Sparse Shrub Research Articles

The response of carbon stocks of drylands in Central Asia to changes of CO2 and climate during past 35 years

Drylands are terrestrial ecosystems sensitive to climate change. There are totally drylands of 5.17 × 106 km2 (above 80% of global total temperate desert area) in Central Asia (CAS), in which significant increases of temperature and changes of precipitation have been detected in recent decades. However, environment-induced changes in terrestrial carbon stocks of these dryland ecosystems have not been well investigated. With the Arid Ecosystem Model (AEM), this study was devoted to analyze spatiotemporal changes of carbon stocks in drylands over CAS during the past 35 years (1980–2014) and to quantify contributions to these changes of various factors, including temperature, precipitation, and atmospheric CO2 concentration. Over the study period, total stocks of vegetation carbon (VEGC), soil organic carbon (SOC), and litter carbon (LTRC) averaged 2.8 ± 0.05 Pg C, 45.2 ± 0.01 Pg C, and 0.3 ± 0.004 Pg C(1Pg = 1015 g) in CAS, respectively. Meanwhile, total carbon (TOTC) declined by 0.7 Pg C. Climate change caused TOTC to decrease by 1.3 Pg C. In contrast, CO2 enrichment effect caused TOTC to increase by 0.9 Pg C. The effects of different factors on TOTC changes varied spatially. Precipitation was the dominant factor regulating TOTC change in 40.9% of the study area, mainly in the desert sparse shrub region in northwest Kazakhstan and the dryland region of southern Xinjiang of China, in which vegetation growth was mainly limited by water resource. CO2 dominated the change of TOTC in 38.3% of the study area, mainly in the lower altitude regions of Tianshan mountain, in which the hydrothermal condition was relatively suitable for vegetation growth. Ecosystems in southern Xinjiang of China and northwest Kazakhstan are fragile to climate change.

Catchment based hydrology under post farmland abandonment scenarios

Vegetation expansion following farmland abandonment is a complex process that depends on multiple natural and human-induced factors, resulting in differences in the evolution of land cover on former cultivated fields, with various environmental implications. To assess the complexity of the hydrogeomorphological consequences of farmland abandonment, the Instituto Pirenaico de Ecología (CSIC) and the University of La Rioja monitored three small catchments, representative of different post land abandonment scenarios, in the Pyrenees and Iberian Range respectively. In the Pyrenees, a fourth small catchment, covered by natural forest, was monitored as a reference for an undisturbed environment. This study describes the evolution of land use in the abandoned catchments and examines its implications on catchment hydrological connectivity. It also analyses the hydrological responses of the three abandoned scenarios to similar rainfall events, and compares them to that of natural forested areas. .Vegetation tended to increase in the three catchments, but there were important differences in the characteristics of the current land cover. Arnás, the catchment left to a process of natural revegetation, contained a mosaic of shrubs (64%) and forest (27%) at different stages of succession, largely conditioned by the topography and soil properties. Araguás_afforestation was extensively afforested in the 1960s, with 75% of this catchment currently covered by forest, most of it planted artificially. In Munilla, occupied by terraced fields, vegetation recovery was partly restrained by the introduction of cattle, and 80% of the catchment was covered by sparse shrubs. Land abandonment resulted in a general reduction in computed hydrological connectivity in the three studied catchments, except in localized areas close to the main channel, new forest roads and trails, and upstream of terrace wall collapses, all areas of increased hydrological connectivity. The decrease in hydrological connectivity was much lower in Munilla, characterized by an absence of dense vegetation and still dominated by a terraced topography. The hydrological responses of the catchments to similar rainfall events differed significantly, showing the influence of not only vegetation cover but of the properties of soil remaining after previous agricultural activities. Significant storm-flow discharge was observed in Arnás, even under dry conditions, with high peakflows and fast responses. Lower streamflow response was observed in Araguás_Afforestation under dry conditions; however, once the soils were wet the hydrological response was notable and was characterized by high peakflow. The response under afforested trees differed greatly from that of a catchment covered by natural forest, with the latter characterized by gentler hydrographs. The hydrological response in Munilla was the lowest, with long response times and recessions, associated with the thick soils of the terraced fields. These results demonstrated the large variability of post land abandonment scenarios and associated hydrological implications, and highlighted the need to consider these differences to reduce future uncertainties in forecasting water resources and soil conservation.

