Juniper Stands Research Articles

The Application of Fire Behavior Modeling to Fuel Treatment Assessments at Army Garrison Camp Williams, Utah

Large wildfires (>40 ha in size) occur about every three years within Army Garrison Camp Williams, located near South Jordan, Utah, USA. In 2010 and 2012, wildfires originating on the practice firing range burned beyond the camp’s boundaries into the adjacent wildland-urban interface areas. The political and public reaction to these escaped fires was intense. Fire researchers at Utah State University were asked if a spatially organized system of fuel treatments could be developed to prevent such incidents in the future. We used a combination of empirically based guidelines and semi-physical fire modeling systems, coupled with climatological data, to make assessments of fire behavior potential for the sagebrush steppe vegetation/fuel types found in AGCW, that also considered slope steepness. The results suggested the need for removal of woody vegetation within 20 m of firebreaks and a minimum firebreak width of 8.0 m in grassland fuels. In stands of juniper, a canopy coverage of 25% or less is recommended. In Gambel oak stands along the northern boundary of the installation, a fuelbreak width of 60 m for secondary breaks (used for segmenting large areas of fuels) and 90 m for primary breaks (used for protecting urban development and valuable natural resources) is recommended.

Predictive Mapping of Low-Density Juniper Stands in Prairie Landscapes of the Northern Great Plains

Expanding distributions of native juniper species have had significant ecological and economic impacts on prairie ecosystems of the Great Plains. Juniper encroachment reduces rangeland production by decreasing herbaceous biomass and affecting natural ecosystem functions as it alters other native plant communities, microclimates, and soils. Juniper distribution maps are needed to support proactive management, but they often underestimate the extent of low-density juniper stands. Our objectives were to extend a previous juniper mapping study by 1) fitting a predictive ecological model for low-density (< 15% fractional cover) juniper stands and assessing the classification accuracy, 2) determining the habitat variables that had the strongest associations with low-density juniper, and 3) applying the model to map low-density juniper stands, where proactive management has the greatest potential for stopping further juniper encroachment. The study area included counties bordering the Missouri River in southeastern South Dakota and northeastern Nebraska covering approximately 23 000 km2. Environmental predictors included seed source distance and density, as well as topography, climate, soils, and land use variables. Areas of low-density juniper were identified by visual interpretation of sample plots from digital aerial photography. We used a machine-learning approach to classify low-density juniper with the random forests algorithm. Model accuracy was high with an area under the receiver operating characteristic curve of 0.884. Variables related to seed sources were the most important predictors, and precipitation, slope angle, and the local intensity of human land use also had substantial influences. A previous map based on Landsat imagery identified 209 968 acres (84 971 ha) as juniper with in the study area, and this study found an additional 430 648 acres (174 277 ha) classified as low-density juniper stands. These results can provide agencies and land managers with more accurate information about the distribution of juniper, and the underlying techniques can be extended to map woody plant encroachment in other areas.

The Ecological Status of Juniperus foetidissima Forest Stands in the Mt. Oiti-Natura 2000 Site in Greece

Junipers face multiple threats induced both by climate and land use changes, impacting their expansion and reproductive dynamics. The aim of this work is to evaluate the ecological status of Juniperus foetidissima Willd. forest stands in the protected Natura 2000 site of Mt. Oiti in Greece. The study of the ecological status is important for designing and implementing active management and conservation actions for the species’ protection. Tree size characteristics (height, breast height diameter), age, reproductive dynamics, seed production and viability, tree density, sex, and habitat expansion were examined. The data analysis revealed a generally good ecological status of the habitat with high plant diversity. However, at the different juniper stands, subpopulations present high variability and face different problems, such as poor tree density, reduced numbers of juvenile trees or poor seed production, inadequate male:female ratios, a small number of female trees, reduced numbers of seeds with viable embryos, competition with other woody species, grazing, and illegal logging. From the results, the need for site-specific active management and interventions is demonstrated in order to preserve or achieve the good status of the habitat at all stands in the region.

