Natural Cover Research Articles

From the Ground Up: Prairies on Reclaimed Mine Land—Impacts on Soil and Vegetation

After strip mining, soils typically suffer from compaction, low nutrient availability, loss of soil organic carbon, and a compromised soil microbial community. Prairie restorations can improve ecosystem services on former agricultural lands, but prairie restorations on mine lands are relatively under-studied. This study investigated the impact of prairie restoration on mine lands, focusing on the plant community and soil properties. In southeast Ohio, 305 ha within a ~2000 ha area of former mine land was converted to native prairie through herbicide and planting between 1999–2016. Soil and vegetation sampling occurred from 2016–2018. Plant community composition shifted with prairie age, with highest native cover in the oldest prairie areas. Prairie plants were more abundant in older prairies. The oldest prairies had significantly more soil fungal biomass and higher soil microbial biomass. However, many soil properties (e.g., soil nutrients, β-glucosoidase activity, and soil organic carbon), as well as plant species diversity and richness trended higher in prairies, but were not significantly different from baseline cool-season grasslands. Overall, restoration with prairie plant communities slowly shifted soil properties, but mining disturbance was still the most significant driver in controlling soil properties. Prairie restoration on reclaimed mine land was effective in establishing a native plant community, with the associated ecosystem benefits.

Limited evidence for the use of livestock for the conservation management of exotic plant cover

Livestock grazing has been used for conservation management in some situations to reduce exotic plant cover, but supporting empirical evidence is scant. This is particularly true for eastern Australian semiarid woodlands and forests. We surveyed 451 sites across three broad semiarid vegetation communities (cypress pine, black box, red gum) in eastern Australia to examine the effects of recent and longer-term (historic) grazing by livestock on exotic (and native) plant cover. Because our focus was the use of domestic livestock for conservation management, our sites were mostly located in conservation reserves, travelling stock routes and native production forests where domestic grazing is approved via permit. We also included recent grazing by kangaroos and rabbits, which occur widely with livestock across the study sites. Structural equation modelling revealed that recent sheep and cattle grazing was associated with increased exotic plant cover in two of the three communities (cypress pine, black box), and historic grazing was associated with lower exotic (and native) plant cover across all communities. Recent cattle grazing-induced reductions in exotic plant cover in the red gum community resulted from declines in the palatable exotic annual grass Ehrharta longiflora. Higher intensity grazing by rabbits, sheep and cattle in the cypress pine community increased exotic plant cover by suppressing the negative effect of native cover on exotic cover. Higher intensity rabbit grazing reinforced the negative effect of nitrogen on native plant cover, resulting in increases in exotic cover. Overall, we found strong evidence that domestic livestock grazing reduces native plant cover either directly or indirectly in all three communities, but limited evidence that it would be a useful conservation management strategy to reduce exotic plant cover in these communities.

Senecionetum fluviatilis in Poland from a European perspective – diversity, distribution and threats

Senecio sarracenicus is a rare river corridor plant, featured on Red Data Lists of threatened flora in several European countries. The habitat typical for this species is protected in the European Union. The species constitutes its own association Senecionetum fluviatilis, but syntaxonomic separateness of this community was rejected by some authors who assigned it to the Convolvulo sepium-Cuscutetum europaeae. Comprehensive analysis of phytosociological material from different European countries was conducted using classification and ordination methods, and both associations from Poland were compared. The study showed a clear separation between both associations in terms of species composition and community structure as well as microhabitats they occupy in river valleys. The species composition of the Senecionetum fluviatilis is similar within Europe regardless of sample location. In Poland, Solidago gigantea is the most frequent neophyte among alien species penetrating the association under study. Although S. gigantea does not affect the diversity and total species richness, it does reduce the native species cover; when its coverage is large (>25%), it may in addition reduce the number of native species. This means that S. gigantea has a substitutive relation to native components of the association Senecionetum fluviatilis, particularly with respect to Senecio sarracenicus.

Knowledge of Native Edible Plants in a Monoculture Plantation-Dominated Landscape

The loss of forests is a factor that could account for the loss of local knowledge about edible plants. In Chile, the replacement of native vegetation by monoculture plantations of exotic trees has been the main cause of forest loss in recent times. We assess whether this loss of forests affects knowledge of wild edible plants by conducting household surveys in coastal rural localities in south-central Chile, subject to different degrees of replacement of forests. Based on the extinction of experience concept, we analyzed changes in knowledge of edible plants, as well as their gathering and use, through interviews comprised of freelisting and open-ended questions. Our results suggest that loss of native vegetation leads to a reduction in knowledge and use of native edible plants by the local population, but that this reduction occurs at a slower pace than land-use change. Individuals exposed to abundant native forest cover in the past have greater knowledge of edible plants today.

