Point Transect Research Articles

Bird Commmunity in Bagek Kembar Mangrove Essential Ecosystem Area (EEA), Sekotong, West Lombok

Birds are wildlife found in many habitats, such as beaches, swamps, mountains and lowlands. This study aims to determine the bird community in the Bagek Kembar essential ecosystem area, West Lombok Regency. Data was collected using the transect path method (exploration) and point count. The research was conducted in November-December. Observation was carried out in the morning at 06.30- 09.30 and in the afternoon at 15.30-18.30 Central Indonesian Time (GMT +8) with representatives of 3 observation locations: pond area, rehabilitation mangrove and natural mangrove. Data collection was done using transect lines (cruising) and point count. The results showed that there were 57 bird species from 23 families categorised into migratory birds (18 species), protected birds (12 species), and six species of birds categorised as NT (Near Threatened). The results of the abundance index of species included in the highest dominant category are Cerulean Kingfisher (Alcedo coerulescens), with a value of 7.87% found in the pond area. Furthermore, the results of the diversity index of the three areas have a high diversity index value of 3.900.

Joint inference for telemetry and spatial survey data.

Data integration, the joint statistical analysis of data from different observation platforms, is pivotal for data-hungry disciplines such as spatial ecology. Pooled data types obtained from the same underlying process, analyzed jointly, can improve both precision and accuracy in models of species distributions and species-habitat associations. However, the integration of telemetry and spatial survey data has proved elusive because of the fundamentally different analytical approaches required by these two data types. Here, "spatial survey" denotes a survey that records spatial locations and has no temporal structure, for example, line or point transects but not capture-recapture or telemetry. Step selection functions (SSFs-the canonical framework for telemetry) and habitat selection functions (HSFs-the default approach to spatial surveys) differ in not only their specifications but also their results. By imposing the constraint that microscopic mechanisms (animal movement) must correctly scale up to macroscopic emergence (population distributions), a relationship can be written between SSFs and HSFs, leading to a joint likelihood using both datasets. We implement this approach using maximum likelihood, explore its estimation precision by systematic simulation, and seek to derive broad guidelines for effort allocation in the field. We find that complementarities in spatial coverage and resolution between telemetry and survey data often lead to marked inferential improvements in joint analyses over those using either data type alone. The optimal allocation of effort between the two methods (or the choice between them, if only one can be selected) depends on the overall effort expended and the pattern of environmental heterogeneity. Examining inferential performance over a broad range of scenarios for the relative cost between the two methods, we find that integrated analysis usually offers higher precision. Our methodological work shows how to integrate the analysis of telemetry and spatial survey data under a novel joint likelihood function, using traditional computational methods. Our simulation experiments suggest that even when the relative costs of the two methods favor the deployment of one field approach over another, their joint use is broadly preferable. Therefore, joint analysis of the two key methods used in spatial ecology is not only possible but also computationally efficient and statistically more powerful.

Diversity of Bird Species in Training and Model Forest of Faculty of Forestry Science, National University of Laos A case study of Napo Village, Sangthong District, Vientiane Capital

This research are the objectives to study the diversity of bird species in 3 different forest areas: forest plantation area, agricultural land and natural forest area. Which the tools used in the study are the interviews with people who found types of bird species in the area and direct survey belong point transects or point count with take note and then analyzed by formula frequency ratio and dominant ratio. From the interview, there are 53 species of birds, 43 genus and 9 orders in the study area as forest plantation area of 30 species, 24 genus, 6 orders, agricultural land area of 31 species, 24 genus, 9 orders, and nature forest area of 12 species, 10 genus, 3 orders. From the actual survey in 3 areas it was found that there are 49 bird species, 37 genus and 11 orders. Species were not found in the survey but found in the interview of 17 species, 16 genus, 7 orders, and species found outside of the interview of 15 species, 14 genus, 6 orders. In that there are 2 species in the prohibited category of poultry or his list 1, namely: the Nokkotpeut (Centropus sinensis), and the KaiKuaNin (Lophura diardi), but from the actual survey it was found only by the NokkotPeut (Centropus sinensis), As for the KaiKuaNin (Lophura diardi) is not found, Status by Threatened Species List of IUCN and aquatic and wildlife list of Laos: 7 species and 1 species on the list (1) of 2008 aquatic and wildlife.

