Mechanical impacts of climbing on cliff vegetation: Contrasting management concepts

Succession is a basic natural process of ecosystem recovery, it may start completely de novo (primary succession) or after serious disturbance of the previous ecosystem (secondary succession). Despite most reclamation and restoration approaches depending on it and despite extensive previous research, we found no worldwide review that would describe the pattern of vegetation cover and woody vegetation recovery in individual types of succession and explore major factors that affect the speed of vegetation recovery. To fill this gap we have searched world literature and extracted data about 244 succession series about total vegetation cover and 113 about woody vegetation cover. The rate of vegetation cover recovery is significantly slower during primary succession than during secondary succession, this however not apply to woody vegetation. The type of disturbance affects the speed of recovery, post‐mining sites recover fastest among primary succession and older fields were the fastest among secondary succession, the slowest one being succession in glacier retreats. Latitude, soil pH, the size of the disturbed area, temperature, and actual evapotranspiration affect the rate of vegetation recovery in primary succession, while only latitude affects secondary succession. Some other factors affect succession after a specific disturbance. The study shows that succession can be an effective tool to restore vegetation cover and woody vegetation on many occasions. We expect that differences in the nutrient availability determine differences in the rate of total vegetation cover recovery, while soil porosity (compaction) may be an important factor affecting woody vegetation recovery.

Vegetation loss and recovery analysis from the 2015 Gorkha earthquake (7.8 Mw) triggered landslides

SummaryFactors associated with agricultural intensification, for example, loss of seminatural vegetation and pesticide use has been shown to adversely affect the bee community. These factors may impact the bee community differently at different landscape scales. The scale dependency is expected to be more pronounced in heterogeneous landscapes. However, the scale‐dependent response of the bee community to drivers of its decline is relatively understudied, especially in the tropics where the agricultural landscape is often heterogeneous. This study looked at effects of agricultural intensification on bee diversity at patch and landscape scales in a tropical agricultural landscape. Wild bees were sampled using 12 permanent pan trap stations. Patch and landscape characteristics were measured within a 100 m (patch scale) and a 500 m (landscape scale) radius of pan trap stations. Information on pesticide input was obtained from farmer surveys. Data on vegetation cover, productivity, and percentage of agricultural and fallow land (FL) were collected using satellite imagery. Intensive areas in a bee‐site network were less specialized in terms of resources to attract rare bee species while the less intensive areas, which supported more rare species, were more vulnerable to disturbance. A combination of patch quality and diversity as well as pesticide use regulates species diversity at the landscape scale (500 m), whereas pesticide quantity drove diversity at the patch scale (100 m). At the landscape scale, specialization of each site in terms of resources for bees increased with increasing patch diversity and FL while at the patch scale specialization declined with increased pesticide use. Bee functional groups responded differentially to landscape characteristics as well as pesticide use. Wood nesting bees were negatively affected by the number of pesticides used but other bee functional groups were not sensitive to pesticides. Synthesis and Applications: Different factors affect wild bee diversity at the scale of landscape and patch in heterogeneous tropical agricultural systems. The differential response of bee functional groups to agricultural intensification underpins the need for guild‐specific management strategies for wild bee conservation. Less intensively farmed areas support more rare species and are vulnerable to disturbance; consequently, these areas should be prioritized for conservation to maintain heterogeneity in the landscape. It is important to conserve and restore seminatural habitats to maintain complexity in the landscapes through participatory processes and to regulate synthetic chemical pesticides in farm operations to conserve the species and functional diversity of wild bees.

