Changes in the adult sex ratio of six duck species breeding populations over two decades

Despite all efforts,long-term changes in the adult sex ratios of breeding duck populations are still unclear;this uncertainty is especially true for male-bias populations,which are often under the scrutiny of researchers lacking convenient results for the active protection of endangered species.Species with male-bias populations are usually strongly affected by a decline in population size that leads to a higher extinction risk.In this study,we examined our long-term data of the abundance of breeding populations in six duck species(Mallard Anas platyrhynchos,Gadwall Mareca strepera,Red-crested Pochard Netta rufina,Common Pochard Aythya ferina,Tufted Duck Aythya fuligula,and Common Goldeneye Bucephala clangula)from fishponds in South Bohemia,Czechia,between 2004 and 2022.This evidence was used to assess long-term changes in the adult sex ratio in these breeding populations and investigate the possible effects of the NAO index(North Atlantic Oscillation index)on them,indicating climate conditions in winter.We determined a long-term decrease of the proportion of females in the breeding season in two of the six examined species:Common Pochard and Red-crested Pochard,which is driven by the long-term increase in the number of males in contrast to the decreasing or stable number of females likely caused by different migration behaviours between females and males.In the case of Common Pochard,in breeding populations,we estimated 60-65%of males in the early 2000s rising to 75-80%in the early 2020s.However,we establish no significant effects linked to climate conditions of the previous winter in these species as a crucial cause of the changes of the proportion of females in the breeding population.

Deadwood position matters:Diversity and biomass of saproxylic beetles in a temperate beech forest

Deadwood plays a key role for biodiversity in forests.A significant number of beetles from this group are currently listed as endangered in the Red List.In addition to other management recommendations,there have been recent efforts to enrich stands with dead wood to promote biodiversity.An important parameter for forestry enterprises is the optimization of these interventions.The study investigated the abundance,species richness,gamma diversity,conservation value and biomass of saproxylic beetles in natural forests using window traps.A total of 89traps were used for saproxylic beetle monitoring,of which 29 were placed on lying logs,30 on snags and 30 as controls in forest stand space.A total of 35,011 beetles were recorded in 564 species(61 families).Notably,20,515 of these belong to saproxylic beetles(59%)in 311 species(55%),with 62 classified as Red-List species(20%).In the group of'all saproxylic beetles',the results indicate that a diversity and y diversity(q=0)remain consistent across various deadwood types,whileβdiversity showed significant differences.Significant differences were found in the Red-List species group,where a diversity and y diversity differed,with higher values observed in snags.Rarefaction based total species richness of site was estimated to be 391 species,including 74 Red-Listed species.Comparing the sample coverage of the studied stand categories showed that all saproxylic species exhibit a pronounced preference for inhabiting areas featuring lying logs.Conversely,Red-List species mainly inhabit snags,withβdiversity being more similar to snags and forest stand space.Notably,both the conservation value(weighted average by conservation status)and beetle biomass are significantly highest in snags,whereas stand space shows the lowest values across all measured saproxylic beetle indices.Furthermore,the use of traps set on the poles in forest stand space resulted in an underestimation of the actual stand richness by 20%-25%.Our results support the conclusion that snags are indispensable features in beech forests,playing a key role in promoting high species diversity,especially among Red-List species,and supporting the biomass of saproxylic beetles.Consequently,it becomes crucial to incorporate a higher percentage of standing deadwood in managed forests or actively create equivalent environments by introducing high stumps.

