A 2018 Horizon Scan of Emerging Issues for Global Conservation and Biological Diversity.

This is our ninth annual horizon scan to identify emerging issues that we believe could affect global biological diversity, natural capital and ecosystem services, and conservation efforts. Our diverse and international team, with expertise in horizon scanning, science communication, as well as conservation science, practice, and policy, reviewed 117 potential issues. We identified the 15 that may have the greatest positive or negative effects but are not yet well recognised by the global conservation community. Themes among these topics include new mechanisms driving the emergence and geographic expansion of diseases, innovative biotechnologies, reassessments of global change, and the development of strategic infrastructure to facilitate global economic priorities

A horizon scan of global conservation issues for 2014

This paper presents the output of our fifth annual horizon-scanning exercise, which aims to identify topics that increasingly may affect conservation of biological diversity, but have yet to be widely considered. A team of professional horizon scanners, researchers, practitioners, and a journalist identified 15 topics which were identified via an iterative, Delphi-like process. The 15 topics include a carbon market induced financial crash, rapid geographic expansion of macroalgal cultivation, genetic control of invasive species, probiotic therapy for amphibians, and an emerging snake fungal disease. © 2013 Elsevier Ltd

Radiocarbon Dating of Soil Organic Matter Fractions in Andosols in Northern Ecuador

Volcanic ash soils (Andosols) may offer great opportunities for paleoecological studies, as suggested by their characteristic accumulation of organic matter (OM). However, understanding of the chronostratigraphy of soil organic matter (SOM) is required. Therefore, radiocarbon dating of SOM is necessary, but unfortunately not straightforward. Dating of fractions of SOM obtained by alkali-acid extraction is promising, but which fraction (humic acid or humin) renders the most accurate 14C dates is still subject to debate. To determine which fraction should be used for 14C dating of Andosols and to evaluate if the chronostratigraphy of SOM is suitable for paleoecological research, we measured 14C ages of both fractions and related calibrated ages to soil depth for Andosols in northern Ecuador. We compared the time frames covered by the Andosols with those of peat sequences nearby to provide independent evidence. Humic acid (HA) was significantly older than humin, except for the mineral soil samples just beneath a forest floor (organic horizons), where the opposite was true. In peat sections, 14C ages of HA and humin were equally accurate. In the soils, calibrated ages increased significantly with increasing depth. Age inversions and homogenization were not observed at the applied sampling distances. We conclude that in Andosols lacking a thick organic horizon, dating of HA renders the most accurate results, since humin was contaminated by roots. On the other hand, in mineral soil samples just beneath a forest floor, humin ages were more accurate because HA was then contaminated by younger HA illuviated from the organic horizons. Overall, the chronostratigraphy of SOM in the studied Andosols appears to be suitable for paleoecological research

Radiocarbon Dating of Soil Organic Matter Fractions in Andosols in Northern Ecuador

Volcanic ash soils (Andosols) may offer great opportunities for paleoecological studies, as suggested by their characteristic accumulation of organic matter (OM). However, understanding of the chronostratigraphy of soil organic matter (SOM) is required. Therefore, radiocarbon dating of SOM is necessary, but unfortunately not straightforward. Dating of fractions of SOM obtained by alkali-acid extraction is promising, but which fraction (humic acid or humin) renders the most accurate 14C dates is still subject to debate. To determine which fraction should be used for 14C dating of Andosols and to evaluate if the chronostratigraphy of SOM is suitable for paleoecological research, we measured 14C ages of both fractions and related calibrated ages to soil depth for Andosols in northern Ecuador. We compared the time frames covered by the Andosols with those of peat sequences nearby to provide independent evidence. Humic acid (HA) was significantly older than humin, except for the mineral soil samples just beneath a forest floor (organic horizons), where the opposite was true. In peat sections, 14C ages of HA and humin were equally accurate. In the soils, calibrated ages increased significantly with increasing depth. Age inversions and homogenization were not observed at the applied sampling distances. We conclude that in Andosols lacking a thick organic horizon, dating of HA renders the most accurate results, since humin was contaminated by roots. On the other hand, in mineral soil samples just beneath a forest floor, humin ages were more accurate because HA was then contaminated by younger HA illuviated from the organic horizons. Overall, the chronostratigraphy of SOM in the studied Andosols appears to be suitable for paleoecological research.

