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[Objective] The study aims to explore the influence of spring rest grazing on the niche of Carex tibetikobresia meadow plants, and to provide data and theoretical guidance for grassland restoration and biodiversity protection. [Methods] Grazing and four grazing-off time treatments (20, 30, 40, and 50 d) were set during the green-returning period. Plant community was investigated in the middle of July of the second year, and the grazing-off time were taken as the environmental gradient to study the niche of plant populations in the C. tibetikobresia meadow. [Results] After 30, 40, and 50 days of rest grazing, the importance value and aboveground biomass of Cyperaceae were significantly increased compared to grazing, while the importance value of poisonous weeds showed the opposite trend. The aboveground biomass of Cyperaceae, Gramineae, and broad-leaved edible grasses were increased most significantly after 50 days of rest grazing, increasing by 220.99%, 69.73%, and 139.37%, respectively. The niche width (NB) of C. tibetikobresia S. R. Zhang, Helictotrichon tibeticum (Roshev) Holub, Elymus nutans Griseb, and Festuca rubra were the largest (0.999), while that of Ranunculus indivisus (Maxim.) Hand.-Mazz. was the smallest (0.889). There were 55 pairs with niche overlap value (N O) greater than 0.990, accounting for 26.10% of the total, and 3 pairs with N O less than 0.75, accounting for 1.43%. [Conclusion] Longer rest grazing time in spring promotes the growth of Cyperaceae and Gramineae, and inhibites the growth of poisonous weeds. The higher the importance value of C. tibetikobresia meadow species, the wider its niche width, which is more conducive to the growth of excellent pasture and can effectively promote the restoration of grassland.

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In order to provide a guide for plant selection of ecological restoration at antimony (Sb) mining ecological damaged sites, species composition, importance value, niche, and interspecific associations of tree, shrub, and herb layers were examined at Sb mining site in Nandan City, Guangxi, China. The results showed that 23 vascular plant species were recorded at the Sb mining ecological damaged site, belonging to 22 genera and 13 families, primarily Gramineae, Cyperaceae, Fabaceae, and Asteraceae. The highest importance values for trees, shrubs, and herbs were observed in Rhus chinensis (56.7%), Coriaria nepalensis (56.3%), and Eremochloa ciliaris (44.0%), which were characterized by fairly large niche widths of 1.58, 1.32 and 1.57, respectively. The highest niche overlap values were found between R. chinensis and Triadica sebifera in the tree layer, and between Thysanolaena latifolia in the herb layer, with the value of 0.68 and 0.99, respectively. Shrub layer exhibited a lower range of niche overlap (0.30-0.42), suggesting significant niche differentiation among different species. In the tree and shrub layers, most species showed insignificantly negative associations, the proportion was 83.3% and 66.7%, respectively, indicating that the plant community was not stable. Herb layer generally exhibited significantly positive correlations, with 52.4% of species pairs showing positive correlation, indicating weak resource competition among species. Overall, plant community at Sb mining ecological damaged site was unstable. In the process of ecological restoration, trees and shrubs that can adapt to the conditions and have positive associations should be prioritized in species selection, such as R. chinensis, C. lanceolata, C. nepalensis, and B. nivea. This will promote vegetation positive succession, rehabilitate the ecosystem and ensure sustainable development at Sb mining ecological damaged sites. [ABSTRACT FROM AUTHOR]

To analyze the community characteristics of tropical monsoon forests with different succession stages, four different plant communities named A, B, C, and D were investigated in this study, respectively, in a typical monsoon forest of Ehuangzhang in Yangchun, Guangdong Province. The species composition, biodiversity and spatial structure were analyzed, their maturity levels’ differences were detemined, succession direction was predicted, and suggestions for optimization were put forward. The results were as follows: (1) The forest layers of the four communities were single. Small diameter at breast height (DBH) class trees and lower forest dominated these communities, owning 1-3 obvious dominant species. (2) The Shannon-Wiener index ranged from 2.72 to 3.74, Simpson index from 0.90 to 0.97, and Pielou evenness index from 0.74 to 0.89, suggesting that their diversity characteristics were significant differences. (3) Their dominance ranged from 0.49 to 0.51, uniform angle from 0.56 to 0.61, mingling from 0.54 to 0.83, forest spatial structure index from 60.57 to 71.44, forest spatial structure distance from 53.15 to 68.53. (4) The analysis of community basic characteristics, diversity characteristics and spatial structural characteristics indicated that the maturity levels in all community ranked D > A > C > B. In conclusion, four communities are currently in the pre- or mid-term succession stages and the development space of DBH and tree height is large. The four communities are in the moderate growth state. All trees show a slight aggregated distribution, and the tree species are moderately, strongly or very strongly mingling. Besides, there is a distance in spatial structure between four communities and ideal forest with the development of maturity levels. The four communities continue to succession with intolerant tree species as the main dominant tree species, and gradually and preliminarily have the typical vegetation characteristics of the district forest climax community. With the development of maturity levels, the four communities’ biodiversity and mingling will increase, the spatial structure will be optimized and the stability will be enhanced. The results of this study provide scientific basis for community construction mechanism and forest structure optimization. In the future, Ehuangzhang tropical monsoon forests should be more regulated and protected, while the ecology of vegetation and biodiversity conservation in the area should be widely monitored and studied in depth.

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The ability of community species to adapt to the environment and use resources and the importance of species in the ecological system in time and space are generally represented by ecological niche. In order to study the niche characteristics and dynamic changes of the dominant species in the arbor layer of the 4hm² Pinus tabuliformis-Quercus wutaishansea mixed forest sample plot in Lingkong Mountain,and to gain a better understanding of the competition and coexistence among species in the sample plot, this study was conducted based on a typical community investigation. Four indices of important value, niche width, niche overlap, and niche similarity were chosen to calculate and analyze the niche characteristics and examine dynamic changes over a period of 10 years from 2011 to 2021. The results showed that: (1) In 2021, the important values for Quercus wutaishansea and Pinus tabuliformis were 19.906 and 13.906, respectively.The niche widths were 0.962 and 0.555, which showed difference compared to those in 2011. Both were much larger than other species, indicating that they occupied an absolutely dominant position in the community. (2) The mean values of niche overlap and similarity of dominant species in the arbor layer of the Lingkong Mountain sample plot have both increased over the past 10 years. Additionally, the species pairs with the highest overlap and similarity values have changed, suggesting an intensification of competition among these species. [ABSTRACT FROM AUTHOR]

