Search Results (552)

To explore the characteristics of species diversity and phylogenetic diversity, as well as the dominant processes of community construction, in different forest types (deciduous broad-leaved forest, mixed coniferous and broad-leaved forest, and Chinese fir plantation) in subtropical regions, analyze the specific driving patterns of soil nutrients and other environmental factors on the formation of forest diversity in different forest types, and clarify the differences in response to environmental heterogeneity between natural forests and plantation forests. Based on 48 fixed monitoring plots of 50 m × 50 m in Shouchang Forest Farm, Jiande City, Zhejiang Province, woody plants with a diameter at breast height ≥5 cm were investigated. Species diversity indices (Margalef index, Shannon–Wiener index, Simpson index, and Pielou index), phylogenetic structure index (PD), and environmental factors were used to analyze the relationship between diversity characteristics and environmental factors through variance analysis, correlation analysis, and generalized linear models. Phylogenetic structural indices (NRI and NTI) were used, combined with a random zero model, to explore the mechanisms of community construction in different forest types. Research has found that (1) the deciduous broad-leaved forest had the highest species diversity (Margalef index of 4.121 ± 1.425) and phylogenetic diversity (PD index of 21.265 ± 7.796), significantly higher than the mixed coniferous and broad-leaved forest and the Chinese fir plantation (p < 0.05); (2) there is a significant positive correlation between species richness and phylogenetic diversity, with the best fit being AIC = 70.5636 and R² = 0.9419 in broad-leaved forests; however, the contribution of evenness is limited; (3) the specific effects of soil factors on different forest types: available phosphorus (AP) is negatively correlated with the diversity of deciduous broad-leaved forests (p < 0.05), total phosphorus (TP) promotes the diversity of coniferous and broad-leaved mixed forests, while the diversity of Chinese fir plantations is significantly negatively correlated with total nitrogen (TN); (4) the phylogenetic structure of three different forest types shows a divergent pattern in deciduous broad-leaved forests, indicating that competition and exclusion dominate the construction of deciduous broad-leaved forests; the aggregation mode of Chinese fir plantation indicates that environmental filtering dominates the construction of Chinese fir plantation; the mixed coniferous and broad-leaved forest is a transitional model, indicating that the mixed coniferous and broad-leaved forest is influenced by both stochastic processes and ecological niche processes. In different forest types in subtropical regions, the species and phylogenetic diversity of broad-leaved forests is significantly higher than in other forest types. The impact of soil nutrients on the diversity of different forest types varies, and the characteristics of community construction in different forest types are also different. This indicates the importance of protecting the original vegetation and provides a scientific basis for improving the ecological function of artificial forest ecosystems through structural adjustment. The research results have important practical guidance value for sustainable forest management and biodiversity conservation in the region. Full article

Deforestation driven by plantations, such as Pinus patula Schiede ex Schltdl. et Cham., is a major cause of biodiversity and functional loss in tropical ecosystems. We assessed the diversity and composition of lichens and bryophytes in four size categories of pine cones, small (3–5 cm), medium (5.1–8 cm), large (8.1–10 cm), and very large (10.1–13 cm), with a total of 150 pine cones examined, where the occurrence and cover of lichen and bryophyte species were recorded. Identification keys based on morpho-anatomical features were used to identify lichens and bryophytes. In addition, for lichens, secondary metabolites were tested using spot reactions with potassium hydroxide, commercial bleach, and Lugol’s solution, and by examining the specimens under ultraviolet light. To evaluate the effect of pine cone size on species richness, the Kruskal–Wallis test was conducted, and species composition among cones sizes was compared using multivariate analysis. A total of 48 taxa were recorded on cones, including 41 lichens and 7 bryophytes. A total of 39 species were found on very large cones, 37 species on large cones, 35 species on medium cones, and 24 species on small cones. This is comparable to the diversity found in epiphytic communities of pine plantations. Species composition was influenced by pine cone size, differing from small in comparison with very large ones. The PERMANOVA analyses revealed that lichen and bryophyte composition varied significantly among the pine cone categories, explaining 21% of the variance. Very large cones with specific characteristics harbored different communities than those on small pine cones. The presence of lichen and bryophyte species on the pine cones from managed Ecuadorian P. patula plantations may serve as refugia for the conservation of biodiversity. Pine cones and their scales (which range from 102 to 210 per cone) may facilitate colonization of new areas by dispersal agents such as birds and rodents. The scales often harbor lichen and bryophyte propagules as well as intact thalli, which can be effectively dispersed, when the cones are moved. The prolonged presence of pine cones in the environment further enhances their role as possible dispersal substrates over extended periods. To our knowledge, this is the first study worldwide to examine pine cones as substrates for lichens and bryophytes, providing novel insights into their potential role as microhabitats within P. patula plantations and forest landscapes across both temperate and tropical zones. Full article

