Plant Diversity Indices Research Articles

Trade-off between herbal and allopathic treatments: An ethnopharmacological case study in Rema-kalenga wildlife sanctuary, Bangladesh

The Rema-Kalenga Wildlife Sanctuary (RKWS) is a protected forest in Bangladesh that houses a variety of rare flora and fauna and supports the sustenance of 13 ethnic communities. This forest's indigenous and other inhabitants traditionally have a strong cultural connection to the plants, particularly medicinal plants. Due to modern allopathic medicine's rapid growth and commercial tree species prioritization, many medicinal plants are now on the verge of endangerment. Under such circumstances, it is crucial to explore how the local community perceives the importance of herbal treatments in contrast to allopathy, the underlying reasons for their perceptions, and the specific ailments for which they use the plants. The main objectives are: 1) to evaluate the perceptions of the local community towards allopathy and herbal medicine using Nussbaum's central capabilities approach, 2) to identify medicinal plant diversity, therapeutic usages, and quantitative indices, 3) to determine the factors that influence the use of medicinal plants. Repeated interviews and field surveys were conducted at the RKWS, interviewing 145 people, including the indigenous community (72.42 %) and traditional healers (8.27 %) from the surrounding seven villages. The study identified 51 medicinal plant species belonging to 39 families for their potent medicinal properties in treating various ailments. The predominant parts of the plants used in the treatments were leaves and roots. The uses were classified into 12 categories according to Nussbaum's central capabilities. The findings identified Aloe vera, Phyllanthus emblica, and Azadirachta indica as highly culturally important species. In contrast, Terminalia arjuna, Swertia chirata, and Azadirachta indica were found to have the highest relative importance. The underlying determinants influencing the preferences of individual users towards herbal medicine were income from agroforestry, beliefs, knowledge, and ethnicity, as revealed by the analysis of the ordinal logit model. The respondents viewed their strong inclination toward herbal medicine with many positive attitudes. Herbal medicine users held a negative perception of allopathy except for affiliation and practical reasons being viewed as the positive outcomes. Conversely, allopathic medicine users expressed mixed perceptions towards the treatment, with both positive and negative aspects being identified. Promoting the sustainable use of medicinal plants and their conservation efforts is imperative for the benefit of present and future generations in this region.

Emotional Perceptions of Thermal Comfort for People Exposed to Green Spaces Characterized Using Streetscapes in Urban Parks

Thermal comfort is a key determinant ruling the quality of urban park visits that is mainly evaluated by equivalent meteorological factors and lacks evidence about its relationship with emotional perception. Exposure to green space was believed to be an available approach to increase thermal comfort, but this argument still needs verification to confirm its reliability. In this study, about ~15,000 streetscapes were photographed at stops along sidewalks and evaluated for green view index (GVI) and plant diversity index in five urban parks of Changchun, Northeast China. The faces of visitors were captured to analyze happy, sad, and neutral scores as well as two net positive emotion estimates. Meteorological factors of temperature, relative humidity, and wind velocity were measured at the same time for evaluating thermal comfort using equivalent variables of discomfort index (DI), temperature and humidity index (THI), and cooling power index (CP). At stops with higher GVI, lower temperature (slope: from −0.1058 to −0.0871) and wind velocity (slope: from −0.1273 to −0.0524) were found, as well as higher relative humidity (slope: from 0.0871 to 0.8812), which resulted in positive relationships between GVI and thermal comfort evaluated as DI (R2 = 0.3598, p < 0.0001) or CP (R2 = 0.3179, p < 0.0001). Sad score was positively correlated with THI (R2 = 0.0908, p = 0.0332) and negatively correlated with CP (R2 = 0.0929, p = 0.0294). At stops with high GVI, more positive emotions were shown on visitors’ faces (happy minus sad scores, 0.31 ± 0.10). Plant diversity had varied relationships with GVI in parks depending on age. Overall, our study demonstrated that using imagery data extracted from streetscapes can be useful for evaluating thermal comfort. It is recommended to plan a large amount of touchable nature provided by vegetation in urban parks so as to mitigate micro-climates towards a trend with more thermal comfort that evokes more positive emotions.

