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Temperate evergreen broad-leaved forest seldom experiences fire, and little is known about the severity at which they burn. During October-November 2018, 70 000 ha of fynbos, thicket, Afrotemperate forest and other lesser vegetation types burnt in the southern Cape of South Africa. This study set out to verify through field observations the accuracy of the differenced Normalised Burn Ratio (dNBR) as an index of fire severity, derived from Sentinel 2 images, in Afrotemperate forest. Stem fire severity and char height were observed for 1 648 trees in 87 plots and linear regression used to test whether these observed measures were related to dNBR. Stem fire severity and char height were collinear, and the latter dropped from further analysis. The strong linear relationship between dNBR and stem fire severity (r2 = 0.69, p

It is hypothesized that in the Holocene dune fynbos-thicket mosaics of the Cape, decades-long absence of fire results in closed-canopy thicket replacing more open fynbos shrublands. We tested this hypothesis by analyzing repeat photographs from 16 sites at Cape St Francis in the south-eastern Cape Floristic Region. The period of monitoring ranged from 55 to 17 year and most sites had been last burnt between 30 and 50 years ago. We divided the sites into coastal (salt wind-exposed) and inland zones and computed, for each pair of photographs, the rate of change of four plant types, namely thicket shrubs, fynbos woody, fynbos herbaceous and grass. Coastal zone sites showed a significant increase in thicket shrub cover and a significant decline in both grass and fynbos herbaceous cover. Fynbos woody cover declined in the face of thicket invasion, but increased in grassy sites, most likely due to a decline in herbivory intensity. No significant changes in plant types were observed in the inland sites, although thicket shrub cover did increase marginally at the expense of fynbos woody plants. However, thicket invasion was restricted to swales and lower dune slopes; the dune fynbos of the upper slopes and crests remains uninvaded by thicket and surprisingly vigorous after 30–50 year without fire. This is consistent with the notion that fynbos species occupy drier sites than thicket in these dune landscapes and regular fire is not a prerequisite for its persistence. Overall, we showed a large increase in woody plant cover throughout the study area. While this pattern is consistent with predictions for vegetation change in response to atmospheric [CO2] pollution, it can also be explained by land use changes experienced in the study area, starting in the early 1960s, involving a shift from subsistence agriculture to holiday resort development and tourism.

Calcrete Bontveld is a mosaic vegetation type found on calcareous flat-topped ridges in the Eastern Cape, South Africa. The mosaic is comprised of thicket clumps (bushclumps) scattered in a grassy dwarf shrubland matrix. The bushclumps appear to function as islands, yet their close resemblance to the adjacent Valley Thicket suggests that they could be remnant thicket patches. This study utilised the Island Biogeography Theory to determine the insularity of bushclumps. We specifically tested if they were indeed isolated communities or remnant thicket patches. Linear regression was used to obtain the slopes of the species-area curves, which indicated that the bushclumps, at all three known Calcrete Bontveld sites, were indeed isolated communities. Whilst the bushclumps of Calcrete Bontveld may mirror the appearance of the adjacent Valley Thicket, they are not remnant thicket patches but have rather developed de novo.

Calcrete Bontveld is a mosaic vegetation that occurs on flat-topped calcareous ridges adjacent to solid Valley Thicket in the Albany Thicket biome of South Africa. It consists of thicket clumps (bushclumps) scattered in a grassy dwarf shrubland matrix. While the bushclumps of Calcrete Bontveld represent the thicket component in the mosaic the extent and nature of similarity between the bushclumps and adjacent solid Valley Thicket remains unresolved. This study considers the relationship between the thicket communities of these two spatially separate but proximal vegetation types. As expected, bushclumps share a substantive compositional similarity and structure with the nearby solid Valley Thicket but minimally so with the surrounding grassy dwarf shrubland matrix. The latter is made up of elements of other biomes with only a few thicket taxa. The Bushclump composition differs from the adjacent solid Valley Thicket in that it is less succulent and less diverse in the number of plant families. A total of 22 Thicket species were absent from the bushclumps – notably a few iconic ones: trees Portulacaria afra, shrubs Cotyledon velutina, Euphorbia mammilaris and Kalanchoe rotundifolia, as well as the geophyte, Gasteria bicolor. By contrast, only 8 taxa were found only in the bushclumps, but not in the local form of solid Valley Thicket (e.g. Ptaeroxylon obliquum and Scolopia zeyheri). Several of these have a Cape Thicket affinity – e.g. trees Colpoon compressum and Pterocelastrus tricuspidatus and the shrub Diospyros dichrophylla. The absence of many adjacent thicket species from the bushclumps provides evidence for exchange exclusion of propagules of some Valley Thicket taxa from the bushclumps of Calcrete Bontveld. However, the unique bushclumps are a suitable habitat for establishment of the more distant Cape-affinity taxa.

This paper analyses Land use land cover (LULC) change in the Northwest (NW) Beach, Point Pelee National Park (PPNP) to understand its effect on sediment transport dynamics for sand dune restoration. Due to development of infrastructure, beginning in the 1960s, sand dunes were completely removed from parts of NW beach. Spatial-temporal changes for LULC were assessed using aerial photos and images for 1959, 1977, 2006 and 2015. Based on the Ecological Land Classification System (Southern Ontario), object based image analysis and feature extraction methods were used to generate classified maps. The photos were the highest quality available in the Parks Canada, PPNP archive. LULC classes included Shoreline Vegetation, Deciduous Thicket, Sand Barren and Dune Type, and Infrastructure. Aerial photographs of LULC change for 1959–1977 and South Western Ontario Orthoimagery Project (SWOOP) images for 2006–2015 were analysed. A large gap exists between 1977 and 2006 as no images were available for that time period. Results indicated a significant increase in the Deciduous Thicket in 2015, acting as a barrier for sand movement to the parking lots. Decrease in the Shoreline Vegetation Type along with an increase in the lake level indicate a decrease in beach width and supply area for sediment transport. Based on the analysis, active management through the removal of cottonwood trees, and policy changes are recommended for dune restoration in Point Pelee. Accuracy assessment of the 2015 classification using an error matrix resulted in an overall accuracy for the LULC classification of 88%.

Arid Thicket transformation by domestic meso-herbivores is purported to follow a state-and-transition model. Our study represents a first attempt to verify this hypothesis in Pruim-Spekboomveld, a variation of Arid Thicket. We correlate structural and compositional attributes of thicket bush clumps to distance from artificial watering points in four piosphere treatments that have had a different rangeland management history. We fit linear, exponential and sigmoid regression models to our data and use Akaike's Information Criterion to select the best fitting model. Furthermore, we compare the end regions of our data in the piosphere treatments to each other and to similar data collected in a transformed and untransformed reference site. We use both the pattern and extent of transformation within and between the treatments and the reference sites, to verify the existence of stable states and ecological thresholds. Our results indicate a threshold reduction in species richness, functional type diversity, succulent shrub diversity, succulent shrub cover and palatable shrub cover; and a corresponding threshold increase in perennial alien invasive and ephemeral forb cover; with an increase in herbivore-induced transformation. These findings suggest that our treatments have crossed a degradation threshold and therefore represent an alternative stable state to the untransformed reference site.

Accurate biomass and carbon flux estimations are essential for global carbon cycle modeling and are useful for setting and evaluating ecological restoration goals. Estimates derived from remote sensing can only be as good as the field data with which they are calibrated. Biomass estimates derived from allometric models are widely used to extrapolate from a plot to a landscape or regional scale, but both species- and/or site- specific models are scarce, and the model development procedure destructive and labour-intensive. Here we present allometric models that estimate biomass for 40 species common in Spekboom Thicket (ST), an arid South African Subtropical Thicket type, and its ecotones. Portulacaria afra (spekboom) is a canopy cover dominant in intact states of ST. Using these simple regression models, based on plant height and canopy diameter parameters, we estimate the aboveground biomass carbon (ABC) and with litter, the total aboveground carbon (AGC) of five sites situated across the Subtropical Thicket biome in South Africa. On each site, adjacent stands were selected that compared two management histories, intact and livestock-degraded, divided by a fence line boundary. Our estimates compared well with results from other studies. The highest AGC for stands in both intact and degraded states were estimated at 43.0 t C ha−1 and 13.0 t C ha−1 respectively, and the lowest at 26.3 t C ha−1 and 2.5 t C ha−1. Large canopy dominant (LCD) species contributed the largest AGC portion at three intact stands. The second largest portion was recorded for spekboom. Overall, the sites to the northeast of the biome recorded the highest AGC pools, consistent with a higher incidence of rainfall, especially in the summer months. In contrast, sites to the west of the biome showed higher mean litter carbon pools. Should intact sites be applied as reference, livestock-degraded subtropical thicket can potentially recover 22 – 27 t C ha−1 in AGC through restoration action.