Estimating the Inbreeding Rate in Natural Populations of The Black-Naped Fruit Dove (Ptilinopus melanasphila)

This research aimed to determine the population of the Black-Naped Fruit Dove (Ptilinopus melanasphila) by estimating population size, sex ratio, effective population, and inbreeding rate, providing a basis for ex-situ design considerations. Data collection employed survey techniques such as the line transect and concentration count point methods. Data analysis focused on determining population size, sex ratio, effective population, and inbreeding rate. The research was conducted in the Sula Islands, North Maluku. Observations and discussions were conducted separately for each location to obtain empirical and comprehensive data serving as a reference for further research. Results revealed the inbreeding rates at the research locations were observed as follows: Soamole village (1.42%), Wai Ipa village (1.56%), and Bega village (1.60%). Sex ratios were observed as follows: Soamole village (male : female ratio of 22.17 : 85.38), Wai Ipa village (male : female ratio of 19.48 : 73.78), and Bega village (male : female ratio of 19.61:80.39). Effective populations were observed as follows: Soamole village (22.39 heads), Wai Ipa village (16.48 heads), and Bega village (16.08 heads). The inbreeding rate is in the good category, while the population number, sex ratio and effective population are in the medium category, however habitat destruction and continuous excessive hunting can result in decline and extinction.

The influence of clearcut harvesting on bird communities in an adjacent protected area in Nova Scotia: Implications for buffer implementation

Human activities adjacent to protected areas have been intensifying as human population grows, with protected areas in some regions effectively becoming islands within a sea of human development. Studies examining the effects of forest harvesting and deforestation on the biodiversity of adjacent protected areas have primarily focused on study areas within the tropics. Due to concerns about impacts of low-retention or clearcut harvesting on biodiversity in adjacent protected areas, the province of Nova Scotia implemented interim harvesting guidelines adjacent to all parks and protected areas in 2019. To examine the effectiveness of these guidelines, we designed a study to quantify the relative influence of previous clearcut harvesting immediately adjacent to Cloud Lake Wilderness Area based on changes in bird communities along transects beginning 100 m inside clearcuts and extending 300 m into the protected area. Ordinations revealed clear differences in the bird communities among transect points; clearcut and edge bird communities differed significantly from those 200 and 300 m inside the protected area and those 100 m inside the protected area comprised of a blend of species from the other 4 transect point locations. Overall species richness and many individual species abundances reflected this pattern as well - 13 species with clear responses across transect point locations were intermediate in abundance at sites 100 m into the protected area. The weight of evidence from our study supports other research showing that the zone of influence from clearcut harvesting on passerine birds in adjacent forest is at least 100 m for many species. These results suggest that a minimum harvesting and development buffer adjacent to protected areas of between 100 and 200 m would be a reasonable management approach if the objective is to minimize the effects of these activities on the bird communities within protected areas. To determine if a partial harvest within the buffer would maintain biodiversity within a protected area will require additional research that directly compares the influence of partial harvesting to no-harvest prescriptions on a variety of taxa. Additional studies in other protected areas that vary in size and have dissimilar landscape contexts, habitat conditions, and bird communities could provide further insight.

Diversity, Encounter Rate and Detection of Non-Volant Nocturnal Mammals on Two Malaysian Islands.

Nocturnal mammals constitute a crucial component of tropical faunal diversity, but not much is known about the effects of anthropogenic disturbance on the habitat use and detectability of these species. We investigated which habitat and environmental variables impact the detectability of non-volant nocturnal arboreal mammals across varying habitat types at two tropical islands with different levels of anthropogenic development in Malaysia. We conducted night transect line and point count surveys following pre-existing paths in Penang Island and Langkawi Island between 2019 and 2020. We used a head torch with red filter and a thermal imaging device (FLIR) to enhance animal detection success. We calculated the encounter rates (individual km-1) for each species as a proxy for abundance. Overall, we detected 17 species, but did not find higher species diversity in intact forested environments compared to disturbed areas. Encounter rates of the most observed species were influenced by 'time after sunset' on the highly developed island of Penang, whereas on the rural island of Langkawi, detection was higher in sites with better canopy connectivity. Different species of non-volant nocturnal arboreal mammals use their respective habitats differently and thus, are differently impacted by varying levels of anthropogenic activities. Our results provided baseline data on the diversity, encounter rate, and detectability of these highly elusive species, which can also help to further improve methodologies for the detection of nocturnal wildlife.