Nature-Based Solutions for Landscape Performance Evaluation—Handan Garden Expo Park’s “Clear as a Drain” Artificial Wetland as an Example

As a technology for water landscape performance that considers landscape, ecological, and social effects, nature-based solutions play a crucial role in enhancing the functionality of integrated ecosystem services on the micro-scale. This study conducted a systematic investigation into the landscape performance of the “Clear as a Drain” composite sponge facility at Handan Garden Expo Park. The following conclusions were drawn: (1) In terms of ecological restoration support services, the “Clear as a Drain” artificial wetland exhibited diverse habitat types, a rich variety of plant species specific to the site’s region, and high plant diversity indices for shrubs (1.776) and herbaceous aquatic plants (3.352). Reclaimed water reused in the artificial terraced wetland promoted plant growth and diversity while contributing to site self-rehabilitation; plants also significantly contributed to carbon fixation, oxygen release, and carbon emission reduction. (2) Regarding ecological restoration regulation services, the artificial wetland effectively purified reclaimed water with substantial improvements observed in incoming water quality during spring, summer, and autumn—particularly notable purification effects were observed during the summer months. Pollutant reduction rates for COD, BOD5 ammonia nitrogen, TP, and TN reached 75.8%, 72.1%, 93.8%, 96.7%, and 90.3%, respectively; different independent subsystems within the wetland demonstrated distinct advantages in pollutant removal; park plants displayed strong air purification capabilities; annual energy savings from park plants could fully cover daily energy consumption for nearby residents. This case could serve as guidance for scientific management and design parameter optimization of other composite sponge facilities.

Analisis Vegetasi Tumbuhan Tingkat Pohon di Kawasan Geopark Silokek Kabupaten Sijunjung

Silokek Geopark Area is a geopark area that is being appointed into a national geopark consisting of 25 geodiversity, 12 biodiversity, and 17 cultural diversity sites. The objective of the study is to determine the composition and structure of vegetation of trees in the Silokek Geopark area, Sijunjung Regency. This research has been conducted from September to December 2022 by using the transect method. The plot was made of 10 plots with a size of 10x10 meters for vegetation that is placed alternately on both sides of the transect. Identification is carried out at the Andalas University Herbarium. Based on the research results, 15 families, 19 genera, 22 species, and 30 individuals were found. The co-dominant families are Moraceae (20%), Ebenaceae (16.67%), and Euphorbiaceae (13.33%). The highest important value index of Ficus Stricta was obtained at 57.86% and the lowest in the Nephelium Lappaceum at 7.36%. The plant diversity index in this area is classified as moderate (H '= 2.85). It is recommended that the government to controlling the diversity of plants in the Silokek Geopark area, considering that this area is a tourist area.

Soil nutrient heterogeneity affects community stability through changing asynchrony in an alpine meadow on the Qinghai-Tibetan Plateau

Soil nutrients are ubiquitously heterogeneously distributed and such heterogeneity can greatly influence plant and population growth, interspecific competition and community structure and productivity. Despite these impacts, it is still unknown how soil nutrient heterogeneity affects community stability. We conducted a three-year experiment in an alpine meadow on the Qinghai-Tibetan Plateau, involving one homogeneous and six heterogeneous treatments of N, P, and K addition. The heterogeneous treatments varied in patch size, patch contrast, and number of patch types. Community stability in the homogeneous treatment tended to be the highest, likely due to high asynchrony among functional groups. However, such effects varied with patch size, patch contrast and number of patch types. Also, the effects of patch contrast and number of patch types on community stability and asynchrony among functional groups depended on patch size. The grass proportion was significantly affected by soil nutrient heterogeneity, and greater number of patch types increased the grass proportion at the small patch size, but not at the large one. Additionally, species richness, Shannon-Weiner index and Simpson index were greater in high patch contrast compared to the homogeneous treatment, but community evenness was not. These results suggest that soil nutrient heterogeneity can influence community stability by modifying functional group asynchrony and community evenness, rather than biomass proportions or other plant diversity indices. Our findings highlight the importance of incorporating soil nutrient heterogeneity in modeling the responses of alpine ecosystems to continuous nitrogen deposition and climate warming.