Propagule pressure, presence of roads, and microsite variability influence dispersal of introduced Quercus rubra in temperate Pinus sylvestris forest

The effective sustainable management of introduced woody species requires understanding of the mechanisms which affect successful colonization in different forest habitats. We studied the spontaneous spread of the alien species – Northern red oak (Quercus rubra) in the Scots pine (Pinus sylvestris) forest located in Poland. We analysed the impacts of seed source distance, presence of and distance from linear structures (public and forest roads) in the landscape, as well as microhabitat diversity, on the distribution of juvenile red oaks. We also studied the effects of types of acorn deposition sites (under shrubs, within clumps of Vaccinium myrtillus, in the open), and ways of seed burial (in moss wefts, in rodent corridors) by animal seed hoarders on seed germination and seedling growth. Field data were collected in six transect lines divided into 3300 plots (1 m2 each). We found that Q. rubra efficiently colonizes Scots pine monoculture. Results of spatially explicit hierarchical generalized linear models showed that distance from acorn sources and occurrence of sparse shrub layers are the most important predictors of Q. rubra ecological success, defined as establishment of juvenile specimens. The presence of roads – potential migration corridors for avian and mammalian acorn consumers/dispersers – favoured non-random red oak spread. The “nurse effect” of native understory components on red oak seed germination and seedling growth was indicated by higher numbers of juvenile specimens as well as by higher proportions of germinated seeds noted under shrubs than in open areas (without shrubs) or within clumps of V. myrtillus. All red oaks developed from seeds buried in compact moss wefts or in spacious caches and corridors created by rodents in the moss layer, which indicated a positive “burial effect”. We conclude that microhabitats make the Scots pine forests very suitable for Q. rubra invasion. Because of the wide distribution of numerous red oak stands in European temperate forests and the presence of numerous oak seed dispersers, the continuous colonization of widespread Scots pine monocultures by Q. rubra must be expected.

Land use change characteristics affected by water saving practices in Manas River Basin, China using Landsat satellite images

The characteristics and influencing factors of land use change under arid conditions were studied in the Manas River Basin in Xinjiang Region, Northwest China. Landsat satellite images acquired in 1976, 1990, 2000, 2010 and 2015 over the study area were used as basic data. Land use change, the rate of change of land use, land use transfer and other aspects revealed the characteristics of land use change and related factors as influenced by water conditions in the basin. The results showed that: (1) Over nearly 50 years, land reclamation in the Manas River Basin resulted in the rapid expansion of an artificial oasis area, and promoted the process of ‘oasis urbanization’, and accelerated the development of the river basin economy. (2) In 2000, the popularization of drip irrigation under mulch technology led to the rapid growth of cultivated land and development land in the watershed. Meanwhile, the water table declined in the desert area of the lower reaches of the river basin, and the area occupied by sparse shrub forest and grassland decreased. (3) Before popularization of water-saving technology, woodland, grassland and development land transformed to cultivated land in the amounts of 93.46 km2, 2542.93 km2 and 137.53 km2, respectively, and woodland transformed in the amount of 189.64 km2. After water-saving technology was popularized, woodland, grassland and development land were transformed into cultivated land in the amounts of 567.41 km2, 1756.2 km2 and 37.36 km2, respectively. (4) The popularization of water-saving technology made the dynamic degree of cultivated land and development land more active, and further increased landscape fragmentation and landscape heterogeneity. The level of urbanization development, the level of economic development and the dry humidity of the basin became the main factors affecting the change of land use in the basin. Keywords: land-use change, spatial characteristics, influencing factor, Manas River Basin, Landsat satellite images DOI: 10.25165/j.ijabe.20171006.3435 Citation: Yang G, Chen D, He X L, Long A H, Yang M J, Li X L. Land use change characteristics affected by water saving practices in Manas River Basin, China using Landsat satellite images. Int J Agric & Biol Eng, 2017; 10(6): 123–133.