Despite increasing interest in including indigenous and local people in forest restoration initiatives, their views on which species are most useful, or reasons behind not planting native tree species are often ignored. Focused on south-western Rwanda, this study addressed these knowledge gaps. We carried out 12 focus group discussions with village elders to determine the following: main benefits provided by native forests, the native species they prefer for different uses, and the main barriers to species’ cultivation. Then, considering other key information from the literature, we performed a ranking exercise to determine which native species had the greatest potential for large-scale tree planting initiatives. Our results show that native forests provide 17 benefits to local communities, some of which cannot be replaced by plantations with exotic species. Among the 26 tree species identified as most useful for timber, firewood, medicine and fodder, ten were ranked as with the greatest potential for restoration initiatives. Of these, two had not been included in recent experimental plantations using native species in Rwanda, and none were considered among the priority species for domestication in Africa. Overall, our study highlights the need to better connect the ecological and social dimension of forest reforestation initiatives in multiple contexts. Full article

The rubber plantations in Sankuru province, located in the Democratic Republic of Congo (DRC), have historically been pivotal to the regional economy. However, the absence of suitable silvicultural practices has promoted self-regeneration, resulting in the proliferation of diverse species. This study aims to characterize species richness and plant structure of these plantations. To this end, 80 subplots measuring 0.25 hectares were meticulously established, with a proportionate division between state-owned and farmer plantations. The results obtained from this study indicate that these plantations are home to approximately 105 species, classified into 33 distinct botanical families, with dominant families such as Fabaceae, Meliaceae, Euphorbiaceae, Olacaceae, Clusiaceae, and Moraceae. Despite the similarity between the two types of plantations (Cs = 58%), significant disparities were observed in terms of individuals, 635 ± 84.06 and 828 ± 144.62 (p < 10⁻³); species, 41 ± 7.49 and 28 ± 4.59 (p < 10⁻³); families, 19 ± 3.06 and 16 ± 1.62 (p < 10⁻²); and basal area, 29.88 ± 5.8 and 41.37 ± 7.57 (p < 10⁻²) for state and peasant plantations, respectively. State plantations exhibited greater diversity (H′ = 1.87) and enhanced equity (J’ = 0.43) than peasant plantations. The diametric structure exhibited an inverted J-shaped distribution, indicating constant and regular regeneration of these plantations. The upper canopy dominates the vertical structure in both types of plantations, with a significantly higher proportion in peasant plantations (83.60%) than in state plantations (73.8%), ANOVA (F (2.24 = 21.78), df = 24; p = 4.03 × 10⁻⁶). The findings indicate that the sustainable management of these plantations could incorporate agroecological principles to promote the coexistence of rubber production and biodiversity conservation while contributing to the restoration of degraded ecosystems and the well-being of local communities. Full article

Tropical rainforests are rapidly disappearing due to human activities, particularly land-use changes, resulting in a heterogeneous mosaic of landscapes that substantially contribute to global terrestrial biodiversity loss. We investigated how changes in land-use affect species richness, composition, and functional guilds of ground-dwelling ants within various land-use systems at a local scale in the Amazonian rainforest. Our focus was to respond to the following: (i) How do local species richness and community composition reflect differences among land-use systems? (ii) Are ground-dwelling ants, especially specialists, negatively impacted by intensified land-use changes? We surveyed 55 sites representing five land-use systems: primary forest, secondary forest, forest corridor, selective logging, and Eucalyptus plantation. We registered 150 ant species, and species richness ranged from 43 to 94. Richness varies according to the land-use systems, likely influenced by differences in habitat structural complexity both vertically and horizontally. Ant species composition and guilds distribution also varied among land-use systems studied. Environments characterized by reduced structural complexity or higher disturbed levels, such as Eucalyptus plantations, tend to support lower resource availability, which may lead to decreased species richness. However, the surrounding matrix appears to play a key role in maintaining regional biodiversity, as evidenced by the absence of differences in ground-dwelling ants diversity across all land-use systems studied. Full article

