Shrub Cover Research Articles

Separating Shrub Cover From Green Vegetation in Grasslands Using Hyperspectral Vegetation Indices

Shrub cover is a key parameter for monitoring woody plant encroachment (WPE) in the background of global grassland degradation. At the critical early encroachment stage, many shrub species are small, and it is impossible to be detected through height parameters. Hyperspectral vegetation indices (HVIs) are valuable tools to estimate vegetation cover, while the effect of shrubs of different cover levels (e.g., low: <35%, moderate: 36–55%, high: >56%) on the spectrum of mixed grassland is still unclear. In this study, narrowband HVIs were created for shrub cover estimation using field hyperspectral data collected in Cypress Hills Interprovincial Park, SK. Published HVIs and newly developed HVIs were examined for the relationship between green shrub cover and total green vegetation (GV) cover. Averaging normalized difference vegetation index (NDVI) was also used to minimize in the variation of shrub cover and GV in each quadrat. Results showed that HVIs SR [600, 800] and NDVI [705, 750] had the highest R2 with green shrub and GV cover (R2 = 0.34 and R2 = 0.30, p-value < 0.05). Blue bands (449 and 489 nm) and SWIR bands (1619 and 1739 nm) combination exhibited the highest accuracy for shrub and GV covers estimation (R2 = 0.60 and 0.40, p-value < 0.05). Averaging NDVI positively correlated with green shrub cover below 30% or above 70%. Three separability metrics (JM, TD, and M) results also showed the red and NIR region may promise to distinguish different shrub cover levels.

Regional beryllium-10 production rate for the mid-elevation mountainous regions in central Europe, deduced from a multi-method study of moraines and lake sediments in the Black Forest

Abstract. Beryllium-10 cosmic-ray exposure (CRE) dating has revolutionized our understanding of glacier fluctuations around the globe. A key prerequisite for the successful application of this dating method is the determination of regional production rates of in situ accumulated 10Be, usually inferred at independently dated calibration sites. Until now, no calibration site has been available for the mid-elevation mountain ranges of central Europe. We fill this gap by determining in situ 10Be concentrations in large boulders on moraines and by applying radiocarbon and infrared-stimulated luminescence (IRSL) dating to stratigraphically younger lake sediments in the southern Black Forest, SW Germany. The dating methods yielded concordant results, and, based on age–depth modelling with 14C ages, the age of a cryptotephra, and IRSL ages, we deduced a regional 10Be production rate in quartz. Calibrating the Black Forest production rate (BFPR) in the Cosmic-Ray Exposure program (CREp) resulted in a spallogenic sea-level and high-latitude (SLHL) production rate of 3.64±0.11 atoms 10Be g−1 quartz a−1 when referring to time-dependent Lal–Stone scaling, the European Reanalysis (ERA)-40 atmosphere model, and the atmospheric 10Be-based geomagnetic database in CREp. The BFPR turned out to be ∼11 % lower than both those at the nearest calibration site in the Alps (4.10±0.10 atoms 10Be g−1 quartz a−1 at SLHL) and the canonical global 10Be production rate (4.11±0.19 atoms 10Be g−1 quartz a−1 at SLHL) in CREp. A stronger weathering and snow cover bias and a higher impact of forest, soil, moss, and shrub cover at the study site likely explain this discrepancy.

Local factors influence the wild bee functional community at the urban-forest interface

IntroductionUrban forests provide necessary habitat for many forest-associated bee species amidst development and fragmentation. These forest fragments provide a variety of important floral and non-floral resources for bees that encompass a diversity of functional guilds characterized by size, diet breadth, nesting, sociality, origin, and seasonality. The relative importance of forest edge vs. interior habitats to these organisms is not well understood.MethodsHere, we compare bee communities between forest edge and interior locations at eight locations in Athens, GA, USA. We also explore the effects of stand structure, tree composition, ground cover type, and the presence of snags and downed wood on these organisms.ResultsWe found bee abundance and richness to be higher at the forest edge than interior with distinct community compositions at both locations. Canopy cover, invasive shrub cover, ground cover, and tree diversity influenced the observed community composition. We also determined that the most impactful functional traits influencing bee community structure in urban forest fragments were nesting substrate, origin (native or exotic to North America), sociality, and diet breadth.DiscussionOur findings will help establish the effects of local forest characteristics on the community composition, diversity, and abundance of wild bees and further our knowledge of the conservation value of urban forests for preserving wild bee communities.

