The Impacts of Flood and Local Communities’ Coping Strategies along the River Gambia

Flood disasters as Climate change hazards are common in developing countries, particularly in communities along the river Gambia. Local communities, for instance, had their local coping strategies that enabled them to stay in their communities even amid these ordeals, and climate change disaster threats. This work strives to understand flood impacts and the local peoples’ adaptation or coping strategies along the River Gambia basin. A community-based cross-sectional research study of 422 research participants of which 294 are males (69.7%) and females 128 (30.3%), and a focus group discussion of 10 groups which comprised 5 female groups and 5 male groups respectively found that 98.6% of the households experienced floods in their community, and 70.6% experienced flood in their houses, 2.1% have impending flood information and 88.4% do not know evacuation centres. The majority of the households had some local coping strategies, but they acknowledged their insufficient effectiveness. The result also shows that the impact of floods on farmlands, roads, buildings, and livestock was greatly felt. Coping strategies such as sandbags, raised elevations, contour bonds, dikes, and buildings on highlands were all found to be common mechanisms the local people used. The study opines that floods affect communities, but the effects vary depending on individual assets.

Plant Biodiversity and Structure of Robusta Coffee (Coffea canephora var. robusta) Agroforests in Cameroon

Agroforests are man-made ecosystems in which crops are associated with a main perennial species like Robusta Coffee Agroforests (RCAs), which is counted among the main modes of perennial crops production in Cameroon. Despite the rich ecosystem services provided, the diversity of Associated Species (AS) found in these RCAs and the structure of the landscapes they form remain little known in Cameroon. The current study aimed to inventory AS and characterize the structure of RCAs in four sites (Ayos, Malantouen, Melong and Nkongsamba) belonging to three robusta coffee production basins in Cameroon. A systematic inventory with dendrometric measurements of the wood AS and coffee trees was carried out on 120 one-hectare plot unit, i.e. 30 plots per site. The results showed that 102 AS belonging to 83 genera and 41 families were identified in these RCAs. The RCAs of Ayos in the dense rainforest zone with bimodal rainfall pattern were the most diverse with 71 species, followed by those of Melong and Nkongsamba with respectively 39 and 33 species respectively in the dense rainforest zone with monomodal rainfall pattern, and Malantouen with 33 species in the high savannahs of the west. Structurally, average coffee tree and AS densities founded ranged from 1208 - 1456 plants/ha and 71 - 214 stems/ha and those of basal area from 7.29 - 17.40 m2/ha for coffee trees and 7.97 - 16.14 m2/ha for AS in function of site. Basis on the vertical stratification, the proportion of the 3 - 6 m stratum, which is mainly represented by introduced AS, varied from 38% - 62% depending on the site. The results of this study showed that RCAs contribute to the conservation of plant biodiversity, given the specific richness identified in these ecosystems.

Evolution history dominantly regulates fine root lifespan in tree species across the world

Understanding the drivers of variations in fine root lifespan is key to informing nutrient cycling and productivity in terrestrial ecosystems.However,the general patterns and determinants of forest fine root lifespan at the global scale are still limited.We compiled a dataset of 421 fine root lifespan observations from 76 tree species globally to assess phylogenetic signals among species,explored relationships between fine root lifespan and biotic and abiotic factors,and quantified the relative importance of phylogeny,root system structure and functions,climatic and edaphic factors in driving global fine root lifespan variations.Overall,fine root lifespan showed a clear phylogenetic signal,with gymnosperms having a longer fine root lifespan than angiosperms.Fine root lifespan was longer for evergreens than deciduous trees.Ectomycorrhizal(ECM)plants had an extended fine root lifespan than arbuscular mycorrhizal(AM)plants.Among different climatic zones,fine root lifespan was the longest in the boreal zone,while it did not vary between the temperate and tropical zone.Fine root lifespan increased with soil depth and root order.Furthermore,the analysis of relative importance indicated that phylogeny was the strongest driver influencing the variation in forest fine root lifespan,followed by soil clay content,root order,mean annual temperature,and soil depth,while other environmental factors and root traits exerted weaker effects.Our results suggest that the global pattern of fine root lifespan in forests is shaped by the interplay of phylogeny,root traits and environmental factors.These findings necessitate accurate representations of tree evolutionary history in earth system models to predict fine root longevity and its responses to global changes.