This paper assesses the complexity and diversity of vegetation in grassy strips with spontaneous plants between tree rows in three fruit orchards (plum, cherry, apple) in Dolj County, Romania, using structural and biodiversity indices. It addresses the lack of data on spontaneous vegetation in Romanian orchards, supporting improved plantation management and native biodiversity conservation. The study found that grassy strips supported high wild herbaceous diversity and a complex, heterogeneous ecological structure, with the apple orchard showing the highest biodiversity. Species diversity, evaluated through species richness, evenness, and diversity indices (Shannon, Simpson, Menhinick, Gleason, etc.), showed species richness ranging from 30 species in the cherry orchard to 40 in the apple orchard. Several species, including Capsella bursa-pastoris, Geranium pusillum, Poa pratensis, Veronica hederifolia, Lolium perenne, and Convolvulus arvensis, were present in 100% of samples, making them constant species from a phytosociological perspective. Their presence indicates relatively stable plant communities in each orchard. From a phytocoenological view, an ecological plant community is defined not only by species composition but also by constancy and co-occurrence in sampling units. Dominance remained low in all orchards, indicating no single plant dominated, while evenness showed a uniform distribution of species. Full article

Seedlings of the ecologically important, critically endangered tree Ocotea monteverdensisis experience high mortality in the Monteverde, Costa Rica, cloud forests at the onset of the wet season, yet there are no studies suggesting the disease etiology. Here, healthy and diseased plant root and bulk soils were analyzed for various carbon and nitrogen (N) metrics and respiration levels, and DNA sequence-based bacterial and fungal community compositions. All nitrogen metric levels were greater in diseased vs. healthy plant root soils, which could enhance pathogen growth and pathogenic mechanisms. Greater DNA percentages from several potential pathogens were found in diseased vs. healthy plant root soils, suggesting this disease may be associated with a root pathogen. The DNA of the fungus Mycosphaerella was at greater levels in diseased vs. healthy plant root soils than other potential pathogens. Mycosphaerella causes similar diseases in other plants, including coffee, after onset of the wet season. The O. monteverdensis disease also occurs in seedlings planted within or near former coffee plantations at wet season onset. Distance-based linear model analyses indicated that NO₃⁻ levels best predicted the pattern of fungal pathogens in the soils, and Mycosphaerella and Tremella best predicted the patterns of the different N metrics in the soils, supporting their possible roles in this disease. Full article

Soil organic carbon (SOC) mineralization is the conversion of SOC to inorganic forms of carbon (C) by microbial decomposition and conversion. It plays an important role in global C cycling. Currently, most of the studies investigating the effects of different tree species on SOC mineralization focus on forest ecosystems, and few have focused on reservoir water-level drawdown zones. In this study, we used an indoor incubation method to investigate SOC mineralization in the plantation soils of Glyptostrobus pensilis, Taxodium Zhongshanshan, Taxodium distichum and CK (unplanted plantation) in the reservoir water-level drawdown zones. We aimed to explore the effects of different tree species on the process of SOC mineralization in the reservoir water-level drawdown zones by considering both the biological and chemical processes of the soil. The results showed that the rates of SOC mineralization in the G. pensilis and T. Zhongshanshan plantations were 47% and 37%, respectively, higher than those in CK (p < 0.05), whereas the rate of SOC mineralization in T. distichum soils did not differ from that in CK. The structural equation model’s results showed microbial biomass carbon (MBC) is a key driver of SOC mineralization, while SOC and dissolved organic carbon (DOC) concentrations are also important factors that affect SOC mineralization and follow MBC. Compared to soil biochemical properties, the bacterial community composition has relatively little effect on SOC mineralization. Planted forests can, to a degree, change the biochemical properties of the soil in the reservoir water-level drawdown zones, effectively improving soil pH, and significantly increasing the amount of potential soil C mineralization, the content of SOC and the diversity of the soil bacteria (p < 0.05). Full article

The land-use conversion of Masson pine forests to tea fields is extensively practiced across subtropical China, primarily driven by its economic benefit. However, the effects of this conversion on soil fungal communities and functional guilds are poorly understood. Herein, a field experiment was conducted in a Masson pine forest (F), a 5-year-old tea plantation without (FT-CK) fertilization or with (FT-N), and a 30-year-old tea plantation (FT-O) to assess the impact of Masson pine forest-to-tea conversion on soil fungal abundance, community structure, and functional guilds by using qPCR and high-throughput sequencing. Compared to F, fungal abundance significantly decreased by 95%, 68%, and 79% in FT-CK, FT-N, and FT-O, respectively, probably caused by the decreased total nitrogen content and habitat disruption. Fungal alpha diversity significantly increased in FT-N and FT-O compared to FT-CK. FT-O presented the highest percentages of Mortierella among treatments, which favours soil organic carbon accumulation. FUNGuild-based predictions showed that FT-CK and FT-N had higher relative abundances of plant pathogens than F and FT-O. FT-O presented the highest percentages of litter and soil saprotrophs but exhibited the lowest percentages of ectomycorrhizal fungi among treatments, likely driven by increased soil organic carbon, total nitrogen, and total phosphorus content. Our findings demonstrate that Masson pine forest-to-tea conversion significantly degrades soil fungal community and function, highlighting the urgent need for soil management strategies (e.g., organic amendments) to enhance soil health in tea agroecosystems. Full article