The ability of community species to adapt to the environment and use resources and the importance of species in the ecological system in time and space are generally represented by ecological niche. In order to study the niche characteristics and dynamic changes of the dominant species in the arbor layer of the 4hm2Pinus tabuliformis-Quercus wutaishansea mixed forest sample plot in Lingkong Mountain,and to gain a better understanding of the competition and coexistence among species in the sample plot, this study was conducted based on a typical community investigation. Four indices of important value, niche width, niche overlap, and niche similarity were chosen to calculate and analyze the niche characteristics and examine dynamic changes over a period of 10 years from 2011 to 2021. The results showed that: (1) In 2021, the important values for Quercus wutaishansea and Pinus tabuliformis were 19.906 and 13.906, respectively.The niche widths were 0.962 and 0.555, which showed difference compared to those in 2011. Both were much larger than other species, indicating that they occupied an absolutely dominant position in the community. (2) The mean values of niche overlap and similarity of dominant species in the arbor layer of the Lingkong Mountain sample plot have both increased over the past 10 years. Additionally, the species pairs with the highest overlap and similarity values have changed, suggesting an intensification of competition among these species.

This study aimed to determine the species richness, biodiversity, and importance value of selected plants of different land uses in USTP Claveria Campus, Barangay Poblacion, Claveria, Misamis Oriental. Seven sample plots (land uses) comprising 70 sample points were established throughout the 65-ha campus for data collection. The measurement of biometrics and biomass of each plant were conducted to determine the species richness, diversity indices, absolute density, absolute density of each species, relative density of a species, dominance, relative cover, absolute frequency, relative frequency, and importance value of trees using the point-centered quarter method (PCQM). General findings revealed that the campus is rich in tree species (38). Importance values are high for Acacia mangium Willd. (Sites 1 and 6), Swietenia macrophylla King (Sites 2, 3, 4), Vitexparviflora Juss. (Site 5) and Schizolobium parahyba (Vell.) S.F. Blake (Site 7). Species diversity is high at Site 3 (3.27). This study generates a piece of essential information in the implementation relevant to the present and future development of the campus, valuation (i.e. Expanded Reducing Emissions from Deforestation and Forest Degradation), assessment (EIA), and accreditation (i.e. UI Green Metrics World University Ranking). [ABSTRACT FROM AUTHOR]

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Phellodendron amurense is national second-class protected plant. The quantitative analysis on the niche characteristics of dominant tree populations in broad-leaved mixed forest of Phellodendron amurense can provide theoretical basis for the protection of Phellodendron amurense and maintaining species diversity. Based on the 9 th national forest inventory in Jilin Province, the Phellodendron amurense broad-leaved mixed forest community in Changbai Mountain was investigated and the methods of importance value, Levins niche width, Shannon-Wiener niche width and Pianka niche overlap were used to analyze the niche characteristics of dominant tree populations in this region. The results showed that, there were 25 broad-leaved species, accounting for 96. 15% of the total, and the important value of Phellodendron amurense in the broad-leaved mixed forest was the largest. The Levins and Shannon-Wiener niche width indices were basically the same in order. The species with the largest niche width was Phellodendron amurense, followed by Juglans mandshurica. The niche overlap value of species such as Phellodendron amurense with Butula costata, Juglans mandshurica and Ulmus laciniata was large. The niche width and niche overlap degree showed obvious consistency. However, the niche width and niche overlap of some species were opposite, such as Carpinus turczaninowii vs. Quercus dentata, Robinia pseudoacacia, and Tilia tuan, Phellodendron amurense vs. Pinus koraiensis, which was related to the ecological habits, habitat characteristics and spatial distribution of the tree species. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Xinyang Normal University Natural Science Edition is the property of Journal of Xinyang Normal University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: Personality traits such as honesty-humility, emotionality, extraversion, agreeableness, conscientiousness, and openness to experience (HEXACO) have been linked to numerous adaptive outcomes in academic, sport, and physical activity settings; yet little if any such research has been conducted with physical education (PE) students. The aim of this study was to investigate relations between the HEXACO trait personality dimensions and five noteworthy outcomes in PE, namely task and ego goal orientation, importance-value, intention to enroll, and grade. Method: Survey data were gathered from 316 ninth and tenth-grade PE students. Results: Personality collectively predicted each of the outcomes (p <.001). Conclusion: Students with certain personalities—particularly those lower in extraversion—might be more susceptible to some less favorable outcomes in secondary PE. To better differentiate instruction in PE, there may be some merit in increasing physical educator awareness of personality traits and how they might compromise some adaptive outcomes in PE. [ABSTRACT FROM AUTHOR]

No-till avocado orchards in the highlands are gaining importance in eastern Antioquia, Colombia. To evaluate the influence of management, and edaphic properties on the composition of weed communities, 50 Hass avocado orchards were studied in nine municipalities of eastern Antioquia. The variables cover and presence of weeds were used to estimate relative frequency, dominance, and Importance Value (IV); weed management was characterized by a survey. The maximum moisture retention capacity and pH of the soil were also determined. The importance of species, rotation of management strategies, and herbicides were analyzed graphically. The association between weeds dominance, and factors, was evaluated by a generalized linear model. 66 dicots and 28 monocot weeds were classified. Out of the 10 most important species, three foreign species, Melinis minutiflora P. Beauv, Digitaria horizontalis Willd, and Pennisetum clandestinum Hoschst. Ex Chiov were the most representative. The municipalities are grouping the effects of similar management strategies in the territory. Chemical management favored the equilibrium of the weed composition, while mechanical management did not. Soil properties had less influence on the distribution and dominance of weeds. [ABSTRACT FROM AUTHOR]

【Objective】Forest is a region with the richest biodiversity. Researches on plant diversity of different forest types are of great importance to study vegetation characteristics and its conservation. Xinfengjiang Reservoir is an important water source in South China, and forest in the reservoir area has an important role in biodiversity conservation and water purification. The analysis on species diversity of different forest types in the Xinfengjiang reservoir area can provide a scientific basis for the conservation and tending management of forests in the reservoir area.【Method】Three types of typical forests, i.e., evergreen broad-leaved forest, coniferous and broad-leaved mixed forest and coniferous forest were selected as study areas. The tree, shrub and grass in the plots were recorded and species composition and diversity index were analyzed.【Result】The species composition of forest vegetation in the Xinfengjiang reservoir area was relatively rich, with 47 families, 66 genera and 165 species recorded in the sample sites, among them, the numbers of species and individuals of Lauraceae, Fagaceae, Cupressaceae and Rubiaceae were higher. In general, species diversity showed a trend of evergreen broad-leaved forest > coniferous and broad-leaved mixed forest > coniferous forest. The species richness indexes of different forest types ranged from 19 to 32, the Shannon-Wiener indexes from 2.02 to 2.92, the Simpson dominance indexed from 0.77 to 0.92, and the Pielou evenness index from 0.69 to 0.85.【Conclusion】The species diversity of evergreen broad-leaved forests in the reservoir area is high. Scientific and effective tending measures should be taken to promote coniferous forest succession reasonably. Long-term locational monitoring is also necessary to understand the relationship between forest and environmental factors. The study results can provide a scientific basis for conservation and utilization of biodiversity in the Xinfengjiang reservoir area.