Phytoremediation of urban wastewater by model wetlands with ornamental hydrophytes

Phytoremediation offers a cost-effective, non-intrusive, and safe alternative to conventional cleanup techniques. In this study, we used ornamental hydrophytes plants as constructed wetlands to treat urban or rural domestic wastewater. Most ornamental hydrophytes adapted to the wastewater well, and were fairly efficient in scavenging BOD5 （biological oxygen demand 5 d）, COD （chemical oxygen demand）, TN （total nitrogen）, TP （total phosphorus） and heavy metals （Cr, Pb, Cd） in the wastewater. However, the efficiency varied a lot for various species to different contaminants, Iris pseudacorus L. and Acorus gramineus Soland were good choices for treatment of composite-polluted urban wastewater. Some variation in the change of membrane peroxidation and endogenous protective system in responses to wastewater was found among six hydrophytes, which have a correlation with the efficiency of wastewater treatment. It may demonstrate that the developed antioxidative systems of L pseudacorus and A. gramineus contributed much to their superiority. On the other hand, interaction of different components in the wastewater might have certain effects on phytoremediation.

Determination of Air Pollutant Concentrations in Plant Species in Relation to Pollution Sources

Air quality has been a major health issue in urban areas in recent decades. Human activities release a large number of pollutants into the atmosphere which has a direct impact on plant health and leads to ecosystem degradation. The objective of this study is to contribute to a better evaluation of the impact of the air quality of the city of Togo on biological resources. The determination of pollutants was done on samples of plant species with a strong link with the source of pollution. The determination of Sulfur dioxide (SO2) was done by the ripper method. The determination of carbon and estimation of CO2 and CO by the colorimetric method. The determination of nitrogen was done by the Kjeldhal method. The results showed that at the industrial level the amount of CO2 in Alternanthera repens is high with a value of 53.3911 mg/ml. On the other hand, the quantity of CO in Senna occidentalis is 44.3619 mg/ml. In Pithecellobium dulce, the quantity of SO2 and NO2 are evaluated respectively to 0.1588 mg/ml and 0.3696 mg/ml. Regarding to the dumps, the quantity of CO2 in Newbouldia laevis is very high with a value of 65.8508 mg/ml. On the other hand the amount of CO in Senna occidentalis is 51.6106 mg/ml. The quantity of SO2 in Newbouldia laevis is 0.2101 mg/ml and NO2 in Ocimum canum is 0.2744 mg/ml. At the level of roads, the quantities of CO2 and CO in Eragrostis tenella are very high with values respectively equal to 74.4092 mg/ml and 62.2654 mg/ml. On the other hand, the amount of NO2 in Amaranthus sp is 0.2304 mg/ml and that of SO2 in Eragrostis Tenella is 0.1691 mg/ml. The use of a plant bioindicator sensitive to pollutants, allowed concluding that the air of the city of Lome is polluted. The concentration of carbon dioxide and carbon monoxide is much more evident in return when the health of plant species is threatened.

