Shrub Areas Research Articles

Seasonal Food Preference of Cheetal (Axis axis) and Sambar Deer (Cervus unicolor) In Corbett National Park, Uttarakhand

This study is based on two years field study by direct observation and questionnaire method in Bijrani and Jhirna zones of Corbett National Park. Cheetal (Axis axis) and Sambar deer (Cervus unicolor) are found with their sympatric species Barking deer in Corbett Park. The population of Cheetal and Sambar in different vegetative areas of Corbett varies according to the availability of their favourite food (seasonal). This study reveals that Cheetal preferred new sprouting of Cynadon dactylon, green Desmostachya bipinnata, Eulaliopsis binata, Setaria species, Heteropogon species, Imperata cylindrica, Saccharum bengalensis, and Saccharum narenga in grassland. In dense shrub area, Cheetal preferred green tender leaves of Murraya koenegi, Glycosmis arbores, and fruits of Ziziphus mauritiana, Emblica officinalis, and Solanum nigrum. In Sal-mixed forest Cheetal preferred green fallen leaves of Shorea robusta, Adena cordifolia, Mallotus philippensis and leaves & fruits of Syzigium cumini, Agle marmels, Ficus racemosa, Diospyras tomentosa, flowers of Bombax ceiba (calyx), Cassia fistula etc. In the water-side area Cheetal preferred Dalbergia sissoo, S. munja, Phragmites roxburghii and Acacia catechu etc. Sambar is mostly found in dense shrub area and preferred leaves of M. koenegi, G. arbores, E. officinalis, Justicia adhatoda, Z. mauritiana. In Sal-mixed forest, Sambar preferred leaves of S. robusta, A. cordifolia, A. marmeles, Dendrocalamus strictus, and flowers of B. ceiba etc. In grassland, Sambar preferred S. munja, I. cylindrica, D. bipinnata, E. binata. In water-side Sambar preferred A. arabica, P. roxburghii, and D. sissoo on a priority basis. Sambar generally preferred course food like rough leaves, bark, seeds, flowers, soft twigs, and large grasses.

Shrub expansion in maritime forest responding to sea level rise

Expansion of shrubs has been observed in a number of biomes and in response to diverse global change drivers. Noting shrub expansion in coastal forests affected by sea level rise, we began to monitor shrub populations in a transgressing loblolly pine forest in coastal Virginia. Forest study plots spanned a gradient of salinity and progression toward a ghost forest state, from high forest with a relatively closed canopy, to mid and low forest, where there were few remaining live canopy trees. Shrubs of the species Morella cerifera were censused for 3 years from 2019 to 2021. Shrub distributions were compared to distributions of the invasive grass Phragmites australis to test if competition with this invasive species played a role in the observed shrub distribution. Shrubs were most abundant in the mid forest, whereas P. australis was most abundant in the low forest, but we did not detect a negative correlation between changes in occupancy of P. australis and shrubs. Rapid growth of shrubs in the mid and high forest radically changed the forest understory structure during the study period. Basal area of shrubs in the mid and high forest tripled, and shrub occupancy increased from 45 to 66% in the high forest, with high patchiness between plots. A flooding event salinized the site in late 2019, during the study. Following the flood, soil porewater salinities in the low forest remained above levels known to cause mortality in M. cerifera for several months. We postulate that high salinity, rather than competition with P. australis, filters M. cerifera from the low forest, whereas moderate salinity in the mid and high forest favors M. cerifera growth and expansion. The increase in shrubs appears to be a hallmark of salt-affected maritime forest, with the shrub front occurring in advance of other indicators of transgression such as P. australis invasion.

