Ecologies, Volume 4, Issue 2 (June 2023) – 13 articles

The recreational value of a forest is related to the degree of naturalness that can be measured by considering qualitative and quantitative characteristics of deadwood and habitat trees. Forest user groups’ knowledge and opinions towards forest naturalness can support decision-makers in defining strategies. Among user groups, the literature shows a knowledge gap regarding the new generations’ perceptions and opinions related to biodiversity conservation. The aim of this study is to investigate young generations’ perception and preferences towards deadwood in forests. A questionnaire was developed and administrated online—in Italy and Türkiye—to a sample of university students under 25 years old. A total of 407 questionnaires (187 in Italy and 220 in Türkiye) were collected and processed. The results show that students from both countries have a high level of knowledge of deadwood and its role in forests. Most respondents perceive standing dead trees in forests to be aesthetically negative, while large lying deadwood is perceived as aesthetically positive. The attention of young generations towards issues related to biodiversity conservation is confirmed by the significance given in both countries to the management strategy that closely aligns with natural processes of mortality in undisturbed forests, where deadwood is allowed to remain without removal. Full article

In semiarid regions, the deer mouse (Peromyscus maniculatus) is a major small mammal species occupying perennial grassland habitats that include old-fields, native bunchgrass–sagebrush, and some agricultural settings. We investigated population changes in deer mouse populations in perennial grasslands, both natural and old-field, from 1982 to 2003 in southern British Columbia, Canada. Hypotheses (H) predicted that P. maniculatus populations will have (H₁) multiannual fluctuations in abundance driven by population increases from extended breeding in summer and winter; (H₂) relaxed spring reorganization events in some years leading to higher overall recruitment and survival; and (H₃) interspecific competition with montane voles that causes deer mice to be lower in density when voles are higher. P. maniculatus populations in old-field and grass–sagebrush sites had clearly defined periods of high “peak” mean numbers (32–52/ha) and other times of low mean numbers (20–22/ha). Based on mean annual peak density in autumn, deer mouse populations exhibited fluctuations of 3–4 years in both habitats, but this pattern was not always present. The greater numbers of P. maniculatus in high than low years was directly related to population increases from extended breeding seasons and an increased number of lactating females, thereby supporting H₁. Spring breeding season declines occurred but were similar or less in high than low years of mean abundance and were relaxed in comparison to forest populations of deer mice in other studies. Thus, H₂ was supported for recruitment with high numbers of young-of-the-year breeding and total number of juvenile recruits but for survival was equivocal. Total summer survival was consistently higher in high than low population years but juvenile productivity in all years was poor. Mean abundance of P. maniculatus and M. montanus in old-field sites were highly correlated, and hence H₃ was not supported. This latter result is the first, to our knowledge, of P. maniculatus coexisting in a similar pattern of population fluctuations with a Microtus species in a mainland grassland habitat. Higher than average precipitation in the year preceding a peak population of deer mice may have enhanced herbaceous vegetation and contributed to population increases in both habitats. We conclude that the old-field habitat associated with this agricultural setting provides optimum habitat for P. maniculatus and facilitates multiannual population fluctuations in this species. Full article

Wild chimpanzees live in large and complex social communities, but their complexity is determined by the number of potential social partners as well as the frequent changes in group composition due to fission–fusion dynamics. Alternatively, captive housed chimpanzee groups are usually much smaller and less complex. However, studies have shown that groups can be housed in adjacent habitats, potentially increasing the number of social partners, i.e., granting additional relationship opportunities and enhanced social complexity. While most social network studies analyze social groups as closed systems, this study assessed the impact of social interactions between two neighboring groups of chimpanzees, based on two social network indices (Vertex strength centrality and Deviation from edge weight disparity). Furthermore, Linear Mixed Models (LMMs) were employed to assess whether gender, age, and intra-/intergroup directionality influenced these indices. We recorded occurrences of social behaviors, social proximity and whether chimpanzees observed individuals in the other group as a measure of interest. Most social behaviors were directed towards group members; however, 13% were directed towards the neighboring group. Although enclosure barriers constrained the chimpanzee’s capacity to physically interact, it does not necessarily impede social interactions with the outside world. Hence, the presence of neighboring chimpanzees potentially provides additional relationship opportunities, increasing social stimulation and complexity leading to an enriching social environment. Full article

