Deforestation impacts on environmental conditions of headwater streams and Ephemeroptera (Insecta) diversity in Southwestern Amazonia

This study investigates land-cover changes along riparian zones in South Carolina, focusing on intermittent and perennial streams to assess the impact of urbanization, forest loss, and impervious surface expansion on sensitive ecosystems. South Carolina’s diverse geography, ranging from coastal marshes to the Blue Ridge Mountains, and subtropical humid climate, offers a rich context for understanding environmental changes. The research utilizes various geospatial datasets, including the National Land Cover Database (NLCD), National Hydrography Dataset (NHD), and National Agricultural Imagery Program (NAIP) imagery, to evaluate changes in forest cover, urbanization, and impervious surfaces from 2011 to 2021 as a decade of transition. The study areas were divided into buffer zones around intermittent and perennial streams, following South Carolina’s riparian management guidelines. The results indicate significant land-cover transitions, including a total of 3184.56 hectares of non-urban areas converting to forest within the 100 m buffer around intermittent streams. In contrast, 137.43 hectares of forest transitioned to urban land in the same buffer zones, with Spartanburg and Greenville leading the change. Intermittent stream buffers exhibited higher imperviousness (4.6–5.5%) compared to perennial stream buffers (3.3–4.5%), highlighting the increased urban pressure on these sensitive areas. Furthermore, tree canopy loss was significant, with counties such as Greenwood and Chesterfield experiencing substantial reductions in canopy cover. The use of high-resolution NAIP imagery validated the land-cover classifications, ensuring accuracy in the results. The findings emphasize the need for effective land-use management, particularly in the riparian zones, to mitigate the adverse impacts of urban expansion and to safeguard water quality and biodiversity in South Carolina’s streams.

What can the Glasgow Declaration on Forests bring to global emission reduction?

Fixed-width buffer zones on rivers and streams are designed to protect the diverse riparian community and its important function in the ecosystem. However, recent data suggest that riparian areas of some western forests have become more fire prone because of restrictions on fuel reduction treatments within buffer zones. Surprisingly little is known about where and how the plant community transitions from riparian to upland vegetation, but understanding that transition would inform the restoration of riparian forest structure and function and its associated management applications (e.g., prescribed fire or mechanical thinning) that may be necessary to achieve restoration. Using data collected from the Kings River Experimental Watersheds, we assessed the transition in plant structure and composition from riparian near-stream areas to upland locations, in mixed-conifer and red fir forests on headwater streams of the southern Sierra Nevada, CA. Our data strongly support the conclusion that the riparian zone, as evidenced by the riparian plant community, extends beyond 10 m from the stream on these narrow, first- and second-order streams. The herbaceous community at 10 m from the stream was distinct from the upland community and had greater similarity to locations closer to the stream in mixed-conifer forest. Species richness was three to four times greater in riparian areas compared with upland areas, and there was little overlap of the more-abundant herbaceous species. In addition, riparian forests were generally denser, with smaller trees in mixed-conifer forest, but had similar stand structure to upland forests in red fir forest. Differences between mixed-conifer and red fir forests may reflect different departures from the historical fire regime in these two community types. Compared with riparian areas of wetter climates, riparian areas of dry climates, such as the Sierra Nevada, may harbor even greater species diversity relative to nearby upland areas, indicating that buffer zones of restricted management may be justified in these forests if the goal is the preservation of biodiversity. However, perhaps more important, these findings, along with recent literature, highlight the need to identify site-specific goals when undertaking restoration of riparian forests in the western USA: herbaceous biodiversity, fuels reduction, historic tree composition and structure, and/or water quality.

