scholarly journals The Relative Importance of Agricultural and Wetland Habitats to Waterbirds in the Sacramento–San Joaquin River Delta of California

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
W. David Shuford ◽  
Matthew Reiter ◽  
Kristin Sesser ◽  
Catherine Hickey ◽  
Gregory Golet
Keyword(s):  
Central Valley ◽  
Positive Association ◽  
Open Water ◽  
Biodiversity Loss ◽  
Habitat Associations ◽  
Conservation Strategies ◽  
San Joaquin River ◽  
Conservation Actions ◽  
Surrounding Landscape ◽  
Abundance And Distribution

Biodiversity loss from agricultural intensification underscores the urgent need for science-based conservation strategies to enhance the value of agro-ecosystems for birds and other wildlife. California’s Central Valley, which has lost over 90% of its historical wetlands and currently is dominated by agriculture, still supports waterbird populations of continental importance. A better understanding of how waterbirds use available habitat is particularly needed in the Sacramento–San Joaquin Delta, an ecosystem under threat. From 2013 to 2015, we studied waterbird habitat associations in the Delta during fall migration and winter by conducting diurnal counts at random locations in key waterbird habitats throughout the Delta. Waterbird use of cover types (agricultural crops and managed wetlands) varied substantially among waterbird groups, by season, and among geographic sub-regions of the Delta. Overall, wetlands were particularly important to waterbirds in fall. In winter, wetlands and flooded rice and corn were important to many waterbird groups, and non-flooded corn and irrigated pasture to geese and cranes. The factors that influenced waterbird abundance and distribution also varied substantially among groups and differed at various geographic scales. In both seasons, most groups had a positive association at the field level with flooded ground and open water, and a negative association with vegetation. Given the great uncertainty in the future extent and pace of habitat loss and degradation in the Delta, prioritizing the conservation actions needed to maintain robust waterbird populations in this region is urgent. For the Delta to retain its importance to waterbirds, a mosaic of wetlands and wildlife-friendly crops that accounts for the value of the surrounding landscape must be maintained. This includes restoring additional wetlands and maintaining corn, rice, alfalfa, and irrigated pasture, and ensuring that a substantial portion of corn and rice is flooded in winter.

scholarly journals The Relative Importance of Agricultural and Wetland Habitats to Waterbirds in the Sacramento–San Joaquin River Delta of California

2018 ◽  
Vol 16 (4) ◽  
Author(s):  
W. David Shuford ◽  
Matthew Reiter ◽  
Kristin Sesser ◽  
Catherine Hickey ◽  
Gregory Golet
Keyword(s):  
Central Valley ◽  
Positive Association ◽  
Open Water ◽  
Biodiversity Loss ◽  
Habitat Associations ◽  
Conservation Strategies ◽  
San Joaquin River ◽  
Conservation Actions ◽  
Surrounding Landscape ◽  
Abundance And Distribution

Biodiversity loss from agricultural intensification underscores the urgent need for science-based conservation strategies to enhance the value of agroecosystems for birds and other wildlife. California’s Central Valley, which has lost over 90% of its historical wetlands and currently is dominated by agriculture, still supports waterbird populations of continental importance. A better understanding of how waterbirds use available habitat is particularly needed in the Sacramento–San Joaquin Delta, an ecosystem under threat. From 2013 to 2015, we studied waterbird habitat associations in the Delta during fall migration and winter by conducting diurnal counts at random locations in key waterbird habitats throughout the Delta. Waterbird use of cover types (agricultural crops and managed wetlands) varied substantially among waterbird groups, by season, and among geographic subregions of the Delta. Overall, wetlands were particularly important to waterbirds in fall. In winter, wetlands and flooded rice and corn were important to many waterbird groups, and non-flooded corn and irrigated pasture to geese and cranes. The factors that influenced waterbird abundance and distribution also varied substantially among groups and differed at various geographic scales. In both seasons, most groups had a positive association at the field level with flooded ground and open water and a negative association with vegetation. Given the great uncertainty in the future extent and pace of habitat loss and degradation in the Delta, there is an urgency to prioritize conservation actions needed to maintain robust waterbird populations in this region. For the Delta to retain its importance to waterbirds, it will be necessary to maintain a mosaic of wetlands and wildlife-friendly crops that accounts for the value of the surrounding landscape. This includes restoring additional wetlands and maintaining corn, rice, alfalfa, and irrigated pasture, and ensuring that a substantial portion of corn and rice is flooded in winter.

