Soil available phosphorus (SAP) and potassium (SAK) are indispensable for crops, and their stocks are important for food production needed for a growing global population. This study analysed 991 soil profiles across a large part of Romania covering forestland, grassland and cropland in almost all ecological regions. This study investigated SAP and SAK stocks for different soil depths and characterized their magnitude and variability within land uses under different environmental ecosystems, soil classes and soil types, for a better soil and land management under a temperate-continental climate. Cropland soils present the highest SAP and SAK stocks. Chernozems, Phaeozems and Vertosols possess the highest SAP and SAK stocks in Romania, representing the largest country's pool. Both SAP stocks and SAK stocks are significantly correlated with basic environmental properties, existing direct correlations between SAP, SAK, soil organic carbon (SOC) and total nitrogen (TN) stocks. For all land uses, SAP and SAK stocks correlated significantly and directly with each other, as well as with annual temperature, clay content, pH and sum of base cations, and inversely with altitude, slope and annual precipitation. The best predictive values using multiple regression models and basic environmental driving factors were found for forestland stocks of SAP and SAK, followed by grassland stocks, while the lowest prediction occurred for cropland stocks, probably due to the long-term additional nutrient input performed by farmers in cropland that changed the natural conditions otherwise present in grassland, and especially in forestland. Based on these results some management measures are discussed.

Downy brome is a cleistogamous facultative winter-annual grass weed that invades cropland, pastureland, and ruderal areas in western North America. Glyphosate-resistant downy brome, the first known glyphosate-resistant grass weed in Canada, was confirmed in a glyphosate-resistant canola field in southern Alberta in 2021. A controlled-environment study was conducted to determine the impact of preemergence soil-applied residual herbicides on glyphosate-resistant and susceptible downy brome in two field soils. Flumioxazin/pyroxasulfone (70/89 g ai ha−1), carfentrazone/pyroxasulfone (18/150 g ai ha−1), sulfentrazone/pyroxasulfone (100/100 or 150/150 g ai ha−1), and saflufenacil/pyroxasulfone (36/120 g ai ha−1) resulted in excellent (≥90%) visible control and downy brome biomass reduction 8 wk after treatment (WAT). The low rate of carfentrazone/pyroxasulfone (12/100 g ai ha−1) resulted in good (≥80%) visible control and biomass reduction 8 WAT, while the low and medium rates of saflufenacil/pyroxasulfone (18/60 or 25/84 g ai ha−1) resulted in ≥80% biomass reduction but suppression only (66% to 75%) based on visible control. Flumioxazin alone (105 g ai ha−1) resulted in good visible control (81%) 8 WAT in a sandy loam soil, but poor (13%) control in a clay loam soil. Soil type affected plant growth as evidenced by reduced growth in the untreated sandy loam soil compared to clay loam soil. The glyphosate-resistant population emerged and grew more vigorously than the glyphosate-susceptible population resulting in greater plant densities in the untreated control and some less-effective herbicide treatments. These results suggest that mixtures of a protoporphyrinogen oxidase-inhibiting herbicide with the very-long-chain fatty acid elongase inhibitor pyroxasulfone applied preemergence at ≥89 g ai ha−1 could be effective components of an herbicide layering strategy targeting glyphosate-resistant and glyphosate-susceptible downy brome.

Conversion of primary forest into oil palm plantations is common in tropical countries, affecting soil properties, ecosystem services and land-use management. However, little is known about the short-range spatial soil distribution that is important for soil scientists, ecologists, entomologists, mycologists or microbiologists. In this study, seven soil properties (pH, EC (µS/m), P (mg/kg), NO3- (mg/kg), N%, C% and C:N) were measured to quantify the spatial autocorrelation across primary forest, selectively logged forest and oil palm plantation in Sabah, Malaysian Borneo. Local variograms were calculated (range ∼5 m) to determine the short-range variation, and a decision tree as well as principal component analysis were implemented to determine if the overall (global) mean differed between land uses. As hypothesised, oil palm soils deviated the most from primary forest soils, which had more fluctuating variograms and in general, a shorter range. Oil palm plantations also showed a difference in the global mean except for electrical conductivity. Selectively logged forests also differed in their short-range spatial structure; however, the global mean and variance remained similar to primary forest soil with the exception of labile phosphorus and nitrate. These results were attributed to initial plantation development, removal of topsoil, fertiliser application and topography.