International audience; We explored the ecological impact of a nitrogen-fixing shrub (Ulex europaeus, common gorse) cultivated as an intercrop species in the interlines of a young stand of maritime pine (Pinus pinaster). Nitrogen fixing species are well-known for their advantage of increasing the soil fertility in agriculture. Nevertheless, in forest ecosystems, their use is uncommon except in some associations in the tropics. The Landes de Gascogne forest range (SW France) has soil fertility issues and Ulex europaeus is a vigorous plant, native to this region. Therefore, an investigation of the association of this N-fixing species with trees is worthwhile. To this end, we compared a standard pine plantation management (control) with a treatment where gorse seeds were sown in the interlines at tree plantation (gorse sowing). This factor was combined with a phosphorus supply (control versus P-fertilisation), resulting in four treatments. The forestry practices evaluated here distinguish two main periods: a first period of six years after tree plantation when gorse individuals grew as an intercrop and formed dense vegetation, and a second period of three years after crushing this vegetation in the interlines. In the first period, pine mortality in the gorse sowing treatment was higher during the dry season than in the control treatment, suggesting competition for water. Pine diameter growth was reduced, but not height growth, indicating avoidance of light competition with gorse. In the presence of gorse, pine foliar-N was appreciably enhanced relative to the control, and natural pine pruning occurred, while pine browsing by animals was limited due to the protection of the thorny gorse thickets surrounding the trees. In the second period, soon after crushing the gorse vegetation in the interlines, enrichment of nitrogen in needles continued, suggesting a fertilising effect of the gorse remnants. Crushing also freed the pines from shrub competition and a “catch-up growth” was identified regarding diameter and stem volume growth. Two years after the gorse crushing, tree size and biomass were similar in the experimental treatments regardless of gorse sowing or not. Overall, during the first nine years after tree plantation, gorse introduction in the pine tree forests had various effects. On the one hand, gorse induced competition for light and water. On the other hand, it resulted in high inputs of nitrogen and organic matter into the ecosystem which could lead to sustained soil fertility and this might improve tree nutritional status. We recommend continuing the assessment of such pine-gorse forestry associations for longer observation periods and in very nutrient-poor sites in this forest range.

Riparian forests in tropical drylands support high biodiversity and provide crucial ecosystem services. Yet, fertile soil, water availability and trees as a source of charcoal and timber make them a favourable place for settlements and subsistence agriculture. The present study aimed at evaluating the floristic diversity of riparian forest remnants in semi-arid Kenya as a basis for developing conservation and management strategies. Plant diversity was assessed along the Nzeeu and Kalundu rivers in Kitui County, Eastern Province, where riparian forest patches were intermingled with agricultural and grazing lands and invasive thickets dominated by Lantana camara. Diameter at breast height (DBH) and height of woody species (DBH > 5 cm) were recorded in a total of 74 transects (50 m × 10 m) laid out perpendicular to the rivers on both sides at 300 m intervals. In each transect, the distribution of six land cover types was mapped out and the distance of each plant individual from the river bank was noted. Overall, 631 individuals were recorded representing 85 woody species, of which 12 were exotic timber and fruit trees. Human activities mostly reached within 10 m of the river margin; indigenous vegetation covered only 12% of the transect area but had 188 tree individuals and 49 tree species (including 3 exotics), whereas agricultural land had a mean cover of 52%, 168 individuals and 39 species, including 9 exotics. Ordination and multi-level pattern analysis showed that Euphorbia bicompacta Bruyns, endemic to Kenya, and Commiphora samharensis Schweinf. were characteristic of indigenous vegetation, whereas Acacia species dominated in invasive thicket, grazing land and agricultural land. Only two species, Shirakiopsis elliptica (Hochst.) Esser and Rauvolfia caffra Sond., were clearly associated with the river bank, while the others represented a mix of riparian species with a broader ecological amplitude and typical dryland species. The study highlights that the area still supports viable remnants of indigenous riparian vegetation, whereas tree diversity on agricultural land is strongly shaped by human preferences and shows lack of recruitment. Targeted management interventions could support the maintenance of indigenous tree diversity with positive effects for overall biodiversity, soil protection and livelihood diversification. For instance, it is recommended to facilitate natural tree regeneration and to plant a variety of indigenous tree species, especially on the river banks. Further research is necessary to assess the status of riparian vegetation along similar dryland rivers in Kenya and Africa to adequately manage these important areas for biodiversity and ecosystem services.

In the Appalachian Mountains of eastern North America, mountain laurel (Kalmia latifolia) thickets in mixed-oak (Quercus spp.) stands can lead to hazardous fuel conditions, forest regeneration problems, and possible forest health concerns. Generally, land managers use mechanical means or prescribed fire to control mountain laurel thickets, but these treatments are expensive, dangerous to implement, or have short-term effectiveness. From 2012 to 2016, we compared the effectiveness of three herbicides applied as broadcast foliar treatments at varying rates and in different months for reducing mountain laurel thickets. Triclopyr (ester formulation) top-killed mountain laurel within a few weeks at most month/rate combinations, but subsequent sprouting reduced overall effectiveness by year 3. Conversely, imazapyr provided little initial control of mountain laurel, but by year 3, the herbicide had killed nearly all the treated shrubs with no subsequent sprouting regardless of the month of application or rate. Glyphosate had limited effectiveness; spraying in August at 8 and 12 L/ha killed the mountain laurel over 3 years with little sprouting while all others treatments had little or no impact. From these results, it appears that several month/rate combinations of all three herbicides have potential for controlling mountain laurel thickets and merit further testing to refine application procedures.

The high structural heterogeneity of primary forests is assumed to positively affect various ecosystem traits and functions, e.g. biodiversity, resilience and adaptability. Against this background, old-growth forest structures are emulated in many managed forests. To properly emulate such structures, quantitative reference values are required, through which primary forests are characterized. In this study, we used the stand structural complexity index (SSCI), derived from terrestrial laser scanning (TLS), to characterize and compare the structures in European beech (Fagus sylvatica L.) dominated forests along a management gradient, ranging from differently managed stands, over formerly managed but now unmanaged stands to primary forests, which have never been managed. The study objective was to quantify and compare the structural complexity of these forests to give insight into possible reference points for an improved prospective handling of managed forests. The highest stand structural complexity was found in primary forests. While there were no significant structural differences between the managed forests, they were more complex in structure than formerly managed forests that have been set aside as National Parks now. The results also showed that structural complexity significantly differed between the investigated stand age classes. Next to primary forests, thickets growing below sheltering overstory trees in managed forests resulted in high structural complexity values. The findings suggest that specific silvicultural management practices can increase the structural complexity in beech forests. This study may facilitate a ‘management for complexity’ in silvicultural practice and might lead the way towards a more precise promotion of three dimensional forest structures that are associated with specific forest functions as part of the stand management objectives.

Woody plant encroachment is widespread throughout drylands of the world, but rates and patterns of encroachment at the regional scale can be mediated by soil and climate. Climoedaphic properties may therefore help to explain patterns of woody plant dominance. In the Caldenal region of central Argentina, which is experiencing widespread woody plant encroachment, we used stratified and targeted inventory of vegetation and soils alongside climate data to classify vegetation states and then identify factors indicating resistance to woody plant encroachment. We found that three climoedaphic contexts differed in the degree of woody plant dominance. Sandsheet landforms had the lowest likelihood of a shrub thicket state. Within loamy soils, sites with deep soil carbonates in warmer and wetter climates were less likely to feature a shrub thicket state than sites with shallow carbonates in cooler and drier climates. These contexts serve as a basis for recognizing different ecological sites to assist mapping and prioritization of management interventions in the Caldenal region. Simple inventory-based approaches can be helpful for designing land management recommendations in other ecosystems.