ANALYSIS OF THE URBAN HEAT ISLAND USING MICROCLIMATE SIMULATION FOR URBAN QUARTER

This study demonstrates that the development of green infrastructure is an important task in the formation of ur-ban planning strategies to reduce the effect of the urban heat island and improve the ecosystem of the city. Simulation is an effective method for studying the complex mechanisms of urban climate formation at the stage of urban planning. The purpose of this study is to assess the severity of the urban heat island in relation to the quarter, taking into ac-count various scenarios of its landscaping, using modern simulation tools. Based on modeling in the ENVI-met soft-ware and computing complex of the thermal conditions of the quarter on the hottest days, its high thermal heterogenei-ty was established. The maximum temperature values are noted in roads and soils, the minimum – in green areas. The temperature conditions of the quarter changes over time. Exceeding the average temperature of the urban quarter ter-ritory over the average temperature in green areas means the possibility of forming an urban heat island. The calcula-tion established that most of the quarter is located in the urban heat island zone. This is also confirmed by an increase in air temperature in an urbanized area. Recommendations are given to mitigate the urban heat island. Based on the results of the thermal simulation of the quarter, it was established that the most effective solution compared to the orig-inal model is an increase in the area of lawn grass and shrubs by 10%, an increase in the area of trees by 12% and a decrease in asphalt pavements of paths and sites by 5.7%. Such a solution maximizes the mitigation of the urban heat island and provides a high level of comfort for the urban environment. Further research will focus on the development of a multi-factor correlation-regression model to assess the mitigation effect of urban heat islands by means of improv-ing green infrastructure.

Analysis of Land Cover Change Using Sentinel-2 Images at Natural Laboratory of Peat Swamp Forest Area CIMTROP University of Palangka Raya

The Natural Laboratory of Peat Swamp Forest Area known as the Center For International Co-operation in Management of Trofical Peatland (CIMTROP) University of Palangka Raya has been set as specific research area of tropical peat swamps since 1993 and has a 50.000 hectares total area. Natural Laboratory of Peat Swamp Forest Area – CIMTROP University of Palangka Raya is peat and sandy land and as a catchment water area, that is crucial to preserve and protect its ecosystem. This research used remote sensing and GIS technology for land cover monitoring utilize Sentinel-2 images. The purpose of this research was to determine (1) land cover changes in the Natural Laboratory/CIMTROP UPR in 2016 and 2021, (2) The rate of land cover change in the Natural Laboratory/CIMTROP UPR and (3) the causes of land cover change in the Natural Laboratory/CIMTROP UPR. Land cover analysis by interpreting Sentinel-2 images in 2016 and 2021 used Supervised Classification Technique. Based on results of the analysis, there were five land cover classes: forest, shurbs, brush, swamp grass and open land. The accuracy testing process performed uses a confusion matrix method to produce mapping accuracy values for each land cover class. Between 2016 to 2021, the change in forest class decreased from 31.809,40 hectares (67,37%) to 29.888,10 hectares (63,30%). Contrary to the shrub class, there was and increase of 1.762,30 hectares (3,73%) to 2.585,20 hectares (5,47%). The increase in shrub area was due to forest reforestation, degradation and deforestation from the forest and land fires which occurred in previors years.

SPIDERS (ARANEI) OF THE PERIGLACIAL LANDSCAPES OF THE TSEI GORGE, NORTH OSSETIA-ALANIA, CAUCASUS, RUSSIA

In the framework of a comprehensive study of arthropods taking part in the primary successions of the periglacial landscapes in the North Caucasus, spiders were collected from 10 sites of different ages (ranging from 1 to 170 years) in the upper reaches of the Tsei Gorge at altitudes of 2071 to 2336 m a.s.l. As the glacier retreats, meadow communities are formed at the site of bare near-glacial areas, these being first replaced by shrubs in areas aged 10–14 years, and then by forest communities on 30–35-year old surfaces. Spiders appear almost immediately after the retreat of the glacier, and representatives of at least three families are found already in the area that was freed from ice just a year ago. This pioneer complex consists not only of representatives of the alpine fauna, but it also includes species without pronounced altitudinal preferences. However, the primary assemblage is short-lived, being completely replaced in 10–15 years, especially sharp rearrangements of the spider populations being noted during the transition from meadow to the forest stage of succession. In 30–35 years following the retreat of the glacier, the spider complexes reach a level of diversity that is quite comparable with that in developed communities of the mountain forest belt. A comparison of the periglacial assemblages of Caucasian spiders with those formed under similar conditions in the southern and northern mountains of Western Europe indicates a profound regional specificity not only at the level of species, but even at the level of families.