Plant diversity in the understory of Eucalyptus plantations on Hainan Island and its response to environmental factors

Research on understory plant diversity and its response to environmental factors helps in the sustainable development of plantation forests. We investigated the characteristics of understory plant diversity in Eucalyptus plantation forests located in Dongfang, Ding'an, Tunchang, and Lingao on Hainan Island by leveraging the plot survey method, and analyzing how the understory plant diversity in these Eucalyptus plantation forests responds to environmental factors. The results showed that a total of 124 plant species belonging to 62 families and 112 genera were recorded in the sampled plots of the Dongfang, Ding’an, Tunchang, and Lingao regional sites on Hainan Island, among which species of Fabaceae and Poaceae comprised the largest number of plants. The number of species and plant diversity indices of the shrub layer and herb layer in Eucalyptus plantation forests varied at different sites, The richest understory vegetation in Tunchang, located in the center of Hainan Island, and the highest α-diversity whether gauged by species or phylogenetically. The similarity of the understory plant community species was greatest between Ding’an and Tunchang, whereas the difference in composition was largest between Dongfang and the other three sites. Phylogenetically, the understory plant community at Ding’an had the most distant affinities among species, whereas that at Tunchang had the closest affinities among species. The results of the Mantel test and redundancy analysis revealed differing correlations between plant diversity in the shrub layer versus herb layer and various environmental factors. In particular, elevation and annual average temperature are the two main factors influencing plant diversity in the shrub layer, and soil available nitrogen and annual average sunshine duration are the two main factors influencing plant diversity in the herb layer. Variance decomposition showed that the combined effect of soil, climate, and topography factors is the main driver shaping plant diversity in the shrub layer of the understory in Eucalyptus plantation forests, while the combined effect of climate and soil factors is the main one determining plant diversity in their herb layer.

Exclusion of livestock decouples the relationship between plant production and diversity, species richness on complex topography in typical steppe in the Loess Plateau, China

Grazing is widely used in more than one-forth of global terrestrial ecosystems, with three quarters are distributed on complex topography. Grazing and topography have both resulted in degradation of approximately 49 % of natural grasslands. However, research on the interaction between topography and livestock exclusion on grassland characteristics is scarce. This study was carried out on a typical steppe to explore the effect of topography and enclosure year on vegetation characteristics. Aboveground biomass, and species richness were examined for three different enclosure years (0, 3, and 6 years), on four slopes (0°, 15°, 30°, and 45° slope), and three aspects (flat, shady and sunny). The results indicated that: The aboveground biomass on the 0° slope had a greater value after 6 years of the enclosure. Aboveground biomass increased with the increasing enclosure year, while it decreased with increasing slope except enclosure for 0 year on shady slope. Aboveground biomass on the shady slopes was greater than on the sunny slopes. Species richness of community and perennial plants increased with increasing slope and enclosure year. The annual plants richness inversely correlated with slope and enclosure year. All plant diversity indexes increased with increasing enclosure year. Margalef and Shannon-wiener indexes decreased with increasing slope, while Simpson and Pielou indexes increased. This paper demonstrates that aspect, slope and enclosure affect aboveground biomass by affecting other vegetation characteristics. In conclusion, grassland production can be improved with moderate livestock exclusion under different topography.

Vegetation communities and soil properties along the restoration process of the Jinqianghe mine site in the Qilian Mountains, China.