Intensifying crop–fallow systems could address increased weed control costs, increased land or rental costs, reduced crop diversity, and degraded soil properties in water-limited environments. One strategy to intensify such systems could be the insertion of a short-season crop during fallow. But, how this strategy affects soils, crop production, and farm economics needs further research. Thus, we studied the impacts of replacing fallow in a winter wheat (Triticum aestivum L)–corn (Zea mays L.)–fallow system with a short-season spring crop [field pea (Pisum sativum L.)] on crop yields and economics from 2015 to 2019 and 5-yr cumulative effects on soil properties using an experiment in the west-central US Great Plains. After 5 yr, replacing fallow with field pea increased microbial biomass by 294 nmol g−1 and plant available water by 0.08 cm3 cm−3, and reduced bulk density by 0.1 g cm−3 and cone index by 0.73 MPa in the 0–5 cm depth. It had, however, no effect on other soil properties. Field pea yield averaged 2.24 Mg ha−1. Field pea reduced subsequent crop yield by 15–25% in two of three crops compared with fallow. However, economic analysis showed replacing fallow with field pea may improve net income by $144–303 ha−1, although income across the 5 yr differed by $65 ha−1 in favor of fallow. Replacing fallow in winter wheat–corn–fallow rotation with a short-season spring crop offers promise to improve some near-surface soil properties while increasing net economic return during fallow under the conditions of this study.

Continuous rotation of rice with wheat in rice–wheat system has resulted in stagnant yields and reduced profit margins while deteriorating the soil health. Legume incorporation in existing rice–wheat rotations might be a viable option to improve soil health and productivity. We investigated the influence of puddled transplanted flooded rice and direct-seeded rice on weed dynamics, soil health, productivity, and profitability of post-rice wheat and chickpea grown under zero tillage and conventional tillage. The previous direct-seeded rice crop was either sown alone or intercropped with sesbania as brown manure. The experiment comprised different rice–wheat and rice–chickpea systems which had been in place for two years: with and without rice residue retention. The initial soil analysis indicated that the plots with sesbania brown manuring in direct-seeded rice had the lowest soil bulk density (17.2%) and highest soil porosity (19.3%). Zero tillage in wheat or chickpea in the plots previously cultivated with co-culture of sesbania and direct-seeded rice increased total soil organic carbon by 13–22% in both years. The plots with sesbania brown manuring in direct-seeded rice followed by zero till or conventional till wheat and the plots with direct-seeded rice followed by zero till wheat with rice residue retention recorded the greater concentrations of total nitrogen, available phosphorus, and exchangeable potassium. Zero tillage in wheat and chickpea in post-rice sesbania brown manuring plots produced 41% and 43% more grain yield than those in the puddled transplanted flooded rice with conventional tillage and had the highest profitability. Overall, the rice–chickpea systems had better soil health and profitability than rice–wheat cropping systems. In conclusion, direct-seeded rice intercropped with sesbania followed by wheat and chickpea under zero tillage suppressed weed flora and improved soil physical properties, nutrient availability, productivity, and profitability.

The success of sustainable Theobroma cacao (cocoa) production depends on the physical and chemical properties of the soils on which they are established but these are possibly moderated by the management approach that farmers adopt. We assessed and compared soil physico-chemical properties of young, mature and old organic and conventional cocoa agroforestry systems at two depths (0–15 and 15–30 cm) and evaluated the production of cocoa pods, banana and plantain in the two farm types. Cocoa farms under organic management had 20, 81, 88 and 323% higher stocks of soil organic carbon, P, Mn and Cu, respectively, compared to those under conventional management. Higher soil moisture content, electrical conductivity and pH were found on organic systems than the conventional farms. Annual cocoa pod production per tree was similar in both cocoa systems (Org. 10.1 ± 1.1 vs Con. 10.1 ± 0.6 pods per tree). The annual production of banana and plantain was higher on organic farms (186.3 ± 34.70 kg ha−1 yr−1) than conventional systems (31.6 ± 9.58 kg ha−1 yr−1). We concluded that organic management of cocoa agroforestry systems result in soils with the greater overall quality for cocoa production than conventional management and it increases the yield of co-products. Studies focusing on the impact of organic management on cocoa agroforestry systems at the landscape and regional scales are urgently needed to further deepen our understanding and support policy.