Rapid urban growth has become one of the key global drivers of land-use change, significantly impacting the natural environment, particularly vegetation cover. This research focused on quantifying and analyzing the spatial and temporal change of urban growth and its consequent effects on the city’s vegetation cover, assessing the loss and degradation of vegetation cover, and identifying the factors contributing to changes in land use and vegetation. The research problem was the limitation in the way of understanding the spatiotemporal changes in vegetation cover due to urban growth in Kigali city. Therefore, this research was focused on the main objective which was to assess the spatiotemporal change of urban expansion on vegetation cover, a case of Kigali city. Specific objectives were: assessing the driving factors of urban expansion in Kigali city, to analyze the variation change in vegetation cover in Kigali city over twenty-four years and to examine the relationship between urban expansion and vegetation loss in Kigali city. The methods used were library research by reading different books, papers and journals, which helped the researchers to do literature review. Household surveys helped to understand how urban expansion impacts local residents' access to green spaces, environmental changes, and their general perceptions of vegetation loss. Satellite imagery from multiple time frames, processed using advanced GIS and remote sensing techniques, were used to analyze land use/land cover changes, with a focus on vegetation loss and the spatial-temporal dynamics of urban growth. Key informants' interviews provided in-depth, qualitative insights that complemented quantitative data from satellite imagery and GIS analysis. The results provided detailed maps of urban sprawl and vegetation cover changes in Kigali, with a focus on highlighting areas most vulnerable to degradation. Different main drivers of urban change such as population growth, economic development and rural-urban migration have been discussed. To sum up, the study found a significant decrease in vegetation cover over the past 24 years, a percentage of 90% caused by vegetation loss such as urban expansion, deforestation and poor urban planning, while a smaller percentage of 10% noted some efforts to increase vegetation through reforestation and green infrastructure projects land use and zoning regulation and the relationship between urban expansion and vegetation cover has shown that if urban growth is done in a sustainable way vegetation cover can be protected

Social media impact not only our communication and social interactions but also our relationships to the natural environment. Social media can increase understanding of our environment by offering information and sharing calls to action, while at the same time, they might present a glamourised, standardised picture of nature and distract from actual outdoor interactions. The COVID‐19 pandemic presents a unique opportunity to study the spaces created for interactions between the online and offline natural world, especially in countries where movement and thus outdoor activities were restricted during lockdowns. To understand these interactions, we investigated the social media communication of nature conservation and outdoor organisations by analysing Twitter posts of four prominent NGOs in Scotland. We found that during the first COVID‐19‐induced UK lockdown in spring 2020, Scottish nature conservation and outdoor organisations made distinctive efforts in supporting followers to connect with nature in the face of restrictions. Organisations showed signs of moving towards community‐building through sharing experiences often related to nearby nature, while calls for environmental action, more prominent in the previous year, receded in relative importance. Emphasis was put on sensory engagement with, and finding solace in the rhythm of, nature. References to taking action to protect nature now became linked to a green recovery from the pandemic. We conclude that NGOs used social media not as a space separate from the outdoors, but as an augmented space where online and offline interactions were interwoven and a space in which during the COVID‐19 pandemic, new avenues for engagement were being explored. Read the free Plain Language Summary for this article on the Journal blog.

An evaluation framework for quantifying vegetation loss and recovery in response to meteorological drought based on SPEI and NDVI

This study presents a simple approach of spatiotemporal change detection of vegetation cover based on analysis of time series remotely sensed images. The study was carried out at Thathe Vondo Area, which is characterised by episodic variation of vegetation gain and loss. This variation is attributable to timber and tea plantations and their production cycles, which periodically result in either vegetation gain or loss. The approach presented here was implemented on two ASTER images acquired in 2007 and 2017. It involved the combined use of band combination, unsupervised image classification and Normalised Difference Vegetation Index (NDVI) techniques. True colour composite (TCC) images for 2007 and 2017 were created from combination of bands 1, 2 and 3 in red, blue and green, respectively. The difference image of the TCC images was then generated to show the inconsistencies of vegetation cover between 2007 and 2017. For analytical simplicity and interpretability, the difference image was subjected to ISODATA unsupervised classification, which clustered pixels in the difference image into eight classes. Two ISODATA derived classes were interpreted as vegetation gain and one as vegetation loss. These classes were confirmed as regions of vegetation gain and loss by NDVI values of 2007 and 2017. In addition, the polygons of vegetation gain and loss regions were created and superimposed over the TCC images to further demonstrate the spatiotemporal vegetation change in the area. The vegetation change statistics show vegetation gain and loss of 10.62% and 2.03%, respectively, implying a vegetation gain of 8.59% over the selected decade.Significance: Vegetation change detection is essential in environmental monitoring and management of an area. This study presents a simple approach for assessing vegetation change over time. The approach involveschange detection through the difference of spectral values of vegetation pixels of time series remotelysensed images.

