Restoration Of Degraded Lands Research Articles

Remote Sensing of Soil Organic Carbon at Regional Scale Based on Deep Learning: A Case Study of Agro-Pastoral Ecotone in Northern China

The North China agro–pastoral zone is a large, ecologically fragile zone in the arid and semi-arid regions. Quantitative remote sensing inversion of soil organic carbon (SOC) in this region can facilitate understanding of the current status of degraded land restoration and provide data support for carbon cycling research in the region. Deep learning (DNN) for SOC inversion has been W.a hot topic over the past decade, but there have been few studies at the regional scale in the arid and semi-arid zones. In this study, a DNN model with five hidden layers and five skip connections was established using 644 spatially distributed SOC samples and Landsat 8 OLI imagery. The model was compared with the random forest algorithm in terms of generalization ability. The main conclusions were as follows: 1. The DNN algorithm can establish a high-precision SOC inversion model (R2 = 0.52, RMSE = 0.7), with 90% of errors concentrated in the range of −2.5 to 2.5 kg·C/m2; 2. the Boruta variable-screening algorithm can effectively improve the model accuracy of the random forest algorithm, but due to the DNN’s better ability to mine hidden information in the data, the improvement effect on the DNN model accuracy is limited; 3. the SOC samples in arid and semi-arid areas are highly positively skewed, with a significant impact on the modeling accuracy of DNN, and conversion is required to obtain a model with better generalization ability; and 4. in arid and semi-arid regions, SOC has a weak correlation with vegetation indices but a stronger correlation with temperature, elevation, and aridity. This study established a reliable deep learning model for SOC density in a large arid and semi-arid region, providing a reference and framework for the establishment of SOC inversion models in other regions.

People's attitudes and perceptions towards area enclosure in Ethiopian central rift valley: Implications for land restoration and livelihood improvement

Land degradation is a common environmental problem affecting the ecological functions and ecosystem services leading to biodiversity loss and impoverishment of rural livelihood. This study explores people's attitudes and perceptions in central rift valley, Ethiopia. We interviewed 384 households using semi-structured questionnaires, conducted focus group discussions, and key informant interviews. The results showed that 92.1% of the respondents were aware of the role of area enclosure in degraded land restoration; 94.5% had a positive opinion of the establishment of new enclosures; 94.5% agreed to maintain the existing enclosures whereas 88.1% support the expansion. The benefits gained from the enclosure increased significantly with increased vegetation cover (OR = 41.961, P < 0.001). An improvement in the local communities' attitude towards the area enclosure is directly correlated with the economic benefits they obtain from the enclosures. Our results showed that farmers were optimistic to perceive that area enclosure plays a positive role to restore degraded lands thereby improving the livelihood of the local community. We found that the socioeconomic profile of farmers affects their attitude, and perception of the role of area enclosure to improve and restore the degraded area.

Environmental taxes in the European Union and their use as a means of environmental restoration

Environmental degradation caused by intense human activities has allured scientific and social concerns. Environmental taxes are a part of a wider policy context integrating various tools, including pricing instruments, subsidies, and investment in public infrastructure. Environmental taxes are the only fiscal policy tool the revenue which can be used for environmental protection purposes. They are used in modern societies, as means of optimizing consumers’ and producers’ behavior. These taxes generate revenues that can be used by governments to invest in environmental protection projects or in the effective management of natural resources. Eastern European countries’ environmental taxation regime, is a successful example since appropriate policies and actions were used for environmental degradation resilience along with the formerly degraded land restoration and funding environmental information dissemination programs for local communities. The present work aims to unveil successful practices adopted related to the implementation of environmental taxation in European countries and the use of their revenues in projects and actions to protect the environment and limit the anthropogenic impacts. In addition, a comparative analysis of individual EU countries efficiency in the use of taxation for mitigation of natural environment degradation is conducted with significant findings for policymakers.

Cost-benefit analysis of ecological restoration based on land use scenario simulation and ecosystem service on the Qinghai-Tibet Plateau

Ecological degradation is a serious problem across the world constraining regional sustainable development, while ecological restoration is of great significance in alleviating this issue. Cost-benefit analysis of ecological restoration is valid for successful project implementation and planning but large-scale studies are still lacking, especially for the Qinghai-Tibet Plateau (QTP), which has a special geographic location and extremely fragile ecosystems. This study applied patch-generating land use simulation (PLUS) model to simulate different ecological restoration scenarios and quantified their costs and benefits (ecosystem services values). The results indicated that restoration priority areas varied in specific landscapes for different scenarios. For grassland restoration, the scenarios prioritized the southwestern regions with large tracts of grassland. The cost-benefit analysis showed that the benefit cost ratio of farmland afforestation scenario was the largest, with the value of 128.2; and it was the lowest in the degraded land restoration scenario, with the value of 58.44. And the benefit cost ratio of degraded grassland restoration was between the two, which is 80.83. Besides, in the comprehensive restoration scenarios, the benefit cost ratio increased with the increase of the grassland restoration area when the afforestation area and the degraded land restoration area remained unchanged. The results can guide and support ecological restoration planning and policy formulation on the QTP. • This study simulates four categories ecological restoration scenarios. • The benefits and cost of various restoration scenarios are quantified and compared. • Cost-benefit analysis shows that the farmland afforestation has the highest benefit.

Abundance and Diversity of Woody Undergrowth Reservoir as Indicator of Suitable Vegetation Patch for Natural Regeneration

The diversity, abundance and height structure of naturally regenerated woody species were analyzed and compared for undergrowth reservoir associated with vegetation patches as bowal, shrubland and woodland for understanding the effect of vegetation conditions on spatial distribution of woody plants in Sudanian ecosystem. All undergrowth individuals (height 2) laid out in each vegetation patch during rainy season. In total 52 undergrowth species and 2224 stems arranged in 38 genera and 21 families out of which 25, 36 and 38 species were found in bowal, shrubland and woodland respectively and 15 shared species. Combretaceae, Caesalpiniaceae and Mimosaceae families were the most abundant and species density was significantly higher (P < 0.05) in shrubland and woodland than bowal, and increase diversity in only shrubland (P = 0.002) comparing with bowal. Undergrowth was abundantly concentrated in small height class as canopy benefit and indicate a specific-site distribution. Results also showed that bowal had a particular vegetation which vary in function of tree community characters in place (P < 0.05) while woodland and shrubland are similar vegetation patches. As conclusion, the study vegetation patches form suitable regeneration niches for the undergrowth reservoir of limited number of species which in return can be predictor of species richness and abundance and thus the structure of tree community. Woody undergrowth community could be considered in biodiversity management and degraded land restoration. Supplementary works could be undertaken to understand the characteristics of seed bank for bowal, shrubland and woodland regarding the undergrowth and tree communities.

Beneficial services of Glomalin and Arbuscular Mycorrhizal fungi in degraded soils in Brazil

Reducing soil degradation and its impacts on the environment have been one of the main challenges of the 21st century, exacerbated by a direct link between increases in the human population and soil degradation that raises current and future food security concerns. Despite this, experiences worldwide reveal that degraded land restoration projects have either achieved little success or failed. Thus, understanding the underlying causes and devising appropriate restoration mechanisms is crucial. Soil amelioration using beneficial microorganisms, particularly arbuscular mycorrhizal fungi (AMF), is essential and pragmatic. Glomalin, a type of glