Restoring riparian forests according to existing regulations could greatly improve connectivity for forest fauna in Chile

Habitat connectivity is essential to facilitate species movement across fragmented landscapes, but hard to achieve at broad scales. The enforcement of existing land use policies could improve habitat connectivity, while providing legal support for implementation. Our goal was to evaluate how forest connectivity is affected if forests are restored according to existing riparian buffer regulations in Chile. We simulated forest restoration within 30 and 200 m of rivers in 99 large watersheds, following two sections of the forest regulation. We mapped habitat for two model forest species that have different minimum habitat sizes (15 and 30 ha), and for each we identified forest habitats and corridors using image morphology analysis. To quantify change in connectivity, we used a network graph index, the Relative Equivalent Connected Area. We found that both 30- and 200-m riparian buffers could have a positive effect on habitat connectivity. The 200-m buffers increased connectivity the most where forest cover was 20–40% (40% mean increase in connectivity index), while the 30-m buffers increased connectivity the most where forest cover was 40–60% (30% mean increase in connectivity index). The effect of riparian restoration scenarios was similar for both model species, suggesting that effective implementation of existing forest regulation could improve connectivity for fauna with a range of minimum habitat size requirements. Our findings also suggest that there is some flexibility in the buffer sizes that, if restored, would increase habitat connectivity. This flexibility could help ease the social and economic cost of implementing habitat restoration in productive lands.

File: Rojas_etal_2020_riparian_restoration_connectivity_chile_Land_urb_plan.pdf

Conservation planning for island nations: Using a network analysis model to find novel opportunities for landscape connectivity in Puerto Rico

Oceanic islands are important habitats for many endemic species. Global conservation assessments, however, are too coarse to characterize areas of high human influence or landscape connectivity at a resolution that is useful for conservation planning on most islands. Our goal was to identify landscape elements that are essential for the maintenance of structural connectivity among natural habitat patches on islands. Using the Caribbean island of Puerto Rico as a case study, our specific objectives were to: (1) develop a map of the human footprint, and (2) characterize the connectivity of patches exhibiting low human modification that structurally connect the island’s ecological network. We used the human footprint as a measure of impediments to connectivity among Puerto Rico’s natural areas using network analysis. We found that more than half of Puerto Rico’s current land surface had a low human footprint (56%), but that coastal areas were highly affected by human use (82%). Puerto Rico possesses a compact network of natural areas, with a few patches in the interior mountains critical to structural connectivity. The number of isolated patches is very high; more than 60% of the patches were 2000 m or more apart. Identifying sites that are key hubs to connectivity on islands and ensuring they remain undeveloped is one strategy to balance land use and conservation, and to facilitate the persistence of endemic species. We show here how to improve general conservation assessment methods to be more relevant for islands. There is potential to support an interconnected network of natural areas that promotes landscape connectivity in Puerto Rico among noncoastal habitats, because the human activities are concentrated along the coast whereas the interior mountain range has a relatively low human footprint.

File: Guzman-Colon-et-al_2020_Conservation-planning-for-island-nations.pdf

Potential adaptability of marine turtles to climate change may be hindered by coastal development in the USA

Marine turtles may respond to projected climatic changes by shifting their nesting range to climatically suitable areas, which may
result in either increased exposure to threats or fewer threats. Therefore, there is the need to identify whether habitat predicted to
be climatically suitable for marine turtle nesting in the future will be affected by future threats and hinder marine turtles’ ability to
adapt. We modelled the geographic distribution of climatically suitable nesting habitat for marine turtles in the USA under future
climate scenarios, identified potential range shifts by 2050, determined impacts from sea-level rise, and explored changes in
exposure to coastal development as a result of range shifts. Overall nesting ranges of marine turtle species were not predicted to
change between the current and future time periods, except for the northern nesting boundaries for loggerhead turtles. However,
declines in climatically suitable nesting grounds were predicted; loggerhead turtles will experience the highest decreases (10%) in
climatically suitable habitat followed by green (7%) and leatherback (1%) turtles. However, sea-level rise is projected to inundate
78–81% of current habitat predicted to be climatically suitable in the future, depending on species and scenario. Nevertheless,
new beaches will also form, and suitable nesting habitat could be gained, with leatherback turtles potentially experiencing the
biggest percentage gain in suitable habitat.

