Riparian Reserves Research Articles

Disaster Profile and Response in Urban Informal Settlement of Mathare, Nairobi County, Kenya

Disaster is an event that kills 10 or more people or leaves at least 100 people injured, homeless, displaced or evacuated. In extreme cases, these calamities usually impact negatively on the community and disrupt people’s normal living. Kenya’s informal areas are disaster prone due to households living under high voltage transmissions lines, railway line reserves, pipeline reserves, quarries and landfills, riparian reserves and others adjacent to heavy industrial activities. This dogma of urbanization calls for the need to address the planning needs of slums and informal settlements and making cities work for the urban poor entangled in these poverty and disaster traps. The study objective is to evaluate disaster types, causes, response and mitigation strategies in Mathare slums, Nairobi county, Kenya. Retrospective study design was employed on six purposefully sampled key informants. Interviews and focused group discussion were used in data collection. The period of study was from January to December 2023. The study site was Mathare slum, Nairobi County, Kenya. Statistics of disaster victims and response were derived from local government administrator office records. According to data from the local administration office, the period of January to December 2023 recorded eight disasters. There were four cases of fire that raged down households and businesses in Mathare affecting a total of 199 households. Illegal electricity, negligence and arson attacks were identified as causes of fire disaster. Two cases of landslides were recorded that affected six households, two victims were injured but there was no mortality. Illegal structures built on and under the cliffs with no foundation and pillars have been identified as contributor of landslides in Mathare. There were two flood disasters that affected 1500 households with zero mortality. House structures built on riparian land, on drainage ducts and along riverbanks are the main contributors of floods. The study recommends that The government and partners should invest in educating residents on disaster prevention. Relevant government authorities should inspect and approve construction of buildings in Mathare. Arrest and prosecute of arsonists and educate them against the vice. Government to construct and unclog drainage to manage rain water. Demolish illegal structures along the roads to create access in emergency response. Government and partners to set up disaster and relief coordination center in Mathare.

The Effects of Peat Swamp Forest Patches and Riparian Areas within Large Scale Oil Palm Plantations on Bird Species Richness.

It is well established that oil palm is one of the most efficient and productive oil crops. However, oil palm agriculture is also one of the threats to tropical biodiversity. This study aims to investigate how set-aside areas in an oil palm plantation affect bird biodiversity. The research area includes two set-asides areas: peat swamp forest and riparian reserves and two oil palm sites adjacent to reserved forest sites. A total of 3,074 birds comprising 100 species from 34 families were observed in an oil palm plantation landscape on peatland located in the northern part of Borneo, Sarawak, Malaysia. Results showed that efforts by set-asides forest areas in large scale of oil palm dominated landscapes supported distinct bird species richness. High percentage of the canopies and shrub covers had a positive effect on bird species richness at area between oil palm and peat swamp forest. Herbaceous cover with height less than 1 m influenced the abundance of birds in the plantation closed to the peat swamp forest. The set-aside areas in oil palm plantations are essential in supporting bird's refuges and should be part of oil palm landscape management to improve biodiversity conservation. Thus, provided the forest set-aside areas are large enough and risks to biodiversity and habitat are successfully managed, oil palm can play an important role in biodiversity conservation.

Riparian reserves protect butterfly communities in selectively logged tropical forest

AbstractSelective logging is the most widespread habitat disturbance in tropical forests. Primary forest set‐asides along riparian zones are mandated in many countries and a key question is whether these riparian reserves provide biodiversity conservation benefits.We characterise butterfly communities in fixed‐width riparian reserves of 30 m on each bank along narrow streams (<10 m) paired with interior logged forest transects, and in primary forests within a selective logging concession in the south‐western Brazilian Amazon.We found that primary forest species richness was more similar to riparian reserves than to paired interior logged forest points, whereas abundance remained higher in both riparian reserves and interior logged points, likely due to the intrusion of canopy‐dwelling species in disturbed habitats, as previously reported in the literature. Butterfly assemblages within riparian reserves were more similar to unlogged primary forests than interior logged points, and canopy height in riparian reserves was associated with increased assemblage similarity to primary forest points.Changes in abundance relative to primary forest were of a larger magnitude in interior logged points than in riparian reserves within logged forests, highlighting the role of riparian reserves in maintaining primary forest‐like communities. We found no particular primary forest butterfly clades to be more sensitive to changes in abundance than other clades.Synthesis and applications. Mandatory conservation set‐asides around streams or rivers (riparian buffers) have an important role in protecting the abundance and composition of primary forest butterfly assemblages within selective logging concessions in tropical rainforests. This study highlights the need to assess the conservation value of protecting unlogged riparian forest strips in other taxa to inform policy.