The Jordan Valley exemplifies the pressure of multiple human actions including intensive livestock grazing and agriculture on bird diversity. The abundances and occurrence of breeding birds were studied along remnant perennial streams which flow into the River Jordan. A patch – landscape approach was used to study the influences of vegetation cover and disturbances at the local and landscape scales. For 21 species, Principal Component Analysis was used to reveal the importance of each spatial scale and relationships with habitat variables were modeled. The abundances and occurrences of 57% of the species were predicted by local habitat variables only, while most others were apparently influenced by a mixture of habitat and landscape factors. Birds with restricted distribution were associated with less degraded wetland habitat strips with heterogeneous vegetation including reed beds and inundated Tamarix thickets. Some species were negatively influenced by intensive grazing and the spread of invasive mesquite Prosopis juliflora. Most species appeared to be tolerant to low levels of grazing within the habitat and current land use in the surrounding landscape. Based on the results, we emphasize the importance of protecting and managing remnant strips or patches of natural and semi-natural wetland habitats in the Jordan Valley.

Xerophytic thickets occur along the southwestern part of Madagascar. Although providing a wide variety of resources and services to the local population, this particular vegetation is subjected to deforestation. This study focuses on linking dendroclimatology and dendroecology by examining the spatial and temporal variability of the ecological growth conditions. Information from tree rings was retrieved, on one hand, to identify the problem of the limiting effects of past climate on growth and, on the other hand, to show how local environment takes part in the growth pattern of South Soalara species, in the southwestern part of Madagascar. Methods and principles of dendrochronology were applied on nine species belonging to seven botanical families. A total of 42 stem discs from 3 to 5 trees per species were collected at 30 cm height. All discs exhibited visible tree rings, but anatomical distinctness varied between species. This study highlighted the annual formation of tree rings through successful crossdating techniques. Then, from the nine constructed chronologies, species were grouped into three clusters. Analysis between precipitation and radial growth showed that the response to climate occurred mainly in rainy season. Large-scale climatic drivers such as sea surface temperature (SST 1 ) of ENSO 2 regions revealed a teleconnection with tree growth in cluster 1. Mean radial increments were computed from the measured tree ring width and varied from 0.66 to 1.98 mm year−1, showing that those species are slow-growing. All species were recorded as having a certain dendrochronological potential, which was ranked as useful for Rhizogum madagascariense and Terminalia gracilipes, poor for Gyrocarpus americanus and problematic for the other species. It is recommended to increase the number of wood samples and to provide more knowledge on the characteristics of the species in order to improve the quality of the chronology and the climatic signal on tree rings.

Bamboo species have been promoted for utility in both biomass and pulp production because of their high productivity. However, some bamboo species are known to be problematic invaders. Our goal was to use a weed risk assessment (WRA) tool to evaluate and compare invasion risk of non-native running and clumping bamboo species, many of which are under consideration as paper pulp and bioenergy crops in the continental United States. WRAs were conducted for 18 running and 29 clumping bamboo species using a version of the Australian WRA modified for the U.S. We tested for differences in scores and the number of questions answered for clumping and running species, the relationship between the WRA score and the number of questions answered, and the questions that differentiated low and high-risk species. Overall, we found that running bamboo species present a significantly higher invasion risk than clumping species. Only one running bamboo species (Chimonobambusa tumidissinoda) was identified as low risk and one clumping species (Bambusa bambos) was high risk for invasion. History of invasiveness elsewhere, the ability to form dense thickets, and unintentional dispersal of viable rhizome pieces were associated with significantly greater predicted risk. Commercial applications of bamboo should focus on the use of low invasion risk clumping bamboo species to reduce the risk of escape and colonization of nearby natural areas. Further, bamboo-specific best management practices (BMPs) should be implemented to reduce the probability of invasion for species used in commercial production.

Intensive goat farming has transformed more than a million hectares of subtropical thicket in South Africa from a dense closed-canopy shrubland into an open savanna-like system. Restoration of the degraded thicket landscapes can be achieved by planting truncheons of spekboom (Portulacaria afra). The sale of carbon sequestered by spekboom can potentially fund restoration projects. Maximising the rate of spekboom growth at the outset of such projects will be critical for covering upfront costs. To investigate the potential effects of watering on restoration projects, we applied 16 different watering treatments to 320 spekboom truncheons in a nursery environment over eight months. The application of 4 L of water over eight watering events per month achieved the maximal mean increase in basal stem diameter for unrooted truncheons, namely 5.6 ± 1.8 mm. By comparison, application of 6 L of water over four watering events per month resulted in a maximal mean increase of 5.0 ± 3.7 mm for rooted truncheons. The estimated total cost of manually watering truncheons in the field ranged from ZAR560 to ZAR4840 per month for truncheons planted 2 m apart (i.e. 2500 truncheons per hectare), and was ZAR59 per month for truncheons planted in micro-basins 20 m apart (i.e. 25 micro-basins per hectare). The former costs would not be affordable for restoration projects financed through sale of sequestered carbon, but the latter costs would be. Dense planting of truncheons in shallow trenches and/or micro-basins – which would collect rainwater – is a promising new protocol for increasing the rate of carbon sequestration at the start of restoration projects.

Over the past century, beech bark disease has dramatically altered the composition and structure of stands containing American beech (Fagus grandifolia). Management of beech bark disease has focused on reducing beech thickets and identifying resistant trees in aftermath forests. Beech leaf disease is a recently detected invasive disease, now also affecting beech forests. In 2019, a plot network was established in central North America to examine the extent of beech leaf disease spread and the severity of effects on trees and forests. Here, data from this plot network was used to determine the extent to which American beech is exposed to beech leaf disease, beech scale (Cryptococcus fagisuga), and beech bark disease (C. fagisuga and Neonectria spp. complex) in forests surrounding the Great Lakes in southwestern Ontario, northeastern Ohio, western Pennsylvania, and western New York. Beech leaf disease and scale were found to be well established, not only among sites but also in the different canopy layers. Beech bark disease was present, but occurrence was low. Pest accumulation differed between overstory and sapling layers. Beech leaf disease was the primary pest of saplings while both beech leaf disease and beech scale dominated in the overstory. Forest composition was similar throughout the study range; American beech, sugar maple, red maple, and white ash were abundant and common in the sapling and seedling layer. Few invasive plants were evident among saplings and seedlings. Sugar maple and red maple will likely fill small canopy gaps following beech decline or mortality. Intervention should be considered in stands with potential for increasing tree diversity or promoting beech leaf disease-resistant American beech trees to the overstory. New strategies are needed for beech conservation along with research to determine the extent of beech leaf disease resistance in American beech.

The Albany Thicket Biome is highly resistant to a wide variety of disturbances but, once disturbed, lacks the regenerative qualities that allow it to return to its original stable state. This study investigated the degradation status and the remaining extent of intact thicket. Classification of each thicket type was determined using Maximum Likelihood Classification and patch analysis using Fragstats. Of the four major divisions of the Albany Thicket Biome, classification of the Mesic, Valley and Dune Thickets were successful. The classification indicated that almost half of these thicket types has been lost, transformed or degraded by agricultural or urban development. For Dune, Mesic and Valley Thicket, thicket fragment sizes ranged between 6 and 876 km2. Dune Thicket contained the smallest fragments (2 km2) of intact thicket, while Valley Thicket contained the largest fragments (251 km2) of intact thicket of the major divisions of the Albany Thicket Biome. The misclassification of Arid Thicket precluded an accurate determination of the level of degradation and a different approach to assess the degradation status will have to be devised for these open thicket areas that contribute 39% of the original extent of the biome.

Windthrow is a typical gap phrase disturbance that changes forest composition but rarely alter succession trajectories of a forest stand. Catastrophic windthrow such as typhoons is a large but infrequent disturbance that can have long-lasting effects on forest ecosystems. Whether catastrophic windthrow resets successional pathways of forest ecosystems remains inconclusive. We compared forest structure and regeneration patterns between undisturbed and disturbed stands 30 years after a typhoon event in the treeline ecotone of the Changbai Mountains, Northeastern China. Measurements were made using WorldView-1 satellite imaging and fieldwork in two types of large plots, one located in areas affected by the typhoon event and the other in adjacent undisturbed areas. Results showed that community divergence at landscape scale occurred following the typhoon. In non-wind–disturbed stands, forest development followed the successional pathway of both broadleaved and coniferous trees. By contrast, the late-successional coniferous rather than the early successional broadleaved trees occupied the wind–disturbed stands. The alteration mechanism on the forest succession pathway was that herbs formed tall, dense, and persistent mono-dominant thickets after the typhoon, which inhibited the regeneration of broadleaved trees. In contrast to the common knowledge that forest would return to initial successional stage after catastrophic disturbance, we concluded that catastrophic windthrow, different from gap phase windthrow, altered forest successional trajectory.