Fire and development influences on sagebrush community plant groups across a climate gradient in northern Nevada

AbstractThe sagebrush biome covers much of the western United States yet is at risk from ongoing disturbances. Physical disturbances such as fire often overcome the resistance of sagebrush communities to biological disturbances such as invasion by non‐native species, but the impact of burn severity or combined disturbance types on sagebrush community composition remains unclear. We examined the relationship between native functional groups and non‐native annual grass cover to the number of fires, burn severity, anthropogenic development, and vegetation treatments in northern Nevada, USA. We used Bureau of Land Management vegetation monitoring plots and existing climate, fire, and vegetation treatment databases to explore relationships using beta regression. After accounting for mean annual precipitation and temperature, and elevation, we quantified functional group mean cover related to levels of burn severity, numbers of fires, development, and vegetation treatments. Native herbaceous (grass and forb) groups were resilient to fire, but fire caused large declines in shrub and sagebrush cover. Non‐native annual grass cover was associated with higher burn severity and the first fire at a site. We did not find evidence that post‐fire restoration treatments were associated with increased native cover or decreased non‐native cover. However, shrub control and soil disturbing treatments (discing and chaining) were associated with decreased native perennial grass cover and increased non‐native annual grass cover. Functional groups displayed varying patterns related to anthropogenic development and fire. For example, development had a larger impact on non‐native cover at lower levels of burn severity, whereas forbs increased following fire only at lower levels of development. Although in some cases sagebrush communities showed resilience to disturbance, our results showed resistance to invasion by non‐native annual grasses can be overcome by combinations of disturbances at lower levels or by severe events.

Native cover crops enhance arthropod diversity in vineyards of the Cape Floristic Region

Cover crops can enhance biodiversity in perennial agroecosystems, with native cover crops potentially having additional biodiversity benefits. We assessed the effect of native cover crops on vineyard arthropods in the Cape Floristic Region using pitfall traps and vacuum sampling. Generalized linear mixed models and Permanova analyses were used to compared the abundance, species richness and assemblage structure of soil surface-active (free living arthropods found on the soil surface) and plant-dwelling arthropods (arthropods found predominately on the vegetation). We also used model selection and BIO-ENV to determine environmental drivers of arthropod diversity among three treatments of vineyards with bare ground, exotic cover crops or native cover crops, and nearby fynbos remnants as reference sites. Vineyards with native cover crops had significantly higher overall plant-dwelling species richness (52.57 ± 3.03), compared to exotic cover crop (28.64 ± 2.66), bare ground vineyards (18.57 ± 2.98) and even the fynbos sites (21.29 ± 1.78). A similar trend was found for overall plant-dwelling arthropod abundance. In contrast, surface-active arthropod richness was not influenced by treatment, whereas surface-active abundance was higher in less densely vegetated sites. Generally, plant-dwelling arthropods responded strongly to vegetation-related variables, whereas surface-active arthropods were responsive to soil-related parameters. Assemblages in vineyards with native cover crops did not resemble those in the natural reference sites as expected, likely due to disturbance factors, and plant compositional and structural differences. However, both surface-active and plant-dwelling assemblages had a high proportion of unique species in the native cover crop than found in the other treatments. Our results show that native cover crops enhance foliar arthropod diversity over and above exotic cover crops and contributes to farm-scale compositional heterogeneity. It therefore has potential to reduce arthropod diversity loss within farmlands and to contribute to more resilient vineyard agroecosystems.