Aulacaspis yasumatsui Takagi invaded Guam in 2003 and caused the widespread mortality of the indigenous Cycas micronesica K.D. Hill population. The regeneration of the surviving tree population continues to be constrained 20 years later, and a look at the changes in megastrobili traits may inform future conservation management decisions concerning regeneration. We quantified megastrobilus reproductive effort and output from 2001 to 2022 to address this need. The reproductive effort of each megastrobilus was immediately reduced by the invasion, as the number of megasporophylls declined by 29%, and the number of ovules declined by 73% in 2006. Reproductive output was also damaged, as the percent seed set declined by 56% and the number of seeds per strobilus declined by 88%. These fecundity metrics have shown few signs of recovery through 2022. Our results reveal that chronic A. yasumatsui infestations, combined with other invasive herbivore threats, have damaged the host C. micronesica population through a sustained reduction in ovule production and the percent seed set for each megastrobilus, thereby impairing regeneration. This plant response to the biotic threats is distinct from the ongoing mortality of mature trees and emerging seedlings. Conservation interventions may be required to foster a return to adequate regeneration during future attempts to aid C. micronesica recovery. Full article

Harmful cyanobacterial blooms of the toxin-producing Microcystis have become a growing problem for Southwest Florida freshwater bodies. Recently, a 2016 bloom in Lake Okeechobee and a 2018 bloom in the Caloosahatchee River both led to the declaration of a state of emergency for the state of Florida. Fast-acting suppression methods are needed to protect residents and wildlife. Hydrogen peroxide and L-lysine have shown promising results in selectively inhibiting the growth of Microcystis aeruginosa and are more ecologically friendly due to fast degradation in water or the biological enhancement of nontarget organisms, respectively. We further explored the use of hydrogen peroxide, L-lysine, and combined treatments of both chemicals, which have never been tested before, for the rapid suppression of Microcystis. We assessed the susceptibility of seven M. aeruginosa strains and six other phytoplankton (Cyanobium spp., Synechococcus sp., Dolichospermum planctonica, Mychonastes homosphaera, and Chromochloris zofingiensis) commonly found in Florida, and revealed that susceptibility was diverse. All three treatments were effective at inhibiting the growth of M. aeruginosa, mixed treatments (16.7 mg/L hydrogen peroxide: 8 mg/L L-lysine) were most effective with a median growth inhibition ratio of 94.2% on the last day of the experiment, while hydrogen peroxide (16.7 mg/L) (83.8%) and L-lysine (8 mg/L) (78.5%) were less so. We found axenic M. aeruginosa to be significantly more sensitive to hydrogen peroxide when compared with nonaxenic strains (p < 0.01, n = 18). L-lysine was found to be significantly more toxic to M. aeruginosa than other examined cyanobacteria and chlorophyte strains at the end of the experiment (p < 0.001, n = 33), demonstrating its specificity to this cyanobacterium, while hydrogen peroxide and mixed treatments had varying effects on the other tested phytoplankton. Full article