We investigated winter selection of resting sites by wolves in a commercial pine forest to test if roads, settlements, and type of forest influenced the resting behaviour of wolves during the day and at night. At the landscape scale, wolves selected resting sites that were farther from settlements, public roads and high-traffic forest roads than random points. At the fine scale, wolves chose sites that were more concealed and farther from the closest forest road than random points. During the day, wolves tended to rest in thickets and forest with understorey, whereas at night they rested in more open habitats. The concealment of resting sites was higher when wolves rested closer to high-traffic forest roads and during the day. Our results indicate that certain forestry practices enhance concealment opportunities and might therefore be beneficial for wolves

Thinning is recommended in overstocked thickets to improve forest structure and reduce high-intensity stand replacing fires. Many studies have outlined the benefits of thinning for forest growth and reproduction but effectiveness in fire intensity needs more attention. Moreover, the effect that slash generated by thinning may have on fire behavior has been seldom explored. Here we simulated fire behavior on unthinned and thinned Aleppo pine (Pinus halepensis) thickets in Catalonia (Northeast Spain) where woody residues were left in situ. Furthermore, we simulated fire behavior one year later considering the reduction in the dead fuel load, using decomposition rates empirically determined under high and low rainfall. We could also assess the accuracy of our simulations by measuring fire severity on trees in the same study area after a real wildfire. Simulations predicted that thinning prevents the occurrence of active crown fires and reduces mean flame length (from 6.2 ± 0.8 to 1.5 ± 0.2 m), the rate of fire spread (from 5.4 ± 0.9 to 0.9 ± 0.1 m min−1) and the fireline intensity (from 3631 ± 686 to 446 ± 70 kW m−1) compared to unthinned thickets. In the thinned stands these parameters further decrease one year later owing to the decomposition of woody residues. Decomposition of woody residues was observed to be faster under a high rainfall scenario leading to a reduction in simulated flame length and fire intensity twice as fast as under low rainfall. In accordance with the lack of active crown fires and the lower flame length predicted for thinned thickets, fire severity observed after a real wildfire in the study area was lower in thinned than in unthinned stands (respectively, 2.02 ± 0.13 vs. 2.93 ± 0.15 in a scale of 0–4). The agreement between simulations that predicted a reduction in fire intensity in thinned thickets and the lower fire damage (fire severity) observed confirms the benefits of thinning young P. halepensis thickets to reduce fire effects. Moreover, our results indicate that leaving woody residues in situ after the thinning of these young thickets does not increase fire intensity. Yet, the influence of precipitation on the decomposition of woody residues highlights the uncertainties that an increase in drought in Mediterranean-type climates may have in the behavior of future fire events.

The sustainability of woody charcoal production activity is analysed in xerophytic thickets in southwestern Madagascar. The above ground biomass productivity of xerophytic thickets and the biomass corresponding to woody charcoal production in the Soalara-Sud commune were estimated and compared. All individuals >3 cm diameter in 40 4 × 4 m2 plots were harvested for above ground biomass measurements. Four treatments, defined by soil type (lixisol and calcisol) and distance from villages (near ≤ 4 km; far > 4 km), were tested. The growth rings, assumed to be annual, of the shrub trunk with the largest diameter, presumed to be the oldest specimen on each 4 × 4 m2 plot, were counted to estimate the duration of biomass production on the plot. Above ground biomass productivity was estimated by the ratio between above ground biomass and growth rings number. The mean above ground biomass productivity varied between 0.38 and 0.99 t ha−1 year−1 of dry mass according to the four treatments. It did not vary significantly with soil type and increased with distance from villages on lixisol where woody charcoal is produced. The total above ground biomass of xerophytic thickets used for woody charcoal production on the current woody charcoal production site is around 862.55 t year−1 of fresh matter, equivalent to 107.82 t of woody charcoal. However, the effective woody charcoal production on the study site in 2013 was equal to 600.90 t, which is higher than the woody charcoal production allowed by the xerophytic thickets above ground biomass productivity. Consequently, woody charcoal production activity in the study site is unsustainable and will result in the disappearance of mature individuals belonging to species used for woody charcoal production in less than 15 years. Once this occurs, woody charcoal production will be moved to other xerophytic thickets on calcisol.

African elephants (Loxodonta africana) are capable of visibly altering the structure of vegetation through their browsing habits, and such alteration of habitat may be magnified when the broader movements of elephants are restricted by fences. I assessed the structure and composition of the woody and succulent components of Albany thicket vegetation at 10 fenced sites in the Eastern Cape Province, South Africa – five with elephants present, paired with five where elephants were absent. Contrary to expectations, woody and succulent thicket vegetation was structurally similar across the 10 sites, despite the vegetation at the non-elephant sites being slightly taller, denser and more complex than the sites with elephants. Woody plant community composition was also similar across the 10 sites and elephant-induced damage to woody and succulent plants was generally low. Combined, these findings support the idea that at least the woody component of thicket vegetation is generally resilient to the browsing effects of indigenous browsers such as elephants. However, it is also possible that Albany thicket vegetation at the five elephant sites may not have been exposed to elephants for long enough for elephant browsing effects to manifest. Thus, I recommend continued monitoring of elephant browsing in fenced reserves within the Thicket Biome to establish how overall vegetation structure and composition may change over time, and with increases in elephant densities.

Prosopis spp., (or Mesquite), is a desert adapted woody weed which has invaded large parts of arid and semi-arid regions. It has a characteristic deep tap root, and forms dense impenetrable thickets along river banks, flood plains, and seasonal water courses. Several studies have quantified the water use by Prosopis , but there is limited information on how this compares with that of co-occurring groundwater dependent indigenous tree species in the arid and semi-arid tropics. Consequently the effects of removing Prosopis on groundwater, where they co-occur with indigenous trees, are not known. This study quantified the incremental water use by Prosopis invasions compared with the indigenous deep rooted Vachellia karroo ( V. karroo ) trees that normally replace Prosopis once it has been cleared. The study was done in an arid catchment in the Northern Cape Province of South Africa. Stem sap flow dynamics, groundwater levels, and weather data were collected hourly over 15 months in the invaded catchment. Data collection continued for a further 11 months after Prosopis had been cleared to monitor the recovery of the ecosystem from the invasions. There was no significant difference (P = 0.116) in the sap flux density of the two species although Prosopis had a much thinner sapwood depth than V. karroo due to its ring porous wood anatomy. However, at the stand scale Prosopis transpired more than five times more water (∼544 mm y −1 ) than V. karroo (∼91 mm y −1 ) since there were six times more Prosopis than the indigenous species. The removal of Prosopis slowed down the rate of decline of the water table from a pre-clearing peak of ∼8.9–5.0 mm d −1 after alien plant removal. Tree transpiration was accurately predicted by a simple model that used aquifer properties and hourly changes in water table depths with a RMSE of ±0.22 mm d −1 before and ±0.32 mm d −1 after clearing Prosopis .

Increased awareness of the negative impacts of invasive non-native species has led to a rapid increase in clearance programs around the world. One of the main goals of clearance is the restoration of native communities that were present pre-invasion. Little monitoring is typically carried out, however, to verify that native communities return without further management intervention in the years following invasive species removal. We investigated whether the epiphytic plant community of Atlantic oak woodlands, which principally consists of bryophyte species, returned after up to thirty years of recovery following the removal of the invasive non-native shrub Rhododendron ponticum . This community is of international conservation value and is particularly threatened by invasive Rhododendron . We revealed that the epiphytic plant community was able to recover effectively in sites that had been clear from Rhododendron for over fifteen years. This recovery included several species of particular conservation interest with highly restricted European distributions (i.e. ‘Atlantic species’ such as Plagiochila heterophylla ). Total cover and species richness both returned to similar or even higher levels to those found in uninvaded control plots by fifteen or more years following clearance, despite being highly reduced within dense Rhododendron thickets. Overall community composition also recovered to resemble uninvaded control plots in the years following Rhododendron removal. These findings present an encouraging message that at least some native communities can return naturally in the years following invasive species removal and may not require further management interventions to speed their return.