Seventy-five years of vegetation change after fire in Tasmanian alpine heathland

Context Alpine ecosystems are threatened by warming and an associated increase in fire frequency. There is a gap in our knowledge of succession in Tasmanian alpine heath more than 50 years after fire. The literature suggests that the alpine successional progression usually involves decreasing rates of change, decreasing differences among fire ages, ongoing transitions among shrub species, ongoing transitions from some lifeforms/species to others, and that warming results in increases in species richness. Aims We test for these tendencies up to 75 years from fire in alpine vegetation on kunanyi/Mount Wellington, Tasmania, Australia. Methods We documented the changes in vegetation structure and composition between 1998 and 2022 in plots on either side of an alpine fire boundary in the alpine heathland and used earlier data and observations to extend the record of change after fire to 75 years. We put these changes in the context of the only area of alpine vegetation that was not burnt in 1947 or later. Key results The area last burnt in 1947 exhibited declines in all lifeform covers between 1998 and 2022. All lifeforms except tall shrubs and mat shrubs declined in cover in the area last burnt in 1962. By 2022, shrub cover in the 1962-burnt area had not attained equivalence with the area last burnt in 1947. Herbs had the most dramatic decline in both fire-age classes. There were few shrub seedlings in 2022. All but six taxa, three being exotic, were observed in both the plots and previous broader surveys. Increases in species richness caused by the upward migration of lower-elevation species were not observed. The long-unburnt patch lacked the major dominant of the 1947-burnt plots, namely Orites acicularis, and was dominated by a gymnosperm absent from most of the mountain. Conclusions Succession follows the initial floristic composition model. The differences in trajectories from the 1947 and 1962 fires could possibly be due to desiccation or abrasion damage from increasing wind speeds and temperatures. There are strong indications of further potential change in the absence of fire. Implications The slow rate of recovery and its on-going nature emphasise the importance of keeping fire out of this vegetation type.

Vegetation redistribution is predicted to intensify soil organic carbon loss under future climate changes on the Tibetan Plateau

Vegetation redistribution may bring unexpected climate-soil carbon cycling in terrestrial biomes. However, whether and how vegetation redistribution alters the soil carbon pool under climate change is still poorly understood on the Tibetan Plateau. Here, we applied the G-Range model to simulate the cover of herbs, shrubs and trees, net primary productivity (NPP) and soil organic carbon density (SOCD) at the depth of 60 cm on Tibetan Plateau for the individual years 2020 and 2060, using climate projection for Representative Concentration Pathways (RCP) 4.5 and RCP8.5 scenarios with the RegCM4.6 model system. Vegetation redistribution was defined as the transitions in bare ground, herbs, shrubs and trees between 2020 and 2060, with approximately 57.9 % (RCP4.5) and 59 % (RCP8.5) of the area will redistribute vegetation over the whole Tibetan Plateau. The vegetation cover will increase by about 2.4 % (RCP4.5) and 1.9 % (RCP8.5), while the NPP and SOCD will decrease by about −14.3 g C m−2 yr−1 and −907 g C m−2 (RCP4.5), and −1.8 g C m−2 yr−1and −920 g C m−2 (RCP8.5). Shrubs and trees will expand in the east, and herbs will expand in the northwest part of the Plateau. These areas are projected to be hotspots with greater SOCD reduction in response to future climate change, and will include lower net plant carbon input due to the negative NPP. Our study indicates that the SOC pool will become a carbon source under increased air temperature and rainfall on the Tibetan Plateau by 2060, especially for the area with vegetation redistribution. These results revealed the potential risk of vegetation redistribution under climate change in alpine ecosystems, indicating the policymakers need to pay attention on the vegetation redistribution to mitigate the soil carbon emission and achieve the goal of carbon neutrality on the Tibetan Plateau.

