Natural Vegetation Recovery Research Articles

Winter leaf phenology differences facilitate selective control of an invasive plant species by herbicide

Herbicide control of invasive plant species is generally efficient. However, there is a likelihood of the excessive application of non-selective herbicides that kill co-occurring native species and cause environmental toxicity. We present a case study on the control of the invasive exotic Solidago canadensis with photosynthetically active leaves in winter by applying glyphosate. This approach improves herbicide control efficiency, while preventing harm to most co-occurring native plants. We quantified the winter leaf phenology and photosynthetic capacity of S. canadensis and two commonly co-occurring native species. We tested the effects of glyphosate and competition on S. canadensis and native Imperata cylindrica with contrasting winter leaf phenology in both pot and field experiments. Finally, we surveyed the life forms and winter leaf phenology of most co-occurring plant species in eastern China to determine whether most co-occurring species and S. canadensis differ in winter leaf phenology. Old leaves withered much later and new leaves developed much earlier in S. canadensis than in the two co-occurring species. Both the old and new leaves of S. canadensis had high photosynthetic capacity in winter. In summer, glyphosate suppressed the growth of S. canadensis by 20.1–59.5% and growth of I. cylindrica to a greater extent (by 57.6–91.7%), whereas winter application of glyphosate at a certain concentration suppressed the growth of S. canadensis by 91.4–95.6% (the efficiency was higher than summer application), but had no impact on I. cylindrica. Glyphosate application in winter alleviated competition stress from S. canadensis on I. cylindrica. We conclude that winter glyphosate application can increase the selectivity and efficiency of chemical control of invasive S. canadensis, which may shift the competition balance towards native species and favour native vegetation recovery in sites invaded by S. canadensis. The principles of this approach can be applied to any scenario where invasive species and co-occurring species have distinct phenological niche separation.

Assessing the impact of sediment characteristics on vegetation recovery in debris flow fans: A case study of the Ohya Region, Japan

What factors influence natural vegetation recovery in debris flow-prone areas, and how do sediment dynamics play a role? This study investigates these questions in the Ohya debris flow fan, Japan, utilizing various analytical techniques. Through the application of Support Vector Machine (SVM) classification, grain size analysis, accuracy assessment, debris flow analysis, and hotspot analysis, this study assess the distribution of sediments, vegetation classes, and the extent of debris flow events. The findings shed light on the dynamics of vegetation recovery and its relationship with sediment dynamic. The SVM classification outcomes reveal distinct trends in sediment and vegetation distribution along the flow path, particularly noting a significant decrease in vegetation cover from upstream to downstream sections. By employing SVM classification, this study successfully identified 3,282,910 sediment particles and determined their average, minimum, maximum, and standard deviation grain sizes as 7.3 cm, 0.27 cm, 415 cm, and 9.18, respectively. Accuracy assessments of image classification and grain size measurements demonstrate high levels of accuracy, with an overall classification accuracy of 98.82 % and a kappa coefficient of 0.977. Validation of grain size measurements reveals a strong correlation (R2 = 0.997 and y = 1.005× + 0.0661) between field-observed sediment sizes and sizes derived from classified images. Debris flow analysis reveals that the total area affected by debris flow in 2022 was 36,232.7 square meters, decreasing to 14,213.9 square meters in 2023. Hotspot analysis identifies regions of both high and low sediment size concentrations, providing valuable insights into sediment distribution patterns. Examining the natural recovery of vegetation, present study identifies vegetation spots across different study sections. Results show that 55 % of naturally recovering vegetation areas are located in regions unaffected by debris flow events between 2022 and 2023. Among the study sections, the area affected by debris flow in 2023 exhibits the lowest density of vegetation spots. Overall, this study highlights the new generation vegetation recovery and its association with sediment dynamic in the Ohya debris flow fan. The findings contribute valuable insights for understanding natural recovery processes in highly dynamic sedimentation areas, informing the development of effective strategies for ecosystem restoration and management in debris flow-prone regions.