Determining changes in land use/land cover (LULCC) can be used to assess and monitor habitat loss as one of the five global priority causes of biodiversity loss. In South Africa, two national land-cover (NLC) datasets have been developed from satellite imagery obtained in circa 1990 and 2013/2014. The Vhembe Biosphere Reserve (VBR), designated in 2009, is located in the north of the Limpopo Province in South Africa and has a surface area of 30,457 km2. The aim of biosphere reserves is to provide a landscape-scale framework for conservation and sustainable development of an area. The area within a biosphere reserve is prioritised by designating it into one of three zones 1) Core, 2) Buffer, and 3) Transitional Zones. Two national parks and six provincial reserves (PAs) are the current and form part of the proposed updated core areas (pCAs) of the VBR. Intensity analyses was used to assess LULCC in the VBR. The pCAs cover 39.7% of the surface area of the VBR. The PAs cover 39.7% and only 15.8% of the surface area of the pCAs and VBR respectively. Based on the NLC 2013/2014 a majority of the VBR, pCAs and PAs consisted of indigenous vegetation dominated by Woodland/Open bush, Grassland, and Thicket/Dense bush. The extent of transformed land in the VBR declined from 1990 to 2013 by 1697.7 km2. The total amount of change and mean annual change in the VBR was 53.1% and 2.31% respectively. The overexploitation of fuel wood by rural communities in rural areas of the VBR, was partly responsible for the targeted loss of Woodland/Open bush to Thicket/Dense bush and Grasslands. The unquantified presence of novel vegetation and alien invasive plants means that the NLC 1990 and 2013/2014 overestimates the quantity and distribution of the remaining indigenous vegetation in the VBR. In order to address this the distribution of alien and indigenous invasive plant species in the VBR needs to be determined and used to update future NLCs. Assuming a worse-case-scenario of all the coal deposits in the VBR, including the Kruger National Park, being mined it would amount to 24.7% of the surface area of the VBR. Only 6.8% of the area of all the coal deposits in the VBR was transformed with 93.2% currently remaining untransformed. It is recommended that transformation of indigenous vegetation to one of the seven transformed land cover categories and more specifically from coal mining should be restricted to the VBR's Transition Zones.

South Africa continues to receive substantial attention from scholars researching modern human origins. The importance of this region lies in the many caves and rock shelters containing well preserved evidence of human activity, cultural material complexity and a growing number of early modern human fossils dating to the Middle Stone Age (MSA). South Africa also hosts the world's smallest floral kingdom, now called the Greater Cape Floristic Region (GCFR), with high species richness and endemism. In paleoanthropological research, improving our capacity to reconstruct past climatic and environmental conditions can help us to shed light on survival strategies of hunter–gatherers. To do this, one must use actualistic studies of modern assemblages from extant habitats to develop analogies for the past and improve paleoenvironmental reconstructions. Here, we present a phytolith study of modern surface soil samples from different GCFR vegetation types of the south coast of South Africa. In this study, the phytolith concentration and morphological distribution are related to the physicochemical properties of soils, the environmental conditions and the characterization of the vegetation for the different study areas. Our results show that phytolith concentration relates mostly to vegetation types and the dominant vegetation rather than to the type of soils. More abundant phytoliths from Restionaceae and woody/shrubby vegetation are also noted from fynbos vegetation and grass phytoliths are a recurrent component in all the vegetation types in spite of being a minor component in the modern vegetation. The grass silica short cells from these plants, however, suggest a mix of C3 and C4 grasses in most of the vegetation types with a major presence of the rondels ascribed to C3 grasses. The exceptions are riparian, coastal thicket and coastal forest vegetation, which are characterized by the dominance of C4 grass phytoliths.

The Indian Ocean Coastal Belt Forest is extremely biodiverse but is threatened by anthropogenic land-use change. In South Africa, remnant forest patches are divided into highly restricted but protected indigenous forest (IF) and abundant but unprotected coastal thicket/dense bush (DB), which likely represents secondary/regenerating IF. We tested the hypothesis that DB had value for conserving forest-dependent avian taxonomic and functional diversity, as (a) DB is situated with in the forest-anthropogenic land-use mosaic and (b) birds maintain diverse ecosystem functions and are sensitive to environmental change given their varied biological traits. We conducted 149 and 112 fixed-radius point-count surveys of avian communities in 99, and 24, patches of DB and IF, respectively, at each location recording microhabitat vegetation structure. We compared vegetation characteristics and taxonomic species richness between vegetation classes, and tested the breadth of functional trait-space and for significant associations with vegetation structures at each survey location, using RLQ analysis. Vegetation classes differed significantly, but floral species overlap and vegetation structures in DB closely resembled regenerating IF habitat. Specialist ground-nesting and insect-gleaning species corresponded to taller, more diverse IF structures. Other biological traits and total species richness overlapped broadly across both classes, but IF had significantly higher mean species richness. Given the relatively high taxonomic and functional diversity of the avian community in the abundant DB, the scarcity of IF, and the proximity of DB to the anthropogenic land-use mosaic, we recommend allocating suitable DB patches to the Protected Area Network, which may simultaneously help preserve avian taxonomic and functional diversity, facilitate colonisation throughout the fragmented landscape and provide ecosystem services to anthropogenic land uses.

In Southern Finland, rowan (Sorbus aucuparia L.) forms local thickets in young forests where it competes with more valuable conifers. Therefore, these thickets are regularly cut to provide more growing space for conifers. This has been inefficient at preventing excessive sprouting and therefore, new alternatives have been investigated. One of the potential options is to utilize a decay fungus Chondrostereum purpureum (Pers. ex Fr.) Pouzar for controlling sprouting. Spreading mycelia of this fungal species on freshly cut stumps starts a decay process in exposed wood and thus prevents sprouting. In this study, the ability of rowan to sprout after the fungal treatment was investigated at different application times from early spring to late autumn. Three years after the treatment, stump mortality was highest (ca. 40%) among stumps treated in summer and lowest in stumps treated in early spring or late autumn (ca. 20%). Furthermore, sprouts were significantly reduced in stumps treated in summer than in early spring or late autumn. The results indicate that rowan is capable of tolerating fungal infection better in early spring and late autumn than in summer, possibly because in early spring and late autumn resources available for regrowth are in belowground parts of a tree, unlike in summer when nutrients are transported within the stem to leaves and inflorescences. Thus, in rowan, the best sprout control efficacy can be achieved when performed in summer.

Throughout forests of the northern hemisphere, some species of ericaceous shrubs can form persistent understories that interfere with forest regeneration processes. In the Appalachian Mountains of eastern North America, mountain laurel (Kalmia latifolia) may interfere in the regeneration of mixed-oak (Quercus spp.) forests. To verify this possibility, I conducted a dendroecology study from 2001 to 2005 in three mixed-oak stands with mountain laurel thickets to elucidate how and when the thickets originated, developed, and were impacting hardwood seedlings. At all three sites, the oldest mountain laurel dated to the 1930s when the stands emerged from a period of recurring disturbance. However, most of the mountain laurel has originated since the 1950s when the stands were generally undisturbed. More recently, insect defoliations have accelerated the development of the thickets by increasing available sunlight. A strong negative relationship exists between the percent cover of mountain laurel and the density of hardwood seedlings with 20–30% cover being sufficient to inhibit seedling establishment and survival. Perpetuating mixed-oak forests that contain mountain laurel thickets will require reducing shrub cover to less than 20–30% at the beginning of the regeneration process to help ensure adequate densities of hardwood seedlings.