OBJECT-BASED CHANGE DETECTION ON ACACIA XANTHOPHLOEA SPECIES DEGRADATION ALONG LAKE NAKURU RIPARIAN RESERVE

Abstract. Automated mapping of heterogeneous riparian landscape is of high interest to assess our planet. Still, it remains a challenging task due to the occurrence of flooded vegetation. While both optical and radar images can be exploited, the latter has the advantage of being independent acquisition conditions. However, and despite their popularity, the threshold-based approaches commonly used present some drawbacks such as not taking into account the spatial context and providing mixed pixels within class boundaries. In this study, we propose a novel methodology to avoid such issues by using an object-based image analysis approach on polarimetric radar data. We use our workflow to map the degrading Acacia x. species along lake Nakuru Riparian reserve, and obtain highly-accurate results.

Connected riparian reserves retain high avian phylogenetic diversity in Amazonian oil palm

Expansion of oil palm is a major driver of deforestation and species losses. Retention of forested riparian reserves within agricultural landscapes helps to minimize the negative effects on biodiversity and offers refuges for forest species. A key unknown is the evolutionary range and diversity of species that these reserves can support, and which elements of landscape configuration enhance the conservation of phylogenetic diversity. We focus on birds in the Eastern Amazon, a region with rapid expansion of oil palm. Using point counts, we sampled in eleven transects per habitat type: large forest fragments (the most intact forests in the region); riparian reserves, and oil palm plantation. Riparian reserves spanned a variety of widths, distances to nearest forest patches, and connectivity with fragments. Riparian reserves support similar phylogenetic diversity and distinctiveness to large forest fragments and on average 200 million more years of evolutionary history than oil palm plantations. Evolutionary Distinctiveness (ED) was directly impacted by landscape configuration, with lower ED in riparian reserves connected to forest, while Phylogenetic Diversity (PD) and the Mean Pairwise Distance (MPD) in connected riparian reserves and closer to forest was slightly higher. In finding that riparian reserves retain significant avian phylogenetic diversity and distinctiveness, we underscore their key role in maintaining landscape-level biodiversity within oil palm and provide evidence for their continued protection. Support for the importance of maintaining connectivity to forest fragments in protecting phylogenetic diversity suggests that conservation actions should ensure that riparian zones remain connected, potentially benefiting biodiversity within otherwise-isolated forest fragments that dominate the Eastern Amazon.

Low forest-loss thresholds threaten Amazonian fish and macroinvertebrate assemblage integrity

Deforestation is a major threat globally, but especially in tropical regions because they are biodiversity strongholds and carbon storehouses. Some studies have reported changes in species richness and composition in lotic ecosystems with increased forest-loss in their catchment, presumably resulting from the replacement of sensitive taxa by more resistant or tolerant taxa. Also, sensitive taxa respond to deforestation in a non-linear manner and fish and macroinvertebrates have different sensitivities to landscape pressures. Therefore, it is useful to determine the effects of forest-loss on widespread sensitive or threshold taxa in aquatic ecosystems. We used Threshold Indicator Taxa Analysis (TITAN) to assess forest-loss and land use history impacts in 92 eastern Amazonian stream sites. We determined TITAN peak-change thresholds for fish at 1% and 6% of forest-loss at total-catchment and local-riparian spatial extents, respectively, and at 2% and 40% of land-use intensity change at total-catchment and local-riparian spatial extents, respectively. For macroinvertebrates, TITAN peak-change thresholds were 1% and 11% of forest loss at total-catchment and local-riparian spatial extents, respectively, and at 3% of land-use intensity change for both total-catchment and local-riparian spatial extents. Because of these thresholds, inherent ecoregional variability and key literature, we have three major recommendations. 1) Logging should be prohibited in riparian reserves that are at least 100-m wide on each side of headwater streams and in a network of catchments across all biomes and as many landscape types as possible. 2) An ecologically and statistically rigorous monitoring program with standard methods should be implemented to assess and regulate land uses better. 3) Conservation planning areas should consider aquatic biota as well as terrestrial biota.