When does habitat fragmentation matter? A biome‐wide analysis of small mammals in the Atlantic Forest

AbstractAimWhile habitat loss is a primary driver of biodiversity declines worldwide, the role of habitat fragmentation per se is inconclusive, but likely depends on the amount of habitat left in a landscape. Here we aimed to tease apart the effects of habitat amount (percentage of native cover) and a fragmentation metric (number of fragments) on species richness and total abundance.TaxonNative small mammals.LocationSouth American Atlantic Forest biome.MethodsSmall mammal species richness and abundance were obtained from a published database for 96 localities (groups of sampling sites). We then defined circular 100 km2 landscapes centred on each locality. For each landscape, percentage of habitat cover and number of fragments were measured on time frames close to the sampling periods. Effects of habitat amount, fragmentation and their interaction were modelled considering all landscapes, and also within four classes of habitat cover: 0%–10%, 10%–30%, 30%–50%, and 50%–100%.ResultsSpecies richness was mainly affected by percentage of habitat cover, with a three‐fold effect size compared to fragmentation. Yet, in landscapes with <10% or ≥50% of remaining cover, fragmentation positively affected species richness. Total species abundance also increased towards more fragmented landscapes. At the species level, three of the 20 species considered increased in abundance with fragmentation, while four species decreased.Main conclusionPercentage of habitat cover was the main driver of species richness when the entire cover range is considered, but the secondary effects of fragmentation were strong at the extreme ends of this range. Adding habitat patches in landscapes with low cover, or promoting habitat heterogeneity in landscapes with high cover, may boost species richness. However, further increases in species richness following fragmentation in high‐cover landscapes are likely to correspond to disturbance‐adapted species. In addition, such positive effects of fragmentation cannot be presumed to apply to all assemblages and species as some species are negatively affected.

Biodiversity risk from land-cover change in terrestrial priority regions and protected natural areas in northeastern Mexico

Protected areas (PAs), priority terrestrial regions (PTRs) and priority terrestrial sites (PTSs) are strategies for conserving natural resources. However, loss of coverage on the peripheries can lead to isolation between these conservation areas. The present study analyzed the association of the change of coverage inside and outside 2 PAs, 5 PTRs and 128 PTSs in Tamaulipas with the richness and geographic distribution of 5 species groups (strict, semiaquatic and tolerant hydrophiles, as well as gastropods and pteridophytes in 3 periods (1986, 2002 and 2011). In addition, we identified areas with similar species composition and socioeconomic-environmental factors related to the change in coverage. The highest richness and geographic distribution of aquatic plants occurred outside the conservation areas, while the greatest richness of ferns and gastropods was present inside them. The greatest loss of coverage occurred outside the El Cielo Biosphere Reserve and the Sierra de Tamaulipas PA. The loss of native cover increased in the last 30 years and is greater outside the conservation areas, therefore is necessary to propose and implement strategies to reduce the isolation of these areas.

Seed mix design and first year management influence multifunctionality and cost‐effectiveness in prairie reconstruction

Agricultural intensification continues to diminish many ecosystem services in the North American Corn Belt. Conservation programs may be able to combat these losses more efficiently by developing initiatives that attempt to balance multiple ecological benefits. In this study, we examine how seed mix design and first year management influence three ecosystem services commonly provided by tallgrass prairie reconstructions (erosion control, weed resistance, and pollinator resources). We established research plots with three seed mixes, with and without first year mowing. The grass‐dominated “Economy” mix had 21 species and a 3:1 grass‐to‐forb seeding ratio. The forb‐dominated “Pollinator” mix had 38 species and a 1:3 grass‐to‐forb seeding ratio. The grass:forb balanced “Diversity” mix, which was designed to resemble regional prairie remnants, had 71 species and a 1:1 grass‐to‐forb ratio. To assess ecosystem services, we measured native stem density, cover, inflorescence production, and floral richness from 2015 to 2018. The Economy mix had high native cover and stem density, but produced few inflorescences and had low floral richness. The Pollinator mix had high inflorescence production and floral richness, but also had high bare ground and weed cover. The Diversity mix had high inflorescence production and floral richness (comparable to the Pollinator mix) and high native cover and stem density (comparable to the Economy mix). First year mowing accelerated native plant establishment and inflorescence production, enhancing the provisioning of ecosystem services during the early stages of a reconstruction. Our results indicate that prairie reconstructions with thoughtfully designed seed mixes can effectively address multiple conservation challenges.