Assessing the change in soil water deficit characteristics from grassland to forestland on the Loess Plateau

Soil moisture is an important factor that affects terrestrial ecosystems and biological growth and development, and water deficit is one of the major environmental factors threatening vegetation restoration on the Loess Plateau. The purpose was to identify the change in the soil water deficit characteristics from grassland to forestland on the Loess Plateau. In this study, we measured the soil water storage and deficit in abandoned grassland, shrubland, pioneer forestland and climax forestland along with vegetation succession in situ monitor. The results showed that the soil water content and the soil water storage with natural vegetation recovery from the abandoned grassland to shrubland and forestland showed a gradual declining trend. While on the contrary, the soil water deficit was increasing during succession, it was more severe in the deep soil than in the shallow soil layers. And the soil water deficit in July and September of the rainy season as well as that the vigorous growing period of plants was more serious than that in May and November, which are in the non-rainy season on the Chinese Loess Plateau. The vegetation types and soil depth were the key factors affecting the soil water deficiency status in the process of vegetation succession. Water-saving measures should be taken during the vigorous growing period of plants especially for those forest with natural restoration ages >50a on the Loess Plateau. The results could have great potential in the sustainable development of forestry and provide a theoretical basis for effective water management and reasonable vegetation restoration in semiarid loess regions.

Effects of Natural Vegetation Restoration on Soil Physicochemical Properties in Tropical Karst Areas, Southwestern China

Natural soil and vegetation recovery following human disturbance is the primary means of restoring degraded ecosystems globally. However, it remains unclear how vegetation recovery in the tropical karst areas of China affects the soil physicochemical properties. Here, we investigated the impacts of natural vegetation recovery on soil physicochemical properties at different soil depths in tropical karst areas in southwestern China, using a space–time substitution method. We found that with the natural vegetation recovery, soil bulk density (SBD) decreased. Soil pH initially decreased and then increased, reaching its lowest value during the shrubland stage. There was a significant increase in other soil physicochemical factors. In the soil profiles, SBD tended to increase with depth. The pH, total potassium (TK), total phosphorus (TP), and exchangeable calcium remained relatively stable across the different soil layers. TK, TP, available phosphorus, SBD, total nitrogen, pH, exchangeable magnesium, and available potassium significantly contributed to the soil physicochemical properties. Soil physicochemical properties were predominantly directly affected by litter and biological factors, albeit indirectly influenced by topographic factors. Our study provides crucial insights into karst soils and their relationship with vegetation recovery, which are pivotal for steering vegetation restoration and soil amelioration in karst areas.

Multidecadal vegetation transformations of a New Mexico ponderosa pine landscape after severe fires and aerial seeding.

Wildfires and climate change increasingly are transforming vegetation composition and structure, and postfire management may have long-lasting effects on ecosystem reorganization. Postfire aerial seeding treatments are commonly used to reduce runoff and soil erosion, but little is known about how seeding treatments affect native vegetation recovery over long periods of time, particularly in type-converted forests that have been dramatically transformed by the effects of repeated, high-severity fire. In this study, we analyze and report on a rare long-term (23-year) dataset that documents vegetation dynamics following a 1996 post-fire aerial seeding treatment and a subsequent 2011 high-severity reburn in a dry conifer landscape of northern New Mexico, USA. Repeated surveys between 1997 and 2019 of 49 permanent transects were analyzed for differences in vegetation cover, richness, and diversity between seeded and unseeded areas, and to characterize the development of seeded and unseeded vegetation communities through time and across gradients of burn severity, elevation, and soil-available water capacity. Seeded plots showed no significant difference in bare ground cover during the initial years postfire relative to unseeded plots. Postfire seeding led to a clear and sustained divergence in herbaceous community composition. Seeded plots had a much higher cover of non-native graminoids, primarily Bromus inermis, a likely contaminant in the seed mix. High-severity reburning of all plots in 2011 reduced native graminoid cover by half at seeded plots compared with both prefire levels and with plots that were unseeded following the initial 1996 fire. In addition, higher fire severity was associated with increased non-native graminoid cover and reduced native graminoid cover. This study documents fire-driven ecosystem transformation from conifer forest into a shrub-and-grass-dominated system, reinforced by aerial seeding of grasses and high-severity reburning. This unique long-term dataset illustrates that post-fire seeding carries significant risks of unwanted non-native species invasions that persist through subsequent fires-thus alternative postfire management actions merit consideration to better support native ecosystem resilience given emergent climate change and increasing disturbance. This study also highlights the importance of long-term monitoring of postfire vegetation dynamics, as short-term assessments miss key elements of complex ecosystem responses to fire and postfire management actions.