Evaluating the current ecological status and proposing rehabilitation interventions for the low flooded riparian reserve forest in Punjab Pakistan

Aim of Study: The complex community of riparian reserve forest has become of great concern for researchers to develop more viable management strategies. The paper aimed to evaluate the current structural diversity of vegetation and its association with the physical environment of low-lying forest for proposing the rehabilitation interventions. Area of Study: We studied two forests, Chung-Mohlanwal and Dhana-Bheni on both riverbanks along river Ravi in the Jhok riparian reserve forest situated in the southwest of Lahore, Pakistan.Material and Methods: A methodological framework was developed based firstly, on direct comparison of diversity (measured by Hill numbers) and structure of existed vegetation layers (trees, shrubs, herbs, and grasses) and environmental factors (canopy structure, anthropogenic activities, microclimate, and soil characteristics) between the two forests and secondly, on environment-vegetation association using Canonical Correspondence Analysis (CCA) ordination method.Results: Dhana forest was more diverse vegetation layers (Shannon Diversity index 1D < 11) and intact due to plantation of uneven-aged tree stands of varied stand basal area and stem density. Microclimate under this forest could not support the dominant understory positively unlike the monoculture forest. On the contrary, Chung-Mohlanwal forest was under the influence of uncontrolled grazing activities, fuelwood extraction, and invasive species. Multivariate analysis CCA elucidated that most variance was shown by soil characteristics (38.5 %) for understory vegetation in both forests.Research Highlights: Overstory stand structure, species composition, distance to nearby communities, and soil characteristics should be considered for developing forest planting and management strategies.Keywords: Vegetation Structure; Hill Numbers; Grazing; Environment; Management.Abbreviation used: CCA (Canonical Correspondence Analysis); 1D (Shannon Diversity); Ca + Mg (Calcium + Magnesium); Na (Sodium); ECe (Electrical Conductivity); DBH (Diameter at Breast Height); IUCN (International Union for Conservation of Nature); SBA (Stand Basal area); BA (Basal Area); 0D (Richness); 2D (Simpson Index); IVI (Importance Value Index); LU (Livestock Unit); GPS (Global Positioning System); OC (Organic Carbon); OM (Organic matter); SAR (Sodium Adsorption Ratio); N (Nitrogen); P (Phosphorous); K (Potassium); DCA (Detrended Correspondence Analysis); S (Shrub); H (Herb); G (Grass).

Linking instream wood recruitment to adjacent forest development in landscapes driven by stand-replacing disturbances: a conceptual model to inform riparian and stream management

Instream wood plays an important role in stream morphology and creation of fish habitat in conifer forests throughout the temperate zone. In some regions, such as the US Pacific Northwest, many streams currently have reduced amounts of instream wood due to past management activities (timber harvest, wood removal, etc.). These reductions exist against a backdrop of naturally dynamic amounts and distributions of instream wood, which likely fluctuate over time based in part on the stage of development (disturbance and succession) in adjacent riparian forests. Despite many studies on both forest development and instream wood accumulation, the linkages between these processes have not been fully described, particularly as they relate to stream restoration needs. In this paper, we combine literature on forest development, disturbance, and processes that drive instream wood recruitment to more explicitly connect the temporal dynamics of stream wood inputs with the dynamics of adjacent riparian forests. We use moist forests of the Pacific Northwest as an exemplary system, from which to draw broadly applicable patterns for landscapes influenced by stand-replacing disturbance regimes. This conceptual model highlights a U-shaped pattern of instream wood recruitment, in which instream wood is highest after a stand-replacing disturbance and during the old-growth stage, and lowest through the middle stages of forest development (currently the most abundant stages in many landscapes as a result of past forest management practices). This mid-successional period of scarce wood is likely exacerbated in streams with a history of wood removal. The U-shaped pattern suggests that, without higher-than-average levels of disturbance, many streams in landscapes dominated by mid-successional second-growth forests (∼30–80 yr old) will be deficient of instream wood until forest stands are over 200 years old. As such, the balance between the predominant riparian conservation strategy of passive restoration (e.g., unharvested riparian reserves) and the alternative of active restoration (e.g., wood additions and (or) riparian stand treatments) should be carefully considered, depending on management objectives, site context, and potential tradeoffs over time.