The effects of woody plant encroachment and wildfire on plant species richness and composition: Temporal changes in a forest–steppe mosaic

AbstractQuestionsWoody plant encroachment and wildfire may both have major effects on species richness and composition, yet studies that assess these two factors in combination are rare. We asked the following specific questions: (1) how did juniper cover change over a decade in the study area; what are the effects of juniper encroachment and subsequent wildfire on(2) plant species richness; and (3) vegetation composition?LocationSand forest–steppe in Kiskunság, Central Hungary.MethodsWe studied a juniper‐encroached grassland hit by a wildfire. We assessed changes in plant species richness and composition in burnt and unburnt grassland and juniper plots for 11 years following the wildfire. Yearly vegetation sampling was performed in permanent quadrats of 1 m2and 25 m2using visual cover estimation. Temporal changes in juniper cover and species richness were evaluated with generalized linear mixed‐effects models. Compositional changes were analysed by non‐metric multidimensional scaling and fidelity analysis.ResultsAt the beginning of the study, the presence of individual juniper shrubs increased species richness, and did not alter species composition. However, microsites covered by junipers were extremely species‐poor. Juniper growth during the study period caused a sharp decline in species richness at the edge of juniper shrubs and a shift in species composition compared to grassland plots. Wildfire increased species richness both in grassland and juniper plots. It caused only transient compositional responses in grasslands, but converted juniper habitats back to the grassland state.ConclusionsWe conclude that neither moderate juniper encroachment nor wildfire have negative effects on plant species richness in the studied ecosystem. However, as juniper thickening may cause species loss and devastating fires, conservation management should prevent the development of dense juniper stands.

Habitat use of an endangered beetle Carabus hungaricus assessed via radio telemetry

Carabus hungaricus is an endangered habitat specialist of tall-grass steppe occurring in Pannonian region. In this study, we used radio telemetry to examine whether habitat type (different habitat patches in steppe mosaic), sex, daytime, temperature and air pressure affect movement activity of the species. For seven-day tracking during the reproductive period of C. hungaricus in October 2017, we used 10 individuals, five males and five females, equipped by 0.3 g VHF transmitters. We found that the average speed was 1.29 m/h for the fastest individual and 0.21 m/h for the slowest one. Considering the shape of trajectories, beetles mostly randomly walked around; only in few cases they covered larger distances between two tracking sessions. Habitat type significantly affected beetles’ movement; the average speed was higher in grassy patches and under common juniper stands, while it decreased in mosses and litter under bushes. Although there was no effect of sex, daytime and air pressure on beetles’ activity the temperature had a positive effect on movement behaviour. We showed that preferred habitat observed from the human perspective was not in fact equally utilized by C. hungaricus. The availability of suitable patches within steppe mosaic can be therefore crucial for species persistence.

MECHANICAL PROPERTY ASSESSMENT FOR ESTABLISHING DESIGN VALUES OF WESTERN JUNIPER

Western juniper (Juniperus occidentalis) is a conifer that is native to Oregon, California, Washington, Nevada, and Idaho. Juniper is highly decay resistant and, therefore, is a popular choice for fence posts and landscape timbers. Forest management practices over the past 100 yr have resulted in an immense population increase in western juniper stands, transforming the grasslands/sagebrush biome into juniper forests. Landowners have been encouraged to cut back western juniper to restore grassland habitat, but there is no major market associated with juniper lumber. This study assessed the mechanical properties of western juniper to develop its design values for inclusion in the National Design Specification. Small clear samples were prepared from juniper harvested from three locations in eastern Oregon, one location in northeast California, and one location in southwest Idaho according to ASTM D143 for compression, bending, and shear. Average strength values were calculated and compared with similar wood species. Most properties were similar to those of other species, but modulus of elasticity was significantly lower. Compressive properties of western juniper also differed, with compression parallel-to-grain being lower and compression perpendicular-to-grain being relatively higher. Differences between species might be attributed to cell wall structure and distribution of lignin in the cells. Design values for western juniper were calculated using the strength values to establish allowable properties for visually graded lumber. © 2018 by the Society of Wood Science and Technology.

