Is the local extinction of Pinna nobilis facilitating Pinna rudis recruitment?

Until the late 2010s the spiny fan-mussel Pinna rudis shared habitat in many Mediterranean sites with Mediterranean endemic Pinna nobilis, which dominated in abundance but that has gone locally extinct in most of its distribution area due to a recent widespread disease outbreak. In the Columbretes Islands Marine Reserve (NW Mediterranean) both species coexisted until 2017, when P. nobilis populations completely disappeared. In spring 2021 we revisited 7 permanent plots covering 1,485 m2 that had been previously monitored during the period from 2005 to 2009. We found that although previous studies described P. rudis populations as stable with low recruitment rates, recruitment after 2017 increased in comparison to 2005-2009. At least two cohorts of recruits (~3 and ~1 year in age) were to be found both within the plots as well as in other areas throughout the Columbretes archipelago, colonizing areas previously occupied by P. nobilis. We hypothesize that P. rudis has been benefited by the local extinction of the sibling species P. nobilis, most probably as a result of reduced interspecific competition. The ecological role once played mainly by P. nobilis as the dominant species, might now be taken over by P. rudis, whose populations could grow during the oncoming years.

Analysis of geographic centrality and genetic diversity in the declining grasshopper species Bryodemella tuberculata (Orthoptera: Oedipodinae)

Human-induced ecological and climatic changes have led to the decline and even local extinction of many formerly widely distributed temperate and cold-adapted species. Determining the exact causes of this decline remains difficult. Bryodemella tuberculata was a widely distributed orthopteran species before the mid-19th century. Since then, many European populations have suffered drastic declines and are now considered extinct or critically endangered. We used ecological niche modelling based on a large dataset of extant and extinct occurrence data to investigate whether poor climatic suitability in the periphery of its global range was a possible cause of the local extinction of the European populations of B. tuberculata. We also used population genetics based on the COI marker to estimate and compare the genetic diversity of extant populations. We found that Europe still provides highly suitable habitats close to the climatic optimum, contradicting the assumption of climate change as major driver of this decline. Instead, changes in land-cover and other anthropogenic modifications of the habitats at the local scale seem to be the major reasons for local extinctions. Genetic analysis suggests Central Asia as center of diversity with a stable population size, whereas the effective sizes of the remaining European populations are decreasing. We found European genetic lineages nested within Central Asian lineages, suggesting a Central Asian source distribution area. Our results suggest that the declining European populations represent relics of a formerly wider distribution, which was fragmented by changes in land-use. These relics are now threatened by limited connectivity and small effective population sizes. Specific conservation actions, such as the restoration of former or potential new habitats, and translocation of individuals from extant populations to these restored sites may help slow, stall, or even revert the extinction process.

Penegakan Hukum Larangan Berburu Satuan Liar di Wilayah TNK Labuan BAJO Manggarai Barat

The diversity of fauna in Indonesia is Yaranus komodoensis in the Komodo National Park (TNK) Labuan Bajo, East Nusa Tenggara. Currently, Kornodo is suspected of experiencing local extinction, thought to be caused by a reduced deer population due to illegal hunting, law enforcement on the prohibition of hunting wildlife in the area is still ineffective considering that hunting of wild animals is still happening. Efforts are made to increase the effectiveness of law enforcement on wildlife hunting by socializing the community and increasing the number of forest police officers in each region. . The research method used is empirical legal research, meaning that a study examines the problem based on the facts that occur in the field. From the research, there was hunting of deer wildlife in Komodo National Park. The purpose of this research is to determine the enforcement of the law on the prohibition of hunting wildlife in the Kornodo National Park and to find out the effectiveness of enforcing the law on the prohibition of hunting wildlife in the Komodo National Park.

Modelling effects of water regulation on the population viability of threatened amphibians

The regulation of river systems alters hydrodynamics and often reduces lateral connectivity between river channels and floodplains. For taxa such as frogs that rely on floodplain wetlands to complete their lifecycle, decreasing inundation frequency can reduce recruitment and increase the probability of local extinction. We virtually reconstructed the inundation patterns of wetlands under natural and regulated flow conditions and built stochastic population models to quantify the probability of local extinction under different inundation scenarios. Specifically, we explored the interplay of inundation frequency, habitat size, and successive dry years on the local extinction probability of the threatened southern bell frog Litoria raniformis in the Murray River floodplains of South Australia. We hypothesised that the changes in wetland inundation resulting from river regulation are driving the decline of L. raniformis in this system. Since river regulation began in the 1920s, the inundation frequency of many reliable breeding habitats has decreased to a point where they no longer support local populations. Increasing successive dry years drives the probability of local extinction, particularly in smaller wetlands. Larger wetlands and those with more frequent average inundation are less susceptible to these effects. Synthesis and Applications. Although the availability of suitable habitats has reduced, environmental water provision is a promising tool to mitigate the negative impacts of river regulation on amphibian populations. Our modelling approach can be used to prioritise the delivery of environmental water (through pumping or the operation of flow-regulating structures) to minimise the probability of local extinction in L. raniformis and potentially many other frog species. By quantifying the extinction risk of amphibian populations, we can strategically manage environmental water to reduce successive catastrophic breeding failures and increase the probability of persistence.