Soil temperature is a key factor which affects both soil-forming processes and the hydrological balance of water exchange between the atmosphere and the ground. The measured temperature waveforms in the top layer of forest soils demonstrate very characteristic diurnal variations. This paper presents a method of determining the amplitude of the diurnal temperature variation using the Fourier transform. Temperature measurements were carried out in the top layer of soil at a depth of approx. 0.08 m within 4 homogeneous, even-aged stands of different age-classes (from a 12-year-old thicket to a 117-year-old mature stand) and at 3 inter-forest meadows. The main aim of this paper was to relate all parameters in a simple empirical model of diurnal temperature variations in the top layer of soil under a stand to biometric features of stands. The parameters describing the model depend to a large extent on the soil exposure factor and the total biomass of above-ground tree parts. The soil exposure factor and the total biomass of a stand depend solely on the number of trees per hectare, the mean height of a stand, and the mean tree diameter measured at breast height (i.e. at a height of 130 cm), all of which are very easy to measure from the ground. The analyses also show that the amplitude values, particularly in an open field, also depend on the mass of organic matter accumulated in soil. The presented model was verified using measurement results in spruce stands of the Istebna ecotype (the Silesian Beskid Mts.). The model and parametrisation proposed for spruce stands depends solely on easily measurable biometric features and should be readily adaptable to stands composed of other tree species, using appropriate coefficients that differentiate these stands from spruce stands. The necessary improvements to the presented empirical model will be possible after a series of measurements taken within various types of stands. A thorough understanding of the factors determining temperature variation in woodlands may considerably expand the knowledge of the water exchange balance within forest complexes, as well as the estimation of site productivity.

The effects of goat grazing and woody charcoal production are analysed on the diversity, structure, production and regeneration of the xerophytic thickets in southwestern Madagascar. Twenty (20 × 20) m 2 plots were sampled according to soil type (yellow sand and calcareous) and disturbance intensities (low: ungrazed and no woody charcoal production; high: grazed and with woody charcoal production). Woody charcoal production reduced shrub density and biomass and affected species composition on yellow sand soil. In contrast, goat grazing alone did not significantly affect the diversity, mean height, stem and leaf biomass or species composition of xerophytic thickets on calcareous soil. However, shrub regeneration rate was low on both grazed and ungrazed sites. Rainfall variability may be the reason for this low regeneration. Goat grazing at a moderate stocking rate (∼1 head per ha) does not affect xerophytic thickets communities (plant diversity, biomass, regeneration rate). This finding indicates a need to (i) emphasize individual case studies that help to manage shrub pasture in semi arid regions, and (ii) avoid broad generalisations about the negative effects of goats on dry vegetation. Furthermore, goat breeding may be a viable alternative to woody charcoal production in these xerophytic thickets.

Marginal lands could be utilized for increasing energy biomass production independent of industrial roundwood procurement. Dedicated energy biomass production systems on such sites would be based on low stand establishment cost, clear-cutting at an early stage, and coppice regeneration. Harvesters designed for the processing of industrial roundwood are inefficient or too costly to use in small-diameter and dense stands, while insufficient cutting capacity and uneven space distribution of trees limit the use of modified agricultural harvesters developed for short-rotation woody-crop plantations (e.g. willow). We constructed time consumption models for clear-cutting and forwarding of whole trees from un-thinned, small-diameter stands. The data originated from naturally afforested downy birch-dominated stands located in a cutaway peat production area in northern Finland. Stand age varied from 14 to 29 years and stand density was 5150–160,250 trees per hectare. In clear-cutting, a medium-sized forest harvester equipped with an accumulating felling head fitted with a circular saw disc was used, and subsequent forwarding was done using a modified medium-sized forwarder. Cutting productivity was 3–11oven-dry tons (ODt) per effective hour (E 0 -h), and was highly dependent on stand characteristics (e.g. mean whole-tree volume). At a distance of 300 m, for example, the productivity of forwarding in the time study plots was 6.7–10.4 ODt E 0 -h −1 . Our study indicates that energy biomass can be harvested from young downy birch thickets efficiently by clear-cutting with appropriate machinery.

The dry biomes of southern Africa (Desert, Nama Karoo and Succulent Karoo) are home to a rich and diverse xerophytic flora. This flora includes two morphologically diverse clades of Zygophyllaceae, Tetraena and Roepera (Zygophylloideae), which inhabit some of the most arid habitats in the region. Using a plastid phylogeny of Zygophylloideae we assess whether the evolution of putatively adaptive traits (leaf shape, vasculature, mode of water storage and photosynthetic type: C3 versus C4) coincides with the successful colonisation of environments with different drought regimes within southern Africa. Our results show general niche conservatism within arid habitats in Tetraena, but niche shifts from arid to more mesic biomes with longer and/or cooler growing season (Fynbos and Thicket) in Roepera. However, these distinct broad-scale biogeographical patterns are not reflected in leaf anatomy, which seems to vary at more local scales. We observed considerable variability and multiple convergences to similar leaf anatomies in both genera, including shifts between "all cell succulence" leaf types and leaf types with distinct chlorenchyma and hydrenchyma. Our survey of C4 photosynthesis in the Zygophylloideae showed that the C4 pathway is restricted to Tetraena simplex, which also having an annual life history and a widespread distribution, is rather atypical for this group.

Deciduous Zambezi thicket forms a mixed-layered, dry woodland community on deep alluvial soils of the Middle Zambezi Valley. The dominant species are spiny, thicket-forming deciduous shrubs and small trees with no single dominant species and variable composition along the valley. A detailed community study of deciduous thicket along the Middle Zambezi River provided an indication of the wide variation of species-specific characteristics of growth form, phenology, and leaf traits that combine to produce a heterogeneous assemblage. Two families, the Capparaceae and Leguminosae, are particularly well represented. Leaf traits of nitrogen content, specific leaf area, δ 13 C, and δ 15 N are highly variable between species, with indications of some consistency in family traits within the Capparaceae and Leguminosae. A number of species exhibit a strong pattern of association with termite mounds, and termitaria are known to have significant potential impacts on spatial patterns of soil nutrient availability and water relations in savanna communities. There remains a poor understanding of the significance of symbiotic nitrogen fixation in deciduous African thicket, and savanna, and woodland communities and its importance in ecosystem fluxes of nitrogen, and these issues cannot be resolved by simple measurements of δ 15 N alone. Intraregional patterns of variation in leaf traits may impact the broad application of regional ecosystem models, as with those developed in the SAFARI 2000 program, when the variance between species is high, demonstrating that climatic controls on ecosystem δ 15 N abundance are scale‐dependent.

Cecil Charter had taught botany and biology in China and Antigua for five years, when in 1931 he was engaged to conduct a soil survey of the sugarcane-growing areas of Antigua. This was followed by similar surveys elsewhere in the Caribbean. In 1944, he joined the West African Cacao Research Institute in the Gold Coast (now Ghana) to carry out soil investigations in the forest zones of West Africa. In 1949 he moved to organise the soil survey unit in the Gold Coast Department of Agriculture, and, in 1951, to found and direct the new Soil and Land Use Survey Department. He rapidly built up a highly professional unit that produced many practical and useful reports of high quality. He based the surveys on ecological principles, selecting river basins as mapping regions. In the initial absence of qualified soil scientists, he subdivided the soil survey process and trained school leavers as technicians for separate tasks. Teams of these technicians examined soils, vegetation and land use at regular intervals on regularly-spaced traverses cut across the topography. Charter’s contributions to soil science included his recognition of non-residual tropical soils formed in material brought to the surface by soil fauna and treefall. Also, he differentiated between highly acidic upland Oxysols in high-rainfall areas, which he considered unsuitable for cocoa cultivation, and less acidic Ochrosols, which were more suitable. Based on farmers’ experience and his ecological background, he differentiated between forest, thicket and savannah soils within these groups. He strongly advocated genetic and contextual classification of tropical soils.

Coastal thicket vegetation in Brazil (restinga) is characterized by three distinct microhabitats - thicket center, thicket edge, and open area - and the spatial pattern of seed dispersal varies among them. The objectives of this study were to differentiate microhabitats, considering dispersal syndromes and growth forms, and to determine the existence of seasonality in the seed dispersal for this ecosystem where the climate is seasonal. Seeds were monthly captured by seed traps during 24 months. They were counted, identified and dispersal syndromes and growth forms were determined. Number of seeds was low and most species were underrepresented in the seed rain. Abundance, richness, and diversity of seed rain were substantially higher in both thicket microhabitats than in the open area, probably due to the combined effects of seed production and seed retention in thickets, resulting in a non-random aggregated pattern of seed dispersal. Anemochory and zoochory were high in both thicket microhabitats, but in the open area anemochory was predominant. Herbs and shrubs contributed the greatest number of seeds and species in all three microhabitats. Our results showed a general aseasonal seed rain pattern at the community level, in contrast to the seasonal climate in this region. We conclude that seed dispersal face limitations in the plant community, natural regeneration potential is restricted, and degraded thicket vegetation will not be able to naturally regenerate the original biodiversity. Our findings considerably increase knowledge on the seed rain process at the community level and may contribute to the conservation and restoration in sandy coastal ecosystems.