This study quantifies the loss of vegetative cover in Alley and Big springs, Missouri, following a catastrophic, ‘100 year’ flood, and documents their subsequent recovery. Foliar cover of aquatic vegetation was measured in each spring along six transects, each having three sample cells (1 m2, N = 18). Species diversity analyses included taxa richness, Shannon’s diversity index, and Simpson’s diversity index, which were expressed as the effective number of species (S, He, and De). Species metrics were calculated as individual species frequency (ISF), percent foliar cover (PFC), and species importance value (SIV). Post-flood community diversity metrics (S, He, and De) for the springs were largely not significant for most measures (Epps–Singleton test p > 0.05). This suggests that they may not be sufficiently sensitive for detecting change in springs when the sample size is small. Bare substrate increased significantly at Big Spring post-flood (mean = 87.50%; Epps–Singleton test, p = 0.02), but not at Alley Spring (Epps–Singleton test, p = 0.42). Various alga taxa generally exhibited increased frequency and abundance following the flood, which is reflected in their overall higher SIVs. Most hydrophyte species at Alley Spring showed a marked decline compared to the pre-flood average, only to substantially increase in the last year of sampling, thus maintaining their approximate species important values relative to their pre-flood averages. Several hydrophyte species at Big Spring showed significant decreases (Epps–Singleton test p < 0.05) in their respective community metrics, and recovery had not returned to pre-flood levels on the last sampling date. This study showed that loss and recovery of aquatic vegetation in high-magnitude Ozark springs following flooding are a function of flood intensity as well as substrate size and retention, and proximity to the receiving stream.

BackgroundClimate change is altering the fire regime and compromising the post-fire recovery of vegetation worldwide. To understand the factors influencing post-fire vegetation cover restoration, we calculated the recovery of vegetation in 200,000 hectares of western Mediterranean forest burned by 268 wildfires over a 27-year period (1988–2015). We used time series of the Tasseled Cap Transformation Brightness (TCTB) spectral transformation over Landsat imagery to calculate vegetation recovery. Then, we quantified the importance of the main drivers of post-fire vegetation recovery (climate, fire severity, and topography) along an aridity gradient (semi-arid, sub-humid, and humid) using Random Forest models.ResultsIn most models (99.7%), drought duration was the most important factor, negatively affecting post-fire recovery especially in the extremes of the aridity gradient. Fire severity was the second most important factor for vegetation cover recovery, with its effect varying along the aridity gradient: there was a positive relationship between fire severity and recovery in sub-humid and humid areas, while semi-arid areas showed the opposite pattern. Topographic variables were the least important driver and had a marginal effect on post-fire recovery. Additionally, semi-arid areas exhibited a low mean recovery rate, indicating limitations in the short-term recovery after a fire.ConclusionsOur study highlights the key role that drought duration plays in the recovery of vegetation after wildfires in the Mediterranean basin and, particularly, in forests located in climatically extreme areas. The results suggest that the predicted increase in drought duration coupled with a higher frequency and intensity of large fires may modify the structure and composition of Mediterranean forest ecosystems. Our analysis provides relevant information to evaluate and design adaptive management strategies in post-fire recovery hotspots of Mediterranean forest ecosystems.

The arid and semi-arid regions of northwest China are characterized by sparse vegetation and fragile ecosystems, making them highly susceptible to the impacts of climate change and human activities. Based on observed meteorological data, the Normalized Difference Vegetation Index (NDVI), the Lund-Potsdam-Jena dynamic global vegetation model (LPJ), a vegetation recovery potential model, and the MK trend test method, this study investigated the spatiotemporal distribution of vegetation recovery potential in northwest China and its relationship with global warming and increasing precipitation. The results indicated that vegetation in northwest China significantly increased, with greening closely related to trends in warming and wetting during 1982-2019. However, the vegetation recovery potential declined due to climate change. Central and southern Xinjiang and central Qinghai exhibited higher grassland recovery potential, while the central Gobi Desert areas of northwest China had lower recovery potential. The eastern part of northwest China was highly sensitive to drought, with moderate vegetation growth and recovery potential. Remote sensing data indicated a 2.3% increase in vegetation coverage in the region, with an average vegetation recovery potential index (IVCP) of 0.31. According to the results of LPJ model, the average vegetation recovery potential index for northwest China was 0.14, indicating a 1.1% improvement potential in vegetation coverage. Overall, climate warming and wetting facilitated vegetation recovery in northwest China, particularly in mountainous areas. The findings provide valuable insights for ecological restoration efforts and offer practical guidance for combating desertification and enhancing sustainable development. Moreover, these results underline the importance of incorporating vegetation recovery potential into regional policy-making to improve environmental resilience in the face of ongoing climate change.