Aboveground biomass allometric equations and distribution of carbon stocks of the African oak(Afzelia africana Sm.)in Burkina Faso

The significant role of tropical forest ecosystems in the global carbon budget has increased the need for accurate estimates of tropical forest biomass.The lack of large-scale biomass allometric equations hampers the understanding of the spatial distribution of tree biomass and carbon stocks and their influencing factors in West Africa.This study aimed to develop allometric equations to estimate aboveground biomass of African oak(Afzelia africana Sm.)in Burkina Faso and to analyze factors affecting the variability of tree biomass and carbon storage.Sixty individual trees were destructively sampled in four protected areas along two climatic zones.In each climatic zone,log–log models were tested and fitted to each aboveground biomass component and to the total aboveground biomass.Carbon content in tree aboveground components was evaluated using the ash method.All validated equations showed good fit and performance with high explained variance.Allometric equations differed between the Sudano-sahelian zone and the Sudanian zone,except for leaf biomass equations.Both biomass allocation and carbon content varied significantly between tree components but not between climatic zones.Carbon content in tree components followed the patterns of biomass allocation with branches accounting for the highest proportion.In the two climatic zones,carbon contents were 50.18–52.62%for leaves,54.78–54.94%for stems and 54.96–55.99%for branches.Dry biomass ranged from 509.05 to 765.56 kg tree^-1 at site level and from 620.21 to 624.48 kg tree^-1 along climatic zones.Carbon content varied from 53.90%in the Sudano-sahelian zone to 54.39%in the Sudanian zone.This study indicated that climate does not influence aboveground biomass production and carbon sequestration of Afzelia africana along the Sudanosahelian and the Sudanian climatic zones of Burkina Faso.Future studies on climate–growth relationships should contribute to better understanding climate effects on biomass production and carbon storage.

Wild Fruits Traditionally Gathered by the Malinke Ethnic Group in the Edge of Niokolo Koba Park (Senegal)

In rural areas, the local population draws from several forest resources needed for survival including food. Then it is a granary for these native people. Unfortunately, useful wild plants are highly threatened, especially by various human activities. Because of this situation we started with open semi-structured interviews to identify wild fruit plants, their consumed organs and their seasonality in the rural community of Tomboronkoto. Tomboronkoto is located at the edge of the Niokolo-Koba National park (Senegal) and is mainly inhabited by Malinke. We identified 45 wild fruit species belonging to 38 genera that can be divided in 28 botanical families. The more diversified are successively the Anacardiaceae, Tiliaceae, Apocynaceae and Caesalpiniaceae. More than half of the plants inventoried are trees (53%). We can distinguish three categories of fruits depending on their Fidelity Level (FL) that informs us about their popularity: the well-known or common fruits, moderately known fruits and little known fruits. A dozen wild fruits happen to be greatly appreciated with very high fidelity level (100% to 84%). The fruits of Saba senegalensis, Adansonia digitata, Parkia biglobosa, Tamarindus indica and Vitellaria paradoxa are the most variously used because they are appreciated being fresh or cooked. Only fruits of Ficussur are available all year long. The large majority of the most consumed fruits are available between the end of the hot dry season until the middle of the rainy season. This period coincides with the period where crops from the previous rainy season are depleted and the new crops are not yet ripe. Thus, these wild fruits would greatly contribute to food security in this area during the lean period.

Botanical Assessment of Forest Genetic Resources Used in Traditional Cosmetic in Togo （West Africa）

In the current context of REDD＋ opportunities, it is important to evaluate forest genetic resources for local communities＇ benefits. The aim of this ethnobotanical survey with an emphasis in cosmetopoeia--by referring to the word pharmacopoeia--was to explore, investigate, collect and identify natural resources used in traditional cosmetic in Togo for that purpose. The specific objectives were （i） to inventory plant species used as cosmetic in Togolese ethnocultural groups, and （ii） to describe their biological forms for their sustainable use. Based on ethnobotanical approach, this survey identified through multistage sampling design and semi-structured interview, 177 plant species belonging to 167 genera and 59 families with 82.45% dicotyledonous and 17.55% monocotyledonous species. According to life forms, these species were distributed as ligneous （56.50%） and herbaceous （43.50%）. The computation of Whittaker＇s Index of Association led to three communities of ethnic groups. The explanatory effect of the ethnic based-tradition was significant and confirmed by Monte Carlo permutation test （P = 0.0020） after 499 permutations under split-plot constraints. This first outline confirmed ethnobotany as a viable tool in search for plant genetic resources in cosmetic industries. These findings could be incorporated into future conservation management plans of forest genetic resources in Togo and other tropical countries.