Effect of climate change on vegetation phenology of different land-cover types on the Tibetan Plateau

ABSTRACTResearch in vegetation phenology change has been one heated topic of current ecological and climate change study. The Tibetan Plateau, as the highest plateau of the earth, is more vulnerable and sensitive to climate change than many other regions. In this region, shifts in vegetation phenology have been intensively studied during recent decades, primarily based on satellite-retrieved data. In this study, we explored the spatiotemporal changes of vegetation phenology for different land-cover types in the Tibetan Plateau and characterized their relationship with temperature and precipitation by using long-term time-series datasets of normalized difference vegetation index (NDVI) from 1982 to 2014. Diverse phenological changes were observed for different land-cover types, with an advancing start of growing season (SOS), delaying end of growing season (EOS) and increasing length of growing season (LOS) in the eastern Tibetan Plateau where meadow was the dominant vegetation type, but with the opposite changes in the steppe and sparse herbaceous or sparse shrub regions which are mostly located in the northwestern and western edges of the Tibetan Plateau. Correlation analysis indicated that sufficient preseason precipitation may delay the SOS of evergreen forests in the southeastern Plateau and advance the SOS of steppe and sparse herbaceous or sparse shrub in relatively arid areas, while the advance of SOS in meadow areas could be related to higher preseason temperature. For EOS, because it is less sensitive to climate change than SOS, the response of EOS for different land-cover types to precipitation and temperature were more complicated across the Tibetan Plateau.

Land use change characteristics affected by water saving practices in Manas River Basin, China using Landsat satellite images

The characteristics and influencing factors of land use change under arid conditions were studied in the Manas River Basin in Xinjiang Region, Northwest China. Landsat satellite images acquired in 1976, 1990, 2000, 2010 and 2015 over the study area were used as basic data. Land use change, the rate of change of land use, land use transfer and other aspects revealed the characteristics of land use change and related factors as influenced by water conditions in the basin. The results showed that: (1) Over nearly 50 years, land reclamation in the Manas River Basin resulted in the rapid expansion of an artificial oasis area, and promoted the process of ‘oasis urbanization’, and accelerated the development of the river basin economy. (2) In 2000, the popularization of drip irrigation under mulch technology led to the rapid growth of cultivated land and development land in the watershed. Meanwhile, the water table declined in the desert area of the lower reaches of the river basin, and the area occupied by sparse shrub forest and grassland decreased. (3) Before popularization of water-saving technology, woodland, grassland and development land transformed to cultivated land in the amounts of 93.46 km2, 2542.93 km2 and 137.53 km2, respectively, and woodland transformed in the amount of 189.64 km2. After water-saving technology was popularized, woodland, grassland and development land were transformed into cultivated land in the amounts of 567.41 km2, 1756.2 km2 and 37.36 km2, respectively. (4) The popularization of water-saving technology made the dynamic degree of cultivated land and development land more active, and further increased landscape fragmentation and landscape heterogeneity. The level of urbanization development, the level of economic development and the dry humidity of the basin became the main factors affecting the change of land use in the basin. Keywords: land-use change, spatial characteristics, influencing factor, Manas River Basin, Landsat satellite images DOI: 10.25165/j.ijabe.20171006.3435 Citation: Yang G, Chen D, He X L, Long A H, Yang M J, Li X L. Land use change characteristics affected by water saving practices in Manas River Basin, China using Landsat satellite images. Int J Agric & Biol Eng, 2017; 10(6): 123–133.

