scholarly journals Human-Mediated Land Use Change Drives Intraspecific Plant Trait Variation

2021 ◽  
Vol 11 ◽  
Author(s):  
Hayley Schroeder ◽  
Heather Grab ◽  
André Kessler ◽  
Katja Poveda

In the Anthropocene, more than three quarters of ice-free land has experienced some form of human-driven habitat modification, with agriculture dominating 40% of the Earth’s surface. This land use change alters the quality, availability, and configuration of habitat resources, affecting the community composition of plants and insects, as well as their interactions with each other. Landscapes dominated by agriculture are known to support a lower abundance and diversity of pollinators and frequently larger populations of key herbivore pests. In turn, insect communities subsidized by agriculture may spill into remaining natural habitats with consequences for wild plants persisting in (semi) natural habitats. Adaptive responses by wild plants may allow them to persist in highly modified landscapes; yet how landscape-mediated variation in insect communities affects wild plant traits related to reproduction and defense remains largely unknown. We synthesize the evidence for plant trait changes across land use gradients and propose potential mechanisms by which landscape-mediated changes in insect communities may be driving these trait changes. Further, we present results from a common garden experiment on three wild Brassica species demonstrating variation in both defensive and reproductive traits along an agricultural land use gradient. Our framework illustrates the potential for plant adaptation under land use change and predicts how defense and reproduction trait expression may shift in low diversity landscapes. We highlight areas of future research into plant population and community effects of land use change.

BMC Zoology ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Mariëtte Pretorius ◽  
Wanda Markotter ◽  
Mark Keith

Abstract Background Modification and destruction of natural habitats are bringing previously unencountered animal populations into contact with humans, with bats considered important zoonotic transmission vectors. Caves and cave-dwelling bats are under-represented in conservation plans. In South Africa, at least two cavernicolous species are of interest as potential zoonotic hosts: the Natal long-fingered bat Miniopterus natalensis and the Egyptian fruit bat Rousettus aegyptiacus. Little information is available about the anthropogenic pressures these species face around important roost sites. Both bats are numerous and widespread throughout the country; land-use changes and urban expansions are a rising concern for both conservation and increased bat-human contact. Results Our study addressed this shortfall by determining the extent of land-cover change around 47 roosts between 2014 and 2018 using existing land cover datasets. We determined the land-cover composition around important roost sites (including maternity, hibernacula and co-roosts), distances to urban settlements and assessed the current protection levels of roost localities. We detected an overall 4% decrease in natural woody vegetation (trees) within 5 km buffer zones of all roost sites, with a 10% decrease detected at co-roost sites alone. Agricultural land cover increased the most near roost sites, followed by plantations and urban land-cover. Overall, roosts were located 4.15 ± 0.91 km from urban settlements in 2018, the distances decreasing as urban areas expand. According to the South African National Biodiversity Institute Ecosystem Threat Status assessment, 72% of roosts fall outside of well-protected ecosystems. Conclusions The current lack of regulatory protection of cavernicolous bats and their roosts, increasing anthropogenic expansions and proximity to human settlements raises concerns about increased human-bat contact. Furthermore, uncontrolled roost visitation and vandalism are increasing, contributing to bat health risks and population declines, though the extent of roosts affected is yet to be quantified. In an era where pandemics are predicted to become more frequent and severe due to land-use change, our research is an urgent call for the formal protection of bat-inhabited caves to safeguard both bats and humans.


Author(s):  
Yujuan Gao ◽  
Jianli Jia ◽  
Beidou Xi ◽  
Dongyu Cui ◽  
Wenbing Tan

The heavy metal pollution induced by agricultural land use change has attracted great attention. In this study, the divergent response of bioavailability of heavy metals in rhizosphere soil to different...


Author(s):  
Allison Neil

Soil properties are strongly influenced by the composition of the surrounding vegetation. We investigated soil properties of three ecosystems; a coniferous forest, a deciduous forest and an agricultural grassland, to determine the impact of land use change on soil properties. Disturbances such as deforestation followed by cultivation can severely alter soil properties, including losses of soil carbon. We collected nine 40 cm cores from three ecosystem types on the Roebuck Farm, north of Perth Village, Ontario, Canada. Dominant species in each ecosystem included hemlock and white pine in the coniferous forest; sugar maple, birch and beech in the deciduous forest; grasses, legumes and herbs in the grassland. Soil pH varied little between the three ecosystems and over depth. Soils under grassland vegetation had the highest bulk density, especially near the surface. The forest sites showed higher cation exchange capacity and soil moisture than the grassland; these differences largely resulted from higher organic matter levels in the surface forest soils. Vertical distribution of organic matter varied greatly amongst the three ecosystems. In the forest, more of the organic matter was located near the surface, while in the grassland organic matter concentrations varied little with depth. The results suggest that changes in land cover and land use alters litter inputs and nutrient cycling rates, modifying soil physical and chemical properties. Our results further suggest that conversion of forest into agricultural land in this area can lead to a decline in soil carbon storage.