Assessment of wounding factors (natural and anthropogenic) of Juniperus procera and their relation to disease occurrence of Pyrofomes demidofffii in some afromontane forests of Ethiopia

Abstract Wood decay fungus Pyrofomes demidoffii is a cosmopolitan spp. and considered as an important source of damage to Juniperus spp. The aim of the study was to assess the wounding factors of Juniperus procera and their relation to a disease occurrence of P. demidoffii in some afromontane forests of Ethiopia. Disease survey and sample collection was conducted during 2010 in Adaba-Dodola and in Menagesha forests. In Adaba-Dodola forest, sampling was conducted in highly disturbed forest blocks named as non-“WAJIB” and in a relatively undisturbed forest (“WAJIB”) named after the local Afan Oromic language. WAJIB blocks are constitute of Forest Dwellers Association established to protect forest, whereas a non-WAJIB blocks are people living in villages found adjacent to forests with little role in protection of forest. In both study areas, a study quadrat of 20 × 20 m2 within the plot was established at 100 m intervals along a regular grid. In each sampling unit, comprehensive survey was conducted to determine the occurrence of infection by P. demidoffii. About 657 trees (310 in Adaba-Dodola forest and 347 in Menagesha forest) were assessed for the typical signs and symptoms of P. demidoffii. Natural and anthropogenic wounding factors were assessed, and their relationships with disease occurrence of P. demidoffii were determined. Pyrofomes demidoffii was noticed as fruiting bodies and/or white rot on the juniper stands. The disease occurrence of P. demidoffii was significantly higher in juniper stands with a mixed wounding factors followed by wounding by bark-peeling (P

Effects of Site Characteristics, Pinyon-Juniper Management, and Precipitation on Habitat Quality for Mule Deer in New Mexico

Wildlife enterprises are increasingly important to ranch income in the western United States. Habitat management practices that facilitate wildlife are needed for optimal management of multiple-use ranches, particularly for economically important species, such as mule deer (Odocoileus hemionus), that are declining throughout much of their range. We tested the effects of vegetation cover type, site characteristics, pinyon-juniper management treatments, and precipitation on body condition and size of spring-summer-autumn (SSA) home ranges of mule deer to assess habitat quality on the Corona Range and Livestock Research Center (CRLRC), a multiple-use research ranch in eastcentral New Mexico. Accrual of lean tissue and body fat reserves in does was positively associated with use of mechanically cleared juniper, pinyon-juniper woodland, and savannah and increased annual and spring (April to June) precipitation. Size of SSA home ranges of does was negatively associated with use of pinyon-juniper woodland and savannah and mechanically cleared pinyon-juniper stands, indicating that habitat quality was positively associated with use of these types. Conversely, size of SSA home ranges was positively related to use of short grass prairie (does), proportion of short grass prairie in SSA ranges (bucks), and areas of low forage production classes (does, bucks). Overall, habitat quality for deer on CRLRC was most positively associated with a mix of thinned and unmanaged pinyon-juniper habitat. Conversely, habitat quality was negatively associated with use of short grass prairie, which is the most common (77%) vegetation cover type on CRLRC. Management for deer habitat should focus on increasing forage, particularly shrub communities, by opening pinyon-juniper communities while maintaining sufficient area in unmanaged woodland for cover. Deer responses are likely to be greater if management focuses on sites of higher forage production potential within 200 m of unmanaged pinyon- juniper stands.

Phytosociology of Juniperus excelsa M.Bieb. forests in Alborz mountain range in the north of Iran

