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Identifying spatial patterns in the variability of key soil properties to delineate the extent of land degradation could ensure efficient management of natural resources in terrestrial ecosystems. However, little is still known in tropical savannas that are subjected to indiscriminate land use. We evaluated the soil variability at the plot-scale in a terrestrial tropical ecosystem subjected to varying land use/land cover management to assess the impact of uncontrolled land uses on the soil natural capital. The non-invasive, time/cost efficient electromagnetic induction (EMI) technique was assessed for its potential, to determine the effect of land uses on soil spatial variability in a changing land use gradient from pristine land use/land cover conditions. The investigation was carried out in a natural tropical ecosystem in Aripo, Trinidad with soils of predominantly ultisols order and influenced by anthropogenic disturbances. EMI-based apparent electrical conductivity (ECa) measurements were obtained at two depth ranges (shallow = 0-0.5 m and deep = 0-1.5 m). Soil properties showed that the residential anthropogenic land use had a higher mean apparent electrical conductivity shallow (ECa s ) value (ECa s = 305.9 mS/m) than all other land uses. Higher ECa s values in the residential site suggest that human influences can increase the magnitude of electrical conductivity, which can alter the biogeochemical cycles of the soil affecting services provided by the ecosystem. Also anthropogenic land use/land covers exhibited lower coefficient of variation for soil texture (silt and clay) than natural land uses, indicating lower sensitivity of soil texture to land use due to the mixing of soils, which encourages uniformity in anthropogenic sites. Soil texture dominated the ECa s signal in the natural land use/land covers with the relationship between ECa s and silt in the Forest (r = 0.486) and Grass (r = − 0.495) significant at P < 0.05. Soil texture showed greater sensitivity to land use in natural sites than in anthropogenic sites. The dominance of soil texture in the natural sites indicates that in tropical soils that are predominantly light textured (clay content < 21%), silt content controls the EMI signal, which can become of low influence following disturbance. The magnitude of electrical conductivity can increase due to human influences. This can alter the biogeochemical cycles of the soil, affecting services provided by the ecosystem.

Edaphic controls on sedge invasion in a tropicalproperties and water quality could help to explain why the area of sedge is expanding. We 7 conducted an observational study, using geophysical methods and standard sampling techniques

Due to climate change impacts and the resulting sea-level rise, saline waters have been found further inland in tropical riverine estuaries such as the Godineau wetland, Trinidad. The saline water intrusion could constrain mangrove vegetation distribution. We investigated the surface water quality of two river channels (2 km and 6 km), emanating from a tropical wetland and from forest/agriculture at high-tide, respectively. Using a novel boat-mounted geophysical approach, spatially exhaustive river/estuarine salinity data was collected. Water quality parameters -salinity, pH and dissolved oxygen (DO) -were compared with vegetation surveyed along the course of the rivers to determine relationships between plant zonation and water quality. Our findings showed similar trends for salinity and apparent electrical conductivity, which were higher in the 2 km channel (27.10 to 31.80 dS/m) than in the 6 km channel (17.80 to 27.10 dS/m), while pH and DO levels were lower in the 2 km channel than in the 6 km channel due to higher levels of decomposition in the stagnant shorter channel. Red mangrove (Rhizophora mangle) was found in areas with little oxygen, high salinities and high acidity, making it more adaptable to conditions resulting from saline intrusion. Therefore, to replace the mangrove that has been lost due to die-off, the red mangrove maybe used in viable restoration efforts for the protection of inland areas from floods, as well as to provide ecosystem goods and services.