Habitat selection and their interspecific interactions for mammal assemblage in the Greater Khingan Mountains, northeastern China

Patterns of habitat use profoundly influence interactions among wildlife species and ecological communities, the sustainability of species and the stability of populations. The Eurasian lynxLynx lynx,sableMartes zibellina,mooseAlces alces,roe deerCapreolus pygargusand mountain hareLepus timidusare sympatric carnivore and herbivore species in Hanma Nature Reserve in the Greater Khingan Mountains, northeastern China. We conducted snow track sample plot surveys of these mammals during the winter of 2012–2013 and analyzed habitat selection characteristics and interspecific interactions. We screened the preferred habitat variables of each species and predicted their potential occurrence probability by generalized linear mixed model (GLMM) and further, selected the best model of each species that incorporated other species' potential occurrence probability in GLMM. Our results showed that when we only considered habitat factors in the model: 1) river valley was the most favored habitat factor in winter that lynx, moose and mountain hare showed strong selection on; 2) lynx preferred areas with steep slope and coniferous forest; 3) sable only avoided the forest edge; 4) roe deer avoided sparse shrub forest but preferred coniferous forest. When we incorporated other species' presence probability in GLMM: 1) the presence probability of moose and roe deer had no significant relationship with other species; 2) lynx preferred areas with higher mountain hare potential occurrence probability; 3) sable preferred areas with higher mountain hare but less lynx occurrence probability; 4) mountain hare preferred to inhabit areas with sympatric roe deer and lynx. These results will provide guidance for species specific habitat conservation and restoration, and wildlife population management based on interspecific interactions.

Mediterranean mesocarnivores in spatially structured managed landscapes: community organisation in time and space

In the multi-functional and biodiverse cork oak landscapes of Iberia (Montado), agro-silvo-pastoral practices promote landscape heterogeneity and create intricate habitat and resource availability patterns. We used camera-traps to investigate the temporal and spatial organisation of a mesocarnivore community in a Montado landscape in central Portugal. The target carnivore assemblage was largely dominated by three generalist species – the red fox Vulpes vulpes, the European badger Meles meles and the Egyptian mongoose Herpestes ichneumon – while remaining community members – the common genet Genetta genetta and the feral cat Felis silvestris spp. – exhibited restricted distributions. Interspecific differences in activity rhythms and habitat use were particularly marked among widespread species. Low temporal overlap was reported between the diurnal mongoose and predominantly nocturnal red fox and badger. For the latter two species, contrasting differences in habitat use were associated with anthropogenic-induced environmental heterogeneity. Whereas the red fox used more intensively Montado areas preserving dense shrubby understory and avoided semi-disturbed mosaics of sparse shrubs, the badgers displayed the opposite pattern. Our findings add to previous evidence suggesting that the spatial structure created in highly managed landscapes, particularly the diversity of resulting understory structures, promotes the abundance and spread of generalist mesocarnivore species. These may benefit from the surplus of resource amount (e.g. prey) and the creation of different human-made habitats conditions that provide particular combinations of ecological resources favourable to each species requirements. We concur the common view that maintaining understory heterogeneity in Montado landscapes, menaced by current intensification and extensification trends, is important where carnivore persistence is a relevant conservation goal, but alert for potential effects on carnivore assemblages structuring and impacts for specialist species less tolerant to disturbance.

Ecology and Behavior of Alder Flycatchers (Empidonax alnorum) On Their Wintering Grounds In Argentina

ABSTRACT The Alder (Empidonax alnorum) and Willow (E. trailli) flycatchers are cryptic species, and their distribution outside the breeding season is poorly known, owing mostly to identification difficulties. Our new records suggest that large numbers of Alder Flycatchers overwinter in rivers crossing the Chaco region and in the foothill forests of the Yungas of Argentina, significantly increasing their southern wintering range. Records in northern Argentina span 3 November to 23 March. Key habitat for overwintering Alder Flycatchers in Argentina included stands of palo bobo (Tessaria integrifolia) along the Rio Bermejo and tributaries, either in association with sparse shrubs of chilca (Baccharis salicifolia) or more rarely with canebrake (Gynerium sagittatum). Other habitats used were old shrubby ‘madrejones' with Tessaria scrub and sacha cafe (Sesbania virgata), very dense Baccharis salicifolia scrub next to flowing creeks in foothill Yungas and dry Chaco, and riparian forests dominated by palo flojo (...