Juniperus excelsa is one of the specific tree species in the mountainous areas of Iran. It forms the mountainous forests of Irano-Turanian vegetation region. Despite the considerable spread of J. excelsa in Iran, there is no detailed and valid published study on the phytosociology of Iranian juniper stands. The aim of this research is to identify these associations and their characteristics in Alborz mountains in the north of Iran. To this goal, a set of data including floristic data according to Braun-Blanquet method, and important environmental characteristics, were collected. To classify the vegetation, TWINSPAN was used and phytosociology tables were analysed with JUICE software. Diagnostic species were determined by measuring the degree of fidelity and using statistically meaningful measurements. According to the results, the vegetation was classified into six associations and five subassociations. Among them are Cotoneastro nummulariis-Juniperetum excelsae ass. nov., Lonicero ibericae-Juniperetum excelsae ass. nov., Rhamno pallasii-Juniperetum excelsae ass. nov., Rhamno p.-Juniperetum e. ajugetosum chamaecisti subass. nov., Rhamno p.-Juniperetum excelsae gypsophiletosum aretioidis subass. nov., Amygdalo lycioidis-Pistacietum atlanticae hymenocratretosum bituminosoris Kashipazha et al. 2007, Feruletum ovinae ass. nov., Artemisio aucheri-Astragaletum veri Asri 2004, and Artemisio aucheri-Onobrychidetum cornutae ass. nov. The introduced juniper associations were placed in class Junipero-Pistacietea Zohary 1973 and order Juniperetalia excelsae nov.

Climate–growth analysis of Qilian juniper across an altitudinal gradient in the central Qilian Mountains, northwest China

In the context of global warming, it is of high importance to assess the influence of climatic change and geographic factors on the radial growth of high-elevation trees. Using tree-ring data collected from four stands of Qilian juniper (Juniperus przewalskii Kom.) across an altitudinal gradient in the central Qilian Mountains, northwest China, we compared the radial growth characteristics and climate–growth relationships at different elevations. Results indicated that there was little difference in the tree-ring parameters of the four chronologies. Correlation analyses both for unfiltered and 10-year high-passed data of monthly climatic variables and chronologies were presented to investigate the climatic forcing on tree growth, and results revealed that the correlation patterns were consistent among the four sites, especially for high-passed data. We employed the principal components analysis method to obtain the first principal component (PC1) of the four chronologies and computed the correlations between PC1 and climate factors. The PC1 correlated significantly with winter (November–January) temperature, prior August and current May temperature, and precipitation in the previous September and current January and April, indicating that tree growth in this region was mainly limited by cold winter temperature and drought in early growing season and prior growing season (prior August and September). However, the climate–growth relationships were unstable; with an increase in temperature, the sensitivity of tree growth to temperature had decreased over the past few decades. Considering the instability of the climate–growth relationships, climate reconstructions based on tree rings in the study area should be approached with more caution.

Winter resource selection by female mule deer Odocoileus hemionus: functional response to spatio‐temporal changes in habitat

Populations of mule deer Odocoileus hemionus have declined throughout most of their historic range in recent decades, and habitat alteration has been hypothesized as one potential cause of those declines. Consequently, understanding how patterns of behaviour change as landscapes are altered through time may provide important insights into mechanisms underlying observed demographic trends in populations of mule deer. We examined resource selection in relation to habitat change by mule deer on the Tex Creek winter range in southeastern Idaho, USA. We created a GIS‐based map of habitats available to mule deer during two time periods, past (1985‐1986) and current (2007‐2009), to document changes in habitat over time. We then modeled past and current patterns of resource selection by mule deer based on locations obtained from visual observation, radio‐telemetry and GPS collars. Abundance and distribution of juniper Juniperus spp., aspen Populus tremuloides, sagebrush steppe Artemisia spp. and riparian habitat did not change significantly between past and current time periods. In contrast, we documented an increase in grassland from 3.5 to 30.7% of our study area, and a corresponding decrease in agricultural land, which provides high‐quality forage for mule deer, from 37.8 to 12.5% of our study area. Patterns of resource selection largely were similar between the two time periods. Nevertheless, mule deer significantly increased selection of agricultural fields and areas far from roads between the 1980s and 2007‐2009. In addition, juniper stands were strongly selected in all years, and importance values (use × availability rescaled to 100%) for grassland and sagebrush steppe increased between past and current time periods. Our results indicated that mule deer responded behaviourally to declining availability of high‐quality forage (i.e. agricultural land) by increasing selection of agricultural fields. Such functional responses in habitat selection may have important consequences for dynamics of mule deer populations, but additional research is necessary to link those responses to demography and population performance. Although juniper encroachment often is thought to have affected mule deer negatively on many summer ranges, strong selection for juniper in our study highlights the potential importance of that species on winter range, likely because it provides both thermal and hiding cover.