Wetlands dominated by shrubs are ubiquitous features in the Great Lakes Region of North America, yet little is known about the interactions between plants and the environmental conditions of these ecosystems. We measured the response of seven common wetland shrub species and two forbs to soil moisture treatments over a growing season. Average soil moisture content across three treatments ranged from 75%. These soil moisture differences produced a measurable effect on plant growth for six of the nine species tested. While Rosa palustris and Spiraea alba preferred the highest soil moisture treatments, Salix interior, Sambucus nigra, and Solidago uliginosa had higher biomass from moderate soil moisture, with no effect observed for Cornus sericea, Salix discolor, and Viburnum lentago. Most of the growth differences were from aboveground portions of the plants. A significant difference in root-to-shoot ratio (R:S) was found for eight of the species, with contrasting directions of change between the soil moisture treatments. New growth was compared to mean stomatal conductivity to determine an estimated water use efficiency (WUEe), which demonstrated a montonal relationship for six of the species across the measured soil moisture regime. Only the upland goldenrod, Solidago altissima, demonstrated the expected increase in WUEe with decreasing soil moisture, which suggests wetland shrubs are inefficient at low soil moisture. The results of this study provide quantitative data on the range of responses to soil moisture of common species of shrub wetlands, which can be used by wetland managers to improve restoration success.

The Cape south coast presents some of the world's most significant early modern human sites preserving evidence for complex human behaviour during the Middle Stone Age (MSA), and it is centrally located in the megadiverse Greater Cape Floristic Region. The extinct Palaeo-Agulhas Plain (PAP) once abutted this region, forming an important habitat for the subsistence strategies of past hunter-gatherers during the MSA. Here, we use phytoliths — amorphous silica particles that formed in cells of plants — extracted from archaeological deposits of two sites at Pinnacle Point (PP; cave 13B [PP13B] and site 5–6 [PP5-6]) to investigate the interactions between environments and hunter-gatherer foraging strategies along the Cape south coast during Marine Isotope Stage (MIS) 6 to MIS 3. To do this, we developed an analytical approach built on a modern plant and soil reference collection for using phytoliths from archaeological deposits for palaeoenvironmental reconstructions. In the latter phases of MIS 6, phytoliths indicate shrubby vegetation, possibly limestone fynbos, which might have occurred in inland landscapes, and this was the area preferred for plant foraging practices by the inhabitants of PP13B. During MIS 4, phytoliths at PP5-6 indicate the presence thicket and riparian vegetation on the rocky cliffs and the exposed PAP, along with some type of fynbos vegetation above the actual coastal cliffs. During interglacials MIS 5(c-e) and MIS 3 when the PAP was less exposed, the phytolith record points towards a mosaic of habitats with fynbos and thicket/forest, but also a constant presence of vegetation with high grass content dominated by a mix of both C3 and C4 species. Our data suggests a continuous inland regional mosaic of habitats with fynbos, thicket/forest and grassy vegetation that persisted during the glacial-interglacial periods. The changes observed in the phytolith record might be indicative of changes in plant foraging preferences along with slight vegetation movements in accordance with climate changes and sea level fluctuations.

Patent thickets have been identified as a major stumbling block in the development of new technologies, creating the need to accurately identify thicket membership. Various citations-based methodologies ( Graevenitz et al., 2011 ; Clarkson, 2005 ) have been proposed, which have relied on broad survey results ( Cohen et al., 2000 ) for validation. Expert evaluation is an alternative direct method of judging thicket membership at the individual patent level. While this method potentially is robust to drafting and jurisdictional differences in patent design, it is also costly to use on a large scale. We employ a natural language processing technique, which does not carry these large costs, to proxy expert views closely. Furthermore, we investigate the relation between our semantic measure and citation based measures, finding them quite distinct. We then combine a variety of thicket indicators into a statistical model to assess the probability that a newly added patent belongs to a thicket. We also study the role each measure plays, as part of creating a prospective screening model that could improve efficiency of the patent system, in response to Lemley (2001) .

The management of multi-functional landscapes warrants better knowledge of environment-richness associations at varying disturbance levels and habitat gradients. Intensive land-use patterns for agricultural purposes lead to fragmentation of natural habitat resulting in biodiversity loss that can be measured using landscape metrics to assess mammalian richness. Since carnivores and herbivores are likely to show different responses to disturbance, we calculated carnivore, non-carnivore, and total mammal species richness from camera surveys using a first order Jackknife Estimator. Richness was compared along a habitat gradient comprising coastal forest, Acacia thicket, and highland in KwaZulu-Natal, South Africa. We used standardized OLS regression models to identify climatic and disturbance variables, and landscape metrics as predictors of species richness. The estimated total and non-carnivore species richness were highest in coastal forest, while carnivore species richness was highest in highland followed by coastal forest and Acacia thicket. Average monthly maximum temperature was a significant predictor of all richness groups, and precipitation of the wettest month and isothermality determined total and non-carnivore species richness, respectively. These climatic variables possibly limit species distribution because of physiological tolerance of the species. Total mammal richness was determined by mean shape (+) and habitat division (−) while diversity (+) and patch richness (−) explained carnivore species richness. Mean shape index (+) influenced non-carnivore richness. However, habitat division and patch richness negatively influenced total mammal richness. Though habitat patch size and contiguity had a weak positive prediction, these metrics demonstrated the importance of habitat connectivity for maintaining mammal richness. The identification of these climatic and landscape patterns is important to facilitate future landscape management for mammal conservation in forest-mosaics.

The K/P boundary, 66 Ma, was a critical time in the history of the planet's biota. On the island of Madagascar, few Late Cretaceous species survived the associated extinction, and distance from the various mainland sources then acted as a strong filter for the number of over-water arrivees. Reconstructing the climate of the early Paleogene is vital for understanding the environments to which new colonizers landed and established a toe-hold on the island. Beginning with a “global” air-sea-coupled climate model simulation using the land–sea distribution at 66 Ma, we used dynamical downscaling to construct a scenario for how the atmospheric and oceanic fluid envelopes washed over and around the Madagascar at the start of the Paleocene. Dynamical downscaling of the global model yields a climate model with much finer resolution. We used this method to reconstruct the habitats for known fossil localities from that general period, better understand the ecological diversity of plants and animals that have been hypothesized to have then been present, and evaluate hypotheses regarding the evolutionary history of lemurs—a vast clade of primates endemic to Madagascar whose last common ancestor dates to this time. Our results show an island with a climate notably different from that of today, but not nearly as arid as others have suggested: the spiny thicket biome did not exist; temperatures were lower; rainfall less seasonal.

Identifying unique habitats that support intact mammal assemblages help to prioritize conservation areas. Over time, modifications of native habitats in multi-functional Protected Areas (PAs) can drive changes in mammal populations. We assessed mammalian richness across PA sizes and multi-species occupancy in various habitats, including plantations, in the Maputaland Conservation Unit, South Africa. We collected data from six camera-trap surveys (205 camera-trap stations) between 2013 and 2014 covering PAs that varied in size, habitat diversity and disturbance levels. We included eight habitat covariates for occupancy estimation and narrow vs. wider path as detection covariates. We applied the Royle–Nichols multi-session multi-species hierarchical model to estimate species richness and occupancy dynamics of 39 mammalian species for different PAs, while accounting for imperfect detection. Species richness increased with protected area size. Most large mammals were absent in the smallest PA. Detection probabilities for 90% of the species were 0.40) was estimated for 16 species in grassland and plantation, followed by woodland (15), sand forest (14), coastal lowland forest and dune forests (13 species each), Makatini clay thicket (12) and dry forest thicket (10). Plantation had higher mammal occupancy, presumably attributed to the edge effects of adjacent natural habitats, and the understory grass cover in abandoned and immature plantations. Our findings provided comprehensive inferences on community-wide assemblages for valuable management decision making.