Differences in Morphological, Physiological and Growth Traits between Two Endemic Subspecies of <i>Brassica rupestris</i>Raf.: Implications for Their Conservation

The goal of this work was to analyze the phenological and physiological responses of Brassica rupestris Raf. subsp. hispida Raimondo & Mazzola and Brassica rupestris Raf. subsp. rupestris to environmental factors also in consideration of global change. We used seedlings of the two subspecies originated from wild plants from the natural habitats in Sicily and cultivated in the Botanical Garden of Rome. Leaf morphological and physiological traits and growth dynamic were analyzed as well as the response to an imposed water stress experiment. The results underlined a higher relative growth rate in plant height (RGRH, cm·cm-1·d-1) in B. rupestris subsp. rupestris also attested by the highest plant height (H, cm), leaf area (LA, cm2), specific leaf area (SLA, cm·g-1), total leaf area per plant (TLA, cm2) and total plant dry mass (PDM, g plant-1). Moreover, the significantly highest net photosynthetic rates (A, μmol CO2 m-2·s-1) during the study period of this subspecies was related to the high Chlorophyll content (Chl, SPAD units). B. rupestris subsp. rupestris was also the most tolerant subspecies to imposed water stress showing the highest relative water content (RWC, %), A and water use efficiency (WUE, μmol·mmol-1).

The Survival and Vegetative Growths of a 60 Month-Old Tropical Rainforest Tree Species Trial Established under a Hopea odorata Nurse Stand at an Ex-Tin Mine in Peninsular Malaysia

AFoCo(Asian Forest Cooperation)Project in 2011 has funded a research and development project in Malaysia for enriching a mono-species stand established in an ex-tin mine.The project covered only for a period of 12 months.A study plot of 1 ha size was established in TTAC(Tin Tailings Afforestation Centre).Twenty indigenous tropical rainforest tree species were planted and their five year-old survival count,diameter and H(top height)growths are reported in this study.Some of them are red list species of IUCN(International Union of Conservation of Nature).The survival of the 1 ha planting trial was 53%.Mortality of the tree species is mainly caused by wild boars.The tropical rainforest tree species in this planting trial had similar growth to those planted at good mineral soils.This paper also documented the tending treatments which were implemented during post-planting that have contributed to healthy growth of the mixed-species stand.The mixed-species stand is being properly tended till to-date and hence sustained growth of the stand is anticipated.

The challenge of combining variable retention and prescribed burning in Finland

Historically,wildfires have played an important role in forest dynamics in Fennoscandia.In Finland,the annually burned area has diminished in recent decades.This has led to a decline of fire-adapted habitat types and species,many of which have become red-listed.In Fennoscandia,there is a long tradition of silvicultural burnings to enhance tree regeneration.Recently,prescribed burnings have been modified for biodiversity goals following the recommendations that have emerged from ecological research.Prominent biodiversity gains can be obtained by combining sufficient retention levels with burnings.Consequently,burning and retention have been recommended by recent national red-list assessments,strategies,and forest-management guidelines,and they have been adopted in forest-certification standards in Finland.Contrary to these recommendations,the opposite development has taken place:(1)the ecological efficiency of the criterion concerning prescribed burning in the PEFC forestcertification standard has been impaired,(2)state funding to encourage private forest owners to apply prescribed burning was reduced significantly,and(3)prescribed burnings have been abandoned altogether in commercial state-owned forests.Traditional burnings with variable retention have also been partially replaced with burning of small retention-tree groups.This new method is less risky and cheaper,but its ecological benefits are questionable because small-sized fires produce much smaller areas of burned forest soil with less fire-affected wood than traditional silvicultural burnings.Generally,the widely accepted goal to increase burnings with retention appears difficult to achieve and would require stronger political will and economic support from the government.We identified several actions that could improve the weakened situation of fire-dependent biodiversity and recommend the following:(1)setting a clear goal and ensuring sufficient funding for the burnings—including restoration burnings in conservation areas—and targeting these to specific fire-continuum areas with sufficient retention to ensure the continuity of fire-affected habitats at landscape level;(2)renewing the current subsidizing policies to encourage private landowners to perform prescribed burnings in regeneration areas after final fellings,and to safeguard accidental forest-fire areas as set-asides;(3)renewing the current prescribed-burning criterion of the Finnish PEFC forest-certification standard with more ambitious ecological goals;and(4)re-introducing prescribed burnings in commercial state forests where management targets are under political steering.