Repeated clearing as a mechanism for savanna recovery following bush encroachment

Abstract Many savannas are experiencing increased cover of trees and shrubs, resulting in reduced herbaceous productivity, shifts in savanna functional structure and potential reductions in ecotourism. Clearing woody plants has been suggested as an effective management strategy to mitigate these effects and restore these systems to an open state with higher rates of grass production and herbivory. This study investigated the effectiveness of repeated shrub clearing as a tool to mitigate bush encroachment in a semi‐arid savanna in southern Africa. We present data from a 7‐year experiment in the Mthimkhulu Game Reserve bordering Kruger National Park, South Africa. Colophospermum mopane stems and resprouting shoots were basally cut 2–3 times per year (2015–2022) in three pairs of treatment and control plots of 60 × 60 m. We monitored changes in soil moisture, grass biomass and herbivore activity via dung counts. We assessed C. mopane physiological responses to repeated cutting using non‐structural carbohydrates and stable water isotopes to infer changes to energy storage and functional rooting depth, respectively. The cleared treatment had higher soil moisture and grass biomass than the control treatment. Dung counts showed impala and buffalo visited the cleared treatment more frequently than the control treatment. Repeated cutting had limited effects on C. mopane survival in the first 2–3 years after initial clearing, but 80% of individuals were dead after 7 years. Repeatedly cut C. mopane had lower belowground starch concentrations and used water from shallower soil depths than C. mopane in control plots. Synthesis and applications. Repeated cutting increased soil moisture availability and grass biomass, and attracted charismatic grazing herbivores. While more costly than once‐off clearing methods, this practice created more employment opportunities for a neighbouring rural community. Transforming portions of the ecosystem to a grass‐dominated state may increase ecotourism potential through improved game viewing in open systems.

Changes in diversity of marsh plant communities under shrub encroachment in Sanjiang Plain and their soil control factors

In this study, we explored the changes in plant community diversity and their relationship with soil factors under shrub encroachment pressure by selecting four marsh areas in Sanjiang Plain with different degrees of shrub cover (a, 0≤a≤100%), including marsh with no shrub encroachment (a=0), light shrub encroachment (0<a≤30%), medium shrub encroachment (30%<a≤70%), and heavy shrub encroachment (70%<a≤100%). The results showed that shrub encroachment was the main reason for the heterogeneity of plant community composition in marsh. With shrub encroachment, the dominant species Deyeuxia angustifolia was replaced by Spiraea salicifolia, whereas Carex schmidtii disappeared. However, the importance values of Sanguisorba tenuifolia and Stellaria radians in the community significantly increased by 0.8- and 9.0-fold, respectively. Shrub encroachment resulted in changes of plant community diversity in marsh. The highest α and β diversity in plant community were observed under light shrub encroachment area, whereas there were no significant differences in Shannon and Simpson indices between heavy and no shrub encroachment areas, despite their similarity in plant community composition was the lowest. All the studied soil factors were significantly affected by shrub encroachment, except total phosphorus. There were significant reductions in soil moisture, organic carbon, and total nitrogen in heavy marsh shrub encroachment area by 32.6%, 69.3%, and 66.1%, respectively compared with that in no marsh shrub encroachment area, whereas soil total potassium and total magnesium significantly increased by 33.8% and 40.6%, respectively. Results of redundancy analysis showed that soil organic carbon, moisture content, total nitrogen, and N:P were the main factors controlling the diversity changes of marsh plant community under shrub encroachment pressure.