The study explores the impact of mine grassland restoration on plant communities and soil properties in alpine grasslands, a subject of significant interest due to the observed relationship between grassland changes, plant communities, and soil properties. While prior research has mainly focused on the consequences of grassland degradation on plant diversity and soil characteristics, the specific effects of varying restoration degrees in alpine mining grasslands at the regional scale remain poorly understood. To address this knowledge gap, we established 15 sampling plots (0.5m×0.5m) across five different restoration degrees within alpine mining grasslands in the Qilian Mountains, China. Our objective was to assess the variations in plant diversity and soil properties along these restoration gradients. We conducted comprehensive analyses, encompassing soil properties [soil water content (SWC), available nitrogen (AN), total phosphorus (TP), nitrate nitrogen (NO3-N), ammonium nitrogen (NH4-N), total nitrogen (TN), available phosphorus (AP), soil organic carbon (SOC), nitrate nitrogen, soil pH, and electrical conductivity (EC)], plant characteristics (height, density, frequency, coverage, and aboveground biomass), and plant diversity indices (Simpson, Shannon-Wiener, Margalef, Dominance, and Evenness indexes). Our findings included the identification and collection of 18 plant species from 11 families and 16 genera across the five restoration degrees: Very Low Restoration Degree (VLRD), Low Restoration Degree (LRD), Moderate Restoration Degree (MRD), High Restoration Degree (HRD), and Natural Grassland (NGL). Notably, species like Carex duriuscula, Cyperus rotundus, and Polygonum viviparum showed signs of recovery. Principal component analysis and Pearson correlation analysis revealed that soil pH, SWC, SOC, NO3-N, and AN were the primary environmental factors influencing plant communities. Specifically, soil pH and EC decreased as restoration levels increased, while SWC, AN, TP, NH4-N, TN, AP, SOC, and NO3-N exhibited a gradual increase with greater restoration efforts. Furthermore, the HRD plant community demonstrated similarities to the NGL, indicating the most effective natural recovery. In conclusion, our study provides valuable insights into the responses of plant community characteristics, plant diversity, and soil properties across varying restoration degrees to environmental factors. It also elucidates the characteristics of plant communities along recovery gradients in alpine grasslands.

Vegetation recovery reshapes the composition and enhances the network connectivity of phoD-harboring microorganisms to promote P availability in a karst ecosystem

Soil phoD-harboring microorganisms can facilitate phosphorus (P) transformation and increase the available P (AP) in P-limited soils; however, the mechanism by which these microorganisms enhance AP throughout the vegetation recovery process of karst ecosystems is poorly understood. Accordingly, this study investigates the effect of vegetation recovery on soil AP and the community composition and network connectivity of phoD-harboring microorganisms to elucidate the mechanism by which phoD-harboring microorganisms enhance soil AP in the four vegetation recovery stages (i.e., grassland, shrubland, shrub-arbor forest, and arbor forest) in a karst ecosystem. Results show that soil total P, AP, and microbial biomass P concentrations, as well as alkaline phosphatase activities, litter and soil nutrients, and plant diversity indices (Shannon–Wiener and Pielou) increase with advancing vegetation recovery. Moreover, the diversity indices (Shannon–Wiener and Simpson) and network complexity of the phoD-harboring microorganisms also increase with advancing vegetation recovery, leading to distinct communities among the four recovery stages. Rhizobiales, Pseudomonadales, and Burkholderiales comprise the dominant phoD-harboring microorganism orders. The relative abundances of Pseudomonadales and Burkholderiales increase with advancing vegetation recovery; Rhizobiales is the highest in shrubland and the lowest in grassland. The structural equation model results show that advanced vegetation recovery is associated with increased plant diversity, litter nutrients, and soil nutrients. The network connectivity is enhanced with advancing vegetation recovery accompanied by increasing soil phosphatase activity and P availability. These results suggest that regulating the phoD-harboring microorganism composition and network connectivity is essential to alleviate plant P limitation in karst ecosystems.

Soil and plant attributes under grazing exclusion in semi-steppic semi-arid rangelands, Iran

The aim of this study was to investigate the effect of exclusion (20 years) on the attributes of soil and vegetation in northwest of Iran. Three sites in grazed and three sites in exclusion areas were selected. At each site, three 100 m transects were established for sampling purposes. Soil attributes, including electrical conductivity, pH, calcium carbonate, organic carbon, nitrogen, phosphorus, potassium, clay, silt, calcium, magnesium, and bicarbonate were measured in the lab. Additionally, the primary and secondary attributes of vegetation including density, canopy cover, aboveground net primary production (ANPP) of plant functional types (PFTs), diversity, richness and evenness indices were recorded. The findings of our study indicate that the exclusion site exhibited significantly higher levels of soil organic carbon (1.91%), total nitrogen (0.95%), available phosphorus (1.75 ppm), and soluble potassium (163.52 ppm) compared to the grazed site. However, no significant differences were observed in other soil characteristics between the two sites. Density, canopy cover percentage, ANPP of PFTs (p < .01), diversity (1.92), and richness index (9.64), were higher in the exclusion area (p < .05), while, evenness showed no significant difference. The total species density and canopy cover within the exclusion area were also found to be higher than in grazed areas. Results suggest that exclusion in semi-arid semi-steppes plays an important role in rangeland management.

