19 April 2018

Small Changes in Rainforests Cause Big Damage to Fish Ecosystems


Freshwater fish diversity is harmed as much by selective logging in rainforests as they are by complete deforestation, according to a new study.

Researchers had expected the level of damage would rise depending on the amount of logging and were surprised to discover the impact of removing relatively few trees.

Read More: https://www.eurekalert.org/pub_releases/2018-04/icl-sci041918.php

05 April 2018

Land-use change interacts with climate to determine elevational species redistribution

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Abstract: "Climate change is driving global species redistribution with profound social and economic impacts. However, species movement is largely constrained by habitat availability and connectivity, of which the interaction effects with climate change remain largely unknown. Here we examine published data on 2798 elevational range shifts from 43 study sites to assess the confounding effect of land-use change on climate-driven species redistribution. We show that baseline forest cover and recent forest cover change are critical predictors in determining the magnitude of elevational range shifts. Forest loss positively interacts with baseline temperature conditions, such that forest loss in warmer regions tends to accelerate species’ upslope movement. Consequently, not only climate but also habitat loss stressors and, importantly, their synergistic effects matter in forecasting species elevational redistribution, especially in the tropics where both stressors will increase the risk of net lowland biotic attrition."


Read More: https://www.nature.com/articles/s41467-018-03786-9

29 March 2018

A biodiversity-crisis hierarchy to evaluate and refine conservation indicators

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Abstract: "The Convention on Biological Diversity and its Strategic Plan for Biodiversity 2011–2020 form the central pillar of the world’s conservation commitment, with 196 signatory nations; yet its capacity to reign in catastrophic biodiversity loss has proved inadequate. Indicators suggest that few of the Convention on Biological Diversity’s Aichi targets that aim to reduce biodiversity loss will be met by 2020. While the indicators have been criticized for only partially representing the targets, a bigger problem is that the indicators do not adequately draw attention to and measure all of the drivers of the biodiversity crisis. Here, we show that many key drivers of biodiversity loss are either poorly evaluated or entirely lacking indicators. We use a biodiversity-crisis hierarchy as a conceptual model linking drivers of change to biodiversity loss to evaluate the scope of current indicators. We find major gaps related to monitoring governments, human population size, corruption and threat-industries. We recommend the hierarchy is used to develop an expanded set of indicators that comprehensively monitor the human behaviour and institutions that drive biodiversity loss and that, so far, have impeded progress towards achieving global biodiversity targets."


Read More: https://www.nature.com/articles/s41559-018-0504-8

18 March 2018

A Global Mismatch in the Protection of Multiple Marine Biodiversity Components and Ecosystem Services

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Abstract: "The global loss of biodiversity threatens unique biota and the functioning and services of ecosystems essential for human wellbeing. To safeguard biodiversity and ecosystem services, designating protected areas is crucial; yet the extent to which the existing placement of protection is aligned to meet these conservation priorities is questionable, especially in the oceans. Here we investigate and compare global patterns of multiple biodiversity components (taxonomic, phylogenetic and functional), ecosystem services and human impacts, with the coverage of marine protected areas across a nested spatial scale. We demonstrate a pronounced spatial mismatch between the existing degree of protection and all the conservation priorities above, highlighting that neither the world’s most diverse, nor the most productive ecosystems are currently the most protected ecosystems. Furthermore, we show that global patterns of biodiversity, ecosystem services and human impacts are poorly correlated, hence complicating the identification of generally applicable spatial prioritization schemes. However, a hypothetical “consensus approach” would have been able to address all these conservation priorities far more effectively than the existing degree of protection, which at best is only marginally better than a random expectation. Therefore, a holistic perspective is needed when designating an appropriate degree of protection of marine conservation priorities worldwide."


Read More: https://www.nature.com/articles/s41598-018-22419-1

11 March 2018

World Scientists’ Warning to Humanity: A Second Notice

Trends over time for environmental issues identified in the 1992 scientists’ warning to humanity. The years before and after the 1992 scientists’ warning are shown as gray and black lines, respectively. Panel (a) shows emissions of halogen source gases, which deplete stratospheric ozone, assuming a constant natural emission rate of 0.11 Mt CFC-11-equivalent per year. In panel (c), marine catch has been going down since the mid-1990s, but at the same time, fishing effort has been going up (supplemental file S1). The vertebrate abundance index in panel (f) has been adjusted for taxonomic and geographic bias but incorporates relatively little data from developing countries, where there are the fewest studies; between 1970 and 2012, vertebrates declined by 58 percent, with freshwater, marine, and terrestrial populations declining by 81, 36, and 35 percent, respectively (file S1). Five-year means are shown in panel (h). In panel (i), ruminant livestock consist of domestic cattle, sheep, goats, and buffaloes. Note that y-axes do not start at zero, and it is important to inspect the data range when interpreting each graph. Percentage change, since 1992, for the variables in each panel are as follows: (a) –68.1%; (b) –26.1%; (c) –6.4%; (d) +75.3%; (e) –2.8%; (f) –28.9%; (g) +62.1%; (h) +167.6%; and (i) humans: +35.5%, ruminant livestock: +20.5%. Additional descriptions of the variables and trends, as well as sources for figure 1, are included in file S1.

"Twenty-five years ago, the Union of Concerned Scientists and more than 1700 independent scientists, including the majority of living Nobel laureates in the sciences, penned the 1992 “World Scientists’ Warning to Humanity”. On the twenty-fifth anniversary of their call, we and more than 15,000 scientists from 184 countries look back at their warning and evaluate the human response by exploring available time-series data. Since 1992, with the exception of stabilizing the stratospheric ozone layer, humanity has failed to make sufficient progress in generally solving these foreseen environmental challenges, and alarmingly, most of them are getting far worse. Especially troubling is the current trajectory of potentially catastrophic climate change due to rising GHGs from burning fossil fuels, deforestation, and agricultural production—particularly from farming ruminants for meat consumption. Moreover, we have unleashed a mass extinction event, the sixth in roughly 540 million years, wherein many current life forms could be annihilated or at least committed to extinction by the end of this century."


Read More: https://academic.oup.com/bioscience/article/67/12/1026/4605229

02 March 2018

Secondary Forest Regeneration Benefits Old-Growth Specialist Bats in a Fragmented Tropical Landscape

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Abstract: 'Tropical forest loss and fragmentation are due to increase in coming decades. Understanding how matrix dynamics, especially secondary forest regrowth, can lessen fragmentation impacts is key to understanding species persistence in modified landscapes. Here, we use a whole-ecosystem fragmentation experiment to investigate how bat assemblages are influenced by the regeneration of the secondary forest matrix. We surveyed bats in continuous forest, forest fragments and secondary forest matrix habitats, ~15 and ~30 years after forest clearance, to investigate temporal changes in the occupancy and abundance of old-growth specialist and habitat generalist species. The regeneration of the second growth matrix had overall positive effects on the occupancy and abundance of specialists across all sampled habitats. Conversely, effects on generalist species were negligible for forest fragments and negative for secondary forest. Our results show that the conservation potential of secondary forests for reverting faunal declines in fragmented tropical landscapes increases with secondary forest age and that old-growth specialists, which are often of most conservation concern, are the greatest beneficiaries of secondary forest maturation. Our findings emphasize that the transposition of patterns of biodiversity persistence in island ecosystems to fragmented terrestrial settings can be hampered by the dynamic nature of human-dominated landscapes."

Read More: https://www.nature.com/articles/s41598-018-21999-2