Lessons on direct seeding to restore Neotropical savanna

Tropical grassland-savanna mosaics are threatened globally, but they are challenging to restore because highly competitive pasture grasses inhibit recovery and are not shaded out by the patchy tree cover. We analyzed the outcomes of restoration projects and experiments established over four years in 55 ha of abandoned pastures dominated by invasive C4 grasses within the Neotropical savanna, Central Brazil. We tested the efficacy of direct seeding native grasses, forbs, shrubs and trees in reducing invasive grass cover and increasing native ground cover. We performed a series of experiments aimed at answering questions about the effect of seeding density, soil plowing to control invasive grasses, life form of ground cover species (grass, forb or shrub) and soil type on restoration outcomes. Relative native cover reached 34 ± 3% three rainy seasons after the first seeding experiment. Higher seeding densities and more soil plowing repetitions increased relative native cover. Soil type interacted with the life form of ground cover species to strongly influence relative native cover; two years after seeding, the highest relative native cover was achieved in rocky soils seeded with grasses (78 ± 6%) and the lowest was for seasonally waterlogged soils seeded with shrubs (15 ± 4%). Direct seeding can effectively establish many native Neotropical savanna species of different life forms with better restoration outcomes on rocky soils and with higher seeding densities. Further research is urgent to improve restoration methods, especially to control invasive grasses, to be able to achieve the large-scale restoration targets set internationally.

Climate-mediated changes to grassland structure determine habitat suitability for the critically endangered plains-wanderer (Pedionomus torquatus)

ABSTRACTThe critically endangered and iconic plains-wanderer (Pedionomus torquatus) is phylogenetically distinct and endemic to south eastern Australia, and is a high conservation priority. Furthermore, it relies on critically-endangered native grasslands for its survival, which vary temporally in structure and hence do not always provide suitable habitat. To manage the remaining native grasslands appropriately, it is essential to understand the temporal and spatial dynamics of plains-wanderer habitat preferences. We monitored plains-wanderers and habitat measurements for nine years to link habitat preferences to specific elements of grassland structure. We also observed habitat selection by plains-wanderers at two spatial scales – sites (paddocks) and at microsites (immediate vicinity of the birds). The plains-wanderer population declined rapidly after a dramatic increase in native grass cover in 2011, and recovery of the population since then has been slow. In 2015/16, plains-wanderers were generally encountered at microsites with higher bare ground and cryptogam cover. However, at the site scale, paddocks with plains-wanderers had similar cover of native grass and bare ground than those without plains-wanderers. The results suggest that observation of highly-localised habitat components alone may mask aspects of the habitat selection occurring at larger spatial scales. Plains-wanderers may require areas of denser perennial grass for nesting and shelter, as well as access to the open areas where they are commonly encountered. We discuss how private land used for commercial grazing may be crucial to plains-wanderer conservation. The results also prompt consideration of how we measure and interpret habitat selection for grassland birds globally.

Got shrubs? Precipitation mediates long-term shrub and introduced grass dynamics in chaparral communities after fire

BackgroundShort-term post-fire field studies have shown that native shrub cover in chaparral ecosystems negatively affects introduced cover, which is influenced by burn severity, elevation, aspect, and climate. Using the southern California 2003 Old and Simi fires and the 2008 Sesnon Fire, we investigated the role of native shrubs in post-fire ecosystem responses across gradients of elevation, aspect, climate, burn severities, fire histories, and time. We collected field estimates of species cover in 2004 and 2015 at nested sampling sites. We used structural equation models with introduced and shrub cover as dependent variables.ResultsShrub cover in 2004 was most influenced by the number of reburns, while shrub cover in 2015 was most influenced by the time between the two most recent fires. In 2004, introduced cover was most influenced by burn severity in 2003; similarly, in 2015, introduced cover was most influenced by burn severity in 2008. In both one and twelve years post fire, average precipitation increased the length of time between fires and decreased the number of times a site burned. This direct reduction in the number of times a site had burned due to average precipitation resulted in lower shrub cover one and twelve years post fire. Additionally, mean annual precipitation increased burn severity one year post fire, which resulted in lower introduced cover. However, this indirect relationship between precipitation and introduced cover through burn severity was no longer present twelve years post fire. Shrub cover increased with a longer average time between fires twelve years after fire. Shrub cover did not mediate any indirect relationships between burn severity or fire history metrics and introduced cover in either year, suggesting competitive exclusion of introduced species by shrubs.ConclusionOur research found that significant fire effects on shrub and introduced species are often mediated by precipitation. Precipitation trends are likely to change fire regimes and thus alter plant community dynamics.