Changes in the soil fungal communities of steppe grasslands at varying degradation levels in North China.

The grasslands in North China are rich in fungal resources. However, the knowledge of the structure and function of fungal communities and the role of microbial communities in vegetation restoration and succession are limited. Thus, we used an Illumina HiSeq PE250 high-throughput sequencing platform to study the changing characteristics of soil fungal communities in degraded grasslands, which were categorized as non-degraded (ND), lightly degraded, moderately degraded, and severely degraded (SD). Moreover, a correlation analysis between soil physical and chemical properties and fungal communities was completed. The results showed that the number of plant species, vegetation coverage, aboveground biomass, and diversity index decreased significantly with increasing degradation, and there were significant differences in the physical and chemical properties of the soil among the different degraded grasslands. The dominant fungal phyla in the degraded grassland were as follows: Ascomycota, 44.88%-65.03%; Basidiomycota, 12.68%-29.91%; and unclassified, 5.51%-16.91%. The dominant fungi were as follows: Mortierella, 6.50%-11.41%; Chaetomium, 6.71%-11.58%; others, 25.95%-36.14%; and unclassified, 25.56%-53.0%. There were significant differences in the microbial Shannon-Wiener and Chao1 indices between the ND and degraded meadows, and the composition and diversity of the soil fungal community differed significantly as the meadows continued to deteriorate. The results showed that pH was the most critical factor affecting soil microbial and fungal communities in SD grasslands, whereas soil microbial and fungal communities in ND grasslands were mainly affected by water content and other environmental factors.

Tree growth and density enhanced, while diversity and spatial clustering reduced soil mycorrhizal C and N sequestration: Strong interaction with soil properties in northeastern China

In this paper, the effects of species diversity, tree growth, and spatial clustering on mycorrhizal carbon and nitrogen sequestration and the interaction of soil physicochemical properties in Northeast China were investigated. Based on 720 10 m ∗ 10 m plots in Harbin Experimental Forest Farm of Northeast Forestry University, we determined mycorrhizal biomarkers of easily extractable Glomalin-related soil protein (EEG) and total Glomalin-related soil protein (TG). Four plant diversity indices, seven structural metrics, and five soil properties were also measured. We found that: 1) The low tree diversity plots had 1.08–1.23 times higher TG, EEG, TG-N/TN (proportion of N in TG to TN), and TG-C/SOC (proportion of C in TG to SOC) than the high plots. 2) Tree diameter was negatively correlated with EEG and TG, but positively correlated with the EEG and TG contribution to soil TN and SOC. Soil EEG and TG were positively correlated with under-branch height and tree density. W (Uniform Angle Index, higher W indicates more clustering of tree distribution in the plot) was negatively correlated with the above four ratios and positively correlated with EEG/TG. 3) pH was the most powerful explainer for the GRSP variations (6.8 %, strongest negative association with GRSP/TN, R2 > 0.13), followed by soil electrical conductance (6.5 %, positive relation with TG, p < 0.05), AP (3.2 %). 4) Plant diversity mainly affected GRSP traits through the interaction with soils (0.07), tree growth and density directly increased TG, TG-N/TN, and TG-C/SOC, while tree spatial distribution directly reduced TG-N/TN. Our finding highlighted the important effects of tree diversity and forest structural traits on GRSP amount, carbon sequestration, and nutrient retentions, and could support glomalin-related forest soil management of temperate forests in the high-latitude northern hemisphere.