Biological Control of Erosion of Banana Drains in Côte D’ivoire

The erosion of drains is a major limitation of the quality, the increasing of banana production and the environmental protection of industrial banana in Côte d'Ivoire. It leads inundations, death of banana trees and significant loss of production. Thence, the construction and the maintenance of drain costs too much and causes injure, snake bite, physical traumatisms, many diseases, … These events compromise the sustainable production of banana by reducing seriously worker’s the activities and finally increase the cost of production. The aim of the present work is to contribute to the sustainable development and human capacity building in the third world nations as far as banana production is concerned. The methods used so far to address this phenomenon proved inefficient. The technology innovation in this area has been to grow grass on the outer edges of the channels drained water. This resulted in a systematic reduction of erosion. Better still, it helped fertilize the soil, reduce the deportations of fertilizer and improve the quality of landscape of the plantations. Stenotaphrum secondatum is the best vegetable specie adapted to the biological control against water erosion of drains.

Phytochemical Characterization of the Essential Oils Obtained from Mediterranean Thymus spp. （Lamiacea） Harvested at Different Stages of Growth

To prove more information on the chemical composition of the essential oils of Thymus taxa collected in different Algeria areas, and to determine the effect of harvesting periods on the composition of these essential oils： three Thymus species （T. numidicus, T.ciliatus and T. algeriensis） were collected during two periods of development, the EOs （essential oils） obtained by steam distillation of the aerial parts were analyzed by GC/MS （gas chromatography coupled with mass spectrometry）. During the pre-flowering stage, the RP% （relative percentage） of Eos varied between 1.00% and 1.34% for all the species. The content of EOs increased during the flowering stage and reached particularly 2.10% and 2.85% for T. numidicus （from Berrahal） and T. numidicus （from Tacha）, respectively. GC/MS analysis showed that these oils are very rich in oxygenated monoterpenes group （76.96%-82.11%） when the plants were harvested during the flowering stage of growth. Thymol was the major compound in the EOs contained in T. numidicus （Berrahal） and T. ciliatus with more than 39% and 54%, respectively. Thymus numidicus （Tacha） and T. algeriensis EOs were characterized by high content in p-cimene-7-ol （78.06% and 26.98%, respectively）. These two chemotypes （thymol and p-cimene-7-ol） are considered as antioxidant and antimicrobial agents providing the basis for many applications in processed food preservation and pharmaceutical products.

Determination of the Types of Air Pollutants Prepondering in the City of Lome in Togo (West Africa)

The increase in the urban population and the high concentration of many anthropogenic activities in certain regions of the world lead to atmospheric disturbances. The excess concentration of several chemical elements leads to air pollution. In order to identify the types of air pollutants, a study was carried out in the city of Lomé, the capital of Togo. The objective of this study is to achieve a better knowledge of the types of air pollutants in the city of Lomé. The identification of the various atmospheric pollutants linked to the sources of pollution was made using micro-sensors. The standardized method was used to access target gas concentration levels. The average concentrations of NO2 gaseous pollutants at landfills are on average 0.333 μg/m3;0.403 mg/m3 at the industrial level, at the transport level they are on average 0.434 mg/m3 for the morning and 0.457 mg/m3 for the evening. Concentrations of carbon dioxide (CO2) are higher in industrial areas than in others sources of pollution. The average concentration measured at this level is 1632.79 mg/m3. In terms of road transport, in the mornings the average concentration is 1493.23 mg/m3, in the evening the average concentration is 1354.09 mg/m3. On the other hand, they are lower at the level of the landfills, the average of which is 1265.08 ppm. The highest SO2 concentrations are also observed only in the landfills of Port 1 and Bè_Kpota 2 with concentrations respectively and relatively low and equal to 0.081 mg/m3 and 0.1616 mg/m3. The concentration of ground-level ozone is zero in industries and landfills. On the other hand, at the level of road transport, some values were recorded at the level of two road transports. These are Carrefour Attikoumé Djidjole (17.03 mg/m3) and Carrefour 2 Lions (0.001 mg/m3). The concentrations of carbon monoxide (CO) in the capital at the industrial level are on average 22.57 mg/m3;at landfills it is on average 0.24 mg/m3. In terms of road transport, they are on average 7.890 mg/m3 for the morning and 8.23 mg/m3 for the evening. These results constitute a database for biomonitoring.