File: 2020_Fuentes_et_al-2020-Regional_Environmental_Change.pdf

Short-term vegetation loss versus decadal degradation of grasslands in the Caucasus based on Cumulative Endmember Fractions

Land degradation affects over one-third of the global land area and is projected to become even more widespread
due to climate change and land use pressures. Despite being a critical issue for climate change mitigation,
biodiversity conservation, and food security, the detection of the onset, duration, and magnitude of land de-
gradation remains challenging, as is early identification of short-term vegetation loss preceding land degrada-
tion. Here, we present a new approach for monitoring both short-term vegetation loss and decadal degradation
in grasslands using satellite data. Our approach integrates Spectral Mixture Analysis and temporal segmentation,
and analyzes dense time-series of satellite observations in three steps. First, we unmix all available satellite
observations and aggregate them into monthly composites. Second, we calculate the annual Cumulative
Endmember Fractions and examine their piecewise trends among years to determine the onset, duration, and
magnitude of short-term vegetation loss and decadal degradation. Third, we attribute a decrease in the green
vegetation fraction with a concomitant increase in either open soil, or non-photosynthetic vegetation. We tested
our method mapping short-term vegetation loss and decadal degradation in grasslands in the Caucasus Ecoregion
using the 2001–2018 time series of MODIS 8-day reflectance data. We found strong patterns of short-term
vegetation loss and decadal degradation, mostly in the eastern part of the Caucasus Ecoregion in areas of desert-
and semi-desert natural vegetation. Short-term vegetation loss episodes (3–9 years) were more common and had
greater magnitude than decadal degradation (≥10 years), especially in steppe regions. On average, 9.3% of
grassland area was subjected annually to either decadal, or short-term vegetation loss. Desiccation, i.e., the shift
from green vegetation to dry vegetation, was the most prevalent type of change pathway, with green vegetation
loss to open soil coming second. Decadal degradation and short-term vegetation loss rates were the highest in dry
areas where the potential natural vegetation is sub-shrub deserts, or halophytic, alluvial, and wet lowland
forests. Our findings support known general degradation patterns in the Caucasus Ecoregion, but provide better
understanding of ongoing processes, by detecting exact location, timing, and magnitude of changes. More
broadly, our method advances the monitoring of grasslands by detecting both decadal degradation and short-
term vegetation loss. This flexibility supports adaptive degradation monitoring, aids sustainable land manage-
ment, and provides new information for carbon stock analyses and biodiversity conservation.

File: Lewinska_etal_RSE_2020_CaucasusVegLoss.pdf

Effects of ecotourism on forest loss in the Himalayan biodiversity hotspot based on counterfactual analyses

Ecotourism is developing rapidly in biodiversity hotspots worldwide, but there is limited and mixed
empirical evidence that ecotourism achieves positive biodiversity outcomes. We assessed whether ecotourism
influenced forest loss rates and trajectories from 2000 to 2017 in Himalayan temperate forests. We compared forest
loss in 15 ecotourism hubs with nonecotourism areas in 4 Himalayan countries. We used matching statistics to
control for local-level determinants of forest loss, for example, population density, market access, and topography.
None of the ecotourism hubs was free of forest loss, and we found limited evidence that forest-loss trajectories in
ecotourism hubs were different from those in nonecotourism areas. In Nepal and Bhutan, differences in forest loss
rates between ecotourism hubs and matched nonecotourism areas did not differ significantly, and the magnitude
of the estimated effect was small. In India, where overall forest loss rates were the lowest of any country in
our analysis, forest loss rates were higher in ecotourism hubs than in matched nonecotourism areas. In contrast,
in China, where overall forest loss rates were highest, forest loss rates were lower in ecotourism hubs than
where there was no ecotourism. Our results suggest that the success of ecotourism as a forest conservation
strategy, as it is currently practiced in the Himalaya, is context dependent. In a region with high deforestation
pressures, ecotourism may be a relatively environmentally friendly form of economic development relative to
other development strategies. However, ecotourism may stimulate forest loss in regions where deforestation rates
are low.

File: Brandt_etal_-ConsBio_2019.pdf

Ecotourism is developing rapidly in biodiversity hotspots worldwide, but there is limited and mixed
empirical evidence that ecotourism achieves positive biodiversity outcomes. We assessed whether ecotourism
influenced forest loss rates and trajectories from 2000 to 2017 in Himalayan temperate forests. We compared forest
loss in 15 ecotourism hubs with nonecotourism areas in 4 Himalayan countries. We used matching statistics to
control for local-level determinants of forest loss, for example, population density, market access, and topography.
None of the ecotourism hubs was free of forest loss, and we found limited evidence that forest-loss trajectories in
ecotourism hubs were different from those in nonecotourism areas. In Nepal and Bhutan, differences in forest loss
rates between ecotourism hubs and matched nonecotourism areas did not differ significantly, and the magnitude
of the estimated effect was small. In India, where overall forest loss rates were the lowest of any country in
our analysis, forest loss rates were higher in ecotourism hubs than in matched nonecotourism areas. In contrast,
in China, where overall forest loss rates were highest, forest loss rates were lower in ecotourism hubs than
where there was no ecotourism. Our results suggest that the success of ecotourism as a forest conservation
strategy, as it is currently practiced in the Himalaya, is context dependent. In a region with high deforestation
pressures, ecotourism may be a relatively environmentally friendly form of economic development relative to
other development strategies. However, ecotourism may stimulate forest loss in regions where deforestation rates
are low.