Forest resilience and post-fire conifer regeneration in the southern Cascades, Lassen Volcanic National Park California, USA

Contemporary fire regimes in Californian forests are shifting, with fires becoming larger, more frequent, and increasingly severe. As landscapes transition back to active fire regimes, understanding how the physical environment and biological legacies of past disturbance interact with and determine forest development becomes an increasingly important management concern. We surveyed post-fire regeneration in a wilderness area of Lassen Volcanic National Park (LAVO) with a three-decade history of fires. We tallied conifer seedlings , and measured shrub and ground cover and mature trees in the field, and used geospatial data and water balance models to account for the possible effects of , terrain, live seed sources, vegetation characteristics, and immediate post-fire climate as measured by water balance on conifer regeneration. We used a Random Forest machine learning technique to model how landscape and local factors affect post-fire regeneration stocking and species regeneration occurrence. Post-fire conifer regeneration in LAVO was common: Median post-fire seedling density was close to desired stocking density, 73% of our plots had at least one conifer seedling, and only 16% of plots lacked tree regeneration or mature trees. Likelihood of stocking and individual species’ occurrence was most strongly related to time since fire, distance to forest, elevation, and species of nearest seed source. Tree regeneration increased with time since fire, but this effect was more pronounced at high elevation suggesting an interaction between terrain and time since fire on regeneration. Stocking was most likely on cooler (northeastern) slopes and at lower (<1950 m) elevations, nearer (within 200 m) to live forest patches, and where shrub cover was present but low (<20%). Climatic conditions as represented by water balance for the first five years after a fire did not influence likelihood of stocking but it did influence species occurrence. Distance to conspecific trees was important for species’ regeneration occurrence, and the landscape pattern of species occurrence was consistent with the elevational zonation of forest dominants in LAVO. Adequate tree regeneration of forests with an active fire regime in LAVO indicate that California montane forests are resilient to prescribed fire and managed wildfire and that expanded use of fire to reduce potential for severe fire promotes resilience in California forest landscapes.

Summer habitat selection by Mrs Hume’s Pheasant (Syrmaticus humiae) on Jinzhong Mountain, northwest Guangxi, China: implications for determining effective conservation actions using radio transmitters

Abstract In the present study, summer habitat preference of Mrs Hume’s Pheasant (Syrmaticus humiae) was studied in Jinzhong Mountain Nature Reserve, Guangxi Province. Eight birds were equipped with radio transmitters and habitat characteristics of experiment and control quadrat sites, respectively, were measured. Our results indicated that: 200 m to 400 m distance to habitat edge, less than 200 m distance to water, over 400 m distance to human habitation, over 601 m distance to the road, over 60% tree cover, less than 40% shrub cover, less than 20% herb cover, over 60% leaf litter cover, height of tree over 10.1 m, tree density over 20 individuals per quadrat, shrub height over 2.1 m, shrub density less than 10 individuals per quadrat, height of herb species over 0.5 m, herb density less than 10 Individuals per quadrat, diameter of tree over 30 cm, and abundant food were the habitat characteristics. The elevation, herb density, and height of tree and shrub exhibited no significant differences (), but other factors showed significant differences between quadrat sites and control quadrat plot (). Results of a principal components analysis (PCA) demonstrated that the first five components accounted for 64.282% of the total variance. Food availability in different habitat patches is the vital factor affecting habitat selection by Mrs Hume’s Pheasant; the other factors showed no significant effects on habitat selection by Mrs Hume’s Pheasant in the subtropical forest. This suggests that habitat selection behavior of Mrs Hume’s Pheasant is in fact a trade-off between obtaining food and prey escape, which is an adaptive behavior and a life strategy of this near-threatened bird species.