The movement ecology of the Mauritian flying fox (Pteropus niger): a long-term study using solar-powered GSM/GPS tags

BackgroundFlying foxes (Chiroptera: Pteropodidae) are large bats that often roost in the sun, hence solar-powered GPS/GSM devices can track their movements over extended periods. The endemic Mauritian flying fox (Pteropus niger) has recently been subjected to large-scale culling because of perceived damage to commercial fruit, and a consequent reduction in numbers of > 50% since 2015 resulted in its IUCN Red List Status being up-listed to Endangered. Determining its movements will be important for management and conservation, for understanding potential responses to environmental change, and for understanding population admixture.MethodsTwelve bats were tagged with solar-powered GPS/GSM devices in 2014–2016. Tags remained active for up to almost a year (maximum 359 days: average 139 days (males) and 93 days (females)), providing some of the longest-term data on the movement ecology of bats yet obtained. Eight bats were probably hunted illegally, highlighting the scale of unauthorised persecution.ResultsMales travelled on average 9 km each night, females 6 km. The nightly distance covered by adults of both sexes was higher in winter than in summer, though the opposite pattern occurred for immature males. These differences are probably related to seasonal changes in fruit availability (adults) and to dispersal by immature males. The maximum distance covered during one night was > 92 km. Home ranges of males averaged 74,633 ha, females 31,072 ha. Core foraging areas averaged 2222 ha for males, 1364 ha for females. Fifty roosts were identified, mainly in forest fragments. As the bats disperse seeds of native plants that form forest canopies, conservation of the bats will potentially maintain and enhance native forest cover, in turn providing roosting sites for the bats.ConclusionsSolar-powered GSM tagging provides unprecedented potential for understanding the movement ecology of flying foxes. Mauritian flying foxes often move between the few remnant native forest fragments, which remain important for their conservation, and have potentially important roles in seed dispersal. Their nomadic movement fits with their panmictic genetic structure. Although their ability for long distance movements, sometimes over short timescales, permits rapid responses to local threats and environmental change, being restricted to Mauritius renders the bats extremely vulnerable to intense culling.

A dam in the drylands: Soil geomorphic treatments facilitate recruitment of the endangered Santa Ana River woolly star

AbstractThe long‐term management of aridland riparian ecosystems impacted by dams is crucial to reduce losses of biodiversity, reduce extinction risks for species, and restore ecosystem services. When dams preclude natural flow, safeguarding aridland riparian ecosystems adapted to infrequent, catastrophic floods poses additional challenges owing to the need to consider biological and pattern legacies. Seven Oaks Dam (California, USA) eliminated the occurrence of flooding, scouring, and deposition across the rare plant community downstream. This Riversidian alluvial fan sage scrub or alluvial scrub includes one of the most endangered plants in California, Eriastrum densifolium spp. sanctorum (Santa Ana River woolly star, hereafter called woolly star). In this study, we evaluated the impact of six soil geomorphic treatments on alluvial scrub and woolly star re‐establishment after 5, 7.5, and 13 yr. We implemented a complete randomized block design, with each block incorporating six treatments: cleared, diked, cut, filled‐10 (10 cm soil), filled‐20 (20 cm), and filled‐30 (30 cm), mimicking one or more physical disturbances (pattern legacy) occurring after a natural flood event. We performed plant community surveys (cover, abundance, maturity, invasibility, diversity) on full plots in 2006, representing 7.5 yr of response from the original 1999 treatment, and on half‐plots in 2012, representing 5 yr of response following re‐disturbance in 2007, and 13 yr of response on half‐plots left intact since 1999. We found very limited recruitment of woolly star into control plots (1.2% cover). By contrast, the cut treatment showed consistently higher cover of woolly star (25.3%, 53.4%, 14.3%), after 5, 7.5, and 13 yr, respectively. Other treatments showed responses ranging between these extremes. Similar results were found for total native cover and diversity. Woolly star cover was inversely related to alien grass cover, suggesting that exotic grass invasions inhibit early recovery of the perennial. The re‐establishment of base flows and flood pulses or soil geomorphic disturbances that mimic pattern legacies associated with infrequent, catastrophic flooding could be implemented to sustain downstream ecosystems that include woolly star populations. In the absence of such actions in the Santa Ana River floodplain, the persistence of woolly star as a species appears unlikely.