HABITAT STRUCTURE AND HETEROGENEITY DETERMINE A SUCCESSFUL BREEDING PROBABILITY OF THE LONG-EARED OWL (<i>ASIO OTUS</i>, STRIGIDAE, STRIGIFORMES)

In 2001 to 2020, for each Long-eared owl nest in the Crane Homeland Nature Reserve territory with an area of 48 km2, the following microhabitat parameters were determined using standard field methods: the nest type built by different bird species, the presence of a nest roof, the nesting tree species, and the nest height above the ground. In most cases, for nesting the Long-eared owl reused magpie nests (Pica pica) (77%), and half of the nests were found on willow trees (family Salicaceae) (50%). The nest height above the ground varied from 1.5 to 22 m. Vegetation on the nesting area with a radius of 500 m was determined using the “Semi-Automatic Classification Plugin” automatic vegetation classifier of QGIS software. Five habitat types were so classified: forests, shrubs, meadows, arable land, and satellite image mistakes. Village areas were allocated separately. The average shares of the largest habitat types for over 20 years on the nesting sites included meadows (51.1%) and shrubs (16%). From 2001 to 2020, a habitat change in the breeding area was observed: forest and shrub areas decreased, while the meadow, village and arable land areas increased. An analysis of the effect of habitat types on the nesting success was evaluated by means of the “gbm” and “dismo” modules in the R program using the Boosted Tree classifier algorithm. The presence of such habitat types in the nesting area as villages (24.2%), shrubs (19.3%), meadows (11.8%), and habitat heterogeneity (11.6%) most strongly affected the probability of owl successful nesting. That owls tend to use anthropogenic and agricultural territories is associated with the diversity, easy foraging and more effective protection from predators during the breeding season.

Relationship between NDVI of Patches and Cover Area of Grasses, Shrubs and Bare Soil Components of a Semi-Arid Steppe from North-West Patagonia, Argentina

Distinguishing the contributions of different vegetation cover such as shrubs and grasses components into the primary production in arid and semi-arid rangelands is a key step to understanding changes at a landscape scale. The aim was to assess the contribution of shrubs, grasses and bare soil components into a total biophysical variable at a patch level, and the relationship between that biophysical variable and remote sensing vegetation index, in a grass–shrub steppe from North-West Patagonia, Argentina. We conducted a field survey in the period 2015–2017 to analyzing the relationship between monthly values of Normalized Difference Vegetation Index (NDVI) of two grasses, two shrub species and bare soil, weighted by their cover area at a patch level, and the concomitant patch NDVI records, respectively. The contribution of the patch components to the total NDVI value at a patch level was additive. The relationship between the weighted NDVI of patch components and the concomitant NDVI value at a patch level along time was linear for perennial grasses and deciduous shrub–grass patches, but linearity was not significant for most perennial shrub–grass patches. Differences among patch compositions and their surface reflectance suggest the need to move forward in a more precise distinction of the floristic composition of patches, to better understanding their contribution to NDVI temporal dynamics at a landscape scale.

The current fire regime in northern Andean shrublands hinders tree recruitment and arrests forest succession

The northern Andes is a biodiversity hotspot. However, historical land use and the current increase in wildfires have profoundly altered the landscape. There is an urgent need to understand how successional processes and wildfires operate to support biodiversity management in this region. We studied the effect of wildfire frequency and time since the last fire on vegetation regeneration patterns in a heavily transformed northern Andean landscape. In the past, Andean Forests were common in this region. Quercus once dominated humboldtii, the only Quercus species native to South America, which was frequent in these forests. Using the fire map of the Iguaque Mountains (Colombian Andes), we selected areas with different fire frequencies (three and five fires in thirty years) and the time since the last fire (one to six years) to study post-fire vegetation structure and composition. Resprouting herbs and small shrubs dominated post-fire communities. Their composition was closer to subpáramo vegetation (greater richness and density of herbaceous and shrub species than tree species) than to Andean forests. Indeed, forest species were virtually absent from burned sites, as were obligate seeders. Fire frequency did not affect the composition and structure of the herbaceous layer.Conversely, we found a substantial reduction in species richness and cover of woody species with the increase in fire frequency, a reduction of the basal area of large shrubs and trees, and a trend towards a decrease in the proportion of obligate tree resprouters. The richness, density, and cover of herbaceous species was high the first year after the fire and still showed a small increase until year 6, as the number of obligate resprouters decreased. The basal area of woody species barely increased between years 1 and 6, but the richness and density of shrubs and trees increased gradually during this period. Exotic species were largely herbaceous and dominated by Pteridium aquilinum and Andropogon lehmannii. Their cover was not affected by fire frequency or time since the last fire, although its composition changed. While the cover of Pteridium aquilinum was not affected by fire frequency, it decreased from year 1 to year 6. Our results show that current wildfire regimes in the Iguaque Mountains favor the persistence of fire-tolerant herbs and shrubs, compromise tree recruitment, and arrest forest succession. New integrated fire management strategies are needed to protect remnant forests and establish oak forests in burned shrublands.