LONG SHORT TERM MEMORY APPROACH FOR SHORELINE CHANGE PREDICTION ON ERETAN BEACH

Eretan Beach is one of the beaches in Indramayu and has a reasonably severe abrasion rate from year to year. The Eretan coastline always experiences significant changes due to erosion every year. Therefore, it is necessary to study changes in the coastline at Eretan beach. This study obtained coastline data from the Google Earth engine using CoastSat, a python-based open-source toolkit, from 1992 – 2022. The open-source geographic information system software used to process the data is the Quantum Geographic Information System. This study aims to analyze the Long Short-term Memory (LSTM) algorithm in predicting shoreline changes at Eretan Beach. The eight optimizer functions in the LSTM are used with nine different scenarios to analyze the algorithm's performance. The results of this study show that RMSProp has the best performance compared to other optimizers. The RMSE and MAPE values on the RMSProp are 35.06258 and 2.2923 on the training data and 9.2457 and 1.06786 on the test data. In addition, from the predictions for the next ten years at transect point 251, it was found that there would be an increase in the coastline.

Evaluating methods for measuring in‐river bathymetry: Remote sensing green LIDAR provides high‐resolution channel bed topography limited by water penetration capability

AbstractThe objective was to evaluate the feasibility of measuring bathymetry using airborne green LiDAR in long and variable river reaches (4 km or more), across three rivers with varying gradients, water depths and light penetration (3.5–10 m), using four alternative LiDAR sensors. The accuracy of green LiDAR data was compared to in situ measurements collected by stratified transect point sampling and Multibeam bathymetry. Factors potentially limiting the feasibility of green LIDAR in rivers were explored. If remote sensing signals were reflected by the riverbed, the sensors generally provided elevation data consistent with in situ elevation measurements, indicating high accuracy (±10 cm) across different hydraulic conditions. The loss of green LiDAR data was mainly a consequence of limited signal water penetration capability, that is, water clarity. Secchi depth was a proxy variable strongly associated with green LiDAR penetration capability across rivers. Data loss was low up to the Secchi depth but increased rapidly thereafter. Surface water turbulence (‘white water’) and dark riverbed vegetation also increased green LiDAR signal loss. Sensors with lower point density and therefore less spatial resolution had more signal strength and therefore penetrated deeper water. However, with increasing coverage of surface turbulence (‘white water’), the importance of high point density also increased. Signal power should be balanced with signal density (spatial resolution), depending on river characteristics and project objectives. We conclude that remote sensing green LiDAR bathymetry is a robust method that efficiently provides accurate elevation data across rivers with different hydraulic conditions and water depths.

The influence of bird pest attack on rice damage and production in Kuantan Singingi

Birds pest in rice field activities are one of the important pest that attack. It has even caused 161,4 ha of crop loss and 124.05 ha of heavy damage in Riau. This neet to be handled and managed properly. This study was initiated by identifying the types and effects of bird pest attacks on the damage and productionof rice crops in Kuantan Singingi. This study was used a survey method by making plots (10x10 m), bird pests species and populations by using a point transect. Observations were carried out in the morning, afternoon and evening. Bird species identification refers to the MacKinnon Bird Guide in Sumatera, Jawa, and Bali. Diversity of birds pest was calculated by the Shannon-Wienner index, species richness by margaleft index, and species dominance by the Simpson index. This study were observed 1.045 birds attack of paddy field. Koto Kari site was observed 479 individual, 332 individu in Kampung Baru, and 214 in Sangau Lonchura striata was observed as many as 635 individuals. Species diversity index was 0.667, species richness index 0.288, density 0.616 and dominance value 0.527. the highest frequency of bird pest visit was in Koto Kari sithe which was 42 times while based on the species was Lonchura striata71 times with an attack time in the morning of 83 times. The highest damage to panicles by bird pest was caused by Lonchura maja at 46.09% but the highest loss of rice wight was caused by Lonchura striata.

Diversity and Distribution of Avifauna in the Northeast of Addis Ababa, Central Ethiopia.