Prairie and savanna ecosystems have declined dramatically worldwide. In the Southeastern United States, longleaf pine savannas have been reduced to less than 3% of their pre-European range. Restoring longleaf pine across the area has become a regional goal. Little bluestem (Schizachyrium scoparium (Michx.) Nash) is critical to carrying the ecologically important fire through this ecosystem in some longleaf pine savannas. Little bluestem has a range that spans most of north America and is thought to display ecotypic variation. As a part of a longleaf pine restoration project in Camden, SC, we investigated whether the seed source of little bluestem and the site preparation techniques impacted the survival and growth of broadcasted seeds. In the field and greenhouse, we compared locally and commercially sourced seeds and field site preparation techniques including discing, raking, or no treatment. At the end of the growing season, there were significantly more plants grown from seeds collected locally compared to plants from seeds available commercially. Plants grown from locally collected seeds also invested more heavily in roots than plants grown from commercial seeds. Site preparation techniques did not appear to significantly impact plant survival. Collecting seed locally will help to ensure long-term restoration success by establishing populations of plants that are adapted to the local environmental conditions. Full article

Soil samples taken during archaeological investigations of a historical tannery area in the eastern suburb of the medieval city of Jena have been investigated by 16S r-RNA gene profiling. The analyses supplied a large spectrum of interesting bacteria, among them Patescibacteria, Methylomirabilota, Asgardarchaeota, Zixibacteria, Sideroxydans and Sulfurifustis. Samples taken from soil inside the residues of large vats show large differences in comparison to the environmental soil. The PCAs for different abundance classes clearly reflect the higher similarity between the bacterial communities of the outside-vat soils in comparison with three of the inside-vat soil communities. Two of the in-side vat soils are distinguishable from the other samples by separate use of each abundance class, but classes of lower abundance are better applicable than the highly abundant bacteria for distinguishing the sampling sites by PCA, in general. This effect could be interpreted by the assumption that less abundant types in the 16S r-RNA data tend to be more related to an earlier state of soil development than the more abundant and might be, therefore, better suited for conclusions on the state of the soils in an earlier local situation. In addition, the analyses allowed identification of specific features of each single sampling site. In one site specifically, DNA hints of animal residue-related bacteria were found. Obviously, the special situation in the in-site vat soils contributes to the diversity of the place, and enhances its Beta-diversity. Very high abundancies of several ammonia-metabolizing and of sulphur compound-oxidizing genera in the metagenomics data can be interpreted as an echo of the former tannery activities using urine and processing keratin-rich animal materials. In summary, it can be concluded that the 16S r-RNA analysis of such archaeological places can supply a lot of data related to ancient human impacts, representing a kind of “ecological memory of soil”. Full article

This study investigated the content of ¹³⁷Cs (a long-lived radioactive isotope of caesium) in various parts of Pinus sylvestris L. (Scotch pine) and Dicranum polysetum Sw. (rugose fork-moss) at three different sites within the exclusion zone of the Chornobyl nuclear power plant over two years. The Leliv site is located within the 10 km zone, while the Paryshiv and Dytiatky sampling sites are within the 30 km zone. Samples of different P. sylvestris organs were collected, including 1- and 2-year-old branches and needles and wood and outer bark, and the entire D. polysetum. Sampling was conducted every two weeks throughout the year during 2014 and 2015. The specific activity levels of ¹³⁷Cs in the samples were measured using gamma spectrometry with a CANBERRA gamma spectrometer unit and a coaxial high-purity HPGe semiconductor detector. The study found that at the Leliv and Paryshiv sites, the highest content of ¹³⁷Cs in living organs of P. sylvestris was found in the wood. At the Dytiatky site, the needles and branches of the first and second years had anomalously high concentrations of radiocaesium (¹³⁷Cs). This could be due to a thin layer of forest litter (1.5 cm) at that site. The study also found significant changes in the specific activity levels of ¹³⁷Cs in living pine organs throughout the year. The highest concentration was observed in pine branches and needles in summer, and the maximum values in wood were observed in winter. The study suggests that a constant circulation of ¹³⁷Cs in the soil–plant system can cause seasonal changes in the content of ¹³⁷Cs in living pine organs. Symbiotic mycorrhizal fungi can play an important role in the circulation of radiocaesium in forest ecosystems. The outer bark of P. sylvestris did not show any seasonal changes in the content of ¹³⁷Cs. It may not be involved in radiocaesium redistribution inside the plant but can serve as a long-term source of this radionuclide entering the forest litter. The study found no seasonal changes in the accumulation of ¹³⁷Cs by D. polysetum, which might be due to the physiological characteristics of this plant species. Based on the analysis of the conducted studies, the recommendation is to consider the seasonal changes in the content of ¹³⁷Cs during monitoring activities and when using Scots pine in areas potentially contaminated with this radionuclide. Full article