Author(s):  
A. V. Prishchepov ◽  
F. Schierhorn ◽  
N. Dronin ◽  
E. V. Ponkina ◽  
D. Müller

2014 ◽  
Vol 61 ◽  
pp. 19-38 ◽  
Author(s):  
Dave Murray-Rust ◽  
Derek T. Robinson ◽  
Eleonore Guillem ◽  
Eleni Karali ◽  
Mark Rounsevell

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6255 ◽  
Author(s):  
Citlalli Castillo-Guevara ◽  
Mariana Cuautle ◽  
Carlos Lara ◽  
Brenda Juárez-Juárez

Background The discovery-dominance trade-off is the inverse relationship between the ability of a species to discover resources and the species’ dominance of those resources; a paradigm used to explain species coexistence in ant communities dependent on similar resources. However, factors such as stress (e.g., temperature) or disturbance (e.g., removal of biomass) associated with the change in land use, can modify this trade-off. Here, we aimed to determine the potential effects of land use change on dominance hierarchy, food preferences and on the discovery-dominance trade-off. Methods An experiment with baits was used to investigate the dominance hierarchies of ant communities in a temperate mountain habitat in central Mexico. We evaluated the dominance index (DI), food preferences and discovery-dominance trade-offs of ants inhabiting two types of vegetation: a native oak forest and agricultural land resulting from agricultural land use and grazing. Results The ant communities in both environments were comprised of three species of ants (Monomorium minimum, Myrmica mexicana, and Camponotus picipes pilosulus), four morphospecies (Pheidole sp.1 and Pheidole sp.2, Temnothorax sp. and Lasius sp.) and one genus (Formica spp.). All Formicidae showed values of intermediate to low DI, and this factor did not seem to be influenced by the change in land use. Ants in the modified vegetation (i.e., agricultural land) were found to be numerically greater. Overall, a higher number of visits were registered to the tuna bait, although the duration of foraging events to the honey baits was longer. However, foraging times were dependent on the species considered: the generalized Myrmicinae, M. minimum, the ant species with highest DI, foraged for longer periods of time in the agricultural land and on the tuna bait. Meanwhile, the cold-climate specialist Formica spp., with a lower DI, foraged for longer periods of time in the oak (although not significant) and on the honey bait. We found little evidence of the discovery-dominance trade-off; instead, we found considerable diversity in the strategies used by the different species to access resources. This range of strategies is well represented by the generalized Myrmicinae M. minimum, the cold-climate specialists Formica spp. and Temnothorax sp., and the rare species, as the cold climate specialist Lasius sp. (insinuators). Conclusions Our evaluation shows that transformation of the original habitat does not appear to affect the hierarchical dominance of the ant communities, but it does affect their food preferences. Species with higher DI values such as the generalized Myrmicinae are more skilled at resource acquisition in modified habitats. Our results suggest that change in land use promotes an increase in the diversity of foraging strategies used by different ant species. This diversity may contribute to resource partitioning which favors coexistence.


2018 ◽  
Vol 3 (4) ◽  
pp. 219-226
Author(s):  
Yasfir Ma'arif ◽  
Teuku Fauzi ◽  
Safrida Safrida