Invasive shrub removal benefits native plants in an eastern deciduous forest of North America

AbstractIn eastern deciduous forests of North America, invasive shrubs are increasing in richness and abundance at the expense of native species across taxa. Invasive shrubs create an understory that is more dense than both recent and historical preinvasion conditions. Interest in invasive shrub removal to restore native habitat is growing, but our understanding of natural regeneration following treatment of a diverse invasive shrub community is lagging. Using an invasive shrub removal experiment, we provide insight into the effect of repeated removal of a suite of 18 invasive shrub species dominated by border privet (Ligustrum obtusifolium Siebold & Zucc.). In 2009, invasive shrubs were removed from five 20-m-diameter treatment plots, each with a paired control plot. Seven years later, we find an increase in plant diversity, native understory species abundance, and overstory tree species regeneration for individuals under a meter in height. For plants 1 to 4 m in height, the removal treatment has a positive effect on understory woody species, but there has been no change in regenerating overstory trees. A lack of overstory tree regeneration to greater heights is not surprising, given the time frame and the closed-canopy conditions. However, other factors, such as white-tailed deer (Odocoileus virginianus Zimmermann) browse, could be serving as an impediment to taller tree regeneration in the forest understory. An ambient sampling approach in unmanaged, invaded, and uninvaded forest has been used in other studies to estimate the potential impacts of invasive shrub species to native plant communities. However, in this study the ambient sampling approach underestimated the impacts of invasive shrubs compared to their experimental removal. Overall, invasive shrub removal increased plant diversity and allowed passive natural regeneration of native plants that exceeded native cover in the unmanaged, ambient forest under minimal invasive shrub abundance.

Repeated fires reduce plant diversity in low‐elevation Wyoming big sagebrush ecosystems (1984–2014)

AbstractSagebrush is one of the most imperiled ecosystems in western North America, having lost about half of its original 62 million hectare extent. Annual grass invasions are known to be increasing wildfire occurrence and burned area, but the lasting effects (greater than five years post‐fire) that the resulting reburns have on these plant communities are unclear. We created a fire history atlas from 31 yr (1984–2014) of Landsat‐derived fire data to sample along a fire frequency gradient (zero to three fires) in an area of northern Nevada that has experienced frequent fire in this time period. Thirty‐two percent of our study area (13,000 km2) burned in large fires (over 404 ha) at least once, 7% burned twice, and 2% burned three or more times. We collected plant abundance data at 28 plots (N = 7 per fire frequency), with an average time since fire of 17 yr. We examined fire's effect on plant diversity using species accumulation curves, alpha diversity (Shannon's dominance, Pielou's evenness, and number of species), and beta diversity (Whittaker, Simpson, and Z indexes). For composition, we used non‐metric multidimensional scaling. We then used PERMANOVA models to examine how disturbance history, temperature, precipitation, and aridity around the time of the fire affected subsequent community composition and diversity. One fire fundamentally changed community composition and reduced species richness, and each subsequent fire reduced richness further. Alpha diversity decreased after one fire. Beta diversity declined after the third fire. Cover of exotics was 10% higher in all burned plots, and native cover was 20% lower than in unburned plots, regardless of frequency. PERMANOVA models showed fire frequency and antecedent precipitation as the strongest predictors of beta diversity, while time since fire and vapor pressure deficit for the year of the fire were the strongest predictors of community composition. Given that a single fire has such a marked effect on species composition, and repeated fires reduce richness and beta diversity, we suggest that in lower elevation big sagebrush systems fire should be minimized as much as possible, perhaps even prescribed fire. Restoration efforts should be focused on timing with wet years on cooler, wetter sites.

Cuantificación de la captura de carbono y análisis de las propiedades del suelo en coberturas naturales y una plantación de pino en el páramo de Rabanal, Colombia

Con muestreo puntual sistemático en malla rígida de 48 puntos (350 m entre puntos) aplicado en dos estratos de suelo (profundidades de 0-15 cm y 15-30 cm) se determinó el contenido de carbono orgánico del suelo y el efecto sobre las siguientes propiedades del suelo: densidad aparente; humedad gravimétrica; pH; materia orgánica y porcentaje de carbono. La zona de estudio alcanza 500 hectáreas, contiene una plantación de pino y vegetación nativa del Páramo de Rabanal en Boyacá, Colombia. El carbono orgánico promedio del suelo encontrado a 0-15 y 0-30 cm de profundidad fue de 51,4 t/ha y 108 t/ha respectivamente. Se registraron diferencias estadísticas (p < 0,05) entre la cobertura nativa y la plantación de pino en las dos profundidades para las variables densidad aparente, humedad gravimétrica y pH, mientras que las variables materia orgánica y porcentaje de carbono no mostraron diferencias significativas. Los resultados muestran una reducción en la capacidad hídrica de los suelos del área de estudio debida al aumento de la densidad aparente en los suelos ubicados bajo las plantaciones de pino. Con respecto a los contenidos de carbono, se evidencia una disminución comparada frente a la cobertura de vegetación de páramo, ya que las condiciones propias de la plantación forestal limitan el crecimiento de los diferentes estratos vegetales endémicos de este ecosistema y, de esta manera, la actividad biológica.Ideas destacadas: artículo de investigación sobre la muestra y la metodología que permiten establecer la captura de carbono en suelos de páramo bajo diferentes tipos de uso.