To explore the community structural characteristics and spatial distribution pattern of dominant species, three companion communities of Chimonobambusa angustifolia (Doupengshan, Laoshanjie, and Leigongshan） were selected as research objects, and the communities were investigated using quadrat method. The community vertical structure, diameter class structure, height class structure, species importance value, and spatial distribution pattern of dominant species were studied, and the factors affecting community structure and spatial distribution pattern were also analyzed. The results showed the following: the vertical structure of the three communities was clear, and it could be divided into three layers-tree layer, shrub layer and herb layer from the canopy to the ground. The interlayer plants were underdeveloped with few vines and epiphytes. The diameter class structure（DBH≥1 cm） of the three communities had an inverse "J" shape, indicating successful regeneration, and the average diameter was ranked as follows: Laoshanjie (16.02 cm)＞Leigongshan (11.38 cm)＞Doupengshan（8.98 cm）, but the individual density showed the opposite trend. The diameter class structure of dominant species had an inverse "J" shape in Doupengshan and Leigongshan, implying that the population was a growing type. However, the diameter structure of dominant species had a unimodal type in Laoshanjie. The population of Fagus lucida was a declining type, and there was a degradation risk in the population of Cyclobalanopsis multinervis and Quercus engleriana. Dominant species of Laoshanjie will be replaced gradually by other plants with community succession. Overall, the height class structure of the communities was an inverse "J" shape, and the average height was ranked as follows: Doupengshan (8.14 m)＞Leigongshan (6.87 m)＞Laoshanjie (6.69 m). The height class structures of dominant species were different, and most were an inverse "J" shape, followed by unimodal type. The importance values of communities and layers were different, and the importance values of dominant species accounted for 47.58%, 57.72%, and 25.81% of the importance values of the tree layer in Doupengshan, Laoshanjie, and Leigongshan, respectively. The spatial distribution pattern of dominant species tended to be uniform or clumped in small size (DBH＜10 cm), but it tended to be uniform or random in middle size（10 cm≤DBH＜30 cm） and large size (DBH≥30 cm). This suggest that the community structure and spatial distribution pattern of dominant species in the three communities were comprehensively influenced by combined factors. Community succession time and competitive exclusion were the major factors affecting the community structure, whereas dispersal limitation and competitive exclusion were the major factors affecting the spatial distribution pattern of dominant species. [ABSTRACT FROM AUTHOR]

Abstract This study aimed at evaluating and compare the changes from 2012 to 2016 in the structure and floristic composition of a remnant Araucaria Forest. The entry and mortality rates were 2.2% year-1 and 6.9% year-1, respectively. Among the most represented species, those with the greatest yearly increases in their numbers were Sebastiania brasiliensis, Eugenia uniflora, and Allophylus sp. Average mortality density was 498 ind ha-1, and was particularly high for the following species: Casearia decandra (representing 32.3% of total mortality), Eugenia sp. (27.2%), Cinnamodendron dinisii (24.5%), and Lithraea brasiliensis (25.2%). The pioneer species represented 8.33% of income and 29.17% mortality, and secondary species composed 33.33% and 62.50% of income and mortality, respectively. Climax species accounted for 8.33% of income and did not contribute to mortality. The high tree mortality observed in the present study can be attributed, among others factors, to the effects of natural disturbance that occurred in the period.

Maize is a food crop for millions of people in sub-Saharan Africa. However, severe weed infestation might cause significant yield loss. This study investigated weed composition, abundance and distribution in maize-based cropping systems in the Southern Guinea Savanna of Nigeria. Fields were surveyed between February and March 2022. The Importance Value Index (IVI) of each weed species was determined using relative frequency, relative density, and relative abundance. A total of 29 weed species from 15 families were identified. Poaceae (34.9 %) was the most prevalent weed family, followed by Cyperaceae (26.9 %) and Portulacaceae (12.8 %). The IVI showed that Cyperus rotundus (38.6), Portulaca oleraceae (29.4), Digitaria horizontalis (25.5), Brachiaria deflexa (24.2), Senna obtusifolia (17.6), Ageratum conyzoides (16.0), Cynodon dactylon (12.6), Phyllanthus niruri (11.1) and Eragrostis sp. (10.6) were the most dominant. Principal Component Analysis (PCA) ordination biplot revealed that Setaria pumila was strongly associated with sole maize cultivation, as was Desmodium scorpiurus with maize/rice intercropping, C. dactylon with maize/pepper, Euphorbia hirta with maize/cassava, and Cleome viscosa with maize/amaranthus intercropping. Special attention to these weed species is required when making an informed decision on the choice of weed control measures.to reduce yield losses in endemic areas.

This study reports the forest vegetation community classification of the Sanzai area (Khentii range) in Mongolia using the phytosociological method. The forest vegetation has been classified into five major types characterized by the following associations: Larix sibirica community, Pinus sylvestris community, Betula fusca-Picea obovata community, Betula platyphylla community, and Pinus sibirica community. Ecological characteristics such as species composition, layer structure, vegetation ratio, and the distribution of individual trees based on their diameter at breast height (DBH) are slightly different among the plant communities. In all communities, the significant value was highest in the Larix sibirica with 74.6%, followed by Pinus sibirica (64.2%), Betula platyphylla (59.5%), Pinus sylvestris (53.9%), and Picea obovata (47.7%). Our results of DBH analysis show that the size-frequency distribution of Pinus sylvestris, Pinus sibirica, Larix sibirica, and Picea obovata was a binomial distribution in all the communities, suggesting that for the time being, these species dominate continuously. In addition, it is likely that Betula platyphylla will dominate rapidly because of its higher frequency of young individuals. This indicates the forest condition impairment in the forest of the Sanzai area.