The essential role played by urban vegetation in making urban areas livable is often overlooked in many developing cities. This is the case of Ghana where its capital, Accra is developing at the expense of urban vegetation. This study was conducted at the metropolitan area of Accra to estimate how the extent of vegetation cover has changed in the period of 1986-2013, using remote sensing satellite data from Landsat TM and ETM+. Furthermore, views of key informants were assessed on changes in the livability of the city of Accra which may be attributed to loss of urban green vegetation in the city. It was found that between 1986 and 2013, 42.53 km2 of vegetation was lost representing 64.6% of total vegetation in 1986. The rate of change in vegetation cover between 1986 and 1991 measured around 2.14% of the total land area annually. This however, reduced in the subsequent years measuring 0.26% between 2002 and 2008. Key informants interviewed, also believe that the loss of vegetation in the city creates livability concerns relating to ecosystem functioning, temperature rise and air quality. It is therefore recommended for urban planners and decision makers to address three critical concerns of resilience, sustainability and livability, which are the missing links in the city development agenda.

A regional scale study of the Cretaceous Upper Shuaiba, Bab member, in the northwest part of Oman was carried out to understand the sedimentary basin and rock quality for further reservoir potential. This study utilized data from over 1300 wells drilled in the area targeting the same reservoir or deeper targets. One of the key outcomes of the study was an integrated workflow comparing isopach maps and rock typing to understand the sedimentary basin evolution for rock quality prediction. The results were key in understanding the geological concept behind the reservoir distribution within the various upper Shuaiba clinoforms which are separated by clay rich units. After completing a consistence correlation of all the individual upper Shuaiba units, two set of thickness maps were created i.e., cumulative thickness maps in reference to the base of upper Shuaiba and individual unit thickness maps. The former ones were very useful in understanding the sedimentary basin evolution while the other set of maps were useful in understanding the sedimentary processes which controlled the facies distribution and hence reservoir potential identification. In parallel to the correlation and the thickness mapping a rock type scheme was defined from core data (CRT: Core Rock Typing). The analysis was conducted over 44 out of 60 cored wells. The rock type scheme provides an optimum characterisation of porosity, permeability, and saturation which via geological concepts can then be distributed in 3D. Most rock types can be related to depositional facies and their distribution in a depositional model. The overlay of rock type distribution with the thickness maps largely confirms the existing depositional models of prograding clinoforms, mainly from the NW to the SE. An increase in thickness of each unit from deeper basin to shallower water and the sub-crop below the unconformity is matched by the facies/rock type distribution and associated rock properties. Increased data control was required to consolidate the concepts and to map rock type distribution in more detail. A workflow was therefore developed to interpret rock type from log response (LRT: Log Rock Typing) calibrated by the core-based rock type control. A subsequent more rigorous workflow was adopted for LRT interpretation tied to log-based saturation data and a consistent set of Saturation Height Functions (SHF) along with other verification steps such as the comparison of rock type inferred permeability and MDT derived permeability/ mobility. Integration of the correlation, thickness mapping and rock typing has showed its value in understanding rock type distribution and developing geological concepts. This integrated workflow was utilised and applied in the static model for the field development planning (FDP) of several fields which have undergone successful development. The rock type distribution impacted volumetrics, well placement, well performance analysis, forecasting, and well, reservoir, facility management (WRFM) activities.