We analysed thirty-five 400-m2 plots encompassing forest, savanna and intermediate vegetation types in an ecotonal area in Ghana, West Africa. Across all plots, fire frequency was over a period of 15 years relatively uniform (once in 2–4 years). Although woodlands were dominated by species typically associated with savanna-type formations, and with forest formations dominated by species usually associated with closed canopies, these associations were non-obligatory and with a discrete non-specialized species grouping also identified. Across all plots, crown area index, stem basal area and above-ground biomass were positively associated with higher soil exchangeable potassium and silt contents: this supporting recent suggestions of interplays between potassium and soil water storage potential as a significant influence on tropical vegetation structure. We also found an average NDVI cover increase of ~0.15% year−1 (1984–2011) with plots dominated by non-specialized species increasing more than those dominated by either forest- or savanna-affiliated species. Our results challenge the traditional view of a simple forest vs. savanna dichotomy controlled by fire, and with our newly identified third non-specialized species grouping also potentially important in understanding ecotonal responses to climate change.

Use of biochar (B) and poultry manure (PM) as soil amendments can improve the productivity and sustainability of tropical agriculture. Our fieldwork is the first research on the agronomic use of B and PM for the growth of cocoyam in sandy soil of the humid tropics. In this study, the effects of B, PM and their mixture were investigated on soil properties, mineral and nutrient concentrations, growth, and corm and cormel yields of cocoyam during the 2017 and 2018 cropping seasons. The experiment consisted of 4 × 2 factorial combinations of B (0, 10, 20, and 30 Mg ha−1) and PM (0 and 7.5 Mg ha−1). In both years, the application of B and PM either alone or in combination improved soil physical and chemical properties, plant nutritional status, growth, and corm and cormel yields of cocoyam. The combination of 30 Mg ha−1 B and 7.5 Mg ha−1 PM (B30 + PM7.5) gave the highest corm and cormel yields of cocoyam. Pooled over the 2 years, application of B at 30 Mg ha−1 and PM at 7.5 Mg ha−1 (B30 + PM7.5) significantly increased corm yield of cocoyam by 47 and 66%, respectively, when compared with sole PM at 7.5 Mg ha−1 and B at 30 Mg ha−1. Lowest corm and cormel yields were obtained for the unmanure control. The combination of 30 Mg ha−1 B and 7.5 Mg ha−1 PM is recommended for soil fertility management and cocoyam production in the rainforest agroecology of SW Nigeria.

Differential tree seedling recruitment across forest-savanna ecotones is poorly understood, but hypothesized to be influenced by vegetation cover and associated factors. In a 3-y-long field transplant experiment in the forest-savanna ecotone of Ghana, we assessed performance and root allocation of 864 seedlings for two forest (Khaya ivorensis and Terminalia superba) and two savanna (Khaya senegalensis and Terminalia macroptera) species in savanna woodland, closed-woodland and forest. Herbaceous vegetation biomass was significantly higher in savanna woodland (1.0 ± 0.4 kg m−2 vs 0.2 ± 0.1 kg m−2 in forest) and hence expected fire intensities, while some soil properties were improved in forest. Regardless, seedling survival declined significantly in the first-year dry-season for all species with huge declines for the forest species (50% vs 6% for Khaya and 16% vs 2% for Terminalia) by year 2. After 3 y, only savanna species survived in savanna woodland. However, best performance for savanna Khaya was in forest, but in savanna woodland for savanna Terminalia which also had the highest biomass fraction (0.8 ± 0.1 g g−1 vs 0.6 ± 0.1 g g−1 and 0.4 ± 0.1 g g−1) and starch concentration (27% ± 10% vs 15% ± 7% and 10% ± 4%) in roots relative to savanna and forest Khaya respectively. Our results demonstrate that tree cover variation has species-specific effects on tree seedling recruitment which is related to root storage functions.