Oaks (Quercus spp.) are foundational species in forests and woodlands in the eastern USA. An oak regeneration bottleneck has occurred throughout its range in recent decades, and refining silvicultural treatments to localized conditions has become a focus in addressing this problem. This study was developed to determine species regeneration dynamics among oak and oak competitors on productive sites in response to silvicultural treatments in oak-dominated southern Appalachian mountain forests. The treatments were: an oak shelterwood treatment (25–30% basal area [BA]) reduction through midstory removal with herbicides); a prescribed fire treatment (two, late-dormant season prescribed fires occurring over a 9-yr period); a shelterwood and burn treatment (one, late-dormant season prescribed fire 3–5 yr following 30–40% BA removal); and an unmanaged control. To determine treatment impacts on the regeneration layer, changes in relative and absolute importance values and stems ha-1 (germinants up to stems ≤ 4.9 cm diameter at breast height [DBH]) were calculated at the species group and individual species level 0 and 9 yr postinitial treatment. The greatest relative increases in importance values were 1,401% and 2,995% for the red oak group and yellow-poplar (Liriodendron tulipifera), respectively, in the shelterwood and burn (SWB). Changes in all species groups were predominantly influenced by the smallest size-class (< 0.6 m tall), with the exception of northern red oak (Q. rubra) and yellow-poplar in the SWB. The SWB significantly reduced importance values of all shade-tolerant species groups and was the only treatment to decrease red maple (Acer rubrum) importance value and density over the study duration. The prescribed fire (RXF) treatment increased the red oak group importance value, while simultaneously decreasing yellow-poplar's importance value and increasing red maple's importance value. Changes in the red oak group in the SWB and the RXF were driven by northern red oak. Treatments did not significantly change the importance value of the white oak group. The SWB was the only treatment to significantly decrease overstory BA. The RXF and SWB treatments improved the competitive status of only some oak species, but modifications to these treatments might result in better control of yellow-poplar and red maple competition, further improving oak's competitive status. Although the SWB resulted in modest recruitment of northern red oak saplings, all treatments appear in need of additional follow-up vegetation control to further improve the competitiveness and recruitment of oak into large size-classes. [ABSTRACT FROM AUTHOR]

The N deposition rate is notably increased in China, especially in the Qinghai-Tibetan Plateau (QTP). How plants respond to the projected N deposition on the alpine steppe is still in debate. In this study, to investigate the effects of N deposition on the plant community of the alpine steppe, we simulated N deposition at six different N addition rate levels (0, 8, 24, 40, 56, 72 kg N ha−1 y−1) from 2015 to 2019. Species composition and diversity were investigated as the assessment indices. The results showed that the importance value of grasses significantly increased with the increase of the N addition rate, while that of forbs significantly decreased. A high N addition rate (72 kg N ha−1 y−1) induced species composition change, making Leymus secalinus become the most dominant species within the entire plant community. Compared with the control (without N addition), species richness, Shannon–Weiner diversity, Simpson dominance and Pielou Evenness were significantly reduced under a high N addition rate. The changes of plant diversity in the alpine steppe were closely correlated with dynamics of soil nutrients, especially total carbon (TC), total phosphorus (TP) and ammonia nitrogen (NH4-N). Our findings suggested that a high N deposition rate (72 kg N ha−1 y−1) could significantly change plant composition and reduce the diversity of the alpine steppe, though they were less affected by low N deposition rates at present. With the increase of the N deposition rate, plant composition and diversity of the alpine steppe may be negatively affected in the future. In addition, Leymus secalinus is more competitive than other species with an N deposition rate increase. Soil C, soil P and soil NH4-N variation induced by N deposition might play a key role in regulating changes in plant composition and diversity in the alpine steppe. In addition, longer term field investigation needs to be carried out to testify to this phenomenon with the increase of N deposition in the future. [ABSTRACT FROM AUTHOR]

Copyright of BIOAGRO is the property of Revista BIOAGRO and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background and aims: Restinga vegetation is an ecosystem that extends along the coast of Brazil in several extensions, with phytophysiognomies composed of strata varying from herbaceous to arboreal. The objective of this work was to analyze the structural arrangement, the diversity and distribution of the woody community of an ecotonal restinga on the coast of Maranhão, Northeast Brazil. M&M: For sampling the vegetation, the method of points-quadrants (50 points) was used, whose inclusion criteria was Perimeter at Ground Height ≥ 10cm. Phytosociological parameters, community structure and phytogeographic distribution pattern were analyzed. Results: The sampling resulted in 22 species, 18 genera and 14 families. The most representative families were Myrtaceae, Arecaceae, Fabaceae, Ochnaceae, Polygonaceae e Rubiaceae. The species with the highest Importance Values (IV) were Astrocaryum vulgare (20,36%), Attalea speciosa (19,40%), Himatanthus drasticus (14,72%), Chamaecrista ramosa (10,68%), and Eugenia biflora (10,27%). The Shannon's diversity index was 2,401 nat.ind-1 and Pielou's equality was 0,749. The pattern of local distribution showed that the species are randomly distributed. Conclusions: The structure and dynamics of the ecotonal restinga between the Amazon and Northeastern coastlines indicate that the area has richness and diversity of species with values similar to the restingas of the northeast, highlighting the need for protection and valuation of plants in restinga areas. [ABSTRACT FROM AUTHOR]

Leymus chinensis steppe is subject to degradation under the combined stresses of climate change and human disturbance. This study aimed to determine the independent and compound effects of precipitation and clipping frequency on the community structure and species temporal stability of L. chinensis steppe. Six treatments were applied in a 9-year field study, comprising three precipitation regimes (precipitation reduced by 50%, R1; unchanged from ambient precipitation, R2; and increased by 50%, R3) and two clipping frequencies (clipping once or twice per year, C1 and C2). We evaluated the soil hydrothermal status, dry matter, importance value and temporal stability of five important species (L. chinensis, Artemisia eriopoda, Cleistogenes squarrosa, Potentilla tanacetifolia, and Stipa krylovii) in the L. chinensis community. The results showed: Change in the soil volumetric water content (±2.4%) altered the competitive capability of L. chinensis relative to its associated species. Drought was beneficial to S. krylovii, wet status was favorable to C. squarrosa and P. tanacetifolia, whereas drought and a wet regime both reduced the importance value and temporal stability of L. chinensis. Erratic precipitation, rather than clipping frequency, decreased the temporal stability of L. chinensis. Net primary productivity and dry matter of L. chinensis were strongly correlated under drought or wet regimes. Restoration of the key species L. chinensis and controlling grazing intensity in severe drought or wet conditions are recommended strategies for sustainable management of L. chinensis steppe.