Treatment by glyphosate-based herbicide allowed recovering native species after Oxalis pes-caprae L. invasion: indications from a Mediterranean island

Biological invasions represent a global threat to biodiversity. Particular attention should be devoted to the management of alien plants, focusing on the opportunity to obtain a rapid response to invasion and restoration of the invaded areas. In this study we aimed to evaluate five different methods for controlling Oxalis pes-caprae, a well-known invasive plant native to South Africa, also focusing on the restoration of the native flora. We set an experiment on the island of Montecristo (central Mediterranean). Treatment methods varied from chemical to low risk methods, including manual removal, covering with mulching sheets, and foliar spraying with acetic acid (30% solution) and two different concentrations of glyphosate (3 and 5% solutions, respectively). The total cover of O. pes-caprae and of other native plants was sampled before treatments, and then several times during the subsequent year; while the plant species composition was sampled in late winter (March 2015–2016) and late spring (May 2015–2016). The use of glyphosate was found to be the only efficient control method, leading to a significant decrease in O. pes-caprae cover as well as to a recovery in native species cover and richness. The effect of the other control methods was negligible.

Assessment of Topsoil Salvage and Seed Augmentation in the Restoration of Coastal Sage Scrub on Santa Catalina Island, California

The Catalina Island Conservancy manages over 22,000 acres of coastal (California) sage scrub (CSS) habitat off the coast of Southern California, including much of the infrastructure, roads, and recreation associated with habitat disturbance. Restoration trials were initiated to establish best management practices for roadside and disturbed site revegetation under local site conditions. Site treatments compared excavated native subsoil and surface soil (±20 cm) reapplication practices with and without seed augmentation. Evaluation of native and nonnative germinants indicated that salvaged surface soil alone may not be sufficient to restore native cover. Seeding improved native cover and reduced establishment of nonnative species on unirrigated sites. Evaluation of water potential of seedlings indicated that high-frequency irrigation may favor establishment of nonnative annual grasses. Most compelling for land managers is the indication that CSS habitats may contain a significant nonnative seed bank in spite of the composition of aboveground vegetation, such that disturbance may facilitate habitat-type conversion without seed augmentation or weed control.

A new approach for hydrologic performance standards in wetland mitigation

Wetland restoration performed as a requirement of compensatory mitigation does not always replace lost acreage or functions. Most new projects are required to identify performance standards to evaluate restoration outcomes. Current performance standards are primarily related to vegetation with little to no evaluation of wetland hydrologic regimes. Because of the agreement in the scientific literature about the role of hydrology in creating and maintaining wetland structure and function, hydrologic performance standards may be an ecologically meaningful way to evaluate restoration outcomes. This research tests the use of water level data from project specific reference sites to evaluate restored water levels for three distinct wetland types across the United States. We analyzed existing datasets from past and ongoing wetland mitigation projects to identify the number of years it took water levels in restored wetlands to match reference sites, and to test whether similar water levels between restored and reference sites leads to increased vegetation success. Wetland types differed in the number of years it took for water levels to match reference sites. Vernal pools in California took nine years to match reference sites, fens and wet meadows in Colorado took four years, and forested wetlands in the southeastern US were hydrologically similar to reference sites the first year following restoration. Plant species cover in all three restored wetland types was related to the water level similarity to reference sites. Native cover was higher when water levels were more similar to reference sites, and was lower in areas where water levels were different. Exotic species cover showed the opposite relationship in fens and wet meadows, where hydrologic similarity led to low cover of exotic species. Along with the general agreement of the importance of hydrology for wetland form and function, this research shows that hydrologic performance standards may also lead to increased vegetation success in some wetland types.