To Plant or Not to Plant: When can Planting Facilitate Mangrove Restoration?

Global change processes such as sea level rise and the increasing frequency of severe storms threaten many coastlines around the world and trigger the need for interventions to make these often densely-populated areas safer. Mangroves could be implemented in Nature-Based Flood Defense, provided that we know how to conserve and restore these ecosystems at those locations where they are most needed. In this study, we investigate how best to restore mangroves along an aquaculture coast that is subject to land-subsidence, comparing two common mangrove restoration methods: 1) mangrove restoration by planting and 2) Ecological Mangrove Restoration (EMR); the assistance of natural mangrove regeneration through mangrove habitat restoration. Satellite data revealed that historically, landward mangrove expansion into the active pond zone has mainly occurred through mangrove planting on pond bunds. However, there is potential to create greenbelts along waterways by means of EMR measures, as propagule trap data from the field revealed that propagules of pioneer species were up to 21 times more abundant in creeks of the pond zone than near their source in the coastal zone. This was especially true during the prevailing onshore winds of the wet-season, suggesting that smart seasonal sluice gate management could help to efficiently trap seeds in target ponds. In the coastal zone, field experiments showed that permeable brushwood dams, aimed at expanding mangrove habitat, could not sufficiently overcome subsidence rates to increase natural mangrove expansion in the seaward direction, but did significantly increase the survival of already established (planted) seedlings compared to more wave-exposed sites. The survival and growth rate of EMR-supported plantings greatly varied between species. Out of the four planted species, Rhizophora mucronata had the highest survival (67%) but the lowest growth rate. Whereas the pioneer species Avicennia alba and Avicennia marina had lower survival rates (resp. 35 and 21%), but significantly higher growth rates, even resulting in fruiting young trees within a 16-month timeframe. Overall, we conclude that 1) EMR has potential in the pond zone, given that propagules were observed to reach well into the backwaters; and 2) that mangrove recovery in the coastal zone may be facilitated even at very challenging coastal sites by combining EMR with the planting of pioneer species

To Plant or Not to Plant: When can Planting Facilitate Mangrove Restoration?

Global change processes such as sea level rise and the increasing frequency of severe storms threaten many coastlines around the world and trigger the need for interventions to make these often densely-populated areas safer. Mangroves could be implemented in Nature-Based Flood Defense, provided that we know how to conserve and restore these ecosystems at those locations where they are most needed. In this study, we investigate how best to restore mangroves along an aquaculture coast that is subject to land-subsidence, comparing two common mangrove restoration methods: 1) mangrove restoration by planting and 2) Ecological Mangrove Restoration (EMR); the assistance of natural mangrove regeneration through mangrove habitat restoration. Satellite data revealed that historically, landward mangrove expansion into the active pond zone has mainly occurred through mangrove planting on pond bunds. However, there is potential to create greenbelts along waterways by means of EMR measures, as propagule trap data from the field revealed that propagules of pioneer species were up to 21 times more abundant in creeks of the pond zone than near their source in the coastal zone. This was especially true during the prevailing onshore winds of the wet-season, suggesting that smart seasonal sluice gate management could help to efficiently trap seeds in target ponds. In the coastal zone, field experiments showed that permeable brushwood dams, aimed at expanding mangrove habitat, could not sufficiently overcome subsidence rates to increase natural mangrove expansion in the seaward direction, but did significantly increase the survival of already established (planted) seedlings compared to more wave-exposed sites. The survival and growth rate of EMR-supported plantings greatly varied between species. Out of the four planted species, Rhizophora mucronata had the highest survival (67%) but the lowest growth rate. Whereas the pioneer species Avicennia alba and Avicennia marina had lower survival rates (resp. 35 and 21%), but significantly higher growth rates, even resulting in fruiting young trees within a 16-month timeframe. Overall, we conclude that 1) EMR has potential in the pond zone, given that propagules were observed to reach well into the backwaters; and 2) that mangrove recovery in the coastal zone may be facilitated even at very challenging coastal sites by combining EMR with the planting of pioneer species