Bacterial Community and Diversity of River Ecosystems on the Qinghai-Tibet Plateau Based on 16S rRNA Gene Sequencing

In recent years, the ecosystems on the Qinghai-Tibet Plateau (QTP) have been facing a high risk of degradation due to the impacts of climate change and human activities. As one of the important components in river ecosystems, microbial communities can reflect the overall changes in the watershed and are regarded as indicators of the health of river ecosystems. In order to investigate the diversity and composition characteristics of bacterial communities in river ecosystems on the QTP, 65 samples were collected from the Yellow River, Yangtze River, Lancang River, Nujiang River, Yarlung Tsangpo River, and Qaidam Basin on the QTP in July 2021 and were analyzed using 16S rRNA high-throughput sequencing. The results showed that the detected bacterial communities covered 65 phyla and 1311 genera in total. Bacterial communities had high α-diversity indexes across the rivers, indicating that the bacterial richness and diversity in rivers on the QTP were at a high level. Among them, Chao and observed OTUs had significantly negative relationships with SRP/TP. The dominant phyla were Proteobacteria, Bacteroidota, Actinobacteriota, and Cyanobacteria. The dominant classes were γ-proteobacteria, Bacteroidia, and α-proteobacteria. The dominant genera were Flavobacterium and Limnohabitans. The results of principal coordinate analysis and permutational MANOVA suggested significant differences in bacterial community structure among the rivers on the QTP. Canonical correspondence analysis showed that the significant environmental variables associated with the variation in the bacterial communities were physicochemical properties of the river water, including conductivity, pH, dissolved silicon, and dissolved organic carbon, as well as watershed characteristics, including the average normalized differential vegetation index, average slope, cumulative water channel distance, catchment size, proportion of shrub area, and average elevation. Among them, conductivity had the strongest influence on bacteria distribution on the QTP. These results provide a database and information for understanding the composition characteristics of microbial communities on the QTP and identifying environmental factors influencing the diversity of bacteria communities.

The use of multi-sensor satellite imagery to analyze flood events and land cover changes using change detection and machine learning techniques in the Barito watershed

Indonesia is one of the countries in the world that is frequently affected by floods. Flood disasters can have various negative impacts and therefore need to be analyzed to determine prevention and mitigation measures. This study examined land cover change, flood detection, and flood distribution using multitemporal Sentinel-1 and Landsat-8 satellite imagery in the Barito watershed. A combination of change detection and the application of the Otsu algorithm was used to detect floodplains from Sentinel-1 imagery. Land use/land cover (LULC) changes are detected using a combination of change detection and machine learning in the form of a random forest algorithm. The overlay technique was used to analyze the distribution of floodplains. In this study, the floodplain in the study area was mapped to 109,623 ha. The change detection method detects a decrease in the areas of primary forest, secondary forest, fields, rice fields, shrubs and ponds, respectively, by 13,020 ha, 116,235 ha, 259 ha, 146,696 ha, 47,308 ha, and 9,601 ha. Settlements, bare land, plantations and water bodies increase by 14,879 ha, 64,830 ha, 218,916 ha, and 34,768 ha, respectively. Flooding was mainly found in the classes of rice fields, water bodies and primary forests.