Abstrak  Pertumbuhan  penduduk dan dinamika pembangunan telah menggeser pemanfaatan lahan yang akhirnya menimbulkan kompleksitas permasalahan lahan yang semula berfungsi sebagai media bercocok tanam (pertanian), berangsur-angsur berubah menjadi multifungsi pemanfaatan. Berubahnya pemanfaatan lahan pertanian ke non pertanian dapat disebut juga sebagai alih fungsi lahan. Kabupaten Aceh Besar adalah salah satu kabupaten yang terus menghadapi permasalahan alih fungsi lahan, khususnya lahan sawah. Alih fungsi lahan ini mengakibatkan luas lahan sawah di Aceh Besar terus menurun. Lahan yang paling banyak mengalami alih fungsi lahan adalah jenis lahan sawah yang menjadi lahan non pertanian. Penelitian ini bertujuan untuk mengidentifikasi faktor-faktor yang menyebabkan terjadinya alih fungsi lahan sawah dan mengidentifikasi dampak sosial dan ekonomi yang dialami petani mantan pemilik lahan akibat alih fungsi lahan sawah menjadi lahan non pertanian. Berdasarkan hasil regresi secara parsial dari analisis regresi faktor harga jual, kebutuhan hidup dan kondisi lahan berpengaruh nyata terhadap konversi lahan sawah di  Kecamatan Baitussalam Kabupaten Aceh Besar. Bedasarkan hasil regresi secara serempak dari hasil regresi didapatkan bahwa harga jual, kebutuhan hidup dan kondisi lahan secara serempak mempengaruhi konversi lahan sawah di Kecamatan Baitussalam Kabupaten Aceh Besar. Berdasarkan isu dampak sosial sebagai akibat alih fungsi lahan di lihat dari keinginan kondisi lama, meningkatkan rasa kerjasama dan kekeluargaan, serta kemampuan memenuhi kebutuhan keluarga mendapatkan hasil yang positif dengan nilai ≥ 50%. Berdasarkan isu dampak ekonomi sebagai akibat alih fungsi lahan di lihat dari peningkatan pendapatan mendapatkan hasil yang positif dengan nilai ≥ 50%.Impact Of Paddy Fields Function  On Community Socio-Economic Conditions Of Baitussalam District, Aceh Besar RegencyAbstract  Population growth and the dynamics of development have shifted land use which eventually led to the complexity of the problem of land that used to function as a farming medium (agriculture), gradually becoming a multifunctional use. Changing the use of agricultural land to non-agriculture can also be referred to as land conversion. Aceh Besar District is one of the districts that continues to face the problem of land conversion, especially rice fields. The conversion of this land function has caused the area of paddy fields in Aceh Besar to continue to decline. The land that has experienced the most land use change is the type of rice field that becomes non-agricultural land. This study aims to identify the factors that cause the conversion of paddy fields and identify the social and economic impacts experienced by farmers former landowners due to the conversion of paddy fields to non-agricultural land. Based on the partial regression results from the regression analysis, the factors of selling price, life necessity and land conditions have a significant effect on the conversion of paddy fields in Baitussalam District, Aceh Besar District. Based on the simultaneous regression results from the regression results, it was found that the selling price, life needs and land conditions simultaneously affected the conversion of paddy fields in Baitussalam District, Aceh Besar District. Based on the issue of social impacts as a result of land use change seen from the desires of the old conditions, increasing the sense of cooperation and kinship, as well as the ability to meet family needs get positive results with a value of ≥ 50%. Based on the issue of economic impact as a result of the transfer of land functions, it can be seen from the increase in income that has a positive result with a value of ≥ 50%.


2020 ◽  
Vol 6 (1) ◽  
pp. 54-60
Author(s):  
Khoiratul Hasanah ◽  
Ari Hayati ◽  
Hasan Zayadi

Wild plants are plants whose presence on agricultural land can reduce crop yields. Losses due to wild plants to cultivated plants vary depending on the type of plant cultivated, climate, species of wild plants and technical cultivation applied. This study aims to determine the diversity of wild plants in the land of maize (Zea mays L.) in Bung-bungan Village Bluto District Sumenep Regency. This method uses a descriptive exploratory method, for each wild plant found in ± 3600 m2 of corn land. Sampling of wild plants using a 4x4 m plot method. The measured data includes the number of species and the number of individuals calculating important values ​​and diversity indices. The results of the study showed that the Shannon-Wienner Diversity Index analysis of the highest value in maize plants in plantations was found in land II, which was 2.678 indicating moderate diversity, categorized as moderate because there were not too many wild plants on maize.  Keywords: Corn, diversity, wild plants,  ABSTRAK Tumbuhan liar merupakan tumbuhan yang kehadirannya pada lahan pertanian dapat menurunkan hasil tanaman. Kerugian akibat tumbuhan  liar terhadap tanaman budidaya beragam bergantung dari jenis tanaman yang diusahakan, iklim, jenis tumbuhan  liar dan teknis budidaya yang diterapkan. Penelitian ini bertujuan untuk mengetahui diversitas tumbuhan liar di lahan jagung (Zea mays L.) di Desa Bung-bungan Kecamatan Bluto Kabupaten Sumenep. Metode ini menggunakan metode deskriptif eksploratif, terhadap setiap tumbuhan liar yang ditemukan pada lahan jagung seluas ±3600 m2. Pengambilan sampel tumbuhan liar menggunakan metode plot berukuran 4x4 m. Data yang diukur meliputi jumlah spesies dan jumlah individu menghitung nilai penting dan indeks diversitas. Hasil penelitian menunjukkan analisis Indeks Keanekaragaman Shannon-Wienner tumbuhan liar nilai tertinggi pada tanaman jagung di lkebun terdapat pada lahan II yaitu 2,678 menunjukkan keanekaragaman sedang, di kategorikan sedang karena jenis tanaman liar yang ada pada lahan jagung tidak terlalu banyak. Kata kunci: Jagung, Diversitas, Tanaman liar


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