At the beginning of the physiological growth of tobacco plants, there may be competition with weeds for light, moisture and soil nutrients, which slows down the development of the crop, raises management costs and in some cases, causes losses to the farmer. The objective of this work was to determine the persistence of weeds under chemical control before and after the transplantation of tobacco seedlings, for which a study was carried out in Campoalegre (Huila), at a height of 522 masl. A first sampling was carried out using the methodology by linear transects with 180 quadrants of 0.5 x 0.5 m, in 1.9 ha; later the application of herbicides was carried out and after the transplant a second sampling was implemented. Before transplantation, 16 botanical families with 23 species were identified and later 15 families with 19 species, without the presence of new records. Before transplanting, the highest index of importance value was of the Poaceae and the Cyperus rotundus species, but later the greatest value was presented again by the same family, although Rottboellia cochinchinensis stood out. Likewise, previously transplantation, the greatest diversity was of C. rotundus, dominance of Cleome spinosa and uniformity of Spermacoce assurgens. After transplanting, the greatest diversity and dominance was R. cochinchinensis and the greatest uniformity was Kallstroemia maxima. The survival capacity of the weeds is highlighted before a chemical control where only four species of those initially listed stopped appearing. [ABSTRACT FROM AUTHOR]

Abstract Species distribution models (SDMs) provide useful information about potential presence or absence, and environmental conditions suitable for a species; and high‐resolution models across large extents are desirable. A primary feature of SDMs is the underlying spatial resolution, which can be chosen for many reasons, though we propose that a hybrid lattice, in which grid cell sizes vary with the density of forest inventory plots, provides benefits over uniform grids. We examine how the spatial grain size affected overall model performance for the Random Forest‐based SDM, DISTRIB, which was updated with recent forest inventories, climate, and soil data, and used a hybrid lattice derived from inventory densities. Modeled habitat suitability was compared between a uniform grid of 10 × 10 and a hybrid lattice of 10 × 10 and 20 × 20 km grids to assess potential improvements. The resulting DISTRIB‐II models for 125 eastern U.S. tree species provide information on individual habitat suitability that can be mapped and statistically analyzed to understand current and potential changes. Model performance metrics were comparable among the hybrid lattice and 10‐km grids; however, the hybrid lattice models generally had higher overall model reliability scores and were likely more representative of the inventory data. Our efforts to update DISTRIB models with current information aims to produce a more representative depiction of recent conditions by accounting for the spatial density of forest inventory data and using the latest climate data. Additionally, we developed an approach that leverages a hybrid lattice to maximize the spatial information within the models and recommend that similar modeling efforts be used to evaluate the spatial density of response and predictor data and derive a modeling grid that best represents the environment.

Background: Zelkova schneideriana Hand.-Mazz., is an endangered species mainly distributed in subtropical China. Currently, little is known about its niche and interspecific association. Questions: What are the niche characteristics of Z. schneideriana and other associated species? What are the interspecific associations between these species? Study sites and dates: Z. schneideriana communities in Jiangsu, China in 2019. Methods: Twenty-one 400 m2 plots were studied for importance value, niche breadth and overlap, interspecific association of Z. schneideriana communities. Results: In 39 species of tree layer, Z. schneideriana had the greatest importance value and niche breadth. For the first 10 dominant species, a considerable difference was detected by the Levins index (1.75 - 19.84) and Shannon-Wiener index (0.77 - 3.02). Forty-four out of the 45 species pairs had the value of niche similarity indices ≤ 0.5; 38 species pairs had the value of niche overlap indices ≤ 0.5. Overall interspecific association was not a significantly negative association for variance ratio < 1. χ2 test and Spearman’s correlation coefficient further revealed that above 60 % of species pairs had negative associations, suggesting most dominant species were slightly associated with other species or even independent. Conclusions: Z. schneideriana was a constructive species. Dissimilarity in environmental requirements was found among most dominant tree species, thus decreasing competition. This is likely due to the unstable community in the early stage of succession.

Climate change affects the structure and composition of a plant community and the stability and service functions of grassland ecosystems. However, the influence of warming, increased precipitation and their interaction on plant functional traits in the desert steppe are unclear. Therefore, after simulating warming (ambient temperature, warming 2℃ and warming 4℃) and increasing precipitation (natural precipitation, precipitation increased by 25% and 50%) for 6 years, we measured the morphological characteristics, photosynthesis parameters, carbon (C) and nitrogen (N) contents of leaves of Stipa breviflora Griseb. (S. breviflora), a constructive species in the desert steppe. Results showed that both warming and increased precipitation reduced the importance value (IV) of S. breviflora, while the IV of annual herbs significantly increased (P

In order to provide a guide for plant selection of ecological restoration at antimony (Sb) mining ecological damaged sites, species composition, importance value, niche, and interspecific associations of tree, shrub, and herb layers were examined at Sb mining site in Nandan City, Guangxi, China. The results showed that 23 vascular plant species were recorded at the Sb mining ecological damaged site, belonging to 22 genera and 13 families, primarily Gramineae, Cyperaceae, Fabaceae, and Asteraceae. The highest importance values for trees, shrubs, and herbs were observed in Rhus chinensis (56.7%), Coriaria nepalensis (56.3%), and Eremochloa ciliaris (44.0%), which were characterized by fairly large niche widths of 1.58, 1.32 and 1.57, respectively. The highest niche overlap values were found between R. chinensis and Triadica sebifera in the tree layer, and between Thysanolaena latifolia and Bidens pilosa in the herb layer, with the value of 0.68 and 0.99, respectively. Shrub layer exhibited a lower range of niche overlap (0.30-0.42), suggesting significant niche differentiation among different species. In the tree and shrub layers, most species showed insignificantly negative associations, the proportion was 83.3% and 66.7%, respectively, indicating that the plant community was not stable. Herb layer generally exhibited significantly positive correlations, with 52.4% of species pairs showing positive correlation, indicating weak resource competition among species. Overall, plant community at Sb mining ecological damaged site was unstable. In the process of ecological restoration, trees and shrubs that can adapt to the conditions and have positive associations should be prioritized in species selection, such as R. chinensis , C. lanceolata , C. nepalensis , and B. nivea . This will promote vegetation positive succession, rehabilitate the ecosystem and ensure sustainable development at Sb mining ecological damaged sites.