SPATIAL PROCESSING OF SENTINEL IMAGERY FOR MONITORING OF ACACIA FOREST DEGRADATION IN LAKE NAKURU RIPARIAN RESERVE

Abstract. Tree degradation in National Parks poses a serious risk to the birds and animals and to a larger extent the general ecosystem. The essence of Forest degradation mapping is to detect the extent of damage on the trees over time, hence providing stakeholders with a basis for forest rehabilitation and intervention. The study proposes a workflow for detection and classification of degrading acacia vegetation along Lake Nakuru riparian reserve. Inspired by previous research on the use of Dual Polarized Sentinel 1 Ground Range Detected (GRD) data for vegetation detection, a set of six Sentinel 1 GRD and Sentinel 2 MSI of corresponding dates (2018–2019) were used. Our study confirms the existing correlation between vegetation indices derived from optical sensors and the backscatter indices from S1 SAR image of the same land cover classes. Factors that were used in validating the results include some comparisons between pixelwise and object-based classification, with a focus on the underlying segmentation and classification algorithms, the polarimetric attributes (VV+VH intensity bands) and the reflectance bands (NIR, SWIR & GREEN), the Haralick features (GLCM) vs. some geometric attributes (area & moment of inertia). Classification carried out on the temporal datasets considering geometric attributes and the Random Forest classifier yielded the highest Overall Accuracy (OA) with 94.25 %, and a Kappa coefficient of 0.90.

Riparian Reserves Promote Insectivorous Bat Activity in Oil Palm Dominated Landscapes

The expansion of oil palm agriculture has contributed to biodiversity loss in Southeast Asia and elsewhere in the tropics. Riparian reserves (areas of native forest along waterways) have the potential to maintain forest biodiversity and associated ecological processes within these agricultural landscapes. Using acoustic sampling, we investigated the value of riparian reserves for insectivorous bats in oil palm plantations in Sabah, Malaysian Borneo. We compared general bat activity, foraging activity, and species occupancy between riparian areas in forest and riparian reserves in oil palm plantations. Overall bat activity varied little between riparian reserves in oil palm and riparian forest. Rather, activity was greatest in areas with a high forest canopy, irrespective of how much forest was available within or outside the riparian reserve. Bat foraging activity, as well as the occupancy of two species, was greatest in the forest sites, and while bats were detected in the oil palm riparian reserves, both foraging and occupancy were more associated with topographic ruggedness than forest amount or height. Our results indicate that habitat structure within riparian reserves may be more important than reserve size for supporting insectivorous bat diversity within oil palm landscapes. These findings provide important insights into the extent of the ecological benefits provided by conservation set-asides in forest-agricultural landscapes in the tropics.

A study of landing behaviour by the walnut twig beetle,Pityophthorus juglandis, among host and nonhost hardwood trees in a northern California riparian forest

AbstractThe host selection behaviour of the walnut twig beetle,Pityophthorus juglandis, was assessed by monitoring the landing rates of the beetles with sticky sheet traps on the host and nonhost hardwood branches.Sticky sheet traps were deployed for 8 weeks from 6 June to 2 August. 2017 in the Putah Creek Riparian Reserve, Davis,CA. Branches from host northern California black walnut,Juglans hindsii, were paired with branches from six nonhost hardwood species.The landing rate ofP.juglandis(412 beetles trapped/8 weeks; 389 on host branches, 23 on nonhost branches) was significantly greater on the host branches for all nonhost hardwoods exceptPopulus fremontii. Proportional comparisons of beetle presence also revealed a significant preference for the host branches compared with all but two nonhost species,Acer negundoandP.fremontii.CapturingP.juglandiswithout the use of an aggregation pheromone was a rare event, underscoring the difficulty of studying the initial phases of host selection behaviour in bark beetles. Unbaited funnel traps adjacent to selected host trees in the experiment only captured five individuals over a 19‐week period. None were captured in traps adjacent to nonhost trees.This study provided evidence thatP.juglandisdiscriminates between host and nonhost branches while in‐flight. This directed flight behaviour is likely informed by the recognition of both host and nonhost volatile cues.This study established an ecological context for the development of a semiochemical‐based repellent system for protecting walnut trees from future attacks from this invasive bark beetle.