Macrofungal diversity associated with the scale-leaf juniper trees, Juniperus excelsa and J. foetidissima, distributed in Turkey

In this article, an attempt has been made to establish the qualitative composition of macromycetes in the communities of scale-leaf juniper, Juniperus excelsa M.Bieb. and J. foetidissima Willd., distributed in Turkey. A total of 127 species of macrofungi were registered, 2 belonging to Ascomycota and 125 to Basidiomycota. Of those, 69 species were collected in Juniperus excelsa stands, 23 in J. foetidissima stands, and 35 species in both juniper stands. The ecologic status for the fungal species is as follows: 30 lignicolous and 39 terricolous in J. excelsa stands, 19 lignicolous and 4 terricolous in J. foetidissima, and 31 lignicolous and 4 terricolous in both stands. For Turkey, 23 taxa were new, and 5 of them were new at genus level. The new genera were Pyrenopeziza Fuckel, Amyloathelia Hjortstam & Ryvarden, Byssoporia M.J.Larsen & Zak, Globulicium Hjortstam, and Subulicium Hjortstam & Ryvarden.

GENETIC DIVERSITY AND LOW REPRODUCTIVE SUCCESS IN ISOLATED POPULATIONS OF UTAH JUNIPER (JUNIPERUS OSTEOSPERMA, CUPRESSACEAE)

Utah juniper (Juniperus osteosperma) has greatly expanded its historical range in the western United States. Management plans for the species have focused on curtailing its encroachment into sagebrush and grassland communities. These plans often include burning or other methods of elimination. These methods may result in subdivision or fragmentation of existing juniper stands. We initiated a study at Dugway Proving Ground, a U.S. Army facility, to examine the effects of fragmentation on the reproductive success of Utah juniper in isolated populations. We used enzyme electrophoresis to quantify genetic variability in isolated populations. We also determined population reproductive success by examining juniper fruits for evidence of seed abortion and/or presence of insect parasites. We compared reproductive and genetic variability in isolated populations at Dugway to 2 nonisolated and encroaching Utah juniper populations. The Dugway populations exhibited reduced seed set due to high seed abortion and/or insect seed parasitism, and a loss of genetic variability in comparison to the nonisolated populations. Additionally, there was a significant correlation between reproductive success and genetic variability.

Herbaceous Restoration of Juniper Dominated Grasslands With Chaining and Fire

Juniper (Juniperus spp.) encroachment in grasslands usually progresses toward a stable woody state of mature trees that requires a significant disturbance to shift succession in another direction. Fire alone is often inadequate to shift succession in dense stands of mature juniper and must be preceded by a mechanical treatment such as chaining to reduce juniper competition and increase herbaceous growth that fuels a subsequent fire. However, little long-term data are available that measure combined effects of mechanical and fire treatments on restoration of juniper-dominated grasslands. Here, on a degraded (40% bare ground) north Texas site dominated by redberry juniper (Juniperus pinchotii Sudw), we quantify long-term herbaceous responses to mechanical chaining followed by fire. Two types of chaining, ground-level and elevated, were evaluated and all chained plots were burned 4 years after chaining. Herbaceous and woody responses were measured for several years after both chaining and fire treatments and compared to untreated controls. At study termination, both of the chaining + fire treatments reduced juniper cover from 32% to < 6%, but mortality was < 10%, because most plants basal-sprouted. Total grass production did not increase in chained treatments over the untreated until 3 growing seasons after chaining. Grass production declined the first growing season following the fire treatment, but increased in treated plots to 3 times the untreated the second and third year postfire. Total grass cover in treated plots did not increase over the untreated until the second year after the fire treatment. There was no difference in juniper or herbaceous responses between the 2 chain types. Results suggest increases in herbaceous production from chaining alone were due to increased growth of existing vegetation patches whereas the fire treatment appeared to stimulate herbaceous recruitment into bare soil areas.