We analyzed tidal wetland vegetation patterns in the San Francisco Bay–Delta estuary (Bay–Delta) and discuss their significance for future conservation. Our objective was to conduct a balanced, random sample of six historic “remnant” tidal wetlands along a salinity gradient that ranged from southern San Pablo Bay to the lower Delta. We also wanted to compare diversity among these sites at five different scales, ranging from small subplots to total species per site. We randomly established twenty 0.1-ha plots at each site, and sampled ten 7-m2 circular subplots (subplot scale) in each plot for species presence and cover. We calculated total species per plot (plot scale) and total species per site (site scale) based on these subplot data. We calculated importance values for each species found in subplots based on frequency of occurrence and proportion of total cover at each site. In addition, we recorded species found within the 0.1-ha plot but not sampled in subplots (plot_all scale), and calculated the total species for each site based on these plot_all data (site_all scale). Thus, richness at each site was evaluated at five different scales that ranged from 7 m2 to 20,000 m2. We conducted a one-way ANOVA that compared mean richness among three scales with continuous data: subplot, plot, and plot_all. At lower estuary (San Pablo Bay) sites, richness values at these three scales were significantly lower than upper estuary (Suisun–Delta) sites. In Suisun–Delta sites, significant differences in richness varied, depending on sampling scale. Rush Ranch, a brackish wetland, had the highest average number of species per plot, whereas Sand Mound Slough, a freshwater wetland, had the highest average number of species at the subplot scale and the most total species at the site_all scale. Sand Mound Slough also had the highest number of unique species (22) compared to the other sites. We found a strong negative correlation (r2 = 0.99) between total species number and salinity (the most in the Delta at the lowest salinity, and the least at China Camp with the greatest salinity). Our analysis suggests the following conservation recommendations: (1) restore habitat for freshwater plant species diversity in the Delta; (2) restore transitional brackish wetland habitat in salt marshes of the San Pablo Bay and San Francisco Bay; and (3) focus on control of pepperweed (Lepidium latifolium) in brackish marshes.

The N deposition rate is notably increased in China, especially in the Qinghai-Tibetan Plateau (QTP). How plants respond to the projected N deposition on the alpine steppe is still in debate. In this study, to investigate the effects of N deposition on the plant community of the alpine steppe, we simulated N deposition at six different N addition rate levels (0, 8, 24, 40, 56, 72 kg N ha−1 y−1) from 2015 to 2019. Species composition and diversity were investigated as the assessment indices. The results showed that the importance value of grasses significantly increased with the increase of the N addition rate, while that of forbs significantly decreased. A high N addition rate (72 kg N ha−1 y−1) induced species composition change, making Leymus secalinus become the most dominant species within the entire plant community. Compared with the control (without N addition), species richness, Shannon–Weiner diversity, Simpson dominance and Pielou Evenness were significantly reduced under a high N addition rate. The changes of plant diversity in the alpine steppe were closely correlated with dynamics of soil nutrients, especially total carbon (TC), total phosphorus (TP) and ammonia nitrogen (NH4-N). Our findings suggested that a high N deposition rate (72 kg N ha−1 y−1) could significantly change plant composition and reduce the diversity of the alpine steppe, though they were less affected by low N deposition rates at present. With the increase of the N deposition rate, plant composition and diversity of the alpine steppe may be negatively affected in the future. In addition, Leymus secalinus is more competitive than other species with an N deposition rate increase. Soil C, soil P and soil NH4-N variation induced by N deposition might play a key role in regulating changes in plant composition and diversity in the alpine steppe. In addition, longer term field investigation needs to be carried out to testify to this phenomenon with the increase of N deposition in the future.

Students' conceptions of their academic futures, such as completing secondary school, have been found to play a significant role in their current behavior. Indeed, research regarding future time perspectives (FTP) indicates that students with extended FTPs are likely to be more engaged and less disengaged over time. Extended FTPs comprise two critical motivating elements: the cognitive (i.e., importance value) and the dynamic (i.e., school completion aspirations). Although these elements are hypothetically reciprocally related and without temporal limitation to their motivational effects, these claims have largely gone untested. These claims were examined via longitudinal structural equation modelling with cross-lagged panel analysis and invariance testing in a sample of 1327 Australian secondary school students. Findings indicated that importance value is directionally salient over school completion aspirations (such that it may precede school completion aspirations), both are associated with higher engagement and lower disengagement over time, and evidence of temporal limitations on the motivational benefits of the elements of extended FTPs was not found. School-based interventions that focus on improving importance value and school completion aspirations are discussed. • Explored reciprocal relationship between motivating elements of FTPs: importance value and school completion aspirations • A reciprocal relationship was not found, but importance value predicted subsequent school completion aspirations • Both importance value and school completion aspirations predicted gains in engagement and declines in disengagement • Extended future time perspectives were found to be consistently motivationally effective across secondary school • Extended future time perspectives are beneficial mindsets in secondary school. [ABSTRACT FROM AUTHOR]

Hydric forest communities within the Tampa Bay Watershed were inventoried to assess the effect of urbanization on these systems. Based on aerial photography and site visits, 85 hydric plots were assigned a legacy class—remnant (forest, pre-1948), emergent (forest, post 1948), and managed (actively managed grass on plot). On each plot, diameter at breast height (dbh) and canopy width and species were recorded for trees ≥2.5 cm dbh. A hierarchical agglomerative cluster analysis identified community types within a legacy class and one-way AOV (α =.05) was used to compare structural features within and among legacy classes. Remnant plots (43 plots) were composed of six, natural community types as recognized by the Florida Natural Areas Inventory and no novel communities. Emergent plots (23 plots) were composed of four natural community types and one novel community. Managed plots (19 plots) contained only novel communities. Remnants had the highest species richness (41 species) and only one non-native species. Managed had the lowest species richness (33 species) but highest richness of non-native species (17). Remnant and emergent plots had similar densities for trees ≤32 cm dbh, (803 and 820 stems/ha, respectively), whereas managed plots had only 119 stems/ha. For trees >32 cm dbh, remnant plots had a significantly higher density (196 stems/ha) than emergent (99 stems/ha) and managed (40 stems/ha). These results suggest that legacy did not play a key role in differentiating between emergent and remnant plots but did play a key role in identifying managed plots. [ABSTRACT FROM AUTHOR]