Landsat 8 TIRS-derived temperature and thermal heterogeneity predict winter bird species richness patterns across the conterminous United States

The thermal environment limits species ranges through its influence on physiology and resource distributions
and thus affects species richness patterns over broad spatial scales. Understanding how temperature drives
species richness patterns is particularly important in the context of global change and for effective conservation
planning. Landsat 8's Thermal Infrared Sensor (TIRS) allows direct mapping of temperature at moderate spatial
resolutions (100 m, downscaled by the USGS to 30 m), overcoming limitations inherent in coarse interpolated
weather station data that poorly capture fine-scale temperature patterns over broad areas. TIRS data thus offer
the unique opportunity to understand how the thermal environment influences species richness patterns. Our
aim was to develop and assess the ability of TIRS-based temperature metrics to predict patterns of winter bird
richness across the conterminous United States during winter, a period of marked temperature stress for birds.
We used TIRS data from 2013-2018 to derive metrics of relative temperature and intra-seasonal thermal heterogeneity.
To quantify winter bird richness across the conterminous US, we tabulated the richness only for
resident bird species, i.e., those species that do not move between the winter and breeding seasons, from the
North American Breeding Bird Survey, the most extensive survey of birds in the US. We expected that relative
temperature and thermal heterogeneity would have strong positive associations with winter bird richness because
colder temperatures heighten temperature stress for birds, and thermal heterogeneity is a proxy for
thermal niches and potential thermal refugia that can support more species. We further expected that both the
strength of the effects and the relative importance of these variables would be greater for species with greater
climate sensitivity, such as small-bodied species and climate-threatened species (i.e., those with large discrepancies
between their current and future distributions following projected climate change). Consistent with
our predictions, relative temperature and thermal heterogeneity strongly positively influenced winter bird
richness patterns, with statistical models explaining 37.3% of the variance in resident bird richness. Thermal
heterogeneity was the strongest predictor of small-bodied and climate-threatened species in our models, whereas
relative temperature was the strongest predictor of large-bodied and climate-stable species. Our results demonstrate
the important role that the thermal environment plays in governing winter bird richness patterns and
highlight the previously underappreciated role that intra-seasonal thermal heterogeneity may have in supporting
high winter bird species richness. Our findings thus illustrate the exciting potential for TIRS data to guide
conservation planning in an era of global change.

File: Elsen_et-al_2020_Landsat-8_winterbirdrichness_US.pdf

Conservation of the threatened and endemic Rufous-throated dipper, Cinclus schultzi, in Argentina

The Rufous-throated Dipper Cinclus schulzi is endemic to the Southern Yungas of north-western Argentina and southern Bolivia. The species is categorised as ‘Vulnerable’ on the IUCN Red List on
the basis of small population size and restricted range. The purpose of our study was to determine the distribution of potentially suitable habitat for the Rufous-throated Dipper, estimate its pop-ulation size, and assess potential distribution within strict protected areas, in north-western
Argentina. We surveyed 44 rivers in the Southern Yungas of Argentina from 2010 to 2013 to determine dipper density (i.e. the number of individuals detected per km surveyed). The dipper’s potential distribution was assessed using a maximum entropy modeling approach based on
31 occurrence points and eight bioclimatic and two topographic variables as predictors. The species is dependent on mountain forest rivers, so the potential distribution was restricted to rivers. We estimated dipper population size by multiplying density by the potential distribution along rivers.
Finally, we calculated the extent of suitable habitat contained within the boundaries of Argentina´s National Parks. Dipper density was 0.94  1.55 individuals/km. We estimate that within north-west Argentina there are ~2,815 km of river that are potential habitat, with an area of occupancy of
141 km2 and a population size of 2,657  4,355 dippers. However, of this river extent, less than 5%
is within National Parks. Our results highlight the need to create new and to enlarge existing National Parks that protect the potentially suitable habitat of the species. Although more infor-mation is needed for Bolivia, the country-level area of occupancy and population size of the dipper
found in Argentina provides strong evidence that the IUCN Red List classification of this species as ‘Vulnerable’ is warranted.

File: Politi_et_al_2019_conservation_status_rufousthroated_dipper_cinclus_schulzi_argentina.pdf

On leaves, bugs and birds – how topography influences spring phenology, and habitat quality for birds in the Baraboo Hills

Pine Hollow, one of 4 stream gorge study sites

While walking through a forest in spring we often marvel at the vivid greenness, listen to birdsong, and mind our steps in order not to get into a spider’s web. Enjoying the moment, we usually do not think about the complexity of this environment, nor the intertwined relations among all of its elements. However, what slips our attention is not going unrecognized by Maia Persche – a Master’s candidate in the SILVIS lab. In her research, Maia seeks to discern the role of topography in the timing of vegetation growth onset within forest, and to understand how topographic position potentially shapes songbird habitat.

