The nesting ecology of song thrush (Turdus philomelos) in Stepanakert City of Nagorno-Karabakh and its adjoining areas

Subtropical evergreen broad-leaved forests were selected along an urban (Guangzhou) - suburban (Dinghushan) - rural (Huaiji) gradient in the Pearl River Delta, from which soil samples in different layers were collected. The changes in total organic carbon (TOC), recalcitrant organic carbon (ROC), and active organic carbon (AOC) including readily oxidizable organic carbon (ROOC), microbial biomass carbon (MBC), and water-soluble organic carbon (WSOC) of samples were examined along this urbanization gradient to reveal the influence of urbanization on forest soil organic carbon. Results showed that no significant differences in both TOC and ROC contents were observed in 0-5 cm soil layer along the gradient. In 5-60 cm soil layer, the TOC content was significantly higher in the rural forest than that in the suburban and urban forests, the ROC content was the highest in the suburban forest and no significant difference was observed between the urban and rural forests. The ROOC content was significantly lower in the suburban forest than in the rural (0-60 cm soil layer) and urban (0-10 cm soil layer) forests. The MBC content was significantly lower in the urban forest than that in the suburban and rural forests. The suburban forest had significantly lower WSOC than the urban forest (0-10 cm soil layer). In 0-20 cm layer, the percentage of AOC to TOC of the urban and rural forests was significantly higher than those of the suburban forest, while the percentage of ROC to TOC was the lowest in the rural forest. The significant difference in the percentage of ROC to TOC was only observed in 5-10 cm depth layer between the suburban and urban forests. The results indicated that urbanization increased the active components of soil organic carbon and reduced the stable ones, which could be detrimental to organic carbon accumulation in soils. The rural forest soils were more sensitive to the urbanization.

Urbanization has been rapid across the world but the responses of phosphorus (P) cycling to urbanization have not been well-investigated. This study was to understand the influences of rapid urbanization on forest P cycling in a developing country. Soil P fractions and P resportion were determined for nine slash pine (Pinus elliottii Engelm.) forests along a 30-km long urban-suburban-rural gradient in Nanchang City, southern China. The total P stocks in the surface soils in urban and suburban forests were 317% and 182% higher, respectively, than levels found in rural forests. The concentrations of soil available P, labile P, slow P, occluded P and total extractable P were also much higher in urban and suburban forests than in rural forests (P < 0.05). Soil weathered P concentrations were highest in urban forests. Annual mean foliar P concentrations were enhanced in urban and suburban forests compared to rural forests. The P resorption efficiency (PRE) was higher in rural forests than in suburban and urban forests, while the P resorption proficiency (PRP) was lower in rural forests than in suburban and urban forests. Urbanization associated with high extraneous P inputs has altered soil P status and plant P uptake. Foliar P concentration, PRE and PRP were largely dependent on soil P availability in our study forests.

Recreational use of urban and suburban forests affects plant diversity in a Western Siberian city

Mercury in leaf litter in typical suburban and urban broadleaf forests in China

Temporal and spatial variations in nitrogen transformations in deciduous forest ecosystems along an urban–rural gradient

Urbanization increases the range, but not the depth, of forest edge influences on Pinus sylvestris bark pH

The role of suburban forests is revealed, the main problems of their use by the population are described and the main ways of solving problematic issues are suggested. The legal aspects of the use and management of suburban forests are revealed. The recreational and ecologically sanitizing potential of suburban and urban forests, the range and possibilities of providing them with ecosystem functions are described on the example of Ivano-Frankivsk city territorial community. The general characteristics of the forest cover of Ivano-Frankivsk region are given, the key threats to nature related to human activities in urban and suburban forests are outlined. Based on a critical analytical review of literature data and own observations, key threats to the ecologically balanced functioning of suburban forests of Ivano-Frankivsk city TG have been identified and systematized.