scholarly journals Aridity-driven shift in biodiversity–soil multifunctionality relationships

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Weigang Hu ◽  
Jinzhi Ran ◽  
Longwei Dong ◽  
Qiajun Du ◽  
Mingfei Ji ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Arid Regions ◽  
Environmental Gradients ◽  
Positive Association ◽  
Biodiversity Loss ◽  
Northern China ◽  
Ecosystem Functions ◽  
Conservation Strategies ◽  
Soil Microbial Diversity ◽  
Ecosystem Multifunctionality

AbstractRelationships between biodiversity and multiple ecosystem functions (that is, ecosystem multifunctionality) are context-dependent. Both plant and soil microbial diversity have been reported to regulate ecosystem multifunctionality, but how their relative importance varies along environmental gradients remains poorly understood. Here, we relate plant and microbial diversity to soil multifunctionality across 130 dryland sites along a 4,000 km aridity gradient in northern China. Our results show a strong positive association between plant species richness and soil multifunctionality in less arid regions, whereas microbial diversity, in particular of fungi, is positively associated with multifunctionality in more arid regions. This shift in the relationships between plant or microbial diversity and soil multifunctionality occur at an aridity level of ∼0.8, the boundary between semiarid and arid climates, which is predicted to advance geographically ∼28% by the end of the current century. Our study highlights that biodiversity loss of plants and soil microorganisms may have especially strong consequences under low and high aridity conditions, respectively, which calls for climate-specific biodiversity conservation strategies to mitigate the effects of aridification.

scholarly journals A first assessment of the distribution and abundance of large pelagic species at Cocos Ridge seamounts (Eastern Tropical Pacific) using drifting pelagic baited remote cameras

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0244343
Author(s):  
Marta Cambra ◽  
Frida Lara-Lizardi ◽  
César Peñaherrera-Palma ◽  
Alex Hearn ◽  
James T. Ketchum ◽  
...  
Keyword(s):  
Positive Association ◽  
Open Water ◽  
Distribution Patterns ◽  
Sea Turtle ◽  
Tropical Pacific ◽  
Eastern Tropical Pacific ◽  
Pelagic Species ◽  
Remote Cameras ◽  
Water Ecosystems ◽  
Abundance And Distribution

Understanding the link between seamounts and large pelagic species (LPS) may provide important insights for the conservation of these species in open water ecosystems. The seamounts along the Cocos Ridge in the Eastern Tropical Pacific (ETP) ocean are thought to be ecologically important aggregation sites for LPS when moving between Cocos Island (Costa Rica) and Galapagos Islands (Ecuador). However, to date, research efforts to quantify the abundance and distribution patterns of LPS beyond the borders of these two oceanic Marine Protected Areas (MPAs) have been limited. This study used drifting-pelagic baited remote underwater video stations (BRUVS) to investigate the distribution and relative abundance of LPS at Cocos Ridge seamounts. Our drifting-pelagic BRUVS recorded a total of 21 species including elasmobranchs, small and large teleosts, dolphins and one sea turtle; of which four species are currently threatened. Depth of seamount summit was the most significant driver for LPS richness and abundance which were significantly higher at shallow seamounts (< 400 m) compared to deeper ones (> 400m). Distance to nearest MPA was also a significant predictor for LPS abundance, which increased at increasing distances from the nearest MPA. Our results suggest that the Cocos Ridge seamounts, specifically Paramount and West Cocos which had the highest LPS richness and abundance, are important aggregation sites for LPS in the ETP. However, further research is still needed to demonstrate a positive association between LPS and Cocos Ridge seamounts. Our findings showed that drifting pelagic BRUVS are an effective tool to survey LPS in fully pelagic ecosystems of the ETP. This study represents the first step towards the standardization of this technique throughout the region.

scholarly journals Impact of extreme drought and incentive programs on flooded agriculture and wetlands in California’s Central Valley

2018 ◽  
Author(s):  
Matthew E Reiter ◽  
Nathan Elliott ◽  
Dennis Jongsomjit ◽  
Gregory H Golet ◽  
Mark D Reynolds
Keyword(s):  
Surface Water ◽  
Large Fraction ◽  
Central Valley ◽  
Open Water ◽  
Extreme Drought ◽  
Freshwater Wetland ◽  
Post Harvest ◽  
Incentive Programs ◽  
Managed Wetlands ◽  
The Impact