Wild yam species ( Dioscorea spp.) provide important supplementary food and thus contribute directly to the livelihood and well-being of local people in SW Madagascar. Given the ongoing exploitation of this resource, there is a necessity to identify and predict yam species distribution along environmental gradients to improve our understanding of sustainable management of this resource. Therefore, the aims of the current study were to identify predictors for the distribution of important wild yam species and to spatially predict their availability. To this end species abundance and environmental variables were collected in the field using a systematic sampling approach within a yams collection area of four villages (58 plots). A redundancy analysis (RDA) was conducted to investigate the relationship between wild yam species and 12 environmental variables. Species distribution models and species response curves were established for the most abundant wild yam species using nonparametric multiplicative regression (NPMR). These models were subsequently used in conjunction with geospatial data for predictive mapping. RDA depicted a clear pattern of species habitats with D. alatipes occurring in dry spiny forests on calcareous soils at remote places, while D. bemandry and D. fandra were found in forest habitats on sandy soils with high harvest intensities. The NPMR models explained 88% ( D. alatipes ), 82% ( D . bemandry ) and 37% ( D. fandra ) of the variation in species abundance. Sensitivity analysis indicated the importance of vegetation structure, human interventions, and soil characteristics in determining wild yam distribution. Predicted distribution maps showed that the population of wild yam is scarce and mostly located in restricted areas of open spiny forests and dry spiny forest thickets, where harvest intensity is high. This study highlights the need for long-term assessment and public awareness actions on yam harvest practices as well as the importance of anthropogenic factors for the distribution of yam as a key forest resource in SW Madagascar.

Numerous shrublands exist in areas where soil moisture should support tree growth. In South Africa, the dwarf shrublands of the Nama-Karoo biome and tree-dominated vegetation of the Albany Subtropical Thicket biome share a boundary that is often abrupt. This boundary is not associated with edaphic or rainfall transitions. Field observations and leaf-level experiments suggest that the vulnerability of thicket species to frost damage is responsible for this thicket–shrubland boundary. We tested this hypothesis by establishing cuttings of Portulacaria afra (spekboom) – a dominant thicket succulent shrub that is a keystone species in arid forms of thicket – in two separate transplant experiments. Firstly across a topographic gradient from frost-free, thicket clad slopes to frost-prone, karoo shrubland dominated valley floor; and secondly, inside and outside a thicket clump in the frost-prone valley floor. We quantified the effects of frost on spekboom by measuring photosynthetic efficiency (Fv / Fm), leaf number, estimating the percentage of healthy stem before and after frost events in June 2013. Frost-exposed spekboom cuttings rapidly underwent declines in photosynthetic efficiency, followed by severe leaf and stem necrosis; herbivores played no role in these declines. Those planted on the frost-free valley slopes or under the frost-protecting thicket canopy on the valley floor remained largely unaffected. This supports the hypothesis that frost-exposure is likely to be the main factor determining the growth rates, and ultimately survival of spekboom. These results suggest that frost occurrence is an important factor involved in determining the boundaries between the arid, and spekboom-rich subtypes of Albany Subtropical Thicket, and the frost tolerant shrublands of the Nama-Karoo.

Landscapes of the eastern Cape Floristic Region are extremely rich in biomes. Analysis of the determinants of boundaries between biomes can generate insights and predictions that are useful for the applied ecological sciences. Here we used a historical data set and multivariate methods to explore the determinants of the boundaries of Forest, Fynbos, Grassland, Renosterveld and Thicket biomes in a 1200 km2 area of the Kouga region. The data set comprised 203 (10 m × 10 m) sites with corresponding landscape-scale environmental variables, and 100 sites with corresponding site-bound edaphic (physical and chemical) variables. Of the landscape variables, soil drainage and fire exposure had the strongest biome-specific associations: most Grassland occurred on seasonally waterlogged soils and Renosterveld on moderately drained soils. While Forest was exclusively associated with landscapes protected from fire, much Fynbos and Thicket were found in areas exposed to fires of intermediate frequency; however, in these situations Fynbos is restricted to sandstone-derived soils and thicket to shale-derived soils. Other strong patterns were the restriction of Forest to sandstone-derived soils and of Thicket to soils of deep to intermediate depth. Soils of the majority of Fynbos and Grassland were shallow, rocky and infertile, while those of Forest and Thicket were deep, rock-free and fertile, especially in terms of oxidizable carbon and total nitrogen. The relatively high fertility of Forest and Thicket soils is attributed canopy-induced enrichment in the prolonged absence of fire. Renosterveld occupied soils of intermediate fertility. These patterns can provide useful insights for developing experimental approached to simultaneously assess the determinants of multiple boundaries in the biome-rich landscape of the eastern Cape Floristic Region.

The distribution of South African biomes is expected to be drastically altered as a result of climatic change and increasing atmospheric CO 2 in the 21st century. Developing the capacity to anticipate change is of critical importance if we are to mitigate and efficiently adapt to the reorganization of South African vegetation cover. Dynamic Vegetation Models (DVMs) simulate the distribution and functioning of plant functional types (PFTs) and their interactions. Outputs include biome distribution maps, assessments of carbon cycling and the quantification of plant productivity, all of which can be produced for past, present and future conditions. DVMs were originally conceived of as analogs to general circulation models (GCMs) and applied globally, but to be unbiased globally necessitates choosing parameters and representing processes that may not be regionally appropriate. Models populated with a modified suite of PFTs and parameterized appropriately for local conditions are better suited to studies concerned with vegetation dynamics and global change impacts at the country or continent-scale. In their current form DGVMs do not include the plant types and key processes of many South African biomes. Therefore, while projections of global change impacts are available for biomes dominated by forest trees, savanna trees and grasses, little can be learned about some of our most biodiverse and threatened biomes, particularly the Fynbos and Thicket biomes, and the Succulent Karoo. We outline the limitations of existing DVMs and improvements required before reliable projections of global change impacts on South African biomes can be produced. Reparameterization of some PFTs and fire models could easily be achieved, and would lead to large improvements in model simulations. However, there remain numerous processes and facets of the ecology of South African vegetation that will limit the applicability of DVMs in their current form.

An interesting feature of the Albany Subtropical Thicket biome is where it abruptly changes from dense thicket on hill slopes (usually dominated by Portulacaria afra) to open Nama-Karoo shrublands in the bottomlands. These two vegetation systems are remarkably different from each other in terms of vegetation structure and ecosystem functioning. This abrupt biome boundary could be due to a number of potential explanations, three of which we consider here: the degradation, catena and frost hypotheses. An understanding of this boundary has long term implications for possible boundary shifts due to climate change, and the selection of future thicket restoration sites. We tested the catena hypothesis and predicted that bottomland soils would be richer in fine particles and sodium, and have higher electrical conductivity and pH than the soils of adjacent slopes. At seven localities transects were positioned across the middle portion of the slope and the bottomland area. At each transect soil depth and infiltration was measured and soil samples were analysed for Na, particle size, resistance, clay content and pH. Although pH was the only factor to be significantly higher on the bottomlands (6.0) than on the valley slopes (4.6), there was no clear discrimination between soils from the two landscape positions. Thus our results suggest that the absence of thicket from bottomlands is not under edaphic control but could potentially be driven by climatic factors.

Elephant-induced thicket degradation in the Addo Elephant National Park (AENP), Eastern Cape, South Africa, was assessed during 1973 and 2010 using multitemporal satellite imagery. Changes in the thicket condition, in relation to the AENP expansion, were analyzed using the Normalized Difference Vegetation Index, postclassification, and landscape metrics. The change detection of land-cover classes was analyzed by postclassification. Landscape-spatial metrics were used in order to gain an understanding of vegetation-fragmentation trends. Temporal changes in vegetation gradients in relation to water points and thicket conditions within the botanical reserves were also assessed. The thicket condition was noted to have deteriorated, as the AENP had expanded. An expansion of degraded vegetation away from the water points was identified during the study period. The thicket condition in botanical reserve 1 had fluctuated, whereas it remained constant in reserves 2 and 3. Landscape spatial-metric analyses revealed evidence of increased vegetation fragmentation, as new areas of the AENP had been opened for elephant activity. A progressive decline in intact thicket and an increase in degraded thicket were observed. Remote-sensing techniques can assist with thicket-clump restoration by applying “target monitoring” for the timeous identification of potential-degradation hotspots.