Carbon (C) sequestration and nitrogen (N) and phosphorus (P) accumulation in urban forest green spaces are significant for global climate regulation and alleviating nutrient pollution. However, the effects of management and conservation practices across different urban forest vegetation types on soil C, N, and P contents and stoichiometric ratios remain largely unexplored. We selected forest soils from Guangzhou, a major Metropolis in China, as our study area. Soil samples were collected from two urban secondary forests that naturally regenerated after disturbance (108 samples) and six urban forest parks primarily composed of artificially planted woody plant communities (72 samples). We employed mixed linear models and variance partitioning to analyze and compare soil C, N, and P contents and their stoichiometry and its main driving factors beneath suburban forests and urban park vegetation. These results exhibited that soil pH and bulk density in urban parks were higher than those in suburban forests, whereas soil water content, maximum storage capacity, and capillary porosity were higher in urban forests than in urban parks. Soil C, N, and P contents and their stoichiometry (except for N:P ratio) were significantly higher in suburban forests than in urban parks. Multiple analyzes showed that soil pH had the most pronounced negative influence on soil C, N, C:N, C:P, and N:P, but the strongest positive influence on soil P in urban parks. Soil water content had the strongest positive effect on soil C, N, P, C:N, and C:P, while soil N:P was primarily influenced by the positive effect of soil non-capillary porosity in suburban forests. Overall, our study emphasizes that suburban forests outperform urban parks in terms of carbon and nutrient accumulation, and urban green space management should focus particularly on the impact of soil pH and moisture content on soil C, N, and P contents and their stoichiometry.

The impacts of nitrogen addition on the active carbon pools in forest soils along an urban–rural gradient

The article analyzes the breeding success and ecological features of three species of thrushes (the Song Thrush Turdusphilomelos C.L. Brehm, 1831, the Redwing T iliacus Linnaeus, 1766, the Blackbird T merula Linnaeus, 1758) in the conditions of the Voronezh Nature Reserve, where there has been no economic activity for 100 years. The plant cover consists of pine, oak, aspen, birch and alder forests, but it doesn’t include the spruce Picea abies, which is important for the placement of blackbird nests. The overall breeding success, determined by the modified Mayfield method, in the Song Thrush is 27.9%, the Blackbird is 25.4%, and the Redwing is 40.3%. This is lower than in other parts of the range and is due to the frequent destruction of nests by numerous predators. Reproductive losses greatly increase in the years with a cold spring. The high age of the forest, the great species diversity of plants, the presence of many natural hollows, windbreaks, contribute to the diverse placement of nests in all species of birds, which reduces the pressure of predators. Before the foliage opens, thrushes build nests on broken tree trunks, in half-hollows and hollows, in dense interlacing branches or hop stems Humulus lupulus climbing along tree trunks at a low height from the ground. The blackbird uses hollows and half-hollows more often. The negative impact of predators is also offset by long breeding periods, from mid-April to the first decade of July, which allow repeated attempts at nesting. The Redwing protects the fledglings from enemies the most actively, which can also increase the breeding success.

Soil microorganisms, which are sensitive to environmental changes, affect soil nutrient cycling and play an important role in the biogeochemical cycling. To understand the changes of soil microorganisms in subtropical forest across the urban-rural environmental gradient, we analyzed the differences in soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and microbial community functional diversitiy in Dashu Mountain National Forest Park (urban forest), Zipeng Mountain National Forest Park (suburban forest) in Hefei and Wanfo Mountain(rural forest) in Luan City. Results showed that soil MBC followed an order of rural natural forest (115.07 mg·kg-1) > suburban forest (101.68 mg·kg-1) > urban forest (82.73 mg·kg-1), soil MBN followed an order of rural natural forest (57.73 mg·kg-1) > urban forest (31.57 mg·kg-1) > suburban forest (29.01 mg·kg-1), soil microbial metabolic activities (AWCD), McIntosh index (U) were shown as rural natural forest > suburban forest > urban forest. The main carbon sources used by soil microbial communities in those forests were carboxylic acids, amino acids and carbohydrates, with weak utilization capacity for polyamines and polyphenols. The utilization capacity of soil microorganisms to amino acids, carboxylic acids, polymers and polyphenols followed the order of rural natural forest > suburban forest > urban forest. There were significant spatial variations in the functional characteristics of soil microbial communities under urban-rural environmental gradient, with Tween 80 and β-methyl-D-Glucoside being the characteristic carbon sources as the influencing factors. Soil pH was significantly positively correlated with the microbial McIntosh index and AWCD value, while soil ammonium nitrogen (NH4+-N) showed a significant positive correlation with microbial Shannon diversity index and AWCD value. There was a negative correlation between the microbial Simpson index and soil nitrate nitrogen (NO3--N). Soil pH, NH4+-N and NO3--N were the main factors affecting diversity index of microbial communities. The results suggested that there were significant differences in microbial community characteristics of forest soil in urban-rural environmental gradient forests, and that the metabolic potential and functional diversity of soil microbial community in urban forests were weaker than that of natural forests.