The northern coast of the Iberian Peninsula is an important spawning and nursery area for several marine fish species, some of which are economically exploited by fisheries and under management plans. Larval stages of fish are highly sensitive to environmental change and anthropogenic pressures, and Marine Protected Areas (MPA) can help mitigate the impacts on fish populations. This study investigated the environmental drivers of the temporal and spatial patterns of the larval fish assemblages inhabiting a small coastal MPA along the NW Portuguese Iberian Coast. Seasonal surveys were conducted over two years at nine sampling stations distributed throughout the MPA to collect larval fish samples and water parameters. Results showed that a total of 39 different fish taxa were identified. In terms of abundance, reef-associated species, such as Parablennius gattorugine (54.6%), and marine species that use estuaries as nursery areas, such as Ammodytes tobianus (15.7%) and Clupeidae n.i. (8.8%) dominated the larval fish assemblages. The larval fish assemblages were characterized by a strong temporal pattern that, according to CCA analyses, was related to the temporal variability of water temperature, pH, chlorophyll α, TPM, and also the river flow of an adjacent river. This study showed that 47% of the fish larvae belonged to commercially exploited species, highlighting the importance of this MPA as a nursery area for the early life stages of the fish population. Overall, these new findings emphasize the role of MPAs in ensuring the connectivity of fish species between marine-estuarine habitats and enhancing the conservation of fish populations. Full article

Currently, there is a world coffee production crisis which has been attributed, among other factors, to the COVID-19 pandemic that affected the development of productive agricultural activities. In this scenario, Mexico is in a declining situation by showing a reduction in coffee production areas in recent years. Therefore, it is necessary to promote actions that contribute to the recovery of the resource, particularly in the states with agricultural potential. In the present work, the potentially suitable areas for coffee cultivation are identified through the application of tools that allow for characterizing the biophysical conditions that define the current spatial distribution and, from the analysis of these characteristics, generate a Potential Distribution Model (PDM) of the suitable zones for coffee production. The methodology was developed through the application of the Maximum Entropy (MaxEnt) algorithm, starting with the collection and preparation of coffee presence records, followed by a correlation analysis and identification of significant variables, the subsequent execution of the model in various configurations to observe the contribution of each variable through a jackknife test, and finally validation of the model with a random sample selection of 30%, to achieve an AUC of 0.98 and TSS of 0.96. The present model was able to identify and quantify the environmentally suitable zones for coffee production, highlighting the regions with ideal potential for the specie. These results are intended to serve as a basis for the generation of planning strategies aimed at managing, improving, and increasing coffee production areas, as well as being used to establish biological corridors to promote biodiversity, conservation, and alternative economic activities such as tourism and furthermore for future work on the analysis of production scenarios and impacts of climate change. It is concluded that 30% of Nayarit’s territory has ideal conditions for coffee cultivation, especially the region delimited by the municipalities of Tepic and Xalisco, the eastern zone of Compostela, and the southwest of San Blas, which should be considered as a Priority Conservation Area (APC) for coffee cultivation in the state. Full article