Dehesas are mosaics of open grassland and standalone trees that are diversity reservoirs. However, they have recently faced abandonment and intensification, being replaced by plantations of fast-growing trees or subject to encroachment. Following a change in dehesa communities and structure, a change in soil microbial diversity and functionality in dehesas is expected, but dehesas’ microbial diversity is still a big unknown. In this work, we bring to light the soil prokaryotic taxonomic diversity in dehesa ecosystems and present a first approach to assessing their metabolic diversity through metabarcoding data. For this, we compared three dehesas dominated by different tree species: (i) one dehesa dominated by Quercus ilex; (ii) one dominated by Pinus pinea; and (iii) one dominated by a mixture of Q. ilex and Q. suber. At each dehesa, samples were taken under the canopy and in the open grassland, as well as through two seasons of peak vegetation productivity (autumn and spring). Our results show the following findings: (1) seasonality plays an important role in prokaryotic richness, showing higher values in autumn, and higher evenness in spring; (2) the effect of seasonality on the soil’s prokaryotic diversity is often modulated by the effect of tree species and canopy; (3) taxonomic diversity is driven mainly by the site effects, i.e., the opposite of the metabolic diversity that seemed to be driven by complex interactions among seasons, tree species, and canopies. Full article

The drastic and historic fall in natural rubber prices has prompted many smallholders around the world to abandon rubber plantations in favor of other survival alternatives. In the Lomela and Lodja territories of Sankuru Province (Democratic Republic of Congo), where a historical absence of a rubber market prevails, local communities have conserved rubber plantations inherited from the colonial era (dating back to 1955). Data collected from 401 households enabled us to identify the perceptions and determinants of rubber plantation conservation. The results show that households are highly dependent on forest ecosystem services. Agriculture is the main activity for 81.3% of respondents, in the context of extreme poverty where daily incomes amount to 0.33 USD/person. The patriarchal system favored men, who inherited 97% of the plantations. Men perceived the conservation of the plantations as beneficial, while women perceived it as serving external project interests. Perceptions were significantly influenced by gender, age, social and legal organization, geographical origin, mode of acquisition, main activity, diversification of income sources, membership in a tribal mutuality, access to the informal mutual aid networks, membership in an association and contact with extension services. Conservation was positively and significantly correlated with geographical origin, membership in an association, contact with extension service, consideration of plantations as natural heritage and the ecosystem services provided. These results underline that rubber plantations cannot be understood only in terms of rubber production, but also in terms of their socio-ecological and heritage dimensions. Full article

The increasing rate of atmospheric nitrogen (N) deposition caused by human activities is a global concern. A rise in N deposition can alter the soil microbial community, as demonstrated by most long-term N addition experiments. Nevertheless, it remains unknown how short-term N addition influences the early succession of the soil microbial community in forests. In this study, the responses of the soil microbial community to multi-level and short-term (one-year) N addition in the soil of Larix gmelinii var. principis-rupprechtii (Mayr) Pilg. plantations in the Yanshan Mountains were explored. We used high-throughput sequencing technology to analyze the 16S rRNA of bacteria, the ITS gene of fungi, and the nifH functional gene of N-fixing bacteria. The results revealed a decrease in N-fixing functional gene abundance (such as nifH) and a slight rise in fungal and bacterial copy number due to N addition. N addition influenced the N-fixing bacterial community but had no influence on the fungal and bacterial communities in general. It drastically decreased the diversity of N-fixing microbial communities while having little impact on the diversity of fungi and bacteria. The NO₃⁻-N concentration exhibited a negative connection with the Shannon–Wiener index of the N-fixing microbial community when it exceeded a specific limit. Actinomycetes and N-fixing bacteria were significantly negatively correlated. The changes in soil NO₃⁻-N concentration and abundance of actinomycetes were the main reasons for the decrease in N-fixing microbial community diversity. The results of this study set the groundwork for exploring the initial succession mechanisms of soil microorganisms after N addition. This study offers a scientific theoretical basis for precise management of plantations under N deposition. Full article