Exploring avian species diversity and distribution patterns is vigorous for conservation efforts in biodiversity-rich countries such as Ethiopia. Compared to other species, birds are relatively well-known and easily observed, making them great markers of productivity or biodiversity. Although bird species are found all across the world, their survival and range have been negatively impacted by habitat loss, fragmentation, and destruction. Thus, the goal of this study is to provide baseline data on avifaunal diversity in the Northeast of Addis Ababa, including species richness, distribution, and relative abundance in various habitats conducted from January 2023 to September 2023 using a stratified sampling design into three habitat types: settlement, farmland, and abattoir. A fixed-width line transect sampling method was used at the farmland and settlement, and a point transect was employed at the abattoir site to collect the bird data. The data were compared using Mann-Whitney and Kruskal-Wallis statistical tests in both seasons and habitat types. A total of 42 bird species belonging to twenty-three families, and nine orders were recorded during the study period. Of these, blue-winged goose and wattled ibis are endemic to Ethiopia. Hooded vultures and White-backed vultures are critically endangered species. The mean abundance of bird species significantly varied in the three habitat types (χ2 = 13.6, df = 2, p=0.001). The abundance of bird species was nonsignificant difference between wet and dry seasons (U = -0.874, p=0.381). The highest diversity (H' = 2.74) was recorded at settlement, and the lowest diversity index (H' = 1.09) was recorded at the abattoir in the dry season. In the wet season, the highest diversity (H' = 2.66) was recorded in the farmland, and the lowest (H' = 1.08) was recorded at the abattoir. The highest evenness (J = 0.94 and J = 0.93) was recorded on the farmland in the wet and dry seasons, respectively. In the study area, urbanization is extremely impacting the environment and altering ecosystem services upon which human civilization depends. Most of the avian species observed in the study area are capable and tolerant of human-induced habitats in the city. Therefore, city planners must consider conserving urban bird species' habitats and feeding sites.

Biodiversity Conservation in Mining Landscapes: a Systematic Review of Assessment Approaches in the Philippines

Mining is an important sector of the Philippine economy, but it often results in negative impacts on biodiversity. To mitigate these impacts, it is crucial to assess biodiversity in mining areas and integrate conservation efforts into mining operations. As part of the national policy guidelines on biodiversity compliance for mining companies, this study has conducted a systematic review to examine the various biodiversity assessment methods, tools, sampling designs, diversity parameters, values, and indices used in the Philippines' mining sites. Search engines and research databases were utilized in identifying diversity assessment-related research. Based on the eligibility criteria, only 25 of the 100 papers downloaded and two project terminal reports were eligible and considered in the review. It was found that authors commonly used transect line and quadrat methods for floral studies and transect line, mist netting, point count, and opportunistic sampling for faunal studies. Species abundance, relative abundance, dominance, frequency, relative frequency, density, relative density, percent cover, and importance value were the most frequently assessed biodiversity parameters, whereas the Shannon-Wiener diversity index, Simpson index, species richness, and evenness were the most commonly used indices. Endemism, economic importance, invasiveness, and conservation status were additional factors evaluated. Overall, this review provides an overview of the various biodiversity assessment methods used in the country's mining areas and offers guidance for future assessments in other mining landscapes. The limited number of studies related to biodiversity assessment in mining areas in the Philippines over the last decade highlights the urgent need for more research in this field.

Population Dynamics of Avian Diversity in the District Okara, Pakistan

Pakistan has a varied bird fauna, with over 790 species recorded and their distribution in three zoogeographical zones (Oriental, Palearctic, and Ethiopian), which is exceptional in the world. The data on avian diversity and abundance in the district Okara, Punjab was carried out from January 2022 to January 2023. Data were collected by direct, indirect, and flocks count methods on four transect points used in the study by visiting the field and by interviewing the local people and hunters about the current and past status of the avian fauna of the area. Okara district contains a major wetland for both local and international migratory birds, including falcons, gulls, plovers, snipes, waders, and long-distance migrating birds. A total of 201 avian species of 19 orders and 54 families were recorded. These included 54 winter migrant species, 23 summer migrants, 13 passage migrants, 1 year-round visitor, and 110 resident species. The spotting of seven globally threatened species and three vulnerable also highlights the importance of this area for avian species. A total of 80 species were recorded in the Passeriformes order. The Shannon-Weiner diversity index showed that Transect Point 1 (H′ = 4.906) had the largest diversity of birds, followed by Transect Points 2, 3, and 1, i.e., 4.778, 4.672, and 4.679. Species evenness has varied among transects based on diversity, with values of 0.7266 (TP 1), 0.6719 (TP 2), 0.7082 (TP 3), and 0.7226. (TP 4). The Simpson index (1-D) for Transect Points 1, 2, 3, and 4 was 0.991, 0.9872, 0.9883, and 0.9888, indicating that Transect Points 1 and 2 had the maximum bird species diversity. The findings revealed that the Okara district is home to a large number of resident migratory and endangered bird species. As a result, it is critical to conserving its habitat as well as bird variety by overcoming serious challenges.