The problem of assessing the impact of pollution in protected areas prompted us to apply a combined method of bioindication and spatial mapping of phytoplankton data from six lakes in the Burabay National Nature Park in Northern Kazakhstan. The issue of monitoring planning was quite acute for this landscape-homogeneous area among the Kulunda steppes. Phytoplankton in each of the six lakes was collected in the summer season of 2019 at a total of 54 sampling stations. In total, 139 species of algae and cyanobacteria from seven taxonomic phyla were found in the phytoplankton of the Burabay Park during the study period. Three phyla were the richest in species: diatoms, green algae, and cyanobacteria. Based on species richness, abundance, and biomass, as well as bioindicators and calculated indices of organic pollution and toxic effects, the current ecological state of the lake was assessed as being under the influence of pollution, of the mesotrophic type and with a high capacity for self-purification. Statistical mapping, calculated by the correlation of the species composition and categories of indicators, revealed the zones of anthropogenic impact located on the shores of the lake, and the water of the lakes as weakly alkaline, quality classes 2–3. An increase in the number of cyanobacteria in coastal communities was revealed, which may be associated with an increase in the biogenic load on the lake ecosystems. The results of the analysis and mapping of indicators revealed that two major factors regulated phytoplankton: salinity and organic pollution. The sources of organic pollution are mostly associated with the intake of substances from the coastal zone, where resorts, roads, and settlements are located. Full article

Stem diameter growth in living trees refers to the invariably increase in dimension over a given period. However, reversible stem diameter decrease could occur, related to water movement in the vessels within the wood (on a daily basis) and to tree water deficit and depletion of stored water (on a seasonal basis). Recently, the perennial decrement in stem diameter size has been related to a tree decline pathway, and eventually resulting in tree death. In this study, we analysed stem diameter intra-annual growth dynamics of holm oak (Quercus rotundifolia Lam.) trees for two full growing seasons in distinct woodlands, Laborela and Aldeia dos Fernandes, in southern Portugal (Ourique district). Our focus was to assess stem diameter growth patterns and trends in holm oak trees in endangered woodlands with high tree mortality and to question if perennial decrement. Holm oaks in Laborela were much more sensitive in their stem diameter variations than in Aldeia dos Fernandes and, on average, their stem diameter decreased continuously by 1.0 mm along the 2-year study period, with a slightly higher annual decrease in the first study year (0.6 mm.yr⁻¹). In addition, on average, trees had a higher decrease in stem sectional area of 5.8 cm² in Laborela against a decrease of 3.7 cm² in Aldeia dos Fernandes, where the stem diameter of holm oaks only decreased in the first study year (0.1 mm.yr⁻¹). In each study area, the repeated- measures ANOVA showed that tree size effect influenced the stem diameter variations in contrast to tree crown defoliation. Trees were, on average, relatively smaller in Laborela, with DBH = 35.5 cm against DBH = 40.6 cm in Aldeia dos Fernandes, and were highly sensitive in their stem diameter decrement along two consecutives full growing seasons. This is the first exploratory study on assessing the stem diameter fluctuations on holm oaks to address a decline pathway. Our results revealed that holm oaks can survive during two consecutive growing seasons, with a continuous decrease in their stem diameters, which might indicate one tree’s decline pathway. Full article

In this study, aquatic macroinvertebrates were used as bioindicators to determine the ecological conditions of the Lapa River, located between the municipalities of Cayey and Salinas, Puerto Rico. The water quality of the river was evaluated through the calculation of the Puerto Rico Biological Monitoring Working Party (BMWP-PR), as well as its degree of contamination using the Puerto Rico Family Biotic Index (FBI-PR). Bimonthly sampling was conducted across four sampling sites for a period of 12 months. The sampling sites were positioned upstream and downstream within the nature reserve, and outside and downstream its borders. The BMWP-PR results showed that the site upstream-inside the nature reserve had good water quality, and the site downstream-inside the nature reserve had regular water quality, showing some areas with eutrophication. The water quality outside-downstream from the nature reserve was poor. The FBI-PR results showed that there was mild organic contamination inside the nature reserve, while there was substantial organic contamination in the site that was outside-downstream from the nature reserve. We concluded that the section of the river located within the nature reserve had better ecological conditions than the stretch of the river located outside-downstream of the nature reserve, because it is located within a protected area that has barely been impacted by human activity. Full article