Precipitation seasonality and soil texture interact to shape dryland recovery from severe disturbance

Abstract Disturbances drive large changes in plant composition and ecosystem functioning in drylands, but current understanding of how recovery following disturbance depends on the environment is limited due to challenges in analysing effects of disparate disturbances across abiotic gradients. We combined remote sensing and field observations across 5600+ km of natural gas pipeline corridors and adjacent undisturbed vegetation to investigate how recovery from a uniform, severe disturbance varied with factors that influence water availability in drylands. We found that recovery of net primary production (NPP) often remains incomplete, with only 42% of our sites projected to fully recover within 100 years. NPP recovery was quicker and more complete in regions that receive most of their annual precipitation at low temperatures and have fine‐textured soil; recovery of total shrub cover (median timing of 81 years) was faster on fine‐textured soils in locations that receive most of their annual precipitation at high temperatures. Locations with quick recovery of shrub cover were linked with a shift in dominant shrub species and incomplete NPP recovery. Synthesis. Recovery of NPP and shrub cover in drylands were driven by different environmental factors. For both NPP and shrub cover, locations with high pre‐disturbance values required more time to recover to adjacent undisturbed levels than locations with low pre‐disturbance values. Quick recovery of shrub cover or productivity was generally linked with a shift in dominant plant species or functional group.

Vegetation, fuels, and fire-behavior responses to linear fuel-break treatments in and around burned sagebrush steppe: are we breaking the grass-fire cycle?

BackgroundLinear fuel breaks are being implemented to moderate fire behavior and improve wildfire containment in semiarid landscapes such as the sagebrush steppe of North America, where extensive losses in perennial vegetation and ecosystem functioning are resulting from invasion by exotic annual grasses (EAGs) that foster large and recurrent wildfires. However, fuel-break construction can also pose EAG invasion risks, which must be weighed against the intended fire-moderation benefits of the treatments. We investigated how shrub reductions (mowing, cutting), pre-emergent EAG-herbicides, and/or drill seedings of fire-resistant perennial bunchgrasses (PBGs) recently applied to create a large fuel-break system affected native and exotic plant abundances and their associated fuel loading and predicted fire behavior.ResultsIn heavily EAG-invaded areas, herbicides reduced EAG and total herbaceous cover without affecting PBGs for 2–3 years and reduced predicted fire behavior for 1 year (from the Fuel Characteristic Classification System). However, surviving post-herbicide EAG cover was still > 30%, which was sufficient fuel to exceed the conventional 1.2-m-flame length (FL) threshold for attempting wildfire suppression with hand tools. In less invaded shrubland, shrub reduction treatments largely reduced shrub cover and height by ~ half without increasing EAGs, but then redistributed the wood to ground level and increased total herbaceous cover. Herbicides and/or drill seeding after shrub reductions did not affect EAG cover, although drill seedings increased PBG cover and exotic forbs (e.g., Russian thistle). Fire behavior was predicted to be moderated in only one of the many yearly observations of the various shrub-reduction treatment combinations. Over all treatments and years, FLs were predicted to exceed 1.2 m in 13% of simulations under average (11 km h−1) or high (47 km h−1) wind speed conditions and exceed the 3.4-m threshold for uncontrollable fire in 11% of simulations under high-wind speeds only.ConclusionsPredicted fire-moderation benefits over the first 4 years of fuel break implementation were modest and variable, but, generally, increases in EAGs and their associated fire risks were not observed. Nonetheless, ancillary evidence from shrublands would suggest that treatment-induced shifts from shrub to herbaceous fuel dominance are expected to improve conditions for active fire suppression in ways not readily represented in available fire models.

Cross-scale analysis reveals interacting predictors of annual and perennial cover in Northern Great Basin rangelands.