Old Man Saltbush mortality following fire challenges the resilience of post‐mine rehabilitation in central Queensland, Australia

SummaryLandscape rehabilitation following mining is required to be resilient to disturbance impacts such as fire, drought and disease. As mining companies undergo the process of rehabilitation certification and mine closure, there are notable knowledge gaps on the ecological risks associated with mature rehabilitated landscapes, based largely on the assumption that rehabilitation is analogous to reference communities. However, the response to fire disturbance across a range of landscapes remains largely untested and in particular there is limited understanding of recovery traits of plant species that occur naturally or are commonly seeded into rehabilitation. In August 2018, a controlled fire was applied to 37 hectares of 12‐year‐old coal‐mine rehabilitation in central Queensland, Australia. We used a combination of (i) ground plot surveys and (ii) drone imagery to compare the vegetation response of burnt woody species to unburnt controls prior to, and for, two years following the fire. The survival of the most dominant shrub species found on the rehabilitation site was significantly impacted by the fire. Old Man Saltbush (Atriplex nummularia Lindl. subsp. nummularia) recorded significant post‐fire mortality, with ground surveys recording an average reduction of 89% of stems per hectare across the burnt site, while unburnt controls remained unchanged. The plot data analysis was supported with high spatial and temporal resolution drone imagery, classified using a Random Forest machine‐learning approach. Change analysis of these maps showed a significant decline of 82% in Old Man Saltbush plant density and 92% reduction in foliage cover following the fire. In addition, the mean canopy area of individual Old Man Saltbush shrubs reduced significantly from a pre‐fire mean of 11.3 to 4.8 m2 two years following the fire. A spatial proximity analysis showed that those individuals that survived the fire were located significantly closer to unburnt areas and bare spoil, indicating that discontinuous ground fuel loads can greatly improve the survivability of individuals. This study provides new evidence on the contested fire sensitivity of Old Man Salt bush and demonstrates the risk that future climate‐driven extreme events may have on the resilience of novel ecosystems.

国家公园生态产品价值核算

PDF HTML阅读 XML下载 导出引用 引用提醒 国家公园生态产品价值核算 DOI: 10.5846/stxb202112163575 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家公园研究院研究专项课项目（KFJ-STS-ZDTP-2021-003） Research on accounting of ecological products value in National Parks Author: Affiliation: Fund Project: the Special Program for the Institute of National Parks, Chinese Academy of Sciences 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:生态产品是维系生态安全、保障生态调节功能、提供良好人居环境的自然要素，国家公园作为我国代表性生态系统、自然景观和遗产、野生动植物物种分布的重要区域，是生态产品的重要供给区域，在提供高质量调节服务和文化服务中发挥着重要作用。生态产品总值（GEP）是生态产品价值的总和，并能够客观反映生态系统状况和生态保护成效。以我国首批5处国家公园为研究对象，通过核算其2000年和2015年GEP，得出如下结论：（1）2015年国家公园总GEP为10813.6亿元，主导服务功能是水源涵养和气候调节，占总值的70.0%，单位面积GEP为652.0万元/km2，是全国均值的1.4倍。（2）三江源国家公园GEP最高（4547.7亿元），其次是大熊猫、海南热带雨林国家公园等；海南热带雨林国家公园单位面积GEP最高（5140.5万元/km2），其次是武夷山、大熊猫国家公园等。（3）2000-2015年，国家公园GEP增长1.0%，单位面积GEP基本稳定，三江源和海南热带雨林国家公园增幅较大（3.1%和1.0%），而大熊猫国家公园有所下降（-2.0%），主要与地质灾害导致的森林、灌丛等生态系统面积减少有关。通过核算国家公园GEP，评估国家公园的生态保护成效，探究核算结果在其建设中的应用，推动国家公园的绿色发展及"两山"转化。 Abstract:Ecological products are nature elements that maintain ecological security, guarantee ecosystem service functions, and provide well living environments. National parks are the crucial areas for representative ecosystems, natural landscapes and heritages, and wildlife species, and also the main areas for ecological products supply in China which play an important role in providing high-quality ecological products. Gross Ecosystem Product (GEP) is the sum of the ecological products value and can reflect ecosystem status and protection effectiveness objectively. We took the first batch of national parks as the research objects and calculated the value of their ecological products. The conclusions were as follows. (1) The total GEP of the national parks was 1081.36 billion yuan, and the main ecosystem service functions were water retention (420.09 billion yuan) and climate regulation (336.69 billion yuan), both accounted for 70.0%; the GEP per unit area of the national park was 6.5 million yuan/km2 which was 1.4 times higher than the national average (4.8 million yuan/km2). (2) Three-River-Source National Park had the highest GEP (454.77 billion yuan), and followed by Giant Panda and Hainan Tropical Rainforest National Park (278.14 billion yuan and 226.34 billion yuan); Hainan Tropical Rainforest National Park had the highest GEP per unit area (51.41 million yuan/km2), and followed by Wuyishan and Giant Panda National Park (48.16 million yuan/km2 and 12.23 million yuan/km2). (3) From 2000 to 2015, the total GEP of national parks increased 1.0%, and the GEP per unit area was basically stable. The GEP of Three-River-Source and Hainan Tropical Rainforest National Park increased significantly (3.1% and 1.0%), while Giant Panda National Park decreased 2.0% which mainly related to the reduction of the area of forests, shrubs and other ecosystems caused by geological disasters. By accounting of GEP, this paper aimed to assess the protection effectiveness of national parks, explore the results application in their construction, and promote green development and "two mountains" transformations in the national parks. This paper still had some difficulties and deficiencies. Firstly, due to the difficulty of obtaining data, this paper did not calculate the value of material products and cultural services of national parks; secondly, due to the large geographical span of national parks, it was difficult to obtain localized parameters that were mainly from references, and their accuracy need to be improved. This paper could reflect the state and changes of the ecological environment in a certain period of time within the national park, and provided a scientific basis for the ecological protection and management of national parks. 参考文献 相似文献 引证文献