Results of the eighteenth winter waterbird census in Libya in 2022.

Libyan wetlands are diverse; the coastline of Libya, in particular, has different kinds of wetlands, such as salt marshes, bays, lakes, lagoons, and islands. These varieties in habitats provide good shelters and foraging sites for migratory birds during their journeys between Eurasia and Africa. Since the beginning of the Libyan winter census of waterbirds International waterbirds census (Libya IWC) in 2005, which continued regularly until 2012, it has had relatively the same performance in the number of covered sites. However, since 2013, due to the security situation that Libya has experienced due to wars and conflict, which negatively affected the quality of the IWC in Libya, the number of sites has dramatically decreased, reaching only six locations during the middle of the previous decade. The IWC 2022 aimed to count the birds along the Libyan coast from January 10 to 29. The census activities were conducted from dawn to dusk during the study period by using high-quality Telescopes, binoculars, and digital cameras for the documentation. Point transects method was used to cover the sites. The results of this year showed that a total of 64 sites were covered, and 68 species of waterbirds were counted, with an abundance of 61,850 individuals. During the census period, a total of 52 non-waterbird species found in Wetlands were recorded, and the number of individuals was 14,836 birds. A total of 18 threatened species were observed during this survey, 12 of them are mentioned in the International Union for Conservation of Nature Red List, and nine species are mentioned in the regional activities center of specially protected areas annex II as threatened in the Mediterranean, where the species; Larus audouinii (Payraudeau, 1826), Larus genei (Breme, 1839), and Puffinus yelkouan (Acerbi, 1827) are mentioned in both of them. The lack of the number of ornithologists and bird watchers is still one of the factors affecting the quality of the IWC in Libya, as well as lack of funding remains an important factor that plays a major role in the success of the waterbirds census.

Assessment of Conflict between Humans and the Sclater’s Guenon (Cercopithecus sclateri Pocock 1904) in relation to Plant Species Utilization in Aboh-Mbaise Communal Forest, Imo State, Nigeria

Aims: Assessment of conflict between humans and sclater’s guenon in relation to plant species utilization was carried out to determine the conflict between humans and monkey, and identify the plant species parts utilized by the monkeys in area.
 Place and Duration of Study: The study was conducted in Lagwa community forest, Aboh-Mbaise Local Government Area, Imo State, between December 2019 and November 2021.
 Study Design: The Point transect and visual observation methods were used to collect data on population and food availability.
 Methodology: The research was conducted during the dry and wet seasons. Questionnaire were used to collect information on conflict between humans and guenons, while visual observation and faecal examination were used to identify plant species and part utilized.
 Results: Habitat loss, raiding of farms, destruction of roof tops, and food scarcity were the causes of conflicts between monkeys and humans, while awareness creation and establishment of wildlife sanctuary were ways of reducing conflicts between monkeys and humans. Twenty six plant species were utilized by the monkeys for cover. Pear (21%), oil palm (16%), and mango (13%) were the most utilized during the dry season, while Pterocarpus erinaceous (15%), Dacryodes edulis and Treculia africana (11%) were utilized mostly during the wet season. The monkeys consumed more seeds (63%), less fruits (25%), and leaves (13%) during the wet season, and fruits (71%), leaves and seeds (14%) during the dry season.
 Conclusion: The findings of this research is a guide to understanding the conflict that exist between humans and the sclater’s guenon, as well as communicate the type of plants and parts consumed by the animals. Awareness creation on the need to regenerate the remaining fragmented habitat and establishment of a rehabilitation centre for the animals can be a conflict reduction measure, and can provide alternative food sources for the animals.