Urbanization induced changes in the accumulation mode of organic carbon in the surface soil of subtropical forests

Numerous studies have explored the impacts of nitrogen (N) deposition on soil organic carbon (SOC) dynamics. However, limited research has investigated the modulatory role of N deposition in urban to rural forests and the underlying microbial mechanisms. We carried out a 5-year field study to explore the links between microbial properties (microbial biomass carbon (MBC), microbial diversity, community composition and functions) and the different SOC fractions (particulate organic carbon, POC and mineral-associated organic carbon, MAOC) submitted to three levels of N addition rates (0, 50, and 100 kg N ha-1 yr-1) in urban&amp;#8211;rural gradient forests in eastern China.We discovered that N addition raised the soil ammonium nitrogen concentration in urban and suburban forests. However, it had no effect on soil acidification or POC or SOC accumulation&amp;#65292;and in urban forest the stability was due to the 105 % to 110 % increase in the mineral-associated organic carbon (MAOC) through enhancing peroxidase activity and microbial biomass carbon. On the contrary, high nitrogen input significantly reduced SOC stability in the suburban and rural forest stands. High nitrogen input contributed to the loss of MAOC (-33.6 %) in the suburban forest stand due to the enhancement of microbial biomass nitrogen. High nitrogen addition also decreased the ratio of MAOC to SOC in the rural forest stand by 29.8 % through indirect pathways mediated by the soil Ca2+ concentration and polyphenol oxidase activity. We concluded that SOC in the urban forest was stable when subjected to increased nitrogen deposition, primarily due to the enhancement of MAOC driven by microbial function. This finding has contributed to a better understanding&amp;#160; in predicting forest carbon cycling under conditions of global climate change and urban expansion.

To research attitudes to urban and suburban forests, a questionnaire was given to the random sample of 500 Warsaw residents. The most important factors identified by respondents included unlimited accessibility of urban forests as well as their proximity to urban areas. The main forest recreational activities expected by Warsaw residents were longer walks, natural silence and calm, also the absence of litter. A few respondents were receptive to the idea of managed forests as well as natural forests, if improving the quality of recreation is not taken into account. Respondents were willing to be taxed at 52 PLN/person/year in order to receive the desired level of nontimber forest functions in urban forests. Like residents of other regions of Poland, the respondents specified that the protection of air quality and protection of the natural environment are the most important non-timber forest functions. Among the most frequently visited forests located within the borders of Warsaw city are forests close to Choszczowka, Bielanski forest and the forest in Kolo, which receive respectively 251, 204 and 162 visitors/ ha/day. The management of recreational resources in urban forests is expected to be diverse and adapted to the preferences of visitors.

The European turtle dove Streptopelia turtur breeds in both farmlands and woodlands, and it is important to explore the difference in breeding ecology of this threatened game in these two ecosystem types. This study, carried out during four years (2015–2018), compares nesting features of this species and its breeding success between apple orchards and riparian vegetation in Midelt Province, Morocco. The main result revealed that the nest placement, including nesting-tree height and nest height, is similar between orchards and riparian trees. However, the nest dimensions (big and small diameters) were larger in orchards. Correlations were variable among nest placement parameters and dimensions. On the contrary, in four breeding seasons, where 566 nests were monitored (467 in orchards and 99 in riparian sites), the average breeding success was different (57% of chicks in apple farms and 53% in riparian vegetation). Moreover, in apple orchards, clutches’ failure is due to both predation (18.89% of eggs and 10.54% of chicks) and temperature lowering (5.03% of unhatched eggs and 5.49% of dead chicks), while in riparian vegetation, the loss is due to nest desertion (21.33% of clutches) and mostly predation (33.16% of clutches).