KAJIAN DAS AIR DINGIN DITINJAU DARI PERUBAHAN TUTUPAN LAHAN TAHUN 2008 - 2021

This research was conducted in the Air Dingin watershed of West Sumatra which aim calculating changes of land cover area in Air Dingin watershed (2008 – 2021). To determine land cover changes using maximum likelihood classification by utilizing Arc Map 10.8. It can classify land cover change and Microsoft Excel software to calculate land cover change. The result shows that the landcover change of Air Dingin Watershed in 2008 - 2021 largest increase in the shrub area by 392.60 ha (3.1%) and followed by dry land agriculture which increased 215.18 ha (1.7 %), building area increased by 148.68 ha (1.2%), mixed gardens by 16.94 ha (0.1%). The increase in land area will be followed by a reduction in land cover, which has the largest decrease in forest area, namely 635.58 ha (5.0%), followed by a decrease in paddy fields of 129.25 ha (1.0%) , waters decreased by 8.57 ha (0.1%).

Combined Effects of Stream Hydrology and Land Use on Basin‐Scale Hyporheic Zone Denitrification in the Columbia River Basin

AbstractDenitrification in the hyporheic zone (HZ) of river corridors is crucial to removing excess nitrogen in rivers from anthropogenic activities. However, previous modeling studies of the effectiveness of river corridors in removing excess nitrogen via denitrification were often limited to the reach‐scale and low‐order stream watersheds. We developed a basin‐scale river corridor model for the Columbia River Basin with random forest models to identify the dominant factors associated with the spatial variation of HZ denitrification. Our modeling results suggest that the combined effects of hydrologic variability in reaches and substrate availability influenced by land use are associated with the spatial variability of modeled HZ denitrification at the basin scale. Hyporheic exchange flux can explain most of spatial variation of denitrification amounts in reaches of different sizes, while among the reaches affected by different land uses, the combination of hyporheic exchange flux and stream dissolved organic carbon (DOC) concentration can explain the denitrification differences. Also, we can generalize that the most influential watershed and channel variables controlling denitrification variation are channel morphology parameters (median grain size (D50), stream slope), climate (annual precipitation and evapotranspiration), and stream DOC‐related parameters (percent of shrub area). The modeling framework in our study can serve as a valuable tool to identify the limiting factors in removing excess nitrogen pollution in large river basins where direct measurement is often infeasible.