This study is a part of baseline data gathering for a short-term project in 12 barangays referred to as Quirino Forest Landscape (QFL). The study assessed trees' diversity, biophysical attributes, utilization values, and ecological importance. Quadrat sampling was performed to gather abundance and biometric data of trees with a diameter at breast height of 15 cm and greater. Data analysis employed alpha diversity indices, distance and similarity measures, carbon-based allometric equations, stand-stock table, and other tools. Secondary information and first-hand accounts were used to gather ecological and utilization values. Diversity was very high, highly heterogeneous, and very complex. Diffun was found to have the most contiguous tree assemblage; Cabarroguis and Aglipay share more species than Maddela and Diffun. Analysis of photographed canopies revealed mean canopy closure is 77.41%. Close to half of individual trees fall under 40 cm and 50 cm dbh classes, implying QFL as a secondary forest. Trees have aboveground stored Carbon of 642.87 tons/ha or 1.26 tons/tree. The area host five premium timbers, 10 Philippine Mahogany timbers, Rosewoods, 15 Furniture/Construction, and 95 underutilized species. Slightly more than a third (33.60%) of sampled canopy trees (43 species total) require conservation effort; White Lauan (Shorea contorta) is the most critical. To control further damage, measures to prevent further forest cover loss must be instituted to understand and sustain ecosystem functions. [ABSTRACT FROM AUTHOR]

Copyright of Caldasia is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Forest Research is the property of Forest Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Vegetation restoration by Mount Merapi National Park (TNGM) in Ngablak, Magelang, Central Java need the floristic data composition of understory vegetation. The objectives of this research were to identify and to determine the importance values of each plants species that composed of that restoration area. Sample collections were conducted using survey method for their morphological characters as voucher specimens that were used for species identification. Vegetation analysis was conducted using the quadratic method; shrubs (5x5 m2), grasses and herbs (1x1 m2), and importance values were analysed using relative frequencies and densities. The result shows that understory vegetation on the restoration area in Ngablak was composed of 60 seed plant species from 18 plant families. There were 7 plant families that dominate the region; Papilionaceae (13 species), Asteraceae (11), Poaceae (Grasses) (10), Cyperaceae (Sedges) (5), Amaranthaceae (3), Mimosaceae (3) and Commelinaceae (3). Plants species that have important value more than 25% in this restoration area were Cymbopogon citratus (sereh), Mimosa pudica (Putri malu), Gomphrena serrata (Bunga kancing), Pannisetum purpureum (Rumput gajah), Ageratum conyzoides (Wedusan), dan Euphatorium inulifolium (kirinyuh). The external factors that influence the growth of the understory vegetation are pH of soil and soil moisture.

Species distribution models (SDMs) provide useful information about potential presence or absence, and environmental conditions suitable for a species; and high‐resolution models across large extents are desirable. A primary feature of SDMs is the underlying spatial resolution, which can be chosen for many reasons, though we propose that a hybrid lattice, in which grid cell sizes vary with the density of forest inventory plots, provides benefits over uniform grids. We examine how the spatial grain size affected overall model performance for the Random Forest‐based SDM, DISTRIB, which was updated with recent forest inventories, climate, and soil data, and used a hybrid lattice derived from inventory densities.Modeled habitat suitability was compared between a uniform grid of 10 × 10 and a hybrid lattice of 10 × 10 and 20 × 20 km grids to assess potential improvements. The resulting DISTRIB‐II models for 125 eastern U.S. tree species provide information on individual habitat suitability that can be mapped and statistically analyzed to understand current and potential changes.Model performance metrics were comparable among the hybrid lattice and 10‐km grids; however, the hybrid lattice models generally had higher overall model reliability scores and were likely more representative of the inventory data.Our efforts to update DISTRIB models with current information aims to produce a more representative depiction of recent conditions by accounting for the spatial density of forest inventory data and using the latest climate data. Additionally, we developed an approach that leverages a hybrid lattice to maximize the spatial information within the models and recommend that similar modeling efforts be used to evaluate the spatial density of response and predictor data and derive a modeling grid that best represents the environment. [ABSTRACT FROM AUTHOR]

Copyright of Forest Research is the property of Forest Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of the Roundup Ready(r) technology and the cultivation of a second crop influence the floristic composition of weed communities in Brazilian Central-West region cropping systems. This study has aimed to diagnose the dominant weed species in southwestern Goiás in areas of genetically-modified and conventional soybeans, using phytosociological and floristic surveys. Weed sampling was obtained by collecting all the plants present within a 0.5 m hollow frame, randomly thrown 20 times in each of thirty-five agricultural areas in the 2012/2013 harvest. Field survey was carried out in three periods: before desiccation for soybean sowing, before postemergence herbicide in soybean first application and before postemergence herbicide application in late harvest. A total of 525 m2 was inventoried and 3,219 weeds were collected, which included 79 species, 58 genera and 28 families. Families Poaceae, Asteraceae, Euphorbiaceae, Fabaceae, Amaranthaceae, were the most representative in the survey. Species Cenchrus echinatus, Glycine max, Chamaesyce hirta, Commelina benghalensis, and Alternanthera tenella stood out in importance. The RR+millet soybean treatment had the highest number of species (44), while the conventional soybean + sorghum treatment had the lowest number of species (18). The highest number of species was recorded in first sampling period. Treatments conventional soybean + maize and conventional soybean + millet showed higher similarity (70%), while treatments RR soybean + millet and conventional soybean + sorghum showed the least (51%). Species of difficult control were recorded in all cultivation systems analyzed.

The plant productivity of alpine meadow is predicted to generally increase under a warming climate, but it remains unclear whether the positive response rates will vary with soil water availability. Without consideration of the response of community composition and plant quality, livestock grazing under the current stocking rate might still lead to grassland degradation, even in meadows with high plant biomass. We have conducted a warming experiment from 2010 to 2017 to examine the interactive effects of warming and soil water availability on plant growth and forage quality at individual and functional group levels in an alpine meadow located in the permafrost region of the Qinghai–Tibetan Plateau. Warming-induced changes in community composition, biomass, and forage quality varied with soil water availability. Under dry conditions, experimental warming reduced the relative importance of grasses and the aboveground biomass by 32.37 g m−2 but increased the importance value of forbs. It also increased the crude fat by 0.68% and the crude protein by 3.19% at the end of summer but decreased the acid detergent fiber by 5.59% at the end of spring. The increase in crude fat and protein and the decrease in acid detergent fiber, but the decrease in aboveground biomass and increase the importance value of forbs, which may imply a deterioration of the grassland. Under wet conditions, warming increased aboveground biomass by 29.49 g m−2 at the end of spring and reduced acid detergent fiber by 8.09% at the end of summer. The importance value of grasses and forbs positively correlated with the acid detergent fiber and crude protein, respectively. Our results suggest that precipitation changes will determine whether climate warming will benefit rangelands on the Qinghai–Tibetan Plateau, with drier conditions suppressing grassland productivity, but wetter conditions increasing production while preserving forage quality.

