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Land use has a great impact on soil dynamics. The soils of various land use systems in Central Karakoram have been under immense pressure in the recent past due to certain anthropogenic activities such as land use practices and land use cover changes. These influences have an impact on the spatial distribution of metallic elements (MEs) in the soils of various land uses. Herein, we investigated the occurrence of the MEs, copper (Cu), zinc (Zn), and nickel (Ni), in soils of various land uses such as the permafrost, pasture, forest, and agricultural lands of the Central Karakorum region. The MEs were extracted in exchangeable, adsorbed, organically bound, carbonated, precipitated, and residual forms. The concentrations of MEs showed a significant dependence on the extraction method used, and the extraction trend followed the order of EDTA > HNO3 > KNO3 > NaOH > H2O. Zn showed the highest concentration compared to Ni and Cu in all extractions, whereas the land uses' ME concentration followed the order of agricultural land > permafrost > forest > pasturelands. The highest values of total Zn, Ni, and Cu were 712 ± 01 mg/kg, 656 ± 02 mg/kg, and 163 ± 02 mg/kg, respectively, in agricultural soil. The ME concentration showed significant variations between different land uses, and the highest concentration was noted in agricultural soil. Zn was found to be a dominant ME compared to Ni and Cu. We believe this effort will provide opportunities for scholars to investigate MEs around the globe.

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Micronutrients play a vital role in improving growth and performance of different crops. Management of soil micronutrients for better crop production needs sound understanding of their status and causes of variability. Therefore, in order to evaluate the changes in soil properties and micronutrient contents of soils, an experiment was conducted with soil samples from six soil depths i.e. 0-10, 10-20, 20-40,40-60, 60-80 and 80-100 cm of four prominent land-use systems viz. forest, horticulture, crop land and barren land. Amongst these, the maximum contents of OC (0.36%), clay (19.4%), DTPA-Zn (1.14 mg kg-1), Fe (11.78 mg kg-1), Mn (5.37 mg kg-1), Cu (0.85 mg kg-1) and Ni (1.44 mg kg_1) were observed in soils of forest land use system followed by horticulture, crop land and barren land, respectively. Also, soils of forest landpossessed 29.5, 21.3, 58.4, 51.8 and 44.0% higher DTPA-Zn, Fe, Mn, Cu and Ni as compared to crop land use system. Interactive influence of land use systems and soil depths on distribution of DTPA extractable micronutrients was found to be positive with maximum content at 0-10 cm depth of forest land use and lowest at 80-100 cm of barren land use system, respectively. Correlation analysis explicit positive and significant relationship of OC with DTPA Zn (r = 0.81), Fe (r = 0.79), Mn (r = 0.77), Cu (r = 0.84) andNi (r = 0.80), whereas the correlation results among DTPA micronutrients indicated the highest positivecorrelation of Ni with Cu (r = 0.95) and Mn (r = 0.93) followed by Fe with Zn (r = 0.93). Therefore, inclusion of forest and horticulture land use in crop lands or shift of land use from forest based to crop land resulted in renewal of degraded soil which could be beneficial for enhancing agricultural sustainability.

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Soil respiration, particularly heterotrophic respiration (RH), is a potent source of carbon dioxide (CO2) in the atmosphere. The current research focuses on the evaluation of RH for six land use systems including sloping cropland (SC), shrub land (SD), grassland (GD), shrub & grassland (SGD), newly abandoned cropland (NC) and afforested forest (AF). Heterotrophic respiration showed a diverse seasonal pattern over a year long period that was affected by various soil properties and climatic variables across the six land use systems in a subtropical Karst landscape. The lowest RH scores were found in the SD site (annual cumulative soil CO2 flux: 2447 kg C ha-1), whereas the maximum heterotrophic respiration occurred in the SF site (annual cumulative soil CO2 13597 kg C ha-1). The values of RH were: SC site: 3.8-191.5 mg C m-2 h-1, NC site: 1.04-129 mg C m-2 h-1, GD site: 3.6-100.7 mg C m-2 h-1, SGD site: 0.3-393.5 mg C m-2 h-1, SD site: 3-116 mg C m-2 h-1, and SF site: 10.6-398.2 mg C m-2 h-1. Highly significant (p ≤ 0.01) and positive correlations between RH rate and soil temperature were found for the studied land use types (correlation coefficients as follows; SC: 0.77, NC: 0.61, GD: 0.283, SGD: 0.535, SD: 0.230, SF: 0.85). However, water filled pore space (WFPS), NH4+, NO3-, dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) concentrations showed varied (positive and negative) correlations with RH. The overall results show that soil temperature can be considered as the most limiting factor for RH among all the sites studied in the present research. In these environments, soil heterotrophic respiration significantly correlated with soil temperature, highlighting the significance of climate on heterotrophic respiration.