Endophytic fungi:a source of potential anticancer compounds

Bioactive metabolites produced by different endophytic fungi have wide range of applications in pharmaceutical and herbal medicine research.In contrast to plants,they are barely investigated to their boundless possibilities as storehouses of novel bioactive metabolites.They produce diverse metabolites by different biosynthetic pathways with the host plant.Enthusiasm for endophytes as a characteristic asset for new drugs was roused by the disclosure of paclitaxel-producing endophytic fungi.Anticancer activity is by and large connected with the cytotoxicity of the compounds present in the endophytic fungi.Phylogenetic classification of endophytic fungi is of great interest to mycologists as they can produce novel bioactive compounds with antitumor activity.This article audits anticancer compounds derived from endophytic fungi disengaged from the separate host plant.The endophytic fungi have been grouped by their host plants and anticancer compound synthesized.

Land use patterns and tree species diversity in the Volta Geological Unit, Togo

The application of remote sensing in understanding tree species structural diversity and land use patterns relationship is imperative for reforestation and biodiversity conservation efforts. This study assesses land use patterns and tree species structural diversity in previously reforested hilly sandstone regions of northern Togo. The physical height, and diameter at breast height(DBH) more than 5 cm of all tree species in each given plot were measured in summer 2017. A total of 75 plots of 900 m^2 installed along the toposequence were recorded. In addition, a semi-supervised classification of Landsat 8 images in January of 2018, was also used to classify the land use patterns. 36 tree species and 19 families were recorded for the entire study area. Meanwhile, 19 tree species and 15 families were recorded for the previously afforested zones. The most abundant species included the Sterculiaceae, Zygophyllaceae, Meliaceae, and Mimosaceae. The trees stand structure represented 8.61 ± 0.57 m, 11.28 ± 1.76 cm, and 0.018 ± 0.009 m^2 per hectare for height, diameter and basal area respectively. Major land use patterns were tree and shrub savannahs, parklands and croplands which represented over 60% of the landscape. It is necessary to examine the regeneration and vegetative multiplication potentials of the most frequent and abundant tree species for any eventual future afforestation programs in these hilly sandstone regions of northern Togo.

What is a tree in the Mediterranean Basin hotspot?A critical analysis

Background: Tree species represent 20% of the vascular plant species worldwide and they play a crucial role in the global functioning of the biosphere. The Mediterranean Basin is one of the 36 world biodiversity hotspots, and it is estimated that forests covered 82% of the landscape before the first human impacts, thousands of years ago. However, the spatial distribution of the Mediterranean biodiversity is still imperfectly known, and a focus on tree species constitutes a key issue for understanding forest functioning and develop conservation strategies. Methods: We provide the first comprehensive checklist of all native tree taxa (species and subspecies) present in the Mediterranean-European region (from Portugal to Cyprus). We identified some cases of woody species difficult to categorize as trees that we further called "cryptic trees". We collected the occurrences of tree taxa by"administrative regions", i.e. country or large island, and by biogeographical provinces. We studied the species-area relationship, and evaluated the conservation issues for threatened taxa following IUCN criteria. Results: We identified 245 tree taxa that included 210 species and 35 subspecies, belonging to 33 families and 64 genera. It included 46 endemic tree taxa (30 species and 16 subspecies), mainly distributed within a single biogeographical unit. The countries with the highest tree richness are Greece (146 taxa), Italy (133), Albania (122), Spain (155), Macedonia (116), and Croatia (110). The species-area relationship clearly discriminated the richest central-eastern (Balkans) and northern (Alpine and Cevenno-Pyrenean) biogeographical provinces, against the five western provinces in the Iberian Peninsula. We identified 44 unrecognized "cryptic trees", representing 21% of the total trees. Among the 245 taxa identified, 19 are considered to be threatened (15 CR+EN+VU) or near threatened (4 NT) by IUCN. Conclusions: The Mediterranean-European region includes an unsuspectedly high number of tree taxa, almost 200 tree taxa more than in the central European region. This tree diversity is not distributed evenly and culminates in the central-eastern part of the Mediterranean region, whereas some large Tyrrhenian islands shelter several narrow endemic tree taxa. Few taxa are recognized as threatened in the IUCN Red list, and the vulnerability of these species is probably underestimated.