Urban park, a major component of urban green infrastructure, is an indicator of urban ecological environment system. In this study, 34 urban parks divided into two categories (historical parks (HP) and modern parks (MP)) in Dublin were investigated in 2015; meanwhile, tree composition and diversity, importance value of species and families and size class distribution were compared between two kinds of parks. Result showed that 8603 trees belonging to 139 species, 67 genera and 37 families were enumerated, with 4174 in HP and 4429 in MP. Tree composition in both kinds of parks skewed toward alien tree species without significant difference. According to the species important value, top three tree species Ilex aquifolium, Acer pseudoplatanus and Platanus hispanica found in HP and Acer pseudoplatanus, Tilia sp. and Acer platanoides found in MP were all alien tree species in Ireland. The result of family importance value indicated that the most importance families were Aceraceae, Rosaceae and Tiliaceae in both kinds of parks. Species richness of HP was markedly richer than that of MP; while, the diversity index of Shannon-Wiener was not statistically significant between them. Based upon the relative abundance, several important tree species were more than 10 percent, which was not in accordance with the "rule of thumb--10/20/30". According to the size class of DBH distribution, two categories parks showed different preferences to trees in different historical periods; size class of tree height and crown displayed that communities were crowded in the urban parks of Dublin. It is critical for the management of urban parks of Dublin to increase tree diversity and improve structure of tree species. [ABSTRACT FROM AUTHOR]

Abstract: The sap flux method generates problems when it is applied in a subtropical evergreen broadleaf forest. In this study, 6 dominant species in such a forest were selected to investigate the spatial variances on the stem and individual variances within the forest. The sap flux density (Fd) at 20–40 and 40–60 mm of the xylem for the upper canopy species (Schima superba, Castanea henryi, and Machilus chinensis) accounted 18–60% and 16–37%, respectively, of that at 0–20 mm. For the lower canopy species (Ilex ficoidea, Symplocos ramosissima, and Schefflera octophylla), the highest Fd occurred at 20–40 mm. Tree height (H) was closely related to the radial variances of sap flux in the xylem. Vertically, the mean Fd increased with tree height among different species (p < .01). On this basis, the proportion of mean whole tree transpiration for the 6 tree species was 37.10% (S. superba), 17.73% (C. henryi), 7.15% (M. chinensis), 15.88% (I. ficoidea), 17.36% (S. ramosissima), and 4.76% (S. octophylla). The annual stand transpiration for the 6 tree species was estimated of 366.4 mm. The observed distinct stratification of the water flux that highly related to their importance for different tree species revealed the critical role of tree water use in determining the development of vegetation succession. [ABSTRACT FROM AUTHOR]

Abstract: Dominant species significantly affect interspecific relationships, community structure, and ecosystem function. In the field, dominant species are often identified by their high importance values. Selective foraging on dominant species is a common phenomenon in ecology. Our hypothesis is that dominant plant groups with high importance values are more susceptible to leaf‐mining insects at the regional level. Here, we used the Saihanwula National Nature Reserve as a case study to examine the presence–absence patterns of leaf‐mining insects on different plants in a forest‐grassland ecotone in Northeast China. We identified the following patterns: (1) After phylogenetic correction, plants with high importance values are more likely to host leafminers at the species, genus, or family level. (2) Other factors including phylogenetic isolation, life form, water ecotype, and phytogeographical type of plants have different influences on the relationship between plant dominance and leafminer presence. In summary, the importance value is a valid predictor of the presence of consumers, even when we consider the effects of plant phylogeny and other plant attributes. Dominant plant groups are large and susceptible targets of leaf‐mining insects. The consistent leaf‐mining distribution pattern across different countries, vegetation types, and plant taxa can be explained by the “species‐area relationship” or the “plant apparency hypothesis.” [ABSTRACT FROM AUTHOR]

Old-growth forests provide unique insight into historical compositions of forests in the eastern United States. Plots established within a mixed forest community within Marshall Forest in Rome, Georgia, in 1960 (and remeasured in 1989) were reassessed to determine changes in forest composition. The community has experienced approximately 10% increase in basal area since the previous measurement period. However, changes in species importance have occurred. Chestnut oak (Quercus montana), mockernut hickory (Carya tomentosa), white oak (Quercus alba), and flowering dogwood (Cornus florida) have all decreased in importance, while pignut hickory (Carya glabra), winged elm (Ulmus alata), yellow poplar (Liriodendron tulipifera), and red maple (Acer rubrum) have all increased in importance. Additionally, there are no Pinus spp. saplings in the study area, indicating seedlings are not being recruited into the midstory. These changes indicate continued succession to a composition increasingly dominated by shade-tolerant species. The mixed forest community appears to be transitioning to an oak-hickory community. The assessment of late successional dynamics may help managers of similar forests to determine the best plan of action if they desire to maintain a mixed forest ecosystem. [ABSTRACT FROM AUTHOR]

According to natural conditions and vegetation distribution characteristics of Wenchang Bamenwan Mangrove Forest, sample plots were set up to investigate plant community characteristics in this area, and to explore the diversity characteristics of different subareas and calculate importance values of various tree spedes in the study area. According to the investigation, there are 48 plant species of 42 genera and 28 families in Bamenwan Mangrove Forest, including 29 tree species of 24 genera and 17 families. Among the tree species, those on the top 5 in the importance value list are Hibiscus tiliaceus, Bruguicra sexanguk, Lwnnitzera iittorea, Rhizopboia apiculata, Xyiocaipus granatum. There are 3 shrub species of 3 genera and 3 families, including Ataiantia bwdfolia, Lantana camara and Streblus asper. And there are 16 herbal species of 16 genera and 11 families, including A crostichum aureum, Vemonia dnerea, Acanthus ilidiblius, Alocasia mactotthiza, Synedrelk nodiiiora, Gynuta japonica and etc.. Diversity of the mangrove in different areas varies greatly, Shannon-Wiener index and richness index of semi-mangrove forest are both higher than those of other 3 mangrove forests. Bamenwan Mangrove Forest is characterized by diversified species and complex structures, but the community diversity is unevenly distributed because of the interventions from many factors. More human efforts are suggested to enhance the mangrove protection, so as to enrich the community diversity. [ABSTRACT FROM AUTHOR]