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The Sustainable Development Goals (SDGs) encourage nations to substantially increase food production to achieve zero hunger (SDG 2) while preserving life on land (SDG 15). A key question is how to reconcile these potentially competing goals spatially. We use integer linear programming to develop an 'integrated land use planning framework' that identifies the optimal allocation of 17 crops under different hypothetical conservation targets while meeting agricultural demands by 2030. Intensifying existing cropland to maximum yield before allocating new cropland would reduce land requirement by 43% versus cropland expansion without intensification. Even with yield gap closure, tropical and sub-tropical crops still require expansion, primarily allocated to Venezuela, eastern Brazil, Congo Basin, Myanmar and Indonesia. Enforcement of protected areas, via avoiding conversion in 75% of Key Biodiversity Areas and 65% of intact areas, is vital to attain biodiversity targets but bears large opportunity costs, with agricultural rents dropping from $4.1 to $2.8 trillion. Although nationally constrained forest conservation efforts would earn 9% less agricultural rents compared to globally coordinated conservation solutions, they were also able to reduce intact habitat and forest loss (43% and 35% reduction). Our results demonstrate that careful choice of the allocation of future cropland expansion, could dramatically reduce-but not eliminate-the tradeoffs between the SDGs for food production and land biodiversity conservation.

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Soils contain one of the largest carbon (C) pools in the biosphere with the greatest potential of C sequestration to mitigate climate change impacts. The present study aimed at comparing C sequestration potential of various land use systems including forestlands, croplands, agroforests, and orchards in the arid region of Pakistan. Soil samples from the layers of 0-20, 20-40, 40-60, and 60-80 cm depths were collected and analysed for soil physico-chemical properties namely texture, pH, EC, NPK-soil, organic matter (SOM), and soil organic C (SOC). Additionally, the above and below ground plant biomass and C contents were estimated. Results revealed that the highest C sequestration potential (64.54 Mg ha-1) was in the above ground biomass of forest land and the lowest (33.50 Mg ha-1) in cropland. The below ground plant biomass at 0-20 cm soil depth was 14.09, 12.38, 11.78, 11.76, and 10.92 Mg ha-1 for forest land, mango orchards, agroforests, citrus orchards and cropland, respectively. The respective values in case of total C content were, 6.84, 6.79, 6.10, 5.69 Mg ha-1. Irrespective to the soil depth, below ground biomass and total C followed the order: forest land > mango orchard > citrus orchard > agroforests > crop lands. It is concluded that the forest land have greater potential for C sequestration than the other land use systems studied in the arid region of Pakistan. Therefore, in order to cope up with climate change disasters in Pakistan the massive reforestation project - named the Billion Tree Tsunami of the Government of Pakistan will prove beneficial.

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The knowledge regarding earthworm species richness in subtropical Brazil is limited, particularly in the state of Rio Grande do Sul (RS), where only a few sites have been sampled. In this study we assessed earthworm richness in different ecosystems of RS, prioritizing un-sampled regions. Fifteen ecosystems, including native vegetation and other ecosystems with variable levels of disturbance were sampled in 30 counties in RS, totaling 77 sampling points, mainly in the Pampa biome. Qualitative sampling was performed by handsorting soil monoliths and fixing the earthworms in 4% formalin solution. Species identification was based on morphological characters, and species richness and Shannon (H) and McIntosh (U) diversity indices were calculated for each ecosystem. Twenty-one earthworm species were identified, belonging to seven families: Glossoscolecidae (8), Rhinodrilidae (2), Ocnerodrilidae (4), Megascolecidae (4), Acanthodrilidae (1), Lumbricidae (1) and Criodrilidae (1). From these, ten are new species belonging to the genera: Glossoscolex (6), Fimoscolex (1), Kerriona (1), Eukerria (1), and one aquatic species of the Criodrilidae family, belonging to a new genus. Most of the native species (Urobenus brasiliensis, Fimoscolex n.sp.1 and the Glossoscolex spp.) predominated in ecosystems little altered by human activity, while exotic (Amynthas gracilis, Amynthas rodericensis, Metaphire californica, Aporrectodea trapezoides) and peregrine species (Pontoscolex corethrurus) predominated in areas with more human disturbance. Native ecosystems with lower disturbance, particularly forests and native pastures had higher diversity than disturbed sites. This is the first record of A. rodericencis for Brazil and most sites represent new collection records for the known species in RS.

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The anaerobic ammonium oxidation (anammox) process is globally an important nitrogen-cycling process mediated by specialized microbes. However, still little information is documented about anammox microbial community structure under agricultural soils. The anaerobic incubation experiment was conducted to study the impacts of different land use soils fertilized by 13C-urea on the activity and diversity of anammox bacteria using stable isotope to probe the phospholipid fatty acid (PLFA-SIP). The 13C was preferentially incorporated in ratios PLFAs 16:1ω7c, 16:1ω5c, and 16:0. The results revealed that the abundance of the anammox bacteria (both hzs-ß and hzo) were observed in vegetable soil V1 and paddy soils (R1 and R2) means that they were positively correlated with 13C-urea but were negatively correlated with NO3--N and NH4+-N concentrations. Thus, 13C-PLFAs 16:1ω7c, 16:1ω5c, and 16:0 could be the biomarker as soil anammox. The anaerobic microbial community composition of soils under different land use systems was diverse, and V1, R1, and R2 had similar microbial diversity and higher microbial biomass. The principal component analysis between soil properties and gene abundance suggested that not only pH but also soil organic matter, available P, and available K were important factors for the anammox process. This study suggested that 13C-Urea-PLFA for anaerobic incubation was a simple method to study anammox microbial community structure through affecting the soil nutrients, and the different land use systems played important roles in determining the microbial composition of soils.

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