The shallow subsurface of Groningen, the Netherlands, is heterogeneous due to its formation in a Holocene tidal coastal setting on a periglacially and glacially inherited landscape with strong lateral variation in subsurface architecture. Soft sediments with low, small-strain shear wave velocities (VS30 around 200 m s−1) are known to amplify earthquake motions. Knowledge of the architecture and properties of the subsurface and the combined effect on the propagation of earthquake waves is imperative for the prediction of geohazards of ground shaking and liquefaction at the surface. In order to provide information for the seismic hazard and risk analysis, two geological models were constructed. The first is the ‘Geological model for Site response in Groningen’ (GSG model) and is based on the detailed 3D GeoTOP voxel model containing lithostratigraphy and lithoclass attributes. The GeoTOP model was combined with information from boreholes, cone penetration tests, regional digital geological and geohydrological models to cover the full range from the surface down to the base of the North Sea Supergroup (base Paleogene) at ~800 m depth. The GSG model consists of a microzonation based on geology and a stack of soil stratigraphy for each of the 140,000 grid cells (100 m × 100 m) to which properties (VS and parameters relevant for nonlinear soil behaviour) were assigned. The GSG model serves as input to the site response calculations that feed into the Ground Motion Model. The second model is the ‘Geological model for Liquefaction sensitivity in Groningen’ (GLG). Generally, loosely packed sands might be susceptible to liquefaction upon earthquake shaking. In order to delineate zones of loosely packed sand in the first 40 m below the surface, GeoTOP was combined with relative densities inferred from a large cone penetration test database. The marine Naaldwijk and Eem Formations have the highest proportion of loosely packed sand (31% and 38%, respectively) and thus are considered to be the most vulnerable to liquefaction; other units contain 5–17% loosely packed sand. The GLG model serves as one of the inputs for further research on the liquefaction potential in Groningen, such as the development of region-specific magnitude scaling factors (MSF) and depth–stress reduction relationships (rd).

Sorption and desorption of metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] were measured in Dundee silty clay loam surface and subsurface soils. Soil samples were taken from a profile that had been divided into six sections from the surface to a depth of 175 cm. Metribuzin sorbed weakly to all soils from this profile with Freundlich distribution constants ranging from 0.78 to 1.34 μmole/kg. Soils from lower depths of the profile having higher pH (>7.0) and clay contents (>35%) sorbed significantly more metribuzin than the lower clay content, higher organic matter surface soils. Stepwise regression of the distribution constants against the variables pH, organic matter, clay content, and sand content showed that clay was the single best predictor, with sorption increasing as clay content increased (r2 =0.750). The combination of two variables most related to sorption was clay and pH (r2 =0.860, P= 0.15). Organic matter was not one of the primary variables related to sorption. Metribuzin was easily desorbed in all soils with less than 5% of the originally applied metribuzin remaining after three desorption treatments. This would indicate little tendency for irreversible sorption. This study demonstrates that soil properties within a profile determine sorption and, subsequently, movement of metribuzin.

Precision agriculture (PA) requires reasonably homogeneous areas for site-specific management. This work explores the applicability of digital terrain classes obtained from a digital elevation model derived from UAV-acquired images, to define management units in in a relative flat area of about 6 ha. Elevation, together with other terrain variables such as: slope degree, profile curvature, plan curvature, topographic wetness index, sediment transport index, were clustered using the Fuzzy Kohonen Clustering Network (FKCN). Four terrain classes were obtained. The result was compared with a map produced by a classification of soil properties previously interpolated by ordinary kriging. The results suggest that areas for site-specific management can be defined from terrain classes based on environmental covariates, saving time and cost in comparison with interpolation of soil variables.

Site properties and weed species abundance are known to vary spatially across fields. The extent to which they covary is not well understood. The objective of this research was to assess how canonical correlation analysis could be used to identify associations among site properties and weed species abundance within an agricultural field. A farmer-managed field rotated between Zea mays and Glycine max in Boone County, IA, was grid-sampled for site properties in 1992 and for weed species abundance between 1994 and 1997. Twelve site properties were considered in relation to five weed species that were identified and counted after all weed control operations were completed. Site properties such as total nitrogen, Bray-1 P, percent organic carbon, and texture were spatially variable. Weed species abundance was also spatially variable such that most weeds were found in patches and much of the field was weed-free. Canonical correlation analysis identified one to four significant correlations between linear combinations of site properties and weed species abundance. The first and second pairs of linear combinations explained the majority of variation in the data and were used to identify associations among site properties and weed species abundance. In years with Z. mays, the first pair of linear combinations described an association between herbicide activity and weed presence, and the second described topography and soil texture associations with weed presence. In years with G. max, the single observed association described a link between soil texture and presence of Setaria species and Polygonum coccineum. Several consistent associations were identified across years, indicating that site properties can influence weed abundance. However, annual variation in the associations may be attributed to differences in agronomic and weed management practices for each crop, as well as temporal weather variation influencing weed abundance from year to year. This multivariate technique is an important tool to identify associations between site properties and weed abundance that could help explain observed patchy patterns of weed abundance. These associations are an important first step in the generation of hypotheses to be tested at the whole field scale.

