, hamstr, Undatable) that we linked through a multi-language Jupyter Notebook called LANDO (“Linked age and depth modeling”). Within LANDO we have implemented a pipeline from data integration to model comparison to allow users to investigate the outputs of the modeling systems. In this paper, we focused on highlighting three different case studies: comparing multiple modeling systems for one sediment core with a continuous, undisturbed succession of dating points (CS1 - “Undisturbed sequence”), for one sediment core with scattered dating points (CS2 - “Inconsistent sequence”), and for multiple sediment cores (CS3 - “Multiple cores”). For the first case study (CS1), we showed how we facilitate the output data from all modeling systems to create an ensemble age-depth model. In the special case of scattered dating points (CS2), we introduced an adapted method that uses independent proxy data to assess the performance of each modeling system in representing lithological changes. Based on this evaluation, we reproduced the characteristics of an existing age-depth model (Lake Ilirney, EN18208) without removing age determination data. For the multiple sediment core (CS3) we found that when considering the Pleistocene-Holocene transition, the main regime changes in sedimentation rates do not occur synchronously for all lakes. We linked this behavior to the uncertainty within the modeling process as well as the local variability of the sediment cores within the collection.

Pemijahan Ikan Endemik Pelangi Arfak (Melanotaenia Arfakensis) Secara Alami

Arfak rainbowfish (Melanotaenia arfakensis) is one of the endemic fish of West Papua that can be found in river and lake systems in the Manokwari Regency. Currently, the status of the arfak rainbowfish is nearly extinct. Therefore, this study aimed to know the hatching rate and survival of arfak rainbowfish larvae that were naturally spawned. The results showed that the hatchability of arfak rainbowfish eggs reached 96.9% in A1 aquarium and 96.4% in A2 aquarium. The survival rate of arfak rainbowfish larvae in the A1 aquarium was 67.5%, while the A2 aquarium was 58.7%. The larval survival rate was relatively low. Therefore, further research is needed to increase the survival rate of arfak rainbowfish larvae.