The Upper Guinean Forest region of West Africa, a globally significant biodiversity hotspot, is among the driest and most human-impacted tropical ecosystems. We used Landsat to study forest degradation, loss, and recovery in the forest reserves of Ghana from 2003 to 2019. Annual canopy cover maps were generated using random forests and results were temporally segmented using the LandTrendr algorithm. Canopy cover was predicted with a predicted-observed r2 of 0.76, mean absolute error of 12.8%, and mean error of 1.3%. Forest degradation, loss, and recovery were identified as transitions between closed (>60% cover), open (15–60% cover) and low tree cover (< 15% cover) classes. Change was relatively slow from 2003 to 2015, but there was more disturbance than recovery resulting in a gradual decline in closed canopy forests. In 2016, widespread fires associated with El Niño drought caused forest loss and degradation across more than 12% of the moist semi-deciduous and upland evergreen forest types. The workflow was implemented in Google Earth Engine, allowing stakeholders to visualize the results and download summaries. Information about historical disturbances will help to prioritize locations for future studies and target forest protection and restoration activities aimed at increasing resilience.

Ecological restoration programs reduced forest fragmentation by stimulating forest expansion

Structural and determinate factors for the composition of assemblages of species are diverse. Two theories attempt to explain the pattern of species composition in assemblies using different approaches—i.e., Niche Theory and Neutral Theory. Anurans have complex responses to habitat structure. Species of Pristimantis are good indicators for conservation because they are organisms with direct development. The effect of habitat structure on species of Pristimantis in a bamboo-dominated remnant forest located in southwestern Amazonia is analyzed herein. Active visual and auditory searches in 10 plots of the Biodiversity Research Program (PPBio) were conducted between November 2012 and May 2013. Four hundred and sixty individuals of five species were recorded: Pristimantis altamazonicus, P. diadematus, P. fenestratus, P. reichlei, and P. skydmainus. Neither spatial distance nor the structure of the habitat of the plots affected the composition of Pristimantis. The first axis of PCA explained 45.6% variation of the characterization habitat structure, correlated significantly with the number of Pristimantis, species increasing with trees between 10 ≤ dbh &amp;lt; 30 cm and decreased with density of bamboo. The increase in litter depth and canopy cover influenced in the occurrence of P. reichlei, the occurrence of P. skydmainus decreased with increased density of bamboo and trees dbh ≥ 30 cm and the occurrence of P. diadematus decreased relative to increased canopy cover. Pristimantis diadematus and P. skydmainus were the most restricted species in terms of habitat and were especially susceptible to bamboo density.

Effectiveness of functional zones in National Nature Reserves for the protection of forest ecosystems in China

Forest restoration is a strategy to reverse forest loss and degradation. We overviewed deforestation in the period 1975–2018 in the Brazilian Amazon and the projects, techniques, and scientific publications conducted to recover forest in the area by 2019. We used GIS to assess forest loss and a systematic data collection gathered from 12 universities, five major environmental agencies, and an ad-hoc bibliographic survey that rendered information from 405 restoration projects and 152 published studies. The Brazilian Amazon has undergone an accelerated deforestation in the last 43 years, resulting in 20% (788,353 km2) of its territory deforested by 2018. Deforestation rate was 27,033 km2 yr−1 between 1975 and 1987 and 14,542 km2 yr−1 between 1988 and 2018 (1.97% yr−1 of forest loss between 1975 and 2018). In 2018, 41 Amazonian municipalities were classified as priority areas for monitoring and control deforestation and 21 additional municipalities were deemed as areas with controlled deforestation. Our survey identified 405 projects of forest restoration in 191 municipalities between 1950 and 2017. The majority (229) of these projects used seedling planting as the main forest restoration technique. Forest restoration projects based upon agroforestry systems (144), assisted natural regeneration (27), and natural regeneration (5) were also identified. Despite a considerable number of projects and publications, the region still lacks scientific studies that reinforce the choice of best practices for forest restoration, and the information currently available is not enough to quantify what has already been recovered or the potential area to be restored.