WITHDRAWN: Reconstructing the environmental impact of mining on mountain lakes

Mountain lakes are particularly fragile ecosystems undergoing important transformations associated with ongoing global change. However, the history of anthropogenic impacts on mountain lakes and their catchments is much longer, in many cases featuring millennia of summer pastoral farming. More recently, the growing demand for raw materials and energy linked to industrialization, particularly accelerated since the 19th century CE, meant a further increase in human impact on mountain areas. The Cantabrian Range (northern Spain) constitutes a paradigmatic case of southern European mountain range experiencing intense human impact during the past few millennia and particularly the past two centuries. Here, we have reconstructed the environmental dynamics of this area during the last millennium, with a particular focus on the impact of mining, based on the multidisciplinary analysis (sedimentology, biogeochemistry, magnetic susceptibility, diatoms, pollen, charcoal and dung fungal spores) of sediment cores from Lago de La Cueva (43°03′N, 6°06′W, 1550 m a.s.l.). Changing land use and climate have driven lake dynamics during the last centuries. A major fire-caused deforestation event dated to the late 15th century CE increased erosion and the frequency of intense runoff episodes, in the context of the wetter and colder Little Ice Age. The onset of iron mining activities in the catchment ca. 200 years ago had a strong impact on the lake. Sedimentation rates notably raised and mining waste containing hematite and potentially toxic elements (e.g. Fe, Co, As) was washed into the lake. Additionally, diatom assemblages showed that lake regulation since the early 20th century CE severely altered the natural hydrological regime introducing rapid seasonal lake-level oscillations and increased lakeshore erosion, water turbidity and nutrient loads. The recent environmental restoration, finished in 2006, has involved the re-deposition of large volumes of mine tailing. Although some mining wastewater still arrives into the lake because mine drainage is still active, restoration works have succeeded in reducing erosion rates and nutrient loads. Lower land-use intensity has also contributed to natural vegetation recovery, further diminishing erosion. This study illustrates the complex interactions between human activities (grazing, mining, hydropower) and climate change in defining mountain landscape shifts through time. Moreover, our results highlight the usefulness of paleolimnological research to quantitatively assess the effectiveness of lake restoration programs.

Enhanced Detection of Artisanal Small-Scale Mining with Spectral and Textural Segmentation of Landsat Time Series

Artisanal small-scale mines (ASMs) in the Amazon Rainforest are an important cause of deforestation, forest degradation, biodiversity loss, sedimentation in rivers, and mercury emissions. Satellite image data are widely used in environmental decision-making to monitor changes in the land surface, but ASMs are difficult to map from space. ASMs are small, irregularly shaped, unevenly distributed, and confused (spectrally) with other land clearance types. To address this issue, we developed a reliable and efficient ASM detection method for the Tapajós River Basin of Brazil—an important gold mining region of the Amazon Rainforest. We enhanced detection in three key ways. First, we used the time-series segmentation (LandTrendr) Google Earth Engine (GEE) Application Programming Interface to map the pixel-wise trajectory of natural vegetation disturbance and recovery on an annual basis with a 2000 to 2019 Landsat image time series. Second, we segmented 26 textural features in addition to 5 spectral features to account for the high spatial heterogeneity in ASM pixels. Third, we trained and tested a Random Forest model to detect ASMs after eliminating irrelevant and redundant features with the Variable Selection Using Random Forests “ensemble of ensembles” technique. The out-of-bag error and overall accuracy of the final Random Forest was 3.73 and 92.6%, which are comparable to studies mapping large industrial mines with the normalized difference vegetation index (NDVI) and LandTrendr. The most important feature in our study was NDVI, followed by textural features in the near and shortwave infrared. Our work paves the way for future ASM regulation through large area monitoring from space with free and open-source GEE and operational satellites. Studies with sufficient computational resources can improve ASM monitoring with advanced sensors consisting of spectral narrow bands (Sentinel-2, Environmental Mapping and Analysis Program, PRecursore IperSpettrale della Missione Applicativa) and deep learning.