Analysis of Vegetation and Plant Diversity in High Conservation Value Areas in Oil Palm Plantations

The expansion of oil palm plantations is often rumored to impact the destruction of forests and other ecosystems with high conservation value (HCV). This study aimed to analyze the vegetation and plant diversity in the HCV area of oil palm plantations. The research was conducted on an oil palm plantation in Seruyan District, Central Kalimantan Province, Indonesia with an HCV area of 5379 ha. The research was carried out using the grid transect method on various types of vegetation, divided into four plots: seedlings, saplings, poles and trees. Parameters observed included the number of species, the number of individuals and the level of plant diversity. The results showed that the research location had good vegetation and plant diversity in the HCV area. There were 25 plant species from 17 families with a total of 355 plants. The number of species found in the seedling plots was 11 species (6 families) with a total of 38 plants; in the sapling plots was 16 species (12 families) with a total of 159 plants; in the pole plots was 14 species (11 families) with a total of 43 plants, and in the tree plots was 13 species (10 families) 115 plants. There was variation in the number of species and families in each plot. The overall plant diversity index was low. The diversity index of plants in the plots of seedlings, saplings, poles and trees (and the average) was in the low category.

Influence of plant diversity and spatial pattern of urban green spaces on socioeconomic activities: insights from Xiamen, China

ABSTRACT Urban green space is the fundamental component of urban ecosystems, but the processes and mechanisms underlying the influence of green space structure and quality on human social and economic activities are still unclear. Plant diversity in the green space may have an impact on socioeconomic activities, which can be characterized by the spatial distribution of points of interest (POIs). To test this hypothesis, 16 green spaces on Xiamen Island were taken as the research object to analyze the relationships among five plant diversity indices, three landscape indices, and seven POIs of green spaces. Principal component analysis and the partial least-squares regression model were used to study the distribution of the seven types of POIs and the influence of green space on POI distribution. The results showed that the closer to the green space, the greater the weight of the principal components of medical institutions. The effects of green space on the seven POIs were represented with spatial relationships within the buffers. With the change in buffer gradient, there are influence trends such as the ‘∪’ or ‘∩’ type on various POIs. POIs are more impacted by the internal plant diversity index than by the landscape index of the green space. There was a scale effect of the diversity and landscape indices on the number of POI changes. The effect of the relationship between plant diversity and the spatial pattern of urban green spaces on socioeconomic activities is not direct but rather indirect.

KERAGAMAN FAMILI ARECACEAE DI TAMAN NASIONAL WAY KAMBAS SEBAGAI SUMBER BELAJAR KURIKULUM MERDEKA

This research aims to (1) determine the plant species of the Arecaceae family in the forest area of the Way Kambas SPTN II Bungur National Park (Resort Toto Projo) East Lampung Regency, (2) determine the plant diversity index of the Arecaceae family in the forest area of the Way Kambas SPTN II Bungur National Park (Resort Toto Projo) East Lampung Regency, (3) Find out whether the results of the research are suitable or not to be used as a Biology learning resource in the form of Student Worksheets based on Discovery Learning. The type of research used was descriptive qualitative, with a purposive sampling method combined with line transects. The results found from this research were 15 species from 294 individuals. The results of the overall calculation of the diversity index for the Arecaceae family in the Way Kambas SPTN II Bungur National Park Forest Area (Toto Projo Resort) show a figure of 2.4871, including the medium category. Validation of learning resources is carried out by 5 validators including material expert validation, design validation, and language validation. The validation results from material experts got a score of 81%, validation from design experts got a score of 82%, and validation from language experts got a score of 78%. The feasibility of the Student Worksheets based on Discovery Learning product that was created obtained an average score from all validators, namely 80%, namely with good criteria, and was declared valid and suitable as a student learning resource.

CARACTERIZACIÓN DE SISTEMAS AGROFORESTALES CON CACAO (Theobroma cacao L) EN TRES MUNICIPIOS DEL DEPARTAMENTO DE BOYACÁ, COLOMBIA