Ecosystem Responses to Fire: Identifying Cross-taxa Contrasts and Complementarities to Inform Management Strategies

Changes in fire frequency, extent, and intensity mean that understanding the effects of fire on plants and animals is a primary concern for ecologists and land managers. Given the potentially conflicting fire responses of species both within and across taxonomic groups, prescribing fire regimes based on the response of one or only a few species may have negative consequences for other species. Here, we integrate data collected from a series of independent but complementary studies spanning a 75 + year chronosequence in a semi-arid shrubland ecosystem in south-western Australia to consider how fire management can best promote biodiversity both within and across taxonomic groups (plants, birds, small mammals, and reptiles). Younger fire ages (6–14 years) contained sparse shrubs, large areas of bare ground, and lacked a distinct litter layer and canopy. The oldest vegetation (60–85 years) had a distinct canopy, a well-developed litter layer and cryptogamic crust, higher variability in patch width, and more woody debris. Plant species richness and diversity decreased with time since fire, whereas bird species richness and diversity increased with time since fire, and mammal and reptile species richness and diversity showed no trend. The composition of all four taxonomic groups varied according to time since fire and the presence of 11 species was confined above or below certain fire-age thresholds. Our results support the need to maintain a mix of both younger and older fire ages across the landscape to maximise species diversity, and highlight the particular importance of older fire ages for many species. Future fire management for biodiversity conservation will benefit from identifying and reconciling cross-taxa contrasts and complementarities.

Description of the nest and eggs of the Great-billed Seed-Finch (Sporophila maximiliani)

ABSTRACT Seed-finches are Neotropical passerines highly specialized in the consumption of grass seeds. Most species are endangered because of the conversion of native grasslands into agricultural fields, and they are among the main victims of trapping for the illegal cage-bird trade in South America. The Great-billed Seed-Finch (Sporophila maximiliani) is very rare, with few records in the wild in the last 50 years. Here, we present the first descriptions for nest, eggs, and nesting habitat of the Great-billed Seed-Finch from Mato Grosso state, Brazil. We found the nests (two) on 18 December 2014 and on 8 January 2015. They were located in a seasonally flooded lowland area composed predominantly of herbaceous vegetation and sparse shrubs, mainly Curatella sp. Nests were built in 5 days, and only females participated in nest construction and incubation. Nests were cup-shaped made mainly of stems and tendrils of vines, and their measurements were: outside diameter (85.0, 93.0 mm); inside diameter (55.0, 60....

Vegetative impacts upon bedload transport capacity and channel stability for differing alluvial planforms in the Yellow River source zone

Abstract. The influence of vegetation upon bedload transport and channel morphodynamics is examined along a channel stability gradient ranging from meandering to anabranching to anabranching–braided to fully braided planform conditions along trunk and tributary reaches of the Upper Yellow River in western China. Although the regional geology and climate are relatively consistent across the study area, there is a distinct gradient in the presence and abundance of riparian vegetation for these reaches atop the Qinghai–Tibet Plateau (elevations in the study area range from 2800 to 3400 m a.s.l.). To date, the influence of vegetative impacts upon channel planform and bedload transport capacity of alluvial reaches of the Upper Yellow River remains unclear because of a lack of hydrological and field data. In this region, the types and pattern of riparian vegetation vary with planform type as follows: trees exert the strongest influence in the anabranching reach, the meandering reach flows through meadow vegetation, the anabranching–braided reach has a grass, herb, and sparse shrub cover, and the braided reach has no riparian vegetation. A non-linear relation between vegetative cover on the valley floor and bedload transport capacity is evident, wherein bedload transport capacity is the highest for the anabranching reach, roughly followed by the anabranching–braided, braided, and meandering reaches. The relationship between the bedload transport capacity of a reach and sediment supply from upstream exerts a significant influence upon channel stability. Bedload transport capacity during the flood season (June–September) in the braided reach is much less than the rate of sediment supply, inducing bed aggradation and dynamic channel adjustments. Rates of channel adjustment are less pronounced for the anabranching–braided and anabranching reaches, while the meandering reach is relatively stable (i.e., this is a passive meandering reach).