Exotic annual grass invasion is a widespread threat to the integrity of sagebrush ecosystems in Western North America. Although many predictors of annual grass prevalence and native perennial vegetation have been identified, there remains substantial uncertainty about how regional-scale and local-scale predictors interact to determine vegetation heterogeneity, and how associations between vegetation and cattle grazing vary with environmental context. Here, we conducted a regionally extensive, one-season field survey across burned and unburned, grazed, public lands in Oregon and Idaho, with plots stratified by aspect and distance to water within pastures to capture variation in environmental context and grazing intensity. We analyzed regional-scale and local-scale patterns of annual grass, perennial grass, and shrub cover, and examined to what extent plot-level variation was contingent on pasture-level predictions of site favorability. Annual grasses were widespread at burned and unburned sites alike, contrary to assumptions of annual grasses depending on fire, and more common at lower elevations and higher temperatures regionally, as well as on warmer slopes locally. Pasture-level grazing pressure interacted with temperature such that annual grass cover was associated positively with grazing pressure at higher temperatures but associated negatively with grazing pressure at lower temperatures. This suggests that pasture-level temperature and grazing relationships with annual grass abundance are complex and context dependent, although the causality of this relationship deserves further examination. At the plot-level within pastures, annual grass cover did not vary with grazing metrics, but perennial cover did; perennial grasses, for example, had lower cover closer to water sources, but higher cover at higher dung counts within a pasture, suggesting contrasting interpretations of these two grazing proxies. Importantly for predictions of ecosystem response to temperature change, we found that pasture-level and plot-level favorability interacted: perennial grasses had a higher plot-level cover on cooler slopes, and this difference across topography was starkest in pastures that were less favorable for perennial grasses regionally. Understanding the mechanisms behind cross-scale interactions and contingent responses of vegetation to grazing in these increasingly invaded ecosystems will be critical to land management in a changing world.

Microhabitats shape ant community structure in a spatially heterogeneous grassy woodland

AbstractHabitat structure is a key determinant of local animal diversity, with attributes of vegetation such as cover or complexity generating key resources for different species. However, habitat–diversity relationships can vary across spatial scales, and among different taxa and ecosystem types. Here we report on a study of habitat structure and its effects on ant communities at two spatial scales in a temperate grassy woodland characterized by heterogenous tree and grassland cover. We examined species richness and the occurrence of ground‐dwelling ant species at (1) microhabitat scales defined by a triplet of sites comprising open ground, adjacent to a log, and under a tree, each separated by a few meters, and (2) at macrohabitat scales defined by sites grouped into broader vegetation types defined by low or high levels of shrub and tree cover and separated by 100s of meters. We identified 117 species of ant from 41 genera, from a total of 155,004 individuals collected. Ant community composition differed significantly among microhabitats and macrohabitats, but mean species richness only differed at the microhabitat scale where it was the highest under trees and lower adjacent to logs and in open ground. Notably, ant species within the genera Iridomyrmex, Monomorium, and Pheidole displayed a spectrum of microhabitat preferences, highlighting the ecological flexibility within these groups. By contrast, all species of Melophorus preferred open habitat and all species of Camponotus preferred habitat under trees. Our study shows that ant communities in grassy woodlands are structured by vegetation cover and habitat “openness” most strongly at “microhabitat” scales, which is likely due to a distinct combination of thermal and foraging attributes that vary across relatively small distances. Our results also suggest that broad classifications of ants into functional types based on vegetation preference may not be applicable at small scales where species within the same genus can display contrasting preferences. Land management that promotes habitat heterogeneity at small spatial scales may promote species coexistence and benefit ant diversity more than management activities focusing on larger spatial scales within the same ecosystem.

Rodent communities in a neglected grassland landscape: Investigating species-specific responses of grassland rodents to habitat type and shrub presence

Arid grasslands worldwide are transitioning to scrublands due to shrub encroachment, resulting in habitats with varying shrub cover. Shrubs play a crucial role in grassland ecosystems, offering trade-offs to rodents in terms of visibility, shelter, and food availability, thereby affecting their occurrence and distribution. This study explores the link between habitat characteristics and rodent activity and density, focusing on shrub presence. In the Tirunelveli district of southern India, we measured rodent density and activity across three grassland types with increasing shrub presence. Our findings reveal species-specific responses to shrub density. The Soft-furred rat (Millardia meltada) dominated, showing adaptability to different shrub levels, while the black rat (Rattus Rattus) was least represented. Fine-scale analysis indicates a positive association between shrub presence and rodent captures. Grassland obligate species like the Indian gerbil (Tatera indica) exhibited reduced activity in densely shrubbed sites, whereas semi-arboreal species like the Indian palm squirrel (Funumbulus palmarum) showed increased activity. This study underscores the importance of considering habitat structure in grassland ecosystem management for the conservation of rodent diversity and ecosystem health.