&lt;p&gt;&lt;strong&gt;Background:&lt;/strong&gt; In Colombia, most traditional cocoa crops are developed under agroforestry systems (SAF), associating shrubs and trees that provide shade for cocoa. They generate additional economic income and various ecosystem services. &lt;strong&gt;Objective:&lt;/strong&gt; To characterize agroforestry systems with cocoa in three municipalities in eastern Boyacá (Miraflores, Berbeo, and Páez) belonging to the province of Lengupá. &lt;strong&gt;Methodology:&lt;/strong&gt; A semi-structured interview was applied in 15 selected farms to learn about socioeconomic aspects, agronomic management of cocoa, and the use and management of trees. The botanical and structural composition and the Simpson (S), Shannon-Weaver (H´), and Jaccard (J) plant diversity indices were determined. &lt;strong&gt;Results:&lt;/strong&gt; Cocoa producers in that region develop smallholder production under agroforestry systems with irregular tree species distribution, which are used for wood, firewood, shade, and food. At the regional level, 189 forest individuals accompanying cocoa were found, grouped into 18 families, 17 genera, and 28 species. The municipality of Berbeo presented the highest abundance (73 individuals), followed by Miraflores (67) and finally, Páez (49). In Berbeo, the species with a high importance value index (IVI) were &lt;em&gt;Ceiba pentandra&lt;/em&gt; and &lt;em&gt;Cedrela odorata&lt;/em&gt; (35 and 33, respectively), in Miraflores &lt;em&gt;Trichant&lt;strong&gt;h&lt;/strong&gt;era gigantea &lt;/em&gt;and &lt;em&gt;Persea americana&lt;/em&gt; (44 and 42) and, in Páez &lt;em&gt;Cedrela odorata&lt;/em&gt; (104). &lt;strong&gt;Implications:&lt;/strong&gt; The selective felling of forests in SAF with cocoa, which intensifies the production of wood, has favored the loss of diversity; Therefore, the floristic composition studies serve as a basis to identify other potential forest species for the establishment of SAF to promote the diversification of the productive system and contribute to its resilience and sustainability. &lt;strong&gt;Conclusion:&lt;/strong&gt; The agroforestry systems with cocoa in three municipalities in eastern Boyacá presented a differential composition and diversity, marked by a lower diversity in the municipality of Páez, where the species &lt;em&gt;C. odorata&lt;/em&gt; had greater representation, related to the affinity of farmers for timber species of commercial interest.&lt;/p&gt;

The effects of grazing and fencing on grassland productivity and diversity in alpine grassland ecosystem in the Tibetan highland

Anthropogenic activities, such as grazing and fencing, have been known to alter the productivity and biodiversity of grassland ecosystems, potentially affecting their functioning. However, the impact of these activities on aboveground biomass (AGB) and plant diversity in alpine grasslands at different altitudes, as well as how they may be affected by soil nutrients and environmental climate, is not well understood. To address this knowledge gap, a study was conducted in the Lhasa Valley of Tibet. In 2013, twelve metal fences were set up at mountainous transects, and field surveys were conducted at twelve paired sites in early August 2021. The results of the study showed that AGB was slightly higher in fenced sites compared to grazed sites at altitudes from 4000 to 5100 m, but decreased with altitude at a slower rate in grazed sites. Plant diversity indices exhibited a unimodal pattern with increasing altitude, with no significant differences between fenced and grazed sites. Soil nutrients and environmental climate were found to be positively correlated with plant diversity indices and AGB at both fenced and grazed sites. Multiple linear regression models revealed that AGB and the Shannon index were largely influenced by soil nutrients (AP and AN) rather than by growing season soil temperature at fenced sites, while AGB and the Shannon index were more impacted by growing season soil temperature than by soil nutrients at grazed sites. These findings provide important insights into the impacts of grazing and fencing on above-ground biomass and plant diversity in mountainous environments.

Effects of target tree management on understory regeneration in Pinus massoniana plantations.

To clarify the effects of target tree management on natural forest regeneration, with Pinus massoniana plantations in the low mountainous regions of eastern Sichuan with target tree densities of 100, 150 and 200 trees·hm-2 as test object, we analyzed the effects of management densities on canopy structure, plant diversity, and soil physicochemical properties on understory regeneration. The results showed that the regeneration index increased with management density, which increased 0.08-0.10 in the managed plantations compared with unmanaged sites. When the density of the target trees was 150 trees·hm-2, an increase of 9 regeneration tree species and an increase of 800 trees·hm-2 in quantity were observed. The dominance of herbaceous species was not prominent, but canopy structure was improved, and the regeneration ability of understory plants was enhanced. The impact of habitat factors on the regeneration index ranked as soil total porosity (0.591) > leaf area index (-0.536) > Shannon index (-0.085) > available P (0.053) > total N (-0.007) > Pielou index (-0.005). Target tree management facilitated understory regeneration in the P. massoniana plantations by improving soil pore conditions, reducing leaf area index, and decreasing herbaceous plant diversity index. A management density of 150 trees·hm-2 was more sui-table for target tree management in P. massoniana plantations.