Vaccinium myrtillus stands show similar structure and functioning under different scenarios of coexistence at the Pyrenean treeline

Plant–plant interactions are key drivers of treeline dynamics. At the Pyrenean treeline, the dwarf shrub Vaccinium myrtillus grows in pure stands or in mixed stands with Vaccinium uliginosum or Rhododendron ferrugineum. They form sparse shrub patches that colonize subalpine grasslands, having dramatic impacts on their structure and functioning. We investigated the role of the two co-occurring shrubs as possible modulators of the structure and performance of V. myrtillus in the Central Pyrenees. We analysed biomass, growth, functional parameters, age distribution, N and C concentrations and isotope compositions (δ15N and δ 13C) of V. myrtillus ramets in pure stands, and stands mixed with V. uliginosum or R. ferrugineum. Volume, above-ground biomass and age of the ramets did not differ between stand types. We found lower δ13C values, indicative of lower water-use efficiency (WUE), in leaves and shoots of V. myrtillus in stands with R. ferrugineum than in pure stands. The N content and δ15N of V. myrtillus leaves and shoots in pure stands were higher than in mixed stands, pointing to a competition for N in mixed stands. Our results indicate that V. myrtillus competes for nutrients with its neighbours, but neither this competition nor the lower WUE affect its above-ground performance. Therefore, the interaction with co-occurring shrubs does not have a major effect on V. myrtillus structure and functioning at treeline and, consequently, should not be considered as a key driver on the dynamics of this species in the encroachment of subalpine grasslands.

Larval Habitat Preferences of Vanishing ButterflyHipparchia semeleL.: Surviving on Human-Altered Habitats in the Czech Republic, Central Europe

ABSTRACT The Grayling Hipparchia semele L. belongs to rapidly vanishing butterfly species in its central and western European range. We studied larval microhabitat preferences of two last viable populations of the Grayling in the Czech Republic. The field study was carried out at two types of human-influenced habitats: a fly ash deposit — a postindustrial site partly left under natural succession processes, and a semi-natural extensively grazed xeric calcareous grassland in May and June 2012 and 2013. During five nights, 89 caterpillars were found (fly ash deposit: 8, xeric grassland: 81). The caterpillars were found on steeper slopes covered with sparse shrubs and shorter herbaceous vegetation with high amount of bare soil or rocks. The most frequently observed behaviour was feeding on fine-leaf fescue grasses with varied size of tufts and rather smaller height up to 20 cm. Usage of larval preferences in a way of active conservation management application is discussed.

Threat or opportunity? Browsing preferences and potential impact of Ammotragus lervia on woody plants of a Mediterranean protected area

Much of the biodiversity in the Mediterranean region depends upon extensive livestock rearing. However, this activity is decreasing, especially in arid environments, where considerable biodiversity loss is expected in the near future. Meanwhile, wild ungulate populations are regaining long lost territories and densities. The question arises as to how far wild ungulates could substitute the ecological role traditionally played by extensive livestock. This study focuses on the effect of an exotic wild ungulate, the aoudad (Ammotragus lervia), on the woody vegetation of a semiarid protected area in Southeast Spain where it was introduced in 1970. Forty-five field surveys provided information on the effect of browsing on 92 woody plant species and on the aoudad's feeding behavior. Small shrubs were the most preferred species and showed, on average, higher levels of browsing damage. However, browsing intensity was low in broadleaved trees and negligible in conifers. Highly preferred and sparse shrub species might be severely affected by medium to high aoudad densities. The aoudad could become an opportunity for arid environments that lack native wild ungulates and traditional livestock grazing, since it could partially fulfill most ecological roles played by livestock. However, it could also become a threat should it become overabundant.