Diversity, Abundance, and Habitat Association of Medium and Large-Sized Mammals in Tiski Waterfall, Awi Zone, Ethiopia

The reliable data on faunal diversity, abundance, and habitat preference are essential for proposing and establishing relevant conservation interventions. A survey was done from September 2019 to March 2021 to investigate the diversity, relative abundance, and habitat association of large and medium mammals in Tiski Waterfall, Ethiopia. Data were collected using the line transect survey method in both habitat types. In cliff sites, the point transect was also used. The habitats were populated by large and medium animal species that favor dense forest and shrubland habitats near water sources. During the research, three different habitat categories were evaluated (dense forest, shrubland, and cliff sites). Ten mammalian species were discovered. During the wet season, there were 243 ± 6.6 populations recorded, while during the dry season, there were 204 ± 6.8. Seasonal differences in species abundance were statistically significant p ≤ 0. 001 . The total populations of the three habitat types were 198.2 ± 7.39, 135 ± 5.35, and 114 ± 5.16 for dense forest, shrubland, and cliff site, respectively. All three habitat categories had a great difference in species abundance p ≤ 0. 001 . The olive baboon (Papio anubis) was the most common, accounting for 38 percent of the population, followed by the vervet monkey (Cercopithecus aethiops), which accounted for 23 percent. Leopard (Panthera pardus) and common bushbuck (Tragelaphus scriptus) contributed the least to the total, accounting for only 2% each of the total. The highest diversity of mammalian species was found in dense forest (H′ = 0.98), followed by shrubland (H′ = 0.90), and the cliff location has the lowest diversity (H′ = 0.57). The maximum uniformity of the species was found in dense forests (J = 0.51), followed by a shrub region (J = 0.43), and the remaining of the habitat (J = 0.35). Dense forest and shrubland had the highest species similarity (Sl = 0.67), followed by shrubland and cliff site (SI = 0.61). In dense forests with cliff sites, the similarity was lowest (SI = 0.31) in each. To limit the impact of agricultural growth on big and medium mammals, good habitat management is required.

Avian Diversity and Abundance of Taunsa Barrage Ramsar Site in Punjab, Pakistan

The study of avian species diversity and abundance at the Taunsa Barrage Ramsar site was carried out from September 2019 to March 2020. Taunsa Barrage is an important wetland for international and local migratory birds, including waterfowls, waders, and long-distance migrant avifauna. Data were collected by direct counts made on four-point transects representing a disturbance gradient due to humans and different habitats. Species diversity indices, analysis of variance (ANOVA), and other statistical methods were used to analyze data. A total of 150 avian species of 19 orders and 53 families were recorded. These included 66 migrant species and 84 resident species. The spotting of ten globally threatened species also highlights the importance of wetland for avian species. On average, 1511 ± 373 ( mean ± SD ) species of birds were recorded every month. Shannon’s diversity index indicated that Transect Point 2 had higher species diversity ( H ′ = 3.779 ), followed by Transect Points 3, 4, and 1 ( H ′ = 3.769 , H ′ = 3.491 , and H ′ = 3.457 , respectively). Evenness index showed that birds evenly distributed in September ( E = 0.5584 ) than November ( E = 0.310 9). ANOVA showed a significant difference ( F = 4.800 , df = 3 , P = 0.002 ) of avian diversity and abundance among the transect points. But there was no statistically significant interaction between months ( F = 1.23 , df = 6 , P = 0.233 ). The results showed that the Taunsa Barrage Ramsar site harbors plenty of resident migratory and threatened bird species. Hence, it is important to protect its habitat and need to protect avian diversity by overcoming major threats.

Field Data Collection Methods Strongly Affect Satellite-Based Crop Yield Estimation

Crop yield estimation from satellite data requires field observations to fit and evaluate predictive models. However, it is not clear how much field data collection methods matter for predictive performance. To evaluate this, we used maize yield estimates obtained with seven field methods (two farmer estimates, two point transects, and three crop cut methods) and the “true yield” measured from a full-field harvest for 196 fields in three districts in Ethiopia in 2019. We used a combination of nine vegetation indices and five temporal aggregation methods for the growing season from Sentinel-2 SR data as yield predictors in the linear regression and Random Forest models. Crop-cut-based models had the highest model fit and accuracy, similar to that of full-field-harvest-based models. When the farmer estimates were used as the training data, the prediction gain was negligible, indicating very little advantage to using remote sensing to predict yield when the training data quality is low. Our results suggest that remote sensing models to estimate crop yield should be fit with data from crop cuts or comparable high-quality measurements, which give better prediction results than low-quality training data sets, even when much larger numbers of such observations are available.