Effects of Landscape Fragmentation on Soil Loss in the Cerrado Biome, Brazil

Soil loss stands as a critical global challenge, posing economic and environmental threats to soil and water conservation. This study aimed to assess the impact of landscape changes on soil loss in the Descoberto River basin, encompassing 62 watersheds in the Cerrado biome in central Brazil. We analysed a 32-year time series (1985-2017) of land use and land cover data based on geostatistical techniques and spatiotemporal weighted regression analysis. Principal component analysis condensed 16 landscape metrics into three factors: aggregation/diversity, dispersion/adjacency, and patchiness. The average annual total soil loss across all 62 analysed watersheds was estimated at 73.3 ± 78.2 (standard deviation) ton ha−1. A significant positive correlation was observed between landscape fragmentation and soil erosion, indicating that, as fragmentation increases, soil losses also increase. Furthermore, our analysis revealed a decreasing trend in soil loss rates in recent years, primarily attributed to the recovery of native vegetation since no significant soil management practices were widely implemented in the study area during the study period.

Performance assessment of existing canal-blocking in restoration management of peatland conservation

The aim of this research is to assess existing results of the canal-blocking peatland conservation due to the classification of 5 canal-blocking types on peatland conservation as the management of restoration in the peatland area of Block-C ex-PLG. The low water levels (>40 cm from the surface) during the dry season make dry peatlands susceptible to fires. The back wetting of peatland is the early effort in preventing the peatland fire, which can be carried out on a wide scale by exploiting the available canal network through the overall and integrated canal blocking in unity of peatland hydraulics. The canal blocking due to the five types of canal blocking classification, which is intended to back the discussion of peatland, can give the ecology and society economic impacts that include supporting the natural vegetation recovery, preparation of water supply along season on the peatland hydrologic unity, and to be preventing drought and also the fire that are often happened in the dry season. Land use is suggested based on customization: agriculture and plantation in designated areas, adaptive vegetation in limited plantation zones, and protected areas restored to serve as safeguarded vegetation zones.

Long-term drought promotes invasive species by reducing wildfire severity.

Anthropogenic climate change has increased the frequency of drought, wildfire, and invasions of non-native species. Although high-severity fires linked to drought can inhibit recovery of native vegetation in forested ecosystems, it remains unclear how drought impacts the recovery of other plant communities following wildfire. We leveraged an existing rainfall manipulation experiment to test the hypothesis that reduced precipitation, fuel load, and fire severity convert plant community composition from native shrubs to invasive grasses in a Southern California coastal sage scrub system. We measured community composition before and after the 2020 Silverado wildfire in plots with three rainfall treatments. Drought reduced fuel load and vegetation cover, which reduced fire severity. Native shrubs had greater prefire cover in added water plots compared to reduced water plots. Native cover was lower and invasive cover was higher in postfire reduced water plots compared to postfire added and ambient water plots. Our results demonstrate the importance of fuel load on fire severity and plant community composition on an ecosystem scale. Management should focus on reducing fire frequency and removing invasive species to maintain the resilience of coastal sage scrub communities facing drought. In these communities, controlled burns are not recommended as they promote invasive plants.

Plant-plant interactions influence post-fire recovery depending on fire history and nurse growth form

BackgroundsPlant-plant interactions are among the most important factors affecting the natural recovery of vegetation. While the impacts of nurse plants on species composition and biodiversity are well documented, the effects of different nurse’s growth forms on all biodiversity components including taxonomic, functional, and phylogenetic diversity have been less studied and compared, especially for their effects on different times after fire disturbance. This research was focused on comparing the effects of a perennial grass (Elymus hispidens), a perennial herb (Phlomis cancellata), and a high shrub species (Lonicera nummulariifolia) on species composition and the biodiversity components, and how these impacts change across five sites with short-term (1 and 4 years sites), long-term (10 and 20 years sites) times since last fire and a control site where no fire was known in recorded history in semi-arid shrublands of Fereizi Chenaran located in Northeast of Iran. The changes of species composition and taxonomic, functional, and phylogenetic diversity were calculated with respect to the presence/absence of nurse’s growth forms, fire history, and their interactions.ResultsNurse shrubs affected species composition and all biodiversity components, whereas all indices were reduced when considering Elymus grass as nurse plant. On the other hand, the herb Phlomis enhanced species composition and taxonomic diversity, while it had a negative effect on functional and phylogenetic diversity. Such specific effects of nurse types were mostly observed under long timescales (i.e., 10- and 20-year sites). Interestingly, the relative importance of nurse types and time since the last fire largely explained the variation of species composition and biodiversity components, with larger effects of nurse types on all biodiversity components. However, we found a significant contribution of fire explaining variation of species composition and phylogenetic diversity.ConclusionsThese results indicated nurse plants can affect the post-fire recovery of vegetation by providing specific mechanisms controlling beneficiary relatedness depending on their growth forms and time scales since the last fire. Therefore, these findings suggest perennial plants in the form of nurse species as a useful factor to develop techniques of active restoration in burned ecosystems.