Ancient tea plantations possess extremely important economic and cultivation value. In China, ancient tea plantations with trees over 100 years old have been preserved. However, the status of soil microorganisms, soil fertility, and soil heavy metal pollution in these ancient tea plantations remains unclear. This study took four Dancong ancient tea plantations in Fenghuang, Chaozhou City, and Guangdong Province as the research objects. Soil samples were collected from the surface layer (0–20 cm) and subsurface layer (20–40 cm) of the ancient tea trees. The rhizosphere soil microbial diversity and soil nutrients were determined. On this basis, the soil fertility was evaluated by referring to the soil environmental quality standards so as to conduct a comprehensive evaluation of the soil in the Dancong ancient tea plantations. This study found that Proteobacteria, Acidobacteriota, Chloroflexi, and Actinobacteria were the dominant bacteria in the rhizosphere soil of the Dancong ancient tree tea plantation. Ascomycota and Mortierellomycota are the dominant fungal phyla. Subgroup_2, AD3, Acidothermus, and Acidibacter were the dominant bacterial genera. Saitozyma, Mortierella, and Fusarium are the dominant fungal genera. The redundancy analysis (RDA) revealed that at the bacterial phylum level, Verrucomicrobia showed positive correlations with alkali-hydrolyzable nitrogen (AN), available potassium (AK), and total nitrogen (TN); Proteobacteria exhibited a positive correlation with available phosphorus (AP); and Gemmatimonadetes was positively correlated with total potassium (TK). At the fungal phylum level, Ascomycota demonstrated a positive correlation with TK. TN, AN, and TK were identified as key physicochemical indicators influencing soil bacterial diversity, while TN, AN, AP, and AK were the key physicochemical indicators affecting soil fungal diversity. This study revealed that the soil of Dancong ancient tea plantations has reached Level I fertility in terms of TN, TP, SOM, and AP. TK and AN show Level I or near-Level I fertility, but AK only meets Level III fertility for tea planting, serving as the main limiting factor for soil fertility quality. Considering the relatively abundant TK content in the tea plantations, potassium-solubilizing bacteria should be prioritized over blind potassium fertilizer application. Meanwhile, it is particularly noteworthy that AN and SOM are at extremely high levels. Sustained excess of AN and SOM may lead to over-proliferation of dominant microorganisms, inhibition of other functional microbial communities, and disruption of ecological balance. Therefore, optimizing nutrient input methods during fertilization is recommended. Full article

This research aimed to study changes in the diversity of the soil bacterial community in a jujube forest with different years of abandonment. To this end, we took the mountain jujube forest with different abandoned years (1 a, 3 a, 6a and 20 a) in the Qijiashan jujube experimental demonstration base in Yanchuan County as the research object; we used Illumina Miseq high-throughput sequencing technology to analyze the changes in the soil bacterial community structure and reveal the key environmental drivers of bacterial community variation in the abandoned jujube forest in the study area. The results showed the following findings: (1) Phylum Actinomycetota (34%), Proteobacteria (29%), and Acidobacteriota (13%) were the dominant phyla of the soil bacterial community in the abandoned jujube forest. (2) Abandonment altered the composition of soil bacteria at the OTU level in jujube plantations. (3) There are differences in the soil bacterial community structure across different periods of abandonment in the jujube forest. (4) Soil water content is the main factor affecting the bacterial community structure of the abandoned jujube forest. There are differences in the soil water content of abandoned woodlands, which affects the community structure of soil microorganisms. Full article

Monoculture plantation systems face increasing challenges in sustaining ecosystem multifunctionality (EMF) under intensive management and climate change, with long-term functional trajectories remaining poorly understood. Although biodiversity–EMF relationships are well-documented in natural forests, the drivers of multifunctionality in managed plantations, particularly age-dependent dynamics, require further investigation. This study examines how stand development influences EMF in Castanopsis hystrix L. plantations, a dominant subtropical timber species in China, by assessing six ecosystem functions (carbon stocks, wood production, nutrient cycling, decomposition, symbiosis, and water regulation) of six forest ages (6, 10, 15, 25, 30, and 34 years). The results demonstrate substantial age-dependent functional enhancement, with carbon stocks and wood production increasing by 467% and 2016% in mature stand (34 year) relative to younger stand (6 year). Nutrient cycling and water regulation showed intermediate gains (6% and 23%). Structural equation modeling identified plant diversity and microbial community composition as direct primary drivers. Tree biomass profiles emerged as the strongest biological predictors of EMF (p < 0.01), exceeding abiotic factors. These findings highlight that C. hystrix plantations can achieve high multifunctionality through stand maturation facilitated by synergistic interactions between plants and microbes. Conservation of understory vegetation and soil biodiversity represents a critical strategy for sustaining EMF, providing a science-based framework for climate-resilient plantation management in subtropical regions. Full article