Postfire reproduction of a serotinous conifer, the giant sequoia, in the Nelder Grove, California.

The giant sequoia, a serotinous conifer naturally occurring in mixed-conifer forests of the southern and central Sierra Nevada, California, USA, is the world's largest tree species. Giant sequoia reproduction has been severely lacking over the past century, due to fire exclusion, creating a significant conservation threat. Previous research on postfire sequoia reproduction in high-severity fire areas, relative to low- and moderate-severity areas, is limited. At 6 years postfire, we investigated giant sequoia reproduction in a high-severity fire area, and nearby low-/mixed-severity fire areas, in the Nelder Grove, which burned in 2017 in the Railroad fire. Postfire giant sequoia reproduction was positively correlated with fire severity in terms of density, height (growth), and proportion (relative to other conifer species), and sequoia seedling/sapling density was positively correlated with percent shrub cover. There was no correlation between distance to live sequoia seed source and density of sequoia reproduction. More research is needed in other mixed-severity fire areas, with larger high-severity fire patches, to determine whether a similar postfire response occurs elsewhere.

Could different structural features affect flammability traits in Mediterranean forest ecosystems?

Key messageMediterranean forest stands manifest diverse flammability traits according to their potential ecological successional stage and promoting a gradient from flammable to less flammable ecosystem.From a general consideration of vegetation as ‘fuel’, it has been well proven that plant traits have the potential to promote the forest stand gradient from flammable to less flammable. While the ever-growing literature helps to assess the relationship between plants and their flammability at species level, at the landscape scale this relationship should be evaluated along with a variety of forest features such as structural and stand parameters and from the perspective of successional forest stages. To this end, we clustered several forest stands in Southern Europe (Apulia region, Italy), characterized by oaks, conifers, and arboreal shrub species, according to their flammability traits. We hypothesized that flammability traits change along different horizontal and vertical structural features of forest stands, shifting from high to low-flammability propensity. The results confirmed that forest stands with greater height and diameter classes are associated with traits with a low-flammability propensity. It is worth highlighting the importance of shrub coverage in differentiating the clusters denoting their strong influence in increasing fuel load (litter and fuel bed traits). Finally, our findings lead us to assume that high-flammability propensity traits are associated with typical pioneer successional stages, supporting the notion that later successional forest stands are less flammable and, therefore, that flammability decreases along with succession.

Pyric herbivory in a temperate European wood‐pasture system

Abstract The term pyric herbivory was first introduced in 2009, describing how fire shapes herbivory as burned areas attract herbivores and, simultaneously, herbivory shapes fuel load and fire behaviour. Pyric herbivory results in a mosaic of patches with varying levels of herbivory and grazing intensity fire intensity and frequency. The importance of pyric herbivory for ecosystem heterogeneity and biodiversity has been described for North American, Australian and African systems, but the concept remains largely untested in a European context. We introduced fire and herbivory in a full‐factorial experiment in a temperate European wood‐pasture system to test whether pyric herbivory operates in ways comparable to grassy systems elsewhere in the world. Using camera traps, we observed the behaviour of cattle in burned subplots (49 m2) compared with unburned subplots. We measured grass height and the proportion of the subplot that burned as variables affecting cattle preference and to assess how grazing affects fire behaviour. We also examined the effect on plant species and life‐form composition after six seasons of treatment. Cattle spent more time grazing in burned than in unburned subplots in the most productive paddock, where a larger proportion of the subplot burned. The proportion of a subplot that burned was positively related to pre‐fire grass height. Moreover, both grass height and the proportion of subplot burned declined in the burned subplots during the 6‐year study period and fire and cattle grazing altered the relative cover of graminoids and shrubs (Rubus spp.), with more graminoids in grazed and/or burned subplots and more shrubs in ungrazed subplots at the end of the study. Synthesis and applications. In our temperate European wood pasture, fire and (cattle) grazing interacted in ways comparable to pyric herbivory in grassy ecosystems elsewhere in the world, especially in the most productive paddock. Fire attracted grazing, with cattle grazing longer on subplots that burned more fully. Grazing also affected fire, where over the course of our experiment cattle grazing reduced grass height and the proportion of a subplot that burned. We suggest that pyric herbivory is an interesting management method to further explore in the European context to address the loss of biodiversity in open ecosystems, particularly in more productive sites.