Herbaceous Restoration of Juniper Dominated Grasslands With Chaining and Fire

Juniper (Juniperus spp.) encroachment in grasslands usually progresses toward a stable woody state of mature trees that requires a significant disturbance to shift succession in another direction. Fire alone is often inadequate to shift succession in dense stands of mature juniper and must be preceded by a mechanical treatment such as chaining to reduce juniper competition and increase herbaceous growth that fuels a subsequent fire. However, little long-term data are available that measure combined effects of mechanical and fire treatments on restoration of juniper-dominated grasslands. Here, on a degraded (40% bare ground) north Texas site dominated by redberry juniper (Juniperus pinchotii Sudw), we quantify long-term herbaceous responses to mechanical chaining followed by fire. Two types of chaining, ground-level and elevated, were evaluated and all chained plots were burned 4 years after chaining. Herbaceous and woody responses were measured for several years after both chaining and fire treatments and compared to untreated controls. At study termination, both of the chaining + fire treatments reduced juniper cover from 32% to &lt; 6%, but mortality was &lt; 10%, because most plants basal-sprouted. Total grass production did not increase in chained treatments over the untreated until 3 growing seasons after chaining. Grass production declined the first growing season following the fire treatment, but increased in treated plots to 3 times the untreated the second and third year postfire. Total grass cover in treated plots did not increase over the untreated until the second year after the fire treatment. There was no difference in juniper or herbaceous responses between the 2 chain types. Results suggest increases in herbaceous production from chaining alone were due to increased growth of existing vegetation patches whereas the fire treatment appeared to stimulate herbaceous recruitment into bare soil areas.

Phytosociological affinities and habitat preferences of Juniperus sabina L. and Artemisia santolinifoliaTurcz. ex Bess. in mountain sites of the south‐eastern Gobi Altay, Mongolia

AbstractPlant community composition was analysed for 145 relevés, randomly sampled on steep slopes in the Gobi Gurvan Sayhan National Park, southern Mongolia. Cluster analysis designated seven communities into three main groups, namely mountain steppes, dominance stands of the dwarf shrub Artemisia santolinifolia, and scrub composed of Juniperus sabina. Multivariate classifications corresponded well to available phytosociological classification schemes. Dense mountain steppes on northern exposures, as well as juniper stands on south‐ and east‐facing scree slopes, had high contents of organic matter and cations in the soil, while stands with disturbance‐tolerant species such as Carex stenophylla, annuals, or A. santolinifolia grew on less favourable soils. Stands of the latter species showed some overlap with J. sabina with respect to species composition and site conditions, and specimens of A. santolinifolia were present in most relevés of juniper stands. The complete absence of juniper seedlings suggested an apparent potential replacing of ageing specimens of J. sabina by A. santolinifolia. However, both species were distinct in cluster, ordination and correlation analyses, so this process seems to be still in its infancy. (© 2004 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Sex ratio and sexual dimorphism in mountain dioecious thuriferous juniper (Juniperus thurifera L., Cupressaceae)

Thuriferous juniper (Juniperus thurifera L), a dioecious bush or tree is only found in isolated parts of the western Mediterranean: France, Spain, Algeria and Morocco. These mountain juniper stands are seriously endangered in Morocco as a result of intensive wood removal, and in Europe as a result of recolonization of stands by pines or oaks. Field studies were conducted to investigate sex ratio and sexual dimorphism, never previously examined, in eight different populations in the Atlas mountains and, for comparison, in one of two populations in the French Pyrenees. The sex ratio was female-biased for six of the eight Moroccan stands and especially for the oldest populations. The Pyrenean population showed a similar female-biased ratio. This particular sex ratio is possibly linked to cost of reproduction, paid by both males and females. Sex ratios can also be linked to population dynamics. Males begin to flower slightly younger than females, which explains their apparent dominance in young populations in Morocco or in a recolonization zone with young trees in the Pyrenees. Studies concerning sexual dimorphism in the western High Atlas sites showed no significant difference in phytomass between males and females. Females appear to be significantly taller but with a lower radial growth. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 138, 237–244.