Sediment record from the Kamyshovoe Lake: history of vegetation during late Pleistocene – early Holocene (Kaliningrad District, Russia)

Newly obtained pollen and diatom data from the Kamyshovoe Lake (germ. Dobauen, Vishtynets Highland, Baltic Uplands) controlled by radiocarbon dating allowed to reconstruct the history of local vegetation during late Pleistocene – early Holocene. Pollen records show the formation of birch-predominating forest at ca. 13.4 ka cal. BP and the flourishing of pine towards the second half of the chronozone since about 13.2 ka cal. BP. The transition to the Younger Dryas around 12.7 ka cal. BP led to the development of sparse shrub tundra with Juniperus and communities of steppe herbs. Amelioration of the environmental regime enabled birch and pine woods to spread during the second part of GS-1 event and the Preboreal. The late Preboreal time is marked by the appearance of Populus and an increase in the role of grasses in the vegetation cover, which can be correlated to similar open vegetation phases deduced from other pollen records in Europe (11.3–11.1 ka cal. BP). During the Boreal (since ca. 10.0 ka cal. BP) Corylus had its maximum value, Alnus, Tilia and Quercus appeared and spread while the birch-pine forests retreated.

Habitat selection and use by sympatric, translocated greater sage‐grouse and Columbian sharp‐tailed grouse

ABSTRACTGreater sage‐grouse (Centrocercus urophasianus) and Columbian sharp‐tailed grouse (Tympanuchus phasianellus columbianus) have declined substantially in Washington, USA, primarily because native shrub‐steppe has been converted to agriculture. In response, state and federal agencies have acquired and restored habitat, and augmented and reintroduced grouse to suitable areas. We examined how sympatric, translocated sage‐grouse and sharp‐tailed grouse used space and selected habitats within their spring–summer home ranges and at nest sites within remnant shrub‐steppe surrounded by a matrix of cropland in eastern Washington. Because their life‐history requirements differ, we expected extensive habitat partitioning between species. Using radiolocations of ≥43 birds of each species, we found that sage‐grouse had larger spring–summer home ranges than sharp‐tailed grouse, and the composite of home ranges for sharp‐tailed grouse fell almost completely within the composite of home ranges for sage‐grouse. By creating resource utilization function models using radiolocations of ≥53 birds of each species, we found that areas of highest predicted intensity of use for both species overlapped by >50%, even at the top 5% quantile. Both species used restored fields and areas farther from trees and roads or distribution lines more intensely. Sage‐grouse used less rugged areas more intensely, and both species used 3 levels of shrub cover equally. To compare selection of nest sites relative to available sites for nesting in both species, we created resource selection function models for ≥30 birds of each species and found that sage‐grouse selected areas farther from distribution lines, whereas sharp‐tailed grouse selected restored fields. When we examined vegetation characteristics used by female sage‐grouse and sharp‐tailed grouse at nest sites using a case‐control, use versus non‐use design for ≥26 birds of each species, we found sage‐grouse used areas with greater shrub cover, lower annual forb cover, and taller perennial grasses, whereas sharp‐tailed grouse used areas with greater perennial grass cover and taller perennial grasses and forbs. When we compared habitat features measured at nest sites between species, we found sage‐grouse used areas with greater moderate and dense shrub cover, lower sparse shrub cover, less restored fields, higher patch diversity, and areas farther from distribution lines than sharp‐tailed grouse. These differences resulted in only 38% overlap of areas within the top quartile of relative selection values for nest sites by the 2 species, and <10% at the top 5% quantile. Because many western states are highly fragmented by cropland, understanding how populations of species with different life‐history characteristics, such as sage‐grouse and sharp‐tailed grouse, coexist within remaining tracts of shrub‐steppe at different spatial scales is important for effectively conserving and managing shrub‐steppe communities. © 2015 The Wildlife Society.