Sandy Habitats Play an Important Role in Shrub Encroachment in Grasslands

Shrub species have increased in density and cover in desertification areas, however, the role of sandy habitats in contributing to the expansion of shrubs is poorly understood. Although the effect of sandy habitats on plant growth and reproduction have been demonstrated, most existing studies lack either experimental demonstration or an integrated study during the whole shrub life cycle. We performed field and laboratory experiments to examine the responses of four stages in the life cycle of shrubs (seed germination, plant growth, seed reproduction, clonal reproduction) to sandy habitats (including sand substrate, sand burial and wind erosion) for Caragana shrubs. Results showed that both sand substrate and sand burial facilitated seed germination, seedling biomass, sapling establishment, plant growth, and root-shoot ratio of Caragana. Meanwhile, they both strongly increased seed number and seed preservation, and thus enhanced sexual reproduction. Sand burial favored clonal reproduction of Caragana by promoting the formation of branch-derived ramets, while wind erosion benefited clonal reproduction by facilitating the formation of root-derived ramets. These results suggested that sandy habitats facilitated seed germination, plant growth, sexual reproduction, and clonal reproduction of Caragana, which could explain why shrub abundance, shrub area and shrub height of Caragana in sandy areas was higher than in grasslands. Our study provided an experimental demonstration that sandy habitats promoted the population growth of Caragana shrubs during the whole life cycle and highlighted the significant role of sandy habitats in facilitating shrub encroachment in grasslands.

Relationships between fishery catch rates and land cover along a longitudinal gradient in floodplains of the Amazon River

Land cover is an important driver of patterns of fish diversity and assemblage structure in Amazonian floodplains. In the floodplain of the Amazon River, remarkable changes in the land cover composition across a longitudinal gradient, from the middle Amazon to the lower Amazon, likely affects fishery catch rates at local scales. Here, we investigated potential relationships between fishery catch rates and extent of land cover types in lakes of these two regions, the middle and lower floodplains of the Amazon River. Areas of flooded shrubs, herbaceous vegetation, and open water, within buffers of 1000 and 2000 m, were quantified around the areas of 23 lakes and modeled as predictors of fishing catch rate in the two subregions of the River i.e., the lower and middle Amazon, while these regions were also included as fixed effects of our models. Comparisons of the spatial extent of the land cover types between the two regions showed a predominance of flooded herbaceous vegetation in the downstream-lower portion, and a predominance of flooded shrubs and forests upstream-middle portion. In the models, the region was consistently the variable of greatest relative importance (Σwi > 0.9), and indicates higher fishing catch rate in the middle Amazon region when compared to the lower Amazon. Flooded shrub quantified on the smallest scale was the land cover type of strongest influence driving higher fishing catch rates, regardless of the region. In particular, our results support the idea that loss of flooded shrubs in adjacent areas of floodplain lakes can lead to reduced fishing catch rates at local and regional scales.

Discovery of a fossil dwarf antelope outside of Africa and its implications for the late Miocene ecosystem in the northeast margin of the Tibetan Plateau

As a typical dwarf antelope, the extant Nesotragus is confined to shrub areas of open woodlands and forests in Eastern and Central Africa. Molecular phylogenetic reconstructions reveal that Nesotragus, along with Aepyceros (impala), represents the earliest crown group of Antilopinae. However, to our knowledge, fossils in relation to Nesotragus have to date not been found. Here, we report the recent discovery of a fossil dwarf antelope, Linxiatragus dengi gen. et sp. nov., from the early Late Miocene (10–9 Ma) of the Linxia Basin, adjoining the NE Tibetan Plateau. This is the first report of a fossil dwarf antelope outside of Africa and prior to Pliocene. Phylogenetic reconstructions confirm that L. dengi belongs to the clade of extant Nesotragus. Morphometric studies further suggest that the cranial morphology of Linxiatragus is intermediate between the extant Nesotragus and Gazella. A microwear study indicates that unlike extant Nesotragus, L. dengi was possibly a grazer rather than a browser, revealing that extant Nesotragus are secondarily small, an adaptation to a concealing habitat. l. dengi, as well as some other taxa (e.g., Diceros gansuensis) occurring in the NE margin of the Tibetan Plateau in the early Late Miocene, suggests a relatively arid and open regional paleoenvironmental condition, which mimicked the African Savannah woodlands ecosystem. This ecological implication is consistent with the relatively open lands in the Linxia Basin prior to the tectonic uplift of the NE Tibetan Plateau, as indicated by geological evidence. These findings might provide a new interpretation for the origin and migration of modern Sub-Saharan African Savannah mammalian assemblage through the land-bridge connecting Arabia and Asia after their hard-collision.