Restoration of alvar vegetation on Öland, Sweden

Abstract.Alvars in the Baltic region, particularly on the Swedish islands of Öland and Gotland and in western Estonia, are well‐known for their plant species richness and extensive populations of rare species. Grasslands make up most of alvar vegetation. The extent of these grasslands decreases because of bush enchroachment which takes place in most alvars when traditional land use practice changes, notably when grazing is ceased. The main threat for the alvar grassland is formed by the rapid expansion ofJuniperus communis and Potentilla fruticosain dry and wet sites, respectively.Applied research has been carried out during several years in order to develop plans for the restoration of alvar grassland. Thus it was shown that species richness in areas with a mixture of grassland and shrubland decreases in relation to the increased cover by shrubs. In the case ofJuniperusthere is a distinct drop in species number as soon as the cover exceeds 75‐80%, while the decrease is more gradual with increased cover ofPotentilla.The seed banks under dense stands of these shrubs only contain ca. 20% of the species found in dry and wet alvar meadows. This was confirmed by clearing experiments. Long‐term recordings have shown that establishment of juniper seedlings takes place mainly in half‐open areas between already existing junipers. Intermediate‐sized junipers expanded faster than old and big shrubs.Potentillashrubs recover fast from cutting or burning. After 2‐4 yr they have almost attained their former size. This recovery can be prevented when cattle grazing is introduced.In the framework of a local alvar restoration project on Öland, covering 7000 ha, grazing regimes are re‐established, fences erected and large‐scale clearings carried out. Recently established juniper shrubs are being cleared, intermediate sized junipers (30‐50 yr old) are selectively removed while creating a mosaic landscape with high biological diversity. Older dense juniper stands are left alone or are only partly cleared.Potentillastands in moist areas are cut to create moist meadows which are breeding grounds for waders, and to establish corridors between remaining open areas.Three items are discussed (1) the importance of the Stora Alvar area; (2) re‐introduction of grazing and (3) re‐introduction of species. The outstanding importance of the area regarding species richness and endemism should be recognized through a ‘golden list’ to be used along with red and blue lists.

Endangered stands of thuriferous juniper in the western Mediterranean basin: ecological status, conservation and management

Thuriferous juniper is only found in isolated parts of the western Mediterranean: France (Alps, Pyrenees and Corsican highlands), Spain, Algeria and Morocco. These semi-arid mountain stands, where thuriferous juniper trees grow in low-density open woodland, are seriously endangered: (i) In the Atlas mountains, the thuriferous juniper stands are heavily degraded as a result of the intensive wood removal and livestock activity in these densely populated areas. This situation, which will soon become irreversible unless remedial measures are urgently taken, has produced impoverished soils and hillside instability while contributing to desertification. (ii) In Spain, although livestock activity and cultivation have strongly reduced areas occupied by Juniperus thurifera, stands are still numerous and, in some regions, show a good regeneration due to conservation measures. (iii) In France, the decline in human and livestock activities over recent decades has led to a recolonization of some of the Juniper stands by pines or oak. A forest management system that enables these original stands to survive and regenerate must be undertaken without delay. The dynamics of evolution of these stands is quite different north and south of the Mediterranean. In both cases, conservation measures are urgently required to protect or rehabilitate these original stands with floristic, ecological and socio-economic interest.

Seasonal changes in the abundance and diversity of birds in threatened juniper forest in the southern Asir mountains, Saudi Arabia

SummaryJuniper forest once covered much of the upper slopes (2,000-3,000 m) of the Rift Valley escarpment in the Asir mountains of south-west Saudi Arabia. One of the best preserved tracts is at Raydah near Abha, where a complete altitudinal floristic zonation persists. Although only about 125 bird species have been recorded in the area, the community is of considerable conservation interest due to high densities of endemic species and resident or breeding Afrotropical forest species, together with a wide range of diurnal raptors, owls and nightjars. The forest does not appear to support many Palearctic— African migrants during periods of passage, although several Palearctic species overwinter in considerable numbers. Scrub and mixed deciduous and riparian forest scattered throughout the junipers hold highest bird diversities but the juniper stands are vitally important to the well-being of Yemen Thrush Turdus menachensis, Yemen Warbler Parisoma buryi and Yemen Linnet Carduelis yemenensis populations. The disappearance of juniper forest from neighbouring Yemen necessitates that highest priority conservation action should be given to the remaining intact forests such as Raydah, in an attempt to preserve their unique biodiversity.