Remotely piloted aircrafts (RPAs) are becoming well-known for monitoring forest restoration (FR). Canopy cover percentage on a restoration site is a major indicator for the early phases of FR. We present a protocol to evaluate canopy cover using low-cost RPA and a friendly computational environment. We tested the protocol in six FR projects in the Brazilian Atlantic Forest. After processing the images automatically to generate the digital surface model and the digital terrain model, the canopy cover is measured in QGIS by considering height thresholds in the canopy height model. The results hadF1 values higher than 0.9, which confirms a robust methodology that does not require specific computer science or remote sensing skills. Thus, low-cost RPA proved to be accurate and user-friendly in measuring the canopy cover, which improves monitoring during most FR stages. Such finding plays an important role in FR policies and future works must study a user-friendly protocol for measuring tree height via low-cost drones.

Historical land-use practices have caused forest loss in Cambodia’s Tonle Sap Lake area (TSLA), the largest freshwater lake in Southeast Asia. However, it remains unclear if this deforestation trend had continued since 2001 when the land was designated as protected areas. Using satellite imagery, we investigated forest conversion flows and fragmentation patterns in the TSLA for 1992–2001, 2001–2010, and 2010–2019, respectively. Results show substantial forest losses and fragmentations occurring at the lower floodplain where the protected areas are located until 2010, with some forest regain during 2010–2019. The land conversions indicated that forest clearing and agricultural farming were the primary causes for observed extensive forest loss during 1992–2010. Hence, despite the creating of protected areas in 2001, our findings reveal the persistence of alarming forest loss in the TSLA until 2010. On the other hand, while net forest loss has stopped after 2010, forest regain during 2010–2019 is way too small to restore the region’s total forest area to even the level when the protected areas were established. Thus, more effective planning and implementations of forest management and restoration policies are needed for the TSLA.

The Barandabhar forest corridor (BFC) in the Royal Chitwan National Park is an example of a buffer zone implemented to mitigate the effect of local communities on conservation and the effect of conservation on local communities. However, the effectiveness of these actions for conservation may depend on the intensity of human activity and the species considered. We conducted a field survey within the BFC to study how termite mound occurrences relate to forest edges, human activity and canopy cover, and to examine the spatial patterns of the edge effect in terms of dead wood availability, logging and canopy cover. The results show that termite mound abundance was significantly affected by edge effects such that the abundance increased from ~5 mounds/ha along the edge to ~14mounds/ha in the core areas 2 km inside the forest. The forest edge was partly defined by decreased canopy cover and increased signs of logging. Our results suggest that buffer zone practices may be a valid method to mitigate edge effects on termites in core areas. However, we also found indications of human activities effecting canopy cover that could influence the effectiveness of buffer zone management in this area. Key words: Chitwan, isoptera, spatial distribution, dead wood, gap dynamic, disturbance, microclimate, buffer zone, edge effect.

&amp;lt;p&amp;gt;Soils play an important role in the Earth's greenhouse gas cycle. The gas dynamics in soils are tightly coupled to gas dynamics in plants, trees, and surface waters. Riparian soils receive and process solutes leaching from upland areas and act as crucial buffers of land-use effects on various ecological and biogeochemical properties of surface waters. However, their role in greenhouse gas cycling is poorly understood. Forest clear-cutting often increases the leaching of organic carbon, nutrients and greenhouse gases in groundwater. Unfortunately, the fate of these substances on their way from upland clear-cut areas through riparian forest buffer zones left along streams after clear-cutting is unknown, but highly relevant for watershed-scale greenhouse gas budgets. Here, we performed a watershed-scale experiment to investigate the effect of clear-cutting on greenhouse gas dynamics in riparian forest buffer zones in a Swedish boreal headwater catchment. The experiment included weekly to monthly sampling during April-October before (2020) and after (2021) forest clear-cutting performed in February 2021, and included a treatment watershed and an untreated reference watershed. We measured concentrations of carbon dioxide (CO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;), methane (CH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;) and nitrous oxide (N&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O) in soils using gas probes installed at various depths within the zone of groundwater level fluctuations along four transects from the clear-cut area through riparian forest buffer zones to near-stream sites. We also measured fluxes of these gases between the atmosphere and the forest floor, as well as tree stems, using flux chamber techniques. Initial results suggest that the clear-cutting increased CO&amp;lt;sub&amp;gt;2 &amp;lt;/sub&amp;gt;and CH&amp;lt;sub&amp;gt;4 &amp;lt;/sub&amp;gt;concentrations in clear-cut soils and the center of riparian buffer zones, but not in near-stream sites. In contrast, the concentrations of N&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O in soils were not affected by forest clear-cutting across the full transects. In terms of greenhouse gas exchange with the atmosphere, the clear-cutting did not affect CO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;, CH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt; and N&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O fluxes at the forest floor. Tree stems were consistent emitters of CO&amp;lt;sub&amp;gt;2 &amp;lt;/sub&amp;gt;and CH&amp;lt;sub&amp;gt;4 &amp;lt;/sub&amp;gt;in 2021, but the clear-cut effect remains unclear due to missing reference data before the clear-cut. Together, these results suggest that the clear-cut induced excess of CO&amp;lt;sub&amp;gt;2 &amp;lt;/sub&amp;gt;and CH&amp;lt;sub&amp;gt;4 &amp;lt;/sub&amp;gt;in upland groundwater was likely consumed in riparian soils or emitted through tree stems, assuming that upland and riparian soils were hydrologically connected. Our results stress the potential importance of riparian buffer zones in mediating clear-cut effects on catchment-scale greenhouse gas budgets.&amp;lt;/p&amp;gt;