Thresholds of freshwater biodiversity in response to riparian vegetation loss in the Neotropical region

Abstract Protecting riparian vegetation around streams is vital in reducing the detrimental effects of environmental change on freshwater ecosystems and in maintaining aquatic biodiversity. Thus, identifying ecological thresholds is useful for defining regulatory limits and for guiding the management of riparian zones towards the conservation of freshwater biota. Using nationwide data on fish and invertebrates occurring in small Brazilian streams, we estimated thresholds of native vegetation loss in which there are abrupt changes in the occurrence and abundance of freshwater bioindicators and tested whether there are congruent responses among different biomes, biological groups and riparian buffer sizes. Mean thresholds of native vegetation cover loss varied widely among biomes, buffer sizes and biological groups: ranging from 0.5% to 77.4% for fish, from 2.9% to 37.0% for aquatic invertebrates and from 3.8% to 43.2% for a subset of aquatic invertebrates. Confidence intervals for thresholds were wide, but the minimum values of these intervals were lower for the smaller riparian buffers (50 and 100 m) than larger ones (200 and 500 m), indicating that land use should be kept away from the streams. Also, thresholds occurred at a lower percentage of riparian vegetation loss in the smaller buffers, and were critically lower for invertebrates: reducing only 6.5% of native vegetation cover within a 50‐m riparian buffer is enough to cross thresholds for invertebrates. Synthesis and applications. The high variability in biodiversity responses to loss of native riparian vegetation suggests caution in the use of a single riparian width for conservation actions or policy definitions nationwide. The most sensitive bioindicators can be used as early warning signals of abrupt changes in freshwater biodiversity. In practice, maintaining at least 50‐m wide riparian reserves on each side of streams would be more effective to protect freshwater biodiversity in Brazil. However, incentives and conservation strategies to protect even wider riparian reserves (~100 m) and also taking into consideration the regional context will promote a greater benefit. This information should be used to set conservation goals and to create complementary mechanisms and policies to protect wider riparian reserves than those currently required by the federal law.

Unique songbird communities in mature riparian spruce forest compared with upland forest in southern Yukon

There has been limited study of songbird communities in different habitats of the lowland boreal forests of southern Yukon, including the mature forest valued for timber harvest. Our goal was to describe the songbird community during the breeding season in a mature (≥80 years since wildfire) forest dominated by white spruce (Picea glauca (Moench) Voss) adjacent to streams (n = 23) and wetlands (n = 15) compared with a nearby upland forest. Based on point count surveys, songbird communities were unique in the mature forest in the riparian forest edge position, including greater species richness and four significant riparian indicator species. Songbird communities were also unique in the forest adjacent to streams versus wetlands. We mapped species observations along 300 m transects from riparian to upland forests and identified nine species with greater abundance closer to the riparian forest edge. Many of these species are typically associated with riparian and wetland habitats for breeding. Most of the variability in the songbird community was explained by study site, likely related to high variability in forest type and amount of wetland and open water but also to unmeasured habitat characteristics. Our results increase the knowledge of songbird communities in this unique boreal region and suggest that riparian reserve zones in forest management may be useful for protecting songbird habitat.

Linking Nitrous Oxide and Nitric Oxide Fluxes to Microbial Communities in Tropical Forest Soils and Oil Palm Plantations in Malaysia in Laboratory Incubations

Current understanding of greenhouse gas (GHG) fluxes associated with land-use change from forest to oil palm on mineral soil is not sufficient to provide reliable estimates of emission rates or advice on GHG mitigation strategies. Monocultures of oil palm have expanded in Southeast Asia, mostly replacing tropical forests. The limited data available have indicated that the land-use conversion is associated with a potentially aggravated GHG burden, including nitrous oxide (N2O) and nitric oxide (NO) emissions, with unclear underlying biological mechanisms. In this study, we investigated N2O and NO emission potentials of tropical soils with different land-uses from Sabah, Malaysian Borneo, under laboratory incubation. Under similar controlled conditions, logged forest and oil palm soils showed high and similar potentials of N2O and NO emissions following increase in soil moisture, while the emissions were negligible in a riparian reserve soil irrespective of moisture conditions. Soil N2O and NO emission rates from logged forest soils and oil palm (OP) plantations were of similar magnitude, with average fluxes over the 35 and 22 day incubation periods, respectively, of 11.5 and 1.6 ng N g-1 h-1 (OP) and 15.6 and 6.0 ng N g-1 h-1 (logged forest). Contrarily, the riparian reserve soil did not respond to rewetting and nitrogen application and fluxes were negligible. Furthermore, N2O fluxes were on average about 10 times higher than NO fluxes. The fact that forest soils also have the potential to emit large amounts of N2O and NO, has important implications for land-use change scenarios in the tropics, especially as some scenarios suggest atmospheric N deposition is likely to drastically increase in tropical regions due to biomass burning, increased N-fertilizer use and fossil fuel consumption. Quantification of related gene transcripts implied that Proteobacterial nirS and AniA-nirK (betaproteobacterial clade of Neisseria) containing denitrifiers might continuously contribute to the N2O emissions, while the nitrifiers (ammonia oxidizing archaea in this study) are conditionally active to produce N2O. This study therefore provides some evidence for N2O and NO emissions associated with phylogenetically diverse groups of microorganisms, which might be of importance in modulating the GHG emissions under different land-uses and field conditions.