Habitat use by the endangered Lesser Grey Shrike Lanius minor in Central Romania

In this paper we present data relating to nest density and habitat use by the Lesser Grey Shrike Lanius minor in the Târnava Mare Valley, Romania, using both nesting tree parameters (microhabitat), and habitat parameters measured in a 100m radius around each nest. The density of nests was 0.96 per km². Average distance between nests was 768.4m. Most of the nests (94.1%) were found in poplars, in the region of the middle third of their trunk, especially at the terminal parts of the branches. The birds preferred open habitats, with extended arable field cover. Moreover, the tree and shrub cover were small in areas used for nesting. As poplars are the preferred nesting habitats of this bird, and are scarcely represented in this area, the protection of these trees is critical for conservation of the Lesser Grey Shrike.

KEANEKARAGAMAN SERANGGA PADA TIGA TIPE VEGETASI DI BLOK LAMBOSIR TAMAN NASIONAL GUNUNG CIREMAI

This study aims to determine the diversity of insects and their role in 3 different land covers, namely mixed forest, shrubs and calliandra vegetation in the Lambosir Block area of Gunung Ciremai National Park. This research was carried out in the Lambosir Block in the Gunung Ciremai National Park area in February - June 2022 using 5 traps, namely Butterfly net, Sweep net, Light trap, Aerial bait trap and Yellow Trap. using the total density, frequency and the Shanon Weiner Diversity Index. The results showed that on the land cover of shrubs, calliandra and mixed forests, 42 species of insects were found from 8 orders with 246 individual species with a diversity value of 3.18 or in the high category. The 8 orders found in 3 land covers included Coleoptera 4 species, Diptera 3 species, Hemiptera 4 species, Hymenoptera 4 species, Lepidoptera 23 species, Odonata 1 species, Orthoptera 2 species and Phasmatodea 1 species. In addition to the high diversity category, insects that exist in 3 land covers have various roles such as pollinators, decomposers, assisting ecological succession, bio indicators and predators. The correlation between land cover with the number of species and the number of individual species based on the Scatter plot has a correlation value of 91%.&#x0D; Keywords; Diversity, insect, conservation, rehabilitation zone, Lambosir

Higher avian biodiversity, increased shrub cover and proximity to continuous forest may reduce pest insect crop loss in small‐scale oil palm farming

Abstract One of the key ecosystem services offered by avian biodiversity within agricultural landscapes is natural predation. Nonetheless, the current use of biological control agents such as farmland birds in oil palm plantations is relatively limited. This study aimed to assess the potential roles of avian biodiversity, particularly insectivores that provide natural predation against oil palm herbivorous insects. We also investigated the influence of local‐ and landscape‐scale variables on foliage damage (crown or frond). Our data showed that crown damage decreased with increasing farmland bird richness (overall and insectivore), shrub cover, dried biomass and elevation, but increased with epiphyte cover, oil palm height and distance to continuous forest. Frond damage was negatively related to bird richness (overall, insectivore and non‐insectivore) and non‐insectivore abundance, elevation and shrub cover, while increased with insectivorous abundance, epiphyte cover, oil palm height and distance to continuous forest. We also found that plantations (≥50 ha) were more susceptible to foliage damage from pest insects than smallholdings (&lt;50 ha). There was no evidence that indicate the influence of forest patches on foliage damage. Synthesis and applications. Our study highlights the economic value of conserving biodiversity, most notably, farmland birds and continuous forests with respect to biological control of defoliating pests and maintaining yield productivity in oil palm cultivation. Growers, particularly major plantation companies should make oil palm farming more biodiversity‐friendly in order to increase the number of biological control agents such as birds.