Between 2013 and 2015 a large part of the western United States, including the Central Valley of California, sustained an extreme drought. The Central Valley is recognized as a region of hemispheric importance for waterbirds which use flooded agriculture and wetlands as habitat. Thus, the impact of drought on the distribution of surface water needed to be assessed to understand the effects on waterbird habitat availability. We used satellites to quantify the impact the recent extreme drought on the timing and extent of available waterbird habitat during the non-breeding season (July – May) by examining flooding in agriculture (rice, corn, and other crops) and managed wetlands across the Central Valley. We assessed the influence of habitat incentive programs, particularly The Nature Conservancy’s BirdReturns and the Natural Resources Conservation Service’s Waterbird Habitat Enhancement Program (WHEP), at offsetting waterbird habitat loss related to drought. Overall, we found significant declines in open water in post-harvest agriculture (20 – 80% declines) and in managed wetlands (47 – 59% declines) during the 2013 – 2015 drought compared to non-drought years 2000 – 2011. Crops associated with the San Joaquin Valley, specifically corn, as well as wetlands in that part of the Central Valley exhibited larger reductions in open water than rice and wetlands in the Sacramento Valley. However, seasonal wetlands on protected lands had a marginally significant (P<0.10) higher amount of open water in the drought years than those on non-protected lands. A large fraction of the daily open water in rice during certain times of the year, particularly in the fall for BirdReturns (64%) and the winter for WHEP (100%), may have been provided through incentive programs underscoring the contribution of these programs. However, further assessment is needed to know how much the incentive programs directly offset the impact of drought in post-harvest rice or simply supplemented funding for activities that might have been done regardless. Our, first of its kind, landscape analysis documents the significant impacts of the drought on freshwater wetland habitats in the Central Valley and highlights the value of using satellite data to track surface water and waterbird habitats. More research is needed to understand subsequent impacts on the freshwater dependent species that rely on these systems and how incentive programs can most strategically support vulnerable species during future drought.

scholarly journals Modeling the spatial structure of the endemic mara (Dolichotis patagonum) across modified landscapes

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6367 ◽  
Author(s):  
Milagros Antún ◽  
Ricardo Baldi
Keyword(s):  
Spatial Structure ◽  
Spatial Variation ◽  
Spatial Models ◽  
Distribution Patterns ◽  
Negative Consequences ◽  
Human Presence ◽  
Species Response ◽  
Conservation Actions ◽  
Density Surface ◽  
Abundance And Distribution

Across modified landscapes, anthropic factors can affect habitat selection by animals and consequently their abundance and distribution patterns. The study of the spatial structure of wild populations is crucial to gain knowledge on species’ response to habitat quality, and a key for the design and implementation of conservation actions. This is particularly important for a low-density and widely distributed species such as the mara (Dolichotis patagonum), a large rodent endemic to Argentina across the Monte and Patagonian drylands where extensive sheep ranching predominates. We aimed to assess the spatial variation in the abundance of maras and to identify the natural and anthropic factors influencing the observed patterns in Península Valdés, a representative landscape of Patagonia. We conducted ground surveys during the austral autumn from 2015 to 2017. We built density surface models to account for the variation in mara abundance, and obtained a map of mara density at a resolution of four km2. We estimated an overall density of 0.93 maras.km−2 for the prediction area of 3,476 km2. The location of ranch buildings, indicators of human presence, had a strong positive effect on the abundance of maras, while the significant contribution of the geographic longitude suggested that mara density increases with higher rainfall. Although human presence favored mara abundance, presumably by providing protection against predators, it is likely that the association could bring negative consequences for maras and other species. The use of spatial models allowed us to provide the first estimate of mara abundance at a landscape scale and its spatial variation at a high resolution. Our approach can contribute to the assessment of mara population abundance and the factors shaping its spatial structure elsewhere across the species range, all crucial attributes to identify and prioritize conservation actions.