Movement of Moths Through Riparian Reserves Within Oil Palm Plantations

Tropical forests are becoming increasingly fragmented through conversion to agriculture, with negative consequences for biodiversity. Movement of individuals among the remaining fragments is critical to allow populations of forest-dependent taxa to persist. In SE Asia, conversion of forests to oil palm plantations is a particular threat. Many oil palm dominated landscapes retain forested riparian reserves along streams and rivers, but the extent to which these riparian reserves are used for movement, relative to the oil palm matrix, is poorly understood. We used mark-release-recapture methods to investigate the movement of five moth taxa in riparian reserves connected to a continuous forest area within oil palm matrix in Sabah, Malaysian Borneo. Moths were recaptured on average 68m from the release point, and the mean time to recapture was between 2 and 3 days. Moths showed a significant tendency to move within forested riparian reserves than into adjacent oil palm. When moving within riparian reserves moths also showed a tendency to orient their movement away from the continuous forest into the riparian reserve rather than towards continuous forest or into oil palm. Overall, our results show a role for riparian reserves as movement corridors through oil palm plantations for some invertebrate species, strengthening the case for their retention and re-establishment.

Management of the Effects of Land Use Changes on Urban Infrastructure Capacity: A Case Study of Ruaka Town, Kiambu County, Kenya

Land use change is a major driver to the effects of climate change and other socio-economic and environmental challenges, a major challenge policy makers, planners and urban managers grapple with. Ruaka town is no exception as it faces high rapid land use change with myriad challenges on the management of the effects on urban infrastructure and aggravated by inadequate inter-agencies, coordination and collaboration. The study is an investigation of the effects of land use changes on urban infrastructure (roads, water supply, and wastewater infrastructure). It seeks to answer the drivers of land use changes and document the spatial-temporal land use changes between the years 1988 to 2019, establish their effects on infrastructure. The study establishes decline in vegetation and agriculture and rise in built -up areas which is partially contributed by urbanization and population growth in the area with major land fragmentations and land use conversions. The findings reveal encroachment of development to vegetation and riparian reserves which expose the human population to disasters and calamities in cases of climate change. Lack of approved planning policy has encouraged massive land use changes due to the ad hoc nature of planning using the development control tools which are not documented. The key drivers of land use changes deduced were good accessibility of the area, land speculation for investments, high returns from investments, demand for housing and accommodation and high population growth. The adverse effects on urban infrastructure includes pollution and contamination of water sources, traffic congestion, use of unconventional onsite waste management practices such as pit latrines and septic tanks for waste water management. The study concluded by evolving a management strategy to unravel the challenges through promotion of a sustainable and resilient urban infrastructure. The strategies emphasize on the technical, social, economic, environmental and jurisdictional dimensions.