Optimal Mowing Regime in Enhancing Biodiversity in Seasonal Floodplains along Engineered Channels

The vegetation grown on grasscretes along channelized rivers have been regularly mown in Hong Kong. However, no baseline information on the relationship between different mowing regimes and the biodiversity of such riverbed vegetation is available. We therefore carried out a manipulative experiment along a channelized river to test the effect of mowing frequency and intensity on the abundance and species richness of terrestrial biodiversity. We conducted point counts and transect counts to survey birds, butterflies and Odonates, night surveys for amphibians and reptiles, quadrat surveys for vegetation and sweep net and pan traps for other macroinvertebrates. The results from Generalized Linear Mixed Models (GLMMs) showed a taxon-specific effect of mowing regime. Bird species richness was significantly suppressed in plots mown with high frequency. Both butterfly abundance and species richness were greatly enhanced by low intensity and low frequency mowing. Odonate abundance, and the abundance and species richness of other macroinvertebrates remained high whenever a portion of vegetation was retained as refuge. Amphibians and reptiles did not prefer to utilize the vegetation grown on grasscretes, and thus showed no impact from different mowing regimes. The overall species richness of vegetation was not affected by mowing regimes, but the domination of tall invasive Brachiaria mutica was suppressed by any mowing activity. To cater for the need of most taxa, we propose a mosaic mowing regime, in which most parts along the channelized river could be mown infrequently to 600 mm tall while some of the patches remain unmown.

Temperatures and Cooling Rates Recorded by the New Caledonia Ophiolite: Implications for Cooling Mechanisms in Young Forearc Sequences

AbstractTo unveil how forearc lithosphere cools and re‐equilibrates, we carried out a comprehensive geothermometric investigation of the New Caledonia ophiolite, which represents a rare example of proto‐arc section generated during subduction infancy. A large data set, including more than 80 samples (peridotites and mafic‐ultramafic intrusives), was considered. Closure temperatures calculated for the lherzolites using slow (TREE‐Y) and fast diffusing (TCa‐in‐Opx, TBKN, TCa‐in‐Ol, TOl‐Sp) geothermometers provide some of the highest values ever documented for ophiolitic peridotites, akin to modern sub‐oceanic mantle. Cooling rates deduced from TREE‐Y and TBKN yield values of ≈10−3°C/y, similar to those obtained with TCa‐in‐Ol. These features are consistent with a post‐melting history of emplacement, possibly along a transform fault, and thermal re‐equilibration via conduction. Cpx‐free harzburgites register a high‐T evolution, followed by quenching and obduction. The relatively high TCa‐in‐Ol, TOl‐Sp and cooling rates computed from TCa‐in‐Ol (≈10−3°C/y) are atypical for this geodynamic setting, mirroring the development of an ephemeral subduction system, uplift and emplacement of the Peridotite Nappe. Temperature profiles across the crust‐mantle transect point to high closure temperatures, with limited variations with depth. These results are indicative of injection and crystallization of non‐cogenetic magma batches in the forearc lithosphere, followed by thermal re‐equilibration at rates of ≈10−4–10−3°C/y. Our study shows that the thermal conditions recorded by forearc sequences are intimately related to specific areal processes and previous lithospheric evolution. Thus, detailed sampling and exhaustive knowledge of the geological background are critical to unravel the cooling mechanisms in this geodynamic setting.

Bird-related fault analysis and prevention measures of [formula omitted]400 kV Qinghai-Tibet DC transmission line

Birds’ activities may cause short-circuit damages of transmission line (TL), especially in the areas without tall trees and other vegetation. ±400 kV Qaidam-Lhasa DC TL with an average altitude of about 4650 m in China is the highest DC TL in the world. Since November 2011 to the end of January 2017, there have been a total of 102 short-circuit damages, including 95 damages caused by birds. The damages were mainly caused by the defecation of birds. This paper analyzes the characteristics and causes of flashover damages of the Project. Moreover, A survey of birds along the TL was carried out by using line transect method and point count method, and then the comprehensive improvement measures for such bird-related outages were put forward. The results show that a total of 26 species of birds are involved in the damages, mainly including large or clustered birds such as Gyps himalayensis, Aegypius monachus, Buteo hemilasius, Buteo buteo and Corvus corax. The damages often occur at night in winter and spring. The prevention measures shall be dominated by guiding type and supplemented by isolation type and expulsion type, and focus on the treatment of tension tower. Through improvement, the outages have been greatly reduced from 2018 to now.