Predictability of leaf area index using vegetation indices from multiangular CHRIS/PROBA data over eastern China

This study analyzed the predictability of leaf area index (LAI) to the variation of vegetation type, observation angle, and vegetation index (VI). The analysis was conducted by using the R2 of the LAI-VI models between in situ measured LAIs and VIs derived from CHRIS/PROBA data. The results show that the discrepancy of vegetation type mostly influences the LAI-VI models. The predictability of LAI to the variation of both vegetation type and index demonstrates the differences of oblique/vertical and backward/forward observations, and backward series are greater than the forward. The predictabilities of LAI to the variation of observation angle are greatest for the soil-adjusted VIs and least for the traditional ratio-based indices. Multivariable linear modeling with all VIs from all five angles yields acceptable accuracy except for the sparse shrub. The backward less-oblique observation (−36 deg) is the only angle chosen in the modeling for grass, shrub, and broad leaf forest, while the nadir view performs best for forests with coniferous trees. These results provide a reference to multiangular LAI estimation for different vegetation communities. VIs accounting for angular soil effects require further investigation in the future.

Vertical distribution of soil moisture and surface sandy soil wind erosion for different types of sand dune on the southeastern margin of the Mu Us Sandy Land, China.

Soil moisture is a critical state affecting a variety of land surface and subsurface processes. We report investigation results of the factors controlling vertical variation of soil moisture and sand transport rate of three types of dunes on the southeastern margin of the Mu Us Sandy Land. Samples were taken from holes drilled to a depth of 4 m at different topographic sites on the dunes, and were analyzed for soil moisture, grain-size distribution and surface sediment discharge. The results show that:(1) The average soil moisture varies in different types of dunes, with the following sequences ordered from highest to lowest: in the shrubs-covered dunes and the trees-covered dunes the sequence is from inter-dunes lowland to windward slope to leeward slope. The average moisture in the bare-migratory sand dunes is sequenced from inter-dunes lowland to leeward slope to windward slope.(2) Vegetation form and surface coverage affect the range of soil moisture of different types of dunes in the same topographic position. The coefficient of variation of soil moisture for shrubs-covered dunes is higher than that of other types of dune.(3) The effect of shrubs on dune soil moisture is explained in terms of the greater ability of shrubs to trap fine-grained atmospheric dust and hold moisture.(4) The estimated sand transport rates over sand dunes with sparse shrubs are less than those over bare-migratory dunes or sand dunes with sparse trees, indicating that shrubs are more effective in inhibiting wind erosion in the sandy land area.

Simulating alpine vegetation net primary productivity by remote sensing in Qinghai Province, China

Primary productivity of ecosystem is important indicator about ecological assessment. Remote sensing technology has been used to monitor net primary productivity (NPP) of ecological system for several years. In this paper; the remotely sensed NPP simulation model of alpine vegetation in Qinghai Province of Tibet Plateau was set up based on the theory of light use efficiency. Firstly a new approach based on mixed pixels and Support Vector Machine (SVM) algorithm were used to correct simulated NPP values derived from Moderate Resolution Imaging Spectroradiometer (MODIS) data. Finally; spatial distribution and monthly variation characteristics of NPP in Qinghai Province in 2006 were analyzed in detail. The result showed that NPP of vegetation in Qinghai Province in 2006 ranged from 0 to 422 gC/m2/a and the average NPP was 151 gC/m2/a. NPP gradually increased from northwest to southeast. NPP of different vegetation types were obviously different. The average NPP of broad-leaved forest was the largest (314 gC/m2/a); and sparse shrub was the smallest (101 gC/m2/a). NPP in Qinghai Province significantly changed with seasonal variation. The accumulation of NPP was primarily in the period (from April to September) with better moist and heat conditions. In July; the average NPP of vegetation reached the maximum value (43 gC/m2). In our model; the advantage of traditional LUE models was adopted; and our study fully considered typical characteristics of alpine vegetation light use efficiency and environmental factors in the study area. Alpine vegetation is the most important ecological resource of Tibet Plateau; exactly monitoring its NPP value by remote sensing is an effective protection measure.