Spring leaf emergence on a hillside in Baxter’s Hollow

To gain insight into these questions, Maia undertook the challenging tasks of measuring tree phenology, and conducting invertebrate and bird surveys in her study area in the Baraboo Hills of Southern Wisconsin. In order to relate these data to each other, each type of survey was carried out at the same 70 locations during narrow time windows throughout the season. Tree phenology surveys occurred in April and May, and invertebrate and bird surveys were repeated throughout the bird breeding season, or until the end of July. At each location, additional data was collected on temperature, tree species composition, and site characteristics. Over the course of two field seasons, she detected 53 insectivorous bird species, and tracked the seasonal abundance of common invertebrate orders (Lepidoptera, Araneae, Hemiptera, Hymenoptera, Diptera and Coleoptera).

Early May at an upland study site in Devil’s Lake State Park

Based on only a portion of measurements collected, Maia has already drawn some interesting preliminary conclusions. Trees leafed out slightly later in stream gorges than in uplands, and although invertebrate biomass was related to tree phenology, it did not appear to follow a predictable yearly pattern. However, sheltered stream gorges supporteded high invertebrate biomass during the mid- and late summer. This could be important for double-brooded bird species that still have active nests in July and can be limited by food availability in some habitats. Overall, stream gorges supported the highest bird species richness, perhaps due to stable food resources or habitat complexity. Also, a strong association has become evident between particular tree species and invertebrate orders, suggesting that tree composition may be more important than topographic context for some folivorous invertebrates.

Louisiana Waterthrush banded at Baxter’s Hollow

Under shifting climate conditions in deciduous forests, it is important to identify areas where habitat quality for species is likely to remain high. To assess bird territory quality in different topographic situations, Maia used feather growth bar analysis for a few widely distributed forest species (Wood Thrush, Red-eyed Vireo, and Ovenbird). She captured birds throughout her study area using mist nets, playback calls, and bird models. She then banded the birds, took structural measurements, and pulled one tail feather. Growth bars, or horizontal bands along the feather, correspond to diet richness of the bird while the feather was growing, and will be used to assess social dominance and habitat quality. Although this approach provides a detailed look at habitat quality, it is also the most difficult to carry out in the field.

Maia has collected a large amount of data, and analyzing the relationships among different factors and trophic levels is somewhat daunting, but she approaches it with great enthusiasm. Maia is currently working to determine how bird territory density varies according to topographic context. It is definitively worth staying tuned to see what new results Maia uncovers!

The Great Lakes Region is a melting pot for vicariant red fox (Vulpes vulpes) populations

During the Pleistocene, red fox (Vulpes vulpes) populations in North America were isolated in glacial refugia
and diverged into 3 major lineages: the Nearctic-Eastern subclade of eastern Canada, the Nearctic-Mountain
subclade of the western mountains, and the Holarctic clade of Alaska. Following glacial retreats, these genetically
distinct populations of foxes expanded into newly available habitat. Along with subsequent translocation from fur
farms, these expansions have resulted in red foxes now occupying most of the continent. The origin of foxes that
colonized the Great Lakes Region, however, remains unknown. Furthermore, it is unclear whether contemporary
populations inhabiting this region are the result of natural range expansion or if foxes released from fur farms
colonized the landscape in the 1900s. To determine the origin of red foxes in the Great Lakes Region, we collected
genetic samples from 3 groups: 1) contemporary wild foxes, 2) historical wild foxes collected before fur farming,
and 3) fur-farmed foxes from a contemporary fur farm. We constructed a network of mtDNA haplotypes to identify
phylogeographic relationships between the 3 sample groups, and examined genetic signatures of fur-farmed
foxes via the androgen receptor gene (AR) associated with tame phenotypes. Historical wild foxes demonstrated
natural colonization from all 3 major North American lineages, which converged within the Great Lakes Region,
and contemporary wild foxes maintained the historically high genetic diversity. Most contemporary wild foxes
also matched haplotypes of fur-farmed foxes; however, AR was not useful in distinguishing fur-farm origins
in samples of contemporary wild foxes. Our results show that geographically disparate populations naturally
merged in the Great Lakes Region before fur-farmed foxes were introduced. Due to the historically high genetic
diversity in the Great Lakes Region, any introductions from fur farms likely contributed to, but did not create, the
genetic structure observed in this region.

File: KBlack_etal_JOM_2018.pdf

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