利用无忧树和五色梅树叶生物监控机动车辆释放的PM_(10)中的微量元素水平

通过研究大气粒子以及两种植物一无忧树（Saraca indica）和五色梅（Lantana camara）树叶中小于10μm（PM10）颗粒物中可吸入微量元素（钡、铜、铁、锰、铅、钛和钒）的组成和水平，来显示它们之间的关系。树叶从瓦拉纳西（Varanasi）周围的两个地点采集，一个是偏远的对照点（村庄），它的交通量可以被忽略不计，另一个位于城市的中心，交通量很大。

The contribution of fungi to the global economy

Fungi provide ecological and environmental services to humans, as well as health and nutritional benefits, and are vital to numerousindustries. Fermented food and beverage products from fungi are circulating in the market, generating billions of USD.However, the highest potential monetary value of fungi is their role in blue carbon trading because of their ability to sequesterlarge amounts of carbon in the soil. There are no conclusive estimates available on the global monetary value of fungi, primarilybecause there are limited data for extrapolation. This study outlines the contribution of fungi to the global economy and providesa first attempt at quantifying the global monetary value of fungi. Our estimate of USD 54.57 trillion provides a starting point thatcan be analysed and improved, highlighting the significance of fungi and providing an appreciation of their value. This paperidentifies the different economically valuable products and services provided by fungi. By giving a monetary value to all importantfungal products, services, and industrial applications underscores their significance in biodiversity and conservation. Furthermore,if the value of fungi is well established, they will be considered in future policies for effective ecosystem management.

Bioactive metabolites from macrofungi: ethnopharmacology, biological activities and chemistry

Exploration of natural sources for novel bioactive compounds has been an emerging field of medicine over the past decades,providing drugs or lead compounds of considerable therapeutic potential.This research has provided exciting evidence on the isolation of microbe-derived metabolites having prospective biological activities.Mushrooms have been valued as traditional sources of natural bioactive compounds for many centuries and have been targeted as promising therapeutic agents.Many novel biologically active compounds have been reported as a result of research on medicinal mushrooms.In this review,we compile the information on bioactive structure-elucidated metabolites from macrofungi discovered over the last decade and highlight their unique chemical diversity and potential benefits to novel drug discovery.The main emphasis is on their anti-Alzheimer,antidiabetic,anti-malarial,anti-microbial,anti-oxidant,antitumor,anti-viral and hypocholesterolemic activities which are important medicinal targets in terms of drug discovery today.Moreover,the reader’s attention is brought to focus on mushroom products and food supplements available in the market with claimed biological activities and potential human health benefits.