Buffer zones for placing baited traps in grasslands bordering forests and availability of riparian reserves of trees in grasslands: A preliminary study for dung beetle assemblages in East Kalimantan, Indonesia

Buffer zones for placing baited traps in grasslands bordering forests and availability of riparian reserves of trees in grasslands: A preliminary study for dung beetle assemblages in East Kalimantan, Indonesia

Riparian reserves help protect forest bird communities in oil palm dominated landscapes

Abstract Conversion of forest to oil palm agriculture is a significant and ongoing threat to tropical biodiversity. Despite this, little is known about the value of riparian reserves in oil palm and how these conservation set‐asides might best be managed to maintain biodiversity. We characterized bird communities of 28 sites in an oil palm‐forest mosaic in Sabah, Malaysia using 6,104 encounters from 840 point counts. Sites included oil palm riparian reserves of various vegetation quality and reserve widths, which were compared to oil palm streams without a riparian reserve as well as riparian and nonriparian control areas in continuous logged forest. Riparian reserves, oil palm waterways, and control sites in riparian and nonriparian forest supported distinct avifaunal communities. Riparian reserve width, forest quality, and amount of forest cover were the strongest predictors of bird species richness. For forest‐dependent species, each of these predictors had a stronger effect size when compared with all species. On average, reserves held 31% of all species and 30% of forest specialists, whereas riparian forest controls averaged 32% of all species, but 38% of forest species. Riparian reserves with >40 m of natural vegetation on each bank supported similar bird diversity to riparian forest control habitats found in continuous forest. However, to support equivalent numbers of forest‐dependent species and species of conservation concern, reserves would need to be at least 100‐m wide on each bank. The largest numbers of species were found in riparian reserves with above‐ground carbon densities exceeding 75 tC/ha, highlighting the importance of forest quality, as well as width, in supporting riparian bird communities. Synthesis and applications. If designed and protected appropriately, riparian reserves in oil palm estates support diverse bird communities, including many species of conservation concern. This can be achieved by designating large reserves (80–200 m total width). But, to maximize species numbers, forest disturbance should also be minimized prior to conversion as well as during plantation operations.

Land-use change is associated with a significant loss of freshwater fish species and functional richness in Sabah, Malaysia

Global biodiversity is being lost due to extensive anthropogenic land cover change. In Southeast Asia, biodiversity-rich forests are being extensively logged and converted to oil-palm monocultures. The impacts of this land-use change on freshwater ecosystems, and particularly on freshwater biodiversity, remain largely understudied and poorly understood. We assessed the differences between fish communities in headwater stream catchments across an established land-use gradient in Sabah, Malaysia (protected forest areas, twice-logged forest, salvage-logged forest, oil-palm plantations with riparian reserves, and oil-palm plantations without riparian reserves). Stream fishes were sampled using an electrofisher, a cast net and a tray net in 100 m long transects in 23 streams in 2017. Local species richness and functional richness were both significantly reduced with any land-use change from protected forest areas, but further increases in land-use intensity had no subsequent impacts on fish biomass, functional evenness, and functional divergence. Any form of logging or land-use change had a clear and negative impact on fish communities, but the magnitude of that effect was not influenced by logging severity or time since logging on any fish community metric, suggesting that just two rounds of selective impact (i.e., logging) appeared sufficient to cause negative effects on freshwater ecosystems. It is therefore essential to continue protecting primary forested areas to maintain freshwater diversity, as well as to explore strategies to protect freshwater ecosystems during logging, deforestation, and conversion to plantation monocultures that are expected to continue across Southeast Asia.

Abiotic and Biotic Contributors to Support Inter-Epidemic Francisella tularensis in an Agricultural Peri-Urban Environment.

To characterize the inter-epidemic ecology of Francisella tularensis, we surveyed vertebrates and invertebrates for the abundance, spatial distribution, and status of infection at a site in northern California that had evidence of endemic type B tularemia. We collected 2910 mosquitoes, 77 biting flies, 704 ticks, 115 mammals, and 1911 aquatic invertebrates in 2013-2014. Real-time PCR on all mosquitoes, 40 biting flies, 113 aquatic invertebrates, and 650 ticks did not detect F. tularensis DNA. Indirect enzyme linked immunosorbent assay (ELISA) on 109 mammals revealed 2 (of 2, 100%) seropositive feral cats, 1 (of 24, 4.5%) seropositive black rat, and 5 (of 10, 50%) seropositive Virginia opossums. A riparian reserve, ∼1 km from the primate research center, had the highest seroprevalence in mammals and the highest capture success for invertebrate vectors whereas opossums, cats, and ground squirrels in close proximity to the primate center had high seroprevalence and abundant fleas. Well-vegetated regions with standing water appeared to be ideal habitats for biotic components of tularemia enzootic persistence. Mesocarnivores may facilitate the spread of F. tularensis, and high densities of rodents and their fleas may be a mechanism for amplification and spillover.