Grass filter strips are strips of cool or warm season grasses planted adjacent to agricultural streams to reduce nutrient, pesticide, and sediment input. This conservation practice is the most frequently planted riparian buffer type in the United States. Previous studies have not evaluated how grass filter strips alter the structure and function of riparian habitats of agricultural streams. Our objective was to examine the research hypothesis that planting grass filter strips will influence the structure and function of riparian habitats of channelized agricultural headwater streams. We sampled riparian vegetation, quantified coarse particulate organic matter input and nutrient input, and measured water temperature within two unplanted riparian habitat sites, two riparian habitat with grass filter strips sites, and two forested riparian habitat sites of agricultural headwater streams in central Ohio. Forested riparian habitats exhibited greater percent maximum frequency of woody vegetation and reduced water temperatures than unplanted riparian habitats and grass filter strips. Forested riparian habitats also exhibited greater canopy cover, woody vegetation taxa richness, and coarse particulate organic matter input than grass filter strips and greater riparian widths and woody vegetation abundance than unplanted riparian habitats. Grass filter strips did not differ in structure and function from unplanted riparian habitats. We conclude that planting grass filter strips does not influence the structure and function of riparian habitats of channelized agricultural headwater streams.

Large‐scale forest loss and degradation have dire consequences for biodiversity maintenance and provision of vital ecosystem services. Despite recent increasing efforts for forest restoration and sustainable management, there have been no comparative studies of biological taxonomy and multiple ecosystem functions to assess the effectiveness of forest restoration programmes, and how they vary through space and time. Here, we provided a quantitative assessment of the recovery of biodiversity and ecosystem functions by forest restoration in China using a meta‐analysis of 172 studies. We found that biodiversity and ecosystem functions were substantially increased in restored forests comparing with the degraded states. However, these restoration effects varied considerably by degradation origin, restoration approach, restoration age, ecological domains, taxonomic group and ecosystem function that is measured. Results also revealed that forest restoration from degraded states could not lead to full recovery of biodiversity and ecosystem functions, highlighting the irreplaceability of primary forests. We advocate allowing for natural or passive recovery, especially where biophysical conditions are favourable for spontaneous succession, or too harsh for human‐aided restoration, and choosing a combination of passive and active restoration measures based on adaptive management strategies. Our meta‐analysis provided fundamental insights into bridging the gap between small‐scale experiments and broad‐scale management needs towards highly effective and sustainable forest ecosystem restoration. Copyright © 2017 John Wiley &amp; Sons, Ltd.

The influence of timber harvest on the structure and composition of riparian forests in the Coastal Redwood region