How to measure the ecological compensation threshold in the upper Yangtze River basin, China? An approach for coupling InVEST and grey water footprint

Defining a reasonable and feasible watershed ecological compensation threshold is the key to protecting watershed ecological functions and maintaining the sustainable utilization of watershed ecosystems. However, many studies have obtained compensation values that are too high to promote the implementation of ecological compensation policies. This study chose the upper reaches of the Yangtze River as the research area, taking water resources closer to people’s daily needs as the evaluation object. Based on the InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) model and grey water footprint method, the ecological compensation threshold model for water resources was established. Combined with the eco-compensation priority sequence coefficient identification of protected areas and beneficiary areas and allowed for the measurement of the watershed ecological compensation value in 2015 and 2020. Finally, compare the advantages and disadvantages of different ecological compensation calculation methods, compare the gap between different watershed ecological compensation standards and the theoretical threshold globally. The results showed that from 2015 to 2020, the value of the water content in the upper reaches of the Yangtze River increased, while the value of the grey water footprint decreased. The classified watershed ecological compensation beneficiary areas were mainly concentrated in the central-eastern and southern parts of the upper Yangtze River, while the ecological compensation protected areas were concentrated in the western and northwestern parts. The mean absolute values of the watershed ecological compensation thresholds for each prefecture-level city and state ranged from 0.43 to 24.63 billion CNY in 2015 and from 0.67 to 41.60 billion CNY in 2020, which were close to the actual values. Among the different land-use types, the water conservation service value per unit area of shrubs was the highest. The lower limit value of watershed ecological compensation calculated using the grey water footprint method was closer to the amount of compensation in practice than was the commonly used opportunity cost method. The findings of the study can help improve the watershed ecological compensation mechanism in the upper Yangtze River region, promote win–win cooperation among transboundary watershed areas, and form a harmonious and stable green development model.

Spatiotemporal variation of soil water potential and its significance to water balance for a desert shrub area

In dry sandy soil, soil water is naturally redistributed by forces owing to matric and gravitational potential, and temperature gradients. Occurring shrub vegetation strongly influences these patterns by hydraulic redistribution within the soil. This means that plants can move water from moist to drier soil areas to extract nutrients from the drier soil and enhance nutrient uptake. This incorporates both upward and downward transport of water through the roots. Diel soil water potential (ψs) and soil temperature fluctuation were investigated at 30-min intervals for a respectively vegetated desert shrub area and non-vegetated bare area. Soil water potential fluctuations at the vegetated area reflected daytime depletion and nocturnal re-supply of water due to hydraulic redistribution while corresponding fluctuations at the non-vegetated area were mainly due to variation in soil temperature. Thus, the greatest diel ψs variability occurred in the vegetated area that averaged −0.401 MPa with a smaller variation in the non-vegetated area with an average of −0.009 MPa. At the shrub scale, ψs was strongly correlated with root distribution pattern that corroborates that diel variation in the active root zone of the shrub was mainly attributed to hydraulic redistribution. In the non-vegetated area, ψs responded more strongly to temperature gradients. The total of hydraulic redistribution of soil water storage increment accounted for 27 % of the total rainfall through the growing season from April to September. The study shows that it is important to consider biotic-factors such as hydraulic redistribution when analyzing water balance changes and hydrological niche segregation for desert ecosystems.

Identifying priority conservation areas based on ecosystem services change driven by Natural Forest Protection Project in Qinghai province, China

Natural Forest Protection Project (NFPP) is a national project, with great significance to promote the sustainable development of society and economy. NFPP has driven land use change significantly, altering the provision of ecosystem services (ESs) and influencing human well-being. The selection of priority conservation areas would provide a reference for the further implementation of the NFPP. Here we used the InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) model to perform a comprehensive spatio-temporal assessment of the impact of NFPP on ESs provision, and ordered weighted averaging (OWA) method to identify priority conservation areas by balancing ESs tradeoffs in Qinghai province, China. The results showed that ESs were changed with the increase in forest land due to the implementation of the NFPP from 2000 to 2020. Soil retention, habitat quality, carbon storage and water purification increased significantly, while water yield showed a downward trend during the 2000–2020. By selecting priority conservation areas based on multi-scenarios analysis, the priority conservation areas were mainly distributed in the southern regions of Qinghai province and eastern regions of the Haibei Prefecture, and the area of forest, shrub and natural grass accounted for 6.10%, 32.30% and 69.54%, respectively. This study provides critical knowledge of the impact of ecological engineering on provision of multiple ESs. Selecting the priority conservation areas will be beneficial to ecosystem management and ecological sustainable development of the regions.