Assessment of multifunctional landscapes dynamics in the mountainous basin of the Mo River （Togo, West Africa）

In this study, historical landscape dynamics were investigated to（i） map the land use/cover types for the years 1972, 1987, 2000 and 2014;（ii） determine the types and processes of landscape dynamics; and（iii） assess the landscape fragmentation and habitat loss over time. Supervised classification of multi-temporal Landsat images was used through a pixel-based approach. Post–classification methods included systematic and random change detection, trajectories analysis and landscape fragmentation assessment. The overall accuracies（and Kappa statistics） were of 68.86%（0.63）, 91.32%（0.79）, 90.66%（0.88） and 91.88%（0.89） for 1972, 1987, 2000 and 2014, respectively. The spatio-temporal analyses indicated that forests, woodlands and savannahs dominated the landscapes during the four dates, though constant areal decreases were observed. The most important dynamic process was the decline of woodlands with an average annual net loss rate of –2%. Meanwhile, the most important land transformation occurred during the transition 2000–2014, due to anthropogenic pressures. Though the most important loss of vegetation greenness occurred in the unprotected areas, the overall analyses of change indicated a declining trend of land cover quality and an increasing landscape fragmentation. Sustainable conservation strategies should be promoted while focusing restoration attention on degraded lands and fragmented ecosystems in order to support rural livelihood and biodiversity conservation.

The amazing potential of fungi:50 ways we can exploit fungi industrially

Fungi are an understudied,biotechnologically valuable group of organisms.Due to the immense range of habitats that fungi inhabit,and the consequent need to compete against a diverse array of other fungi,bacteria,and animals,fungi have developed numerous survival mechanisms.The unique attributes of fungi thus herald great promise for their application in biotechnology and industry.Moreover,fungi can be grown with relative ease,making production at scale viable.The search for fungal biodiversity,and the construction of a living fungi collection,both have incredible economic potential in locating organisms with novel industrial uses that will lead to novel products.This manuscript reviews fifty ways in which fungi can potentially be utilized as biotechnology.We provide notes and examples for each potential exploitation and give examples from our own work and the work of other notable researchers.We also provide a flow chart that can be used to convince funding bodies of the importance of fungi for biotechnological research and as potential products.Fungi have provided the world with penicillin,lovastatin,and other globally significant medicines,and they remain an untapped resource with enormous industrial potential.

Physiological responses of four herbaceous plants to aluminum stress in South China

Different plants have physiological responses under Al stress,but there is no systematic study to examine physiological responses of herbaceous plants under Al stress.The aim of this study is to investigate the effect of Al on physiological characteristics of four herbaceous plants,which distributed in red soil area in South China,and to analyze the differences in physiological responses to Al stress between the four herbaceous plants.Four herbaceous plants(Pharbitis nil,Cassia occidentlis,Echinochloa colonum and Aeschynomene indica)were used,and the seed germi-nation percentage,the contents of chlorophyll,proline,and malondialdehyde(MDA),membrane permeability(MP),soluble sugar,and activities of peroxides(POD)and cata-lase(CAT)in leaves under five Al^(3+)treatments(0,80,400,2000,and 10000 mg/L)were assayed with the sand culture method.The results showed remarkable effects of Al^(3+)on physiological characteristics of these four herbaceous plants.The seeds of all the four species could not germinate at 10000 mg/L,and the growth of all plants were retarded under the 2000 mg/L Al^(3+)treatment.Compared with the control,2000 mg/L Al^(3+)significantly(P<0.05)reduced the con-tents of chlorophyll a and chlorophyll a+b,and increased the contents of MDA and MP.The content of proline in-creased very significantly(P<0.01)and activities of POD and CAT were depressed.The contents of MDA and MP in leaves of P.nil and A.indica decreased,and the activities of POD and CAT in leaves of the two plants increased under 80 mg/L and 400 mg/L.However,the changes in C.occidentlis leaves were opposite to those of the above two plants.The changes in leaves of E.colonum were similar to those of P.nil and A.indica at 80 mg/L,but were opposite to those at 400 mg/L Al^(3+).It is suggested that plants with higher ac-tivities of POD and CAT,more contents of chlorophyll and proline,and lower contents of MDA and MP consequently improve the tolerance to Al stress under low and middle Al treatments.