Weed seedbanks have been studied intensively at local scales, but to date, there have been no regional-scale studies of weed seedbank persistence. Empirical and modeling studies indicate that reducing weed seedbank persistence can play an important role in integrated weed management. Annual seedbank persistence of 13 summer annual weed species was studied from 2001 through 2003 at eight locations in the north central United States and one location in the northwestern United States. Effects of seed depth placement, tillage, and abiotic environmental factors on seedbank persistence were examined through regression and multivariate ordinations. All species examined showed a negative relationship between hydrothermal time and seedbank persistence. Seedbank persistence was very similar between the two years of the study for common lambsquarters, giant foxtail, and velvetleaf when data were pooled over location, depth, and tillage. Seedbank persistence of common lambsquarters, giant foxtail, and velvetleaf from October 2001 through 2002 and October 2002 through 2003 was, respectively, 52.3% and 60.0%, 21.3% and 21.8%, and 57.5% and 57.2%. These results demonstrate that robust estimates of seedbank persistence are possible when many observations are averaged over numerous locations. Future studies are needed to develop methods of reducing seedbank persistence, especially for weed species with particularly long-lived seeds.

Saflufenacil, a pyrimidinedione herbicide, is used for contact and residual broadleaf weed control in various crops. Bioactivity of saflufenacil in soil was tested in greenhouse and laboratory studies on 29 soils representing a wide range of soil properties and geographic areas across the United States. A greenhouse bioassay method was developed using various concentrations of saflufenacil applied PPI to each soil. Whole canola plants were harvested 14 d after treatment, and fresh and dry weights were recorded. Nonlinear regression analysis was used to determine the effective saflufenacil doses for 50% (ED50,), 80% (ED80), and 90% (ED90) inhibition of total plant fresh weight. Bioactivity of saflufenacil in soil was strongly correlated to soil organic (R = 0.85) and humic matter (R = 0.81), and less correlated to cation exchange capacity (R = 0.49) and sand content (R = −0.32). Stepwise regression analysis indicated that organic matter was the major soil constituent controlling bioactivity in soil and could be used to predict the bioactivity of saflufenacil. Saflufenacil phytotoxicity was found to be dependent on soil property; therefore, efficacy and crop tolerance from PRE and PPI applications may vary based on soil organic matter content and texture classification.

Research on best management practices, including vegetative filter strips, is needed to evaluate the potential for reducing herbicides in surface runoff. Laboratory studies were conducted to determine the influence of different filter strip components on fluometuron adsorption. Samples were taken from a switchgrass filter strip (1-m wide) established on a Brooksville silty clay. Sampled components included switchgrass stems clipped to 4 cm, plant residue on the soil surface, and topsoil < 5-mm, 0.5- to 1-cm, 1- to 3-cm, and 3- to 5-cm deep. The filter strip topsoil samples contained 1.8, 2.2, 2.3, and 2.8% organic matter for the aforementioned depths, respectively, compared with 1.8% in soil collected from an adjacent cropped area. Fluometuron adsorption on each sample was compared at initial concentrations of 0.017, 0.5, 1.0, 2.0, and 4.0 mg L−1, the last of these representing four times the peak concentration in surface runoff. Fluometuron adsorption was greater in soil from filter strip areas than in soil from cropped areas. Averaged over concentration, the soil–water partition coefficient (K d) value for soil 1- to 3-cm and 3- to 5-cm deep was greater than the value for soil from the cropped area. Stems and residue had K d values 4.9- and 4.1-fold greater, respectively, than soil from the cropped area. Average adsorption coefficients normalized for organic carbon content (K oc) of soil < 5-mm and 3- to 5-cm deep from filter strip areas were greater than the values for soil from cropped areas.