In the context of drought events caused by global warming, there is limited understanding of vegetation loss caused by drought and the subsequent recovery of vegetation after drought ends. However, employing a single index representing a specific vegetation characteristic to explore drought’s impact on vegetation may overlook vegetation features and introduce increased uncertainty. We applied the enhanced vegetation index (EVI), fraction of vegetation cover (FVC), gross primary production (GPP), leaf area index (LAI), and our constructed remote sensing vegetation index (RSVI) to assess vegetation drought in Central Asia. We analyzed the differences in drought experiences for different climatic regions and vegetation types and vegetation loss and recovery following drought events. The results indicate that during drought years (2012 and 2019), the differences in vegetation drought across climatic regions were considerable. The vegetation in arid, semiarid, and Mediterranean climate regions was more susceptible to drought. The different indices used to assess vegetation loss exhibited varying degrees of dynamic changes, with vegetation in a state of mild drought experiencing more significantly during drought events. The different vegetation assessment indices exhibited significant variations during the drought recovery periods (with a recovery period of 16 days: EVI of 85%, FVC of 50%, GPP of 84%, LAI of 61%, and RSVI of 44%). Moreover, the required recovery periods tended to decrease from arid to humid climates, influenced by both climate regions and vegetation types. Sensitivity analysis indicated that the primary climatic factors leading to vegetation loss varied depending on the assessment indices used. The proposed RSVI demonstrates high sensitivity, correlation, and interpretability to dry–wet variations and can be used to assess the impact of drought on vegetation. These findings are essential for water resource management and the implementation of measures that mitigate vegetation drought.

The cliff ecosystem is one of the least human-disturbed ecosystems in nature, and its inaccessible and often extreme habitats are home to many ancient and unique plant species. Because of the harshness of cliff habitats, their high elevation, steepness of slopes, and inaccessibility to humans, surveying cliffs is incredibly challenging. Comprehensive and systematic information on cliff vegetation cover is not unavailable but obtaining such information on these cliffs is fundamentally important and of high priority for environmentalists. Traditional coverage survey methods—such as large-area normalized difference vegetation index (NDVI) statistics and small-area quadratic sampling surveys—are not suitable for cliffs that are close to vertical. This paper presents a semi-automatic systematic investigation and a three-dimensional reconstruction of karst cliffs for vegetation cover evaluation. High-resolution imagery with structure from motion (SFM) was captured by a smart unmanned aerial vehicle (UAV). Using approximately 13,000 records retrieved from high-resolution images of 16 cliffs in the karst region Guilin, China, 16 models of cliffs were reconstructed. The results show that this optimized UAV photogrammetry method greatly improves modeling efficiency and the vegetation cover from the bottom to the top of cliffs is high-low-high, and very few cliffs have high-low cover at the top. This study highlights the unique vegetation cover of karst cliffs, which warrants further research on the use of SFM to retrieve cliff vegetation cover at large and global scales.

Bryophytes are often noted for their growth on specific rock types and their value as indicator species. However, some evidence suggests that restriction of a species to specific rock types may be less rigid and could vary under different environmental conditions. We assessed richness and distribution patterns of bryophytes at 22 rock outcrop locations in upstate New York (NY) and coastal Maine (ACAD). At each location, detailed surveys were done in five replicate 5-m by 2-m plots on vertical rock faces. We report on the 194 bryophyte species found in these surveys and present detailed analyses for the 137 species that occurred at two or more of the 22 locations. In general, liverworts were less likely to be dominant within a plot than mosses. Within-site dominance and frequency of liverworts were less well correlated to larger-scale frequency (number of locations and regions of occurrence). In NY, although there was no significant difference in bryophyte richness by rock type, rare species were more often found on calcium-containing rock types. Rock type, soil influence, number of liverwort species, and region were significant correlates with bryophyte species composition patterns. The importance of rock type in explaining species composition patterns was still significant though weaker when ACAD locations were included in the analysis. This difference resulted from a higher prevalence of leafy liverwort species on calcium-containing rock types in ACAD. Our results present further evidence that apparent restrictions to specific rock types may shift depending on environmental conditions such as increased humidity and narrower temperature extremes that occur along the north Atlantic coast.