scholarly journals Land use alters soil propagule banks of wetlands down the soil-depth profile

2020 ◽  
Vol 71 (2) ◽  
pp. 191 ◽  
Author(s):  
Samantha K. Dawson ◽  
Jane A. Catford ◽  
Peter Berney ◽  
Richard T. Kingsford ◽  
Samantha Capon

Many studies have investigated the effects of human disturbances on floodplain propagule banks, but few have examined how these propagule banks change down the soil depth profile. Changes in soil propagule banks with depth can indicate the state of past vegetation and potentially demonstrate the effects of different land uses on the soil profile. Here, we examined changes in soil propagule banks down the soil-depth profile in an Australian floodplain wetland with five different land-use histories, ranging from a, in this case, relatively minor disturbance (clearing) through to more major disturbance (continuous cultivation). Land use had a larger influence than floodplain geomorphology on the propagule distribution of wetland plant-group numbers. An observed decrease in individuals over the depth profile also altered terrestrial plant groups in fields with longer land-use histories. Overall, soil-propagule profiles for terrestrial plants were not as affected by land use as were those of wetland plants. The geomorphological position on the floodplain also altered the soil propagule bank, with areas subject to the most flooding having the highest number of wetland species and retaining more of these species with greater depths. In conclusion, land-use impacts alter soil-propagule banks down the profile, despite most studies focussing on the top few centimetres.

2017 ◽  
Vol 20 (3) ◽  
pp. 459-467 ◽  
Author(s):  
Samantha K. Dawson ◽  
Richard T. Kingsford ◽  
Peter Berney ◽  
David A. Keith ◽  
Frank A. Hemmings ◽  
...  

2014 ◽  
Vol 32 (3) ◽  
pp. 507-513
Author(s):  
R.O. Adereti ◽  
F.O Takim ◽  
Y.A. Abayomi

An experiment was laid down in a screen house to determine the distribution of weed seeds at different soil depths and periods of cultivation of sugarcane in Ilorin, Nigeria. Soil samples from different depth levels (0-10 cm, 11-20 cm and 21-30 cm) were collected after harvesting of canes from three different land use fields (continuous sugarcane cultivation for > 20 years, continuous sugarcane cultivation for < 10 years after long fallow period and continuous sugarcane cultivation for < 5 years after long fallow period) in November, 2012. One kilogram of the sieved composite soil samples was arranged in the screen house and watered at alternate days. Germinating weed seedlings were identified, counted and then pulled out for the period of 8 months. Land use and soil depth had a highly significant (p £ 0.05) effect on the total number of weeds that emerged from the soil samples. The 010 cm of the soil depth had the highest weed seedlings that emerged. There was an equal weed seed distribution at the 11-20 cm and 21-30 cm depths of the soil. Sugarcane fields which have been continuously cultivated for a long period of time with highly disturbing soil tillage practices tend to have larger seed banks in deeper soil layers (11-20 cm and 21-30 cm) while recently opened fields had significantly larger seed banks at the 0-10 cm soil sampling depth.


Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1948
Author(s):  
Flavia Tromboni ◽  
Thomas E. Dilts ◽  
Sarah E. Null ◽  
Sapana Lohani ◽  
Peng Bun Ngor ◽  
...  

Establishing reference conditions in rivers is important to understand environmental change and protect ecosystem integrity. Ranked third globally for fish biodiversity, the Mekong River has the world’s largest inland fishery providing livelihoods, food security, and protein to the local population. It is therefore of paramount importance to maintain the water quality and biotic integrity of this ecosystem. We analyzed land use impacts on water quality constituents (TSS, TN, TP, DO, NO3−, NH4+, PO43−) in the Lower Mekong Basin. We then used a best-model regression approach with anthropogenic land-use as independent variables and water quality parameters as the dependent variables, to define reference conditions in the absence of human activities (corresponding to the intercept value). From 2000–2017, the population and the percentage of crop, rice, and plantation land cover increased, while there was a decrease in upland forest and flooded forest. Agriculture, urbanization, and population density were associated with decreasing water quality health in the Lower Mekong Basin. In several sites, Thailand and Laos had higher TN, NO3−, and NH4+ concentrations compared to reference conditions, while Cambodia had higher TP values than reference conditions, showing water quality degradation. TSS was higher than reference conditions in the dry season in Cambodia, but was lower than reference values in the wet season in Thailand and Laos. This study shows how deforestation from agriculture conversion and increasing urbanization pressure causes water quality decline in the Lower Mekong Basin, and provides a first characterization of reference water quality conditions for the Lower Mekong River and its tributaries.


2019 ◽  
Vol 174 (3-4) ◽  
pp. 339-348
Author(s):  
M. Nadri ◽  
C.-E. Khairi ◽  
A. Ioannidou
Keyword(s):  

Botany ◽  
2020 ◽  
Vol 98 (9) ◽  
pp. 479-488
Author(s):  
Francisco E. Fontúrbel

Mistletoes are a group of flowering plants that have developed a parasitic lifeform through complex eco-evolutionary processes. Despite being considered a pest, mistletoes represent a keystone forest resource and are involved in complex plant–plant and plant–animal interactions. Their parasitic lifeform and specialized ecological interactions make mistletoes an ideal model with which to understand the effects of anthropogenic disturbances in a changing world. The accelerated growth of the human population has altered all ecosystems on Earth, leading to biodiversity loss. Land-use changes (involving habitat loss, fragmentation, degradation, and transformation processes) can alter the ecological scenario for mistletoe by altering hosts, mutualists, and nutrient cycling. Those changes may have large consequences at the community level, changing the spatial structure of mistletoes, as well as interaction effectiveness, facilitation process, interaction disruption, and novel interactions with invasive species, leading to non-analog communities in the long run. Furthermore, climate change effects operate on a global scale, enhancing the effects of land-use changes. As temperatures increase, many species would alter their distribution and phenology, potentially causing spatial and temporal mismatches. But more critical is the fact that water stress is likely to disrupt key ecological interactions. Thus, mistletoes can provide valuable insights for what we can expect in the future, as a result of human disturbances.


2014 ◽  
Vol 47 ◽  
pp. 82-91 ◽  
Author(s):  
Maria Börjesson ◽  
R. Daniel Jonsson ◽  
Svante Berglund ◽  
Peter Almström
Keyword(s):  
Land Use ◽  

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