A review on crocodilian nesting habitats and their characterisation via remote sensing

2019 ◽  
Vol 40 (4) ◽  
pp. 403-423 ◽  
Author(s):  
Gabriela Banon ◽  
Eduardo Arraut ◽  
Francisco Villamarín ◽  
Boris Marioni ◽  
Gabriel Moulatlet ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Forest Canopy ◽  
Open Water ◽  
Site Distribution ◽  
Nesting Site ◽  
Nesting Sites ◽  
Conservation Actions ◽  
Key Variables ◽  
Reproductive Females ◽  
Remote Sensing Methods

Abstract Crocodilians usually remain inside or near their nests during most vulnerable life stages (as eggs, neonates and reproductive females). Thus, protection of nesting sites is one of the most appropriate conservation actions for these species. Nesting sites are often found across areas with difficult access, making remote sensing a valuable tool used to derive environmental variables for characterisation of nesting habitats. In this study, we (i) review crocodilian nesting habitats worldwide to identify key variables for nesting site distribution: proximity to open-water, open-water stability, vegetation, light, precipitation, salinity, soil properties, temperature, topography, and flooding status, (ii) present a summary of the relative importance of these variables for each crocodilian species, (iii) identify knowledge gaps in the use of remote sensing methods currently used to map potential crocodilian nesting sites, and (iv) provide insight into how these remotely sensed variables can be derived to promote research on crocodilian ecology and conservation. We show that few studies have used remote sensing and that the range of images and methods used comprises a tiny fraction of what is available at little to no cost. Finally, we discuss how the combined use of remote sensing methods – optical, radar, and laser – may help overcome difficulties routinely faced in nest mapping (e.g., cloud cover, flooding beneath the forest canopy, or complicated relief) in a relevant way to crocodilians and to other semiaquatic vertebrates in different environments.

scholarly journals Sustainable human behaviours for combating sixth mass extinction

2019 ◽  
Author(s):  
Fatik Baran Mandal
Keyword(s):  
Mass Extinction ◽  
Net Primary Productivity ◽  
Biodiversity Loss ◽  
Life Forms ◽  
Conservation Strategies ◽  
Natural Phenomenon ◽  
Root Cause ◽  
The People ◽  
Sixth Mass Extinction ◽  
The Commons

Background extinction is a natural phenomenon. Anthropogenic biodiversity loss has been addressed from the various view points. The debate is continuing to identify the root cause of the anthropogenic mass extinction, also called the sixth extinction. The present communication discusses various anthropogenic drivers of the biodiversity loss and explains the ongoing sixth mass extinction using Garrett Hardin's “the tragedy of the commons”. Such explanations provide options for policy makers and for us to save the precious biodiversity of our planet. It has been demonstrated that presently we share about one third of the Net Primary Productivity which must be reduced through reducing our food consumption and by reducing our utilization of energy. Promotion of sustainable human behaviours to ameliorate the problem of anthropogenic extinction or the sixth extinction has been discussed in the light of recent findings from neurobiology and molecular biology. Biodiversity conservation through providing benefit to the people may be effective conservation strategies which would save the interest of human civilizations as well as other life forms on the earth.

scholarly journals Conservation and restoration in peopled landscapes in Oceania: Opportunities and challenges

2020 ◽  
Author(s):  
Heiko Wittmer ◽  
V Anton ◽  
MAM Gruber ◽  
L Ireland ◽  
W Linklater ◽  
...  
Keyword(s):  
Community Involvement ◽  
Urban Areas ◽  
Management Strategies ◽  
Biodiversity Loss ◽  
Human Dimensions ◽  
Design And Implementation ◽  
Wilderness Areas ◽  
Conservation Actions ◽  
Conservation Projects

© 2018 CSIRO. While the role of humans in causing high rates of species extinctions worldwide is well established, philosophies and opinions as to how to mitigate the current biodiversity loss are once again hotly debated topics. At the centre of the debate are differences in opinions regarding the value and the best methods of conserving and restoring biodiversity in peopled landscapes. Here we synthesise information from different case studies from Oceania that demonstrate how biodiversity conservation in peopled landscapes will require different, and often novel, socio-ecological approaches. We draw special attention to the importance of prioritising human dimensions in the conservation of different ecosystems, ranging from highly modified urban areas to largely intact wilderness areas. Particularly, we explore the importance of understanding motivations to conserve biodiversity, implementing well designed conservation actions, both socially and ecologically, and involving different stakeholders in the design and implementation of conservation projects. On the basis of our synthesis, we suggest that conservation in peopled landscapes in Oceania offers great opportunities for community involvement, including traditional landowners, in all aspects of conservation planning and implementation. Where uncertainties regarding the suitability of established management strategies exist, novel guidelines should be based on the best available ecological and social evidence to avoid potential negative outcomes.