Comparison of plant diversity between managed and unmanaged forests in Haftkhal, Mazandaran Province, North of Iran

Abstract. Kiasari MSh, Sagheb-Talebi Kh, Rahmani R, Ghelichnia H. 2023. Comparison of plant diversity between managed and unmanaged forests in Haftkhal, Mazandaran Province, North of Iran. Asian J For 7: 106-113. The relationship of plant diversity with silvicultural practices has not been fully understood for the oriental beech forests (Fagus orientalis Lipsky), which is a widespread forest tree in the Hyrcanian Region, Iran. The implementation of appropriate forestry practices in the oriental beech forests is therefore crucial in terms of sustainable forest management. Hence, assessing the impacts of silvicultural practices on plant diversity is essential with the regard to sustainable forest management. This study aimed to compare plant species diversity between two managed and unmanaged forest stands in Mazandaran Province, Iran. Forest inventory in an area of 131 ha was performed using in a systematic random sampling with a 150 × 200 m grid size. In addition, the area of sampling was 100 m2 (10 × 10 m). Twenty and thirty sampling plots were established in managed (compartment No. 8) and unmanaged (compartment No. 36) forests, respectively. Shannon-Wiener and Simpson Indices were used to calculate plant species diversity, while Margalef and Sheldon indices were used to determine species richness and evenness, respectively. The results revealed that 50 and 56 plant species were found in managed and unmanaged forests, respectively. Rosaceae, Asteraceae, and Fabaceae were the main families in these studied areas. This study showed that the diversity and richness of plants in the managed forest slightly increased compared to the unmanaged forest. On the other hand, the evenness of plants in the managed forest slightly decreased compared to the unmanaged forest. Changes in plant diversity indices between managed and unmanaged forests were not statistically significant. This research showed that forest management of oriental beech forests using the single-tree selection cutting has not reduced or weakened the diversity of plant species in the managed forest compared to the unmanaged forest.

Tree diversity, growth status, and spatial distribution affected soil N availability and N2O efflux: Interaction with soil physiochemical properties

Soil nitrogen (N) is an essential nutrient for tree growth, and excessive N is a source of pollution. This paper aims to define the effects of plant diversity and forest structure on various aspects of soil N cycling. Herein, we collected soils from 720 plots to measure total N content (TN), alkali-hydrolyzed N (AN), nitrate N (NO3−-N), ammonium N (NH4+-N) in a 7.2 ha experimental forest in northeast China. Four plant diversity indices, seven structural metrics, four soil properties, and in situ N2O efflux were also measured. We found that: 1) high tree diversity had 1.3–1.4-fold NO3−-N, 1.1-fold NH4+-N, and 1.5–1.8-fold N2O efflux (p < 0.05). 2) Tree growth decreased soil TN, AN, and NO3−-N by more than 13%, and tree mixing and un-uniform distribution increased TN, AN, and NH4+-N by 11–22%. 3) Soil organic carbon (SOC) explained 34.3% of the N variations, followed by soil water content (1.5%), tree diameter (1.5%) and pH (1%), and soil bulk density (0.5%). SOC had the most robust linear relations to TN (R2 = 0.59) and AN (R2 = 0.5). 4) The partial least squares path model revealed that the tree diversity directly increased NO3−-N, NH4+-N, and N2O efflux, and they were strengthened indirectly from soil properties by 1%–4%. The effects of tree size-density (−0.24) and spatial structure (0.16) were mainly achieved via their soil interaction and thus indirectly decreased NH4+-N, AN, and TN. Overall, high tree diversity forests improved soil N availability and N2O efflux, and un-uniform spatial tree assemblages could partially balance the soil N consumed by tree growth. Our data support soil N management in high northern hemisphere temperate forests from tree diversity and forest structural regulations.