It has been proposed that cropping systems can be managed to promote the development of soil microbial communities that accelerate weed seed mortality. We examined soil fungal and bacterial communities, soil C:N ratio, soil particle size fractions, and weed seed mortality in soil from fields with over 10 yr of five contrasting management histories with the objective of determining if seed mortality could be explained by differences in soil properties. Seed mortality of giant foxtail and velvetleaf were greatest in soil from the conventionally managed systems and lowest in soil from a reduced input system. Principal-components analysis of soil microbial communities, as determined through denaturing gradient gel electrophoresis of polymerase chain reaction–amplified ribosomal RNA genes (PCR-DGGE), showed distinct differences in the composition of fungal and bacterial communities among the study soils. The first principal component of the 18S rDNA PCR-DGGE analysis of fungal community composition showed a strong negative correlation with both giant foxtail (− 0.52, P < 0.05) and velvetleaf (− 0.57, P < 0.01) seed mortality, as did ordination with nonmetric multidimensional scaling (NMS) [giant foxtail (− 0.54, P < 0.01) and velvetleaf (− 0.60, P < 0.01)], suggesting that seeds of the two species were affected similarly by changes in the soil fungal community. For giant foxtail, weed seed mortality was also positively correlated (r = 0.48, P < 0.05) with the first NMS axis of the bacterial 16S rDNA analysis. None of the other measured soil properties were significantly correlated with weed seed mortality. Thus, for the soils tested here, management history, microbial community composition, and weed seed mortality were linked. To extend these results to the field, more work is needed to identify components of the fungal and bacterial communities that are active in seed degradation, and to develop conservation biocontrol recommendations for these species.

Identification of associations between site properties and weed species abundance led to the generation of hypotheses as to why weed populations occur where they do, or do not, in agricultural fields. The objective of this research was to use a multivariate statistical technique, canonical correlation analysis, to identify the associations. Two continuous Zea mays production fields under center-pivot irrigation in the central Platte River Valley of Nebraska were grid-sampled between 1994 and 1997 for nine site properties and six to seven weed species. Weed species were identified and counted just prior to postemergence weed control in two adjacent quadrats (1 by 0.38 m) at each grid sampling point. These quadrats represented untreated weed populations emerging between crop rows and treated populations that survived preemergence herbicide banded within the crop row. Canonical correlation analysis identified one to five significant correlations between linear combinations of site properties and weed species abundance depending on field site, years, and between- vs. on-crop row weed populations. The first pair of linear combinations consistently described an association that separated weed species across a gradient of topography and soil type. The second pair of linear combinations described associations between weed species and soil fertility. In all cases, it was hypothesized that management practices strongly interacted with site properties to create the observed associations with weed populations. Other hypothesized mechanisms for weed patchiness include patchiness in available soil moisture that would influence weed seed germination, emergence, and seedling growth. Additional variation in plant-available preemergence herbicide concentration across the field site would vary weed control efficacy. Another mechanism would be variation in soil fertility that affects the growth, reproduction, and competitive ability of both the crop and the weed.

Environmental complexity and spatial heterogeneity are important factors influencing the structure of ant species assemblages. This paper documents the effect of different vegetation and environmental factors on ant community structure and functional group composition in different habitat patches. Ants were sampled at 16 sites distributed across five habitat types in the Kuldiha Wildlife Sanctuary. Sampling was performed 10 times over a 2-y period using pitfall traps. A total of 100 species belonging to 41 genera were collected during the study. Ant species richness was best explained by a combination of percentage grass cover, percentage litter cover and number of saplings whereas percentage litter cover and soil nitrogen concentration significantly explained the variation in ant species abundance. Dominant Dolichoderinae were present only at forest edge and were found to be associated positively with percentage bare ground cover and negatively with percentage litter cover. Generalized Myrmicinae, subordinate Camponotini and tropical climate specialists were prevalent in shaded forest habitats whereas opportunists were more common in two types of open habitat. Our study underpins the influence of vegetational complexity, litter and soil chemical properties on the structure and composition of ant species assemblages and various functional groups across forested habitats in this little-studied region.

This study determined variation in liana diversity, composition and community structure in different topographic habitats, as well as the environmental factors associated with them in the Atewa Range Forest Reserve, Ghana. The above-mentioned liana assemblage attributes were examined in thirty 40 × 40-m plots, randomly demarcated within three topographic habitats at different average altitudes (hill bottom: 85.6 m asl, hill slope: 343 m asl, plateau: 641 m asl). Soil properties, altitude and slope angle were determined for the plots. Using multiple stepwise regression, non-metric multidimensional scaling analysis, and analysis of similarity, environmental factors that influenced the above-mentioned attributes of liana assemblages were determined. The findings revealed significant variation in liana diversity, composition and community structure among the topographic habitats. Liana species composition related with soil P, Mg and moisture, and altitude. Soil Mg and P associated positively with species composition in the hill-bottom habitat while altitude and soil moisture related negatively with it. A reverse trend occurred in the other habitats. Five environmental factors related significantly with liana diversity and community structure as follows – species richness: soil Ca and Mg, altitude; Shannon diversity: soil Ca, altitude; abundance: soil moisture and P, altitude; basal area: soil moisture, P.