Climate Policies and Forest Restoration Challenges in Bahia State South, Brazil

Climate change presents humanity with one of the most complex and pressing challenges of the 21st century. As such, effective public policies and legislation must be implemented to mitigate negative impacts and facilitate the adaptation of societies to new environmental dynamics. These policies are critical in aligning collective efforts toward a more sustainable and resilient economy, providing a crucial legal framework to guide individual, collective, and governmental actions toward climate change mitigation. Thereby, Brazil has committed to restoring 12 million hectares of forests by 2030 as part of its strategy to mitigate climate change. However, the absence of an express initial time frame by law has led to inconsistencies and possible low effectiveness of forest management policies. This study sought to examine Rural Environmental Registries (in Portuguese, Cadastro Ambiental Rural - CAR) of properties in the State of Bahia and assess restoration timetables for legal reserve areas, in addition to the challenges and opportunities associated with the formulation and implementation of forest restoration policies. Considering the implications of forest degradation on the environment and human livelihoods, it is a matter of great significance. As such, it warrants a thorough examination and analysis of the various factors involved, including the role of stakeholders, financial and technical feasibility, and the identification of appropriate goals and targets. The study findings indicate that, in 71% of the properties requiring legal reserve restoration, the timetable exceeded the established legal period of the year 2032. Additionally, in 45% of the cases, the term was calculated from the registration of the rural property in the CAR. Consequently, it was concluded that the erroneous interpretations adopted impede the recovery of native vegetation and, more significantly, the Brazilian goal of forest restoration of 12 million hectares of degraded land by 2030.

Shorebirds-driven trophic cascade helps restore coastal wetland multifunctionality

Ecosystem restoration has traditionally focused on re-establishing vegetation and other foundation species at basal trophic levels, with mixed outcomes. Here, we show that threatened shorebirds could be important to restoring coastal wetland multifunctionality. We carried out surveys and manipulative field experiments in a region along the Yellow Sea affected by the invasive cordgrass Spartina alterniflora. We found that planting native plants alone failed to restore wetland multifunctionality in a field restoration experiment. Shorebird exclusion weakened wetland multifunctionality, whereas mimicking higher predation before shorebird population declines by excluding their key prey – crab grazers – enhanced wetland multifunctionality. The mechanism underlying these effects is a simple trophic cascade, whereby shorebirds control crab grazers that otherwise suppress native vegetation recovery and destabilize sediments (via bioturbation). Our findings suggest that harnessing the top-down effects of shorebirds – through habitat conservation, rewilding, or temporary simulation of consumptive or non-consumptive effects – should be explored as a nature-based solution to restoring the multifunctionality of degraded coastal wetlands.

Post-fire recovery of vegetation in the Chornobyl Radiation and Ecological Biosphere Reserve

ABSTRACT Fires significantly affect the structure and diversity of vegetation. Natural recovery of vegetation after fires in the Chornobyl Exclusion Zone is of special interest because of its status as a nuclear disaster area. This is the first assessment of the potential for natural regrowth of forest and post-fire succession after the catastrophic fires of 2020 that scorched 62 000 ha of forest across the territory. Most of these areas (>80%) have high potential for natural regeneration but, in the first instance, forest species are commonly replaced by wasteland weeds, some of them invasive; 10 alien plant species were identified in the studied plots. Megafires facilitate vegetation shifts and opportunities for invasive species, especially in the early stages of succession.