scholarly journals Survival of a threatened salmon is linked to spatial variability in river conditions

2021 ◽  
Author(s):  
Colby L. Hause ◽  
Gabriel P. Singer ◽  
Rebecca A. Buchanan ◽  
Dennis E. Cocherell ◽  
Nann A. Fangue ◽  
...  
Keyword(s):  
Pacific Northwest ◽  
Chinook Salmon ◽  
Habitat Restoration ◽  
Oncorhynchus Tshawytscha ◽  
Central Valley ◽  
Data Generation ◽  
Habitat Variability ◽  
River Habitat ◽  
San Joaquin River ◽  
The Pacific

AbstractExtirpation of the Central Valley spring-run Chinook Salmon ESU (Oncorhynchus tshawytscha) from the San Joaquin River is emblematic of salmonid declines across the Pacific Northwest. Habitat restoration and fish reintroduction efforts are ongoing, but recent telemetry studies have revealed low outmigration survival of juveniles to the ocean. Previous investigations have focused on modeling survival relative to river discharge and geographic regions, but have largely overlooked the effects of habitat variability. To evaluate the link between environmental conditions and survival of juvenile spring-run Chinook Salmon, we combined high spatial resolution habitat mapping approaches with acoustic telemetry along a 150 km section of the San Joaquin River during the spring of 2019. While overall outmigration survival was low (5%), our habitat-based classification scheme described variation in survival of acoustic-tagged smolts better than other candidate models based on geography or distance. There were two regional mortality sinks evident along the longitudinal profile of the river, revealing poor survival in areas that shared warmer temperatures but that diverged in chlorophyll-α, fDOM, turbidity and dissolved oxygen levels. These findings demonstrate the value of integrating river habitat classification frameworks to improve our understanding of survival dynamics of imperiled fish populations. Importantly, our data generation and modeling methods can be applied to a wide variety of fish species that transit heterogeneous and diverse habitat types.

scholarly journals Integrating citizen science data with expert surveys increases accuracy and spatial extent of species distribution models

2019 ◽  
Author(s):  
O.J. Robinson ◽  
V. Ruiz-Gutierrez ◽  
M.D. Reynolds ◽  
G.H. Golet ◽  
M. Strimas-Mackey ◽  
...  
Keyword(s):  
Survey Data ◽  
Citizen Science ◽  
Species Distribution ◽  
Central Valley ◽  
Habitat Associations ◽  
Biological Information ◽  
Ecological Knowledge ◽  
Science Data ◽  
Trade Offs ◽  
Wide Range

AbstractInformation on species’ habitat associations and distributions, across a wide range of spatial and temporal scales, are a fundamental source of ecological knowledge. However, collecting biological information at relevant scales if often cost prohibitive, although it is essential for framing the broader context of more focused research and conservation efforts. Citizen-science data has been signaled as an increasingly important source of biological information needed to fill in data gaps needed to make more comprehensive and robust inferences on species distributions. However, there are perceived trade-offs of combining highly structured, scientific survey data with largely unstructured, citizen-science data. As a result, the focus of most methodological advances to combine these sources of information has been on treating these sources as independent. The degree to which each source of information is allowed to directly inform a common underlying process (e.g. species distribution) depends on the perceived quality of the data. In this paper, we explore these trade-offs by applying a simplified approach of filtering citizen-science data to resemble structured survey data, and analyze both sources of data under a common framework. To accomplish this, we explored ways of integrating high-resolution survey data on shorebirds in the northern Central Valley of California with observations in eBird for the entire region that were filtered to improve their quality. The integration of survey data with the filtered citizen-science data in eBird resulted in improved inference and predictive ability, and increased the extent and accuracy of inferences on shorebirds for the Central Valley. The structured surveys were found to improve the overall accuracy of ecological inference based only on citizen-science data, by increasing the representation of data collected from high quality habitats for shorebirds (e.g. rice fields). The practical approach we have shown for data integration can be also be used to improve the efficiency of designing biological surveys in the context of larger, citizen-science monitoring efforts, ultimately reducing the financial and time expenditures typically required of monitoring programs and focused research. The simple processing and filtering method we present can be used to integrate other types of data (e.g. camera traps) with more localized efforts (e.g. research projects), ultimately improving our ecological knowledge on the distribution and habitat associations of species of conservation concern worldwide.

Sign in / Sign up

Export Citation Format

Share Document