Biophysical Impact of Multiple Surface Forcings on Land Surface Temperature Over Eastern China

AbstractOver the past decades, human activities have directly or indirectly driven the land surface changes in eastern China. These anthropogenic forcings could trigger biochemical feedback and alter the surface biophysical properties, thus affecting local temperature. However, the latter is recognized as the “noise” and ignored when assessing historical or future climate. Here, we adopt the “observation minus reanalysis” (OMR) method to isolate the biophysical temperature footprint of multiple surface changes in eastern China over 2001–2018, using remote sensing land surface temperature and reanalysis skin temperature. A spatial regression model was used to separate the contributions from different processes. We find the biophysical feedbacks of surface changes have an annual cooling effect of −0.072 K/decade in eastern China, and the contributions from urban expansion, agricultural development, and natural vegetation greening are 0.042, −0.042, and −0.072 K/decade, correspondingly. The Northeast Plain shows agricultural activities induced cooling of −0.040 K/decade; the Loess Plateau shows natural vegetation recovery dominated cooling of −0.145 K/decade; the Huang‐Huai‐Hai Plain demonstrates a predominant urbanization warming effect of 0.124 K/decade; the Middle‐lower Yangtze shows natural vegetation greening related cooling of −0.106 K/decade. Both the intensity of the land surface changes and the temperature sensitivities drive the large spatial variability of the temperature effect. Overall, the temperature effects of surface changes are spatially heterogeneous and show considerable magnitudes. We emphasize that vegetation changes in eastern China show a strong surface cooling effect, and may contribute to the regional climate mitigation in the context of global warming.

Effects of post-fire application of straw mulch strips on soil erosion, soil moisture and vegetation regeneration in European dry heathlands in NW Spain

Applying mulch to severely burned soils is common practice in fire-prone areas such as the NW Spain. Mulch that provides >80% cover can reduce post-fire soil erosion by up to 90%; however, this level of cover can sometimes be difficult to achieve in remote areas due to the logistic constraints. Although application of mulch strips is a possible alternative approach, there is no information available about the effectiveness of this technique. Such information is critical in protected areas where mulch application can modify the recovery of natural vegetation by altering the soil moisture regime.In this study, the effects of the application of 20 m wide straw mulch strips on soil erosion, soil moisture and vegetation recovery were assessed during the first year after a high-severity fire that occurred in September 2020 in two European dry-heathland areas.During the first year after the fire, the mean sediment yields in the untreated plots were 18.5 Mg ha−1 and 33.8 Mg ha−1, respectively at the Lobios and Vilariño study sites. Although the straw mulch strips reduced soil erosion by >70% on average, erosion rates remained high at both sites. Soil moisture contents in mulch-treated areas were significantly higher than in untreated areas during spring and summer.Mulching affected vegetation recovery in different ways, i.e., it had neutral to positive effects, depending on the study site. No alteration in species composition was observed in either of the sites as a result of treatment application.In summary, the reduction in soil erosion after the application of straw mulch strips covering 67% of burned soil under the conditions of the present study under the conditions of the present study reduced a 70–75% of soil erosion after a high-severity wildfire.

Effect of geologic variability on occurrence of collapse and natural vegetation recovery on cutting slopes of a forestry-exclusive road

Effect of geologic variability on occurrence of collapse and natural vegetation recovery on cutting slopes of a forestry-exclusive road

Topsoil and Vegetation Dynamics 14 Years after Eucalyptus grandis Removal in Eastern Cape Province of South Africa.

A great deal of effort has been made to clear invasive alien plants in South Africa, yet it remains unclear if the clearing efforts are yielding positive soil and vegetation recovery trajectories. A few short-term studies have been conducted to monitor soil and vegetation recovery after alien plant removal in South Africa, but convincing, long-term monitoring studies are scarce yet needed. We investigated topsoil and vegetation recovery following Eucalyptus grandis removal 14 years ago by Working for Water in Makhanda, Eastern Cape province of South Africa. The detailed topsoil and vegetation surveys were conducted on forty 10 m × 10 m plots that were in paired cleared and natural sites. The results show no significant differences for the measured soil pH, total N, total C, K, Ca, and Na between the cleared and natural sites, an indication that the two sites are becoming similar. Similarly, the gravimetric soil moisture content shows no significant differences between the two sites, although monthly variations are observed. The topsoils in the cleared sites are hydrophobic as compared to those in the natural sites, which are wettable. We observed no significant vegetation diversity differences between the two sites, with native woody species, such as Crassula pellucida and Helichrysum petiolare, frequently occurring in the cleared sites. We recorded low reinvasion by E. grandis and other secondary invaders like Acacia mearnsii and Rubus cuneifolius in the cleared sites. Based on these results, we conclude that 14 years after E. grandis clearing, both topsoil and vegetation recovery are following a positive trajectory towards the natural sites. However, both reinvasion and secondary invasion have the potential to slow down soil and native vegetation recovery. Recommendations such as timeous follow-up clearing and incorporating restoration monitoring in the WfW clearing programme are discussed.

The Role of Private Reserves of Natural Heritage (RPPN) on natural vegetation dynamics in Brazilian biomes

Despite having the richest biodiversity in the world, Brazil has lost vegetation cover in all biomes, with the agribusiness being an important driver of such changes. Different governance systems, decentralized actions and public policies have been developed to control deforestation, and in this study, we focus on the role of Private Reserves of Natural Heritage (RPPN) as an instrument for the conservation and recovery of natural vegetation. Therefore, we raise the following questions: How many RPPNs are there and what are their spatial distribution? Are RPPNs an important mean of conservation/restoration of Brazilian biomes? Do they contribute (at statistically significant levels) to the conservation of natural vegetation within their respective rural properties compared with rural properties without private reserves? Thus, we investigated the natural vegetation cover (between 1990 and 2018) in rural properties with and without RPPNs looking at the municipalities where RPPNs are found, and analyzing the results at country and biome levels. The results indicate that RPPNs are significantly associated with gains in natural vegetation cover in the Cerrado, Caatinga and Atlantic Forest biomes. We conclude that RPPNs have great potential in recovering natural landscapes associated to the Brazilian biomes. However, their few numbers across the Brazilian territory (1750 units of RPPN) and spatially highly concentrated in the Cerrado and Atlantic Forest, challenges the capacity of this conservation strategy to deal with the environmental degradation promoted by the expansion of economics activities across the country.

Medium-term effects of wildfire severity on soil physical, chemical and biological properties in Pinus halepensis Mill. woodland (Southern Italy): an opportunity for invasive Acacia saligna colonization?

Wildfire frequency and severity have greatly increased in Mediterranean areas in recent decades affecting ecosystems functioning due to alteration in the above- and below-ground process. This study aimed to investigate how wildfire severity, in the medium-term (2–5 years), impacts soil properties within a Pinus halepensis woodland located in the Special Area of Conservation (SAC) of the Natura 2000 network (IT9130006 - Pinewoods of the Ionian Arch). In 2021, four years after a large wildfire in 2017, the woodland still exhibited fire effects with evidence of low, medium or high burn severity in different sites (named LBS, MBS, HBS, respectively). In addition, we observed an area burnt at medium severity that was invaded by Acacia saligna (MBSA site), a fast-growing, highly invasive, drought-tolerant nitrogen-fixing plant, thus we also examined the combined effect of wildfire and A. saligna on the soil. We compared soil properties across burnt sites with a nearby unburnt site (control). Thickness, weight and organic carbon of litter (L) and fermentation (F) layers were measured, alongside physical, chemical and biological properties in the underlying mineral soil (0–10 cm). Our results show that wildfire destroyed the organic layers and these had not recovered four years after the wildfire (except for L-layer within LBS) with a consequent loss (∼2 t C ha−1) of this carbon pool. In mineral soil we identified fourfold increases in N mineralization and nitrification rates across all burnt sites, regardless of the burn severity and A. saligna presence, suggesting an alteration of N-cycle processes. On the contrary, total microbial biomass and soil respiration as well as most of the physical and chemical properties of the soil were comparable between the burnt and control soils. Principal Component Analysis (PCA) highlighted that burn severity affected soil variables with lower changes in LBS than in other burnt soils. Also, the HBS soil did not show greater negative impacts compared to MBS sites. This is probably due to the increased post-fire colonization by herbaceous plants in HBS, favoured by the complete destruction of trees. In this case, waiting for natural vegetation recovery can be a valid management option, but periodic monitoring of fire-soil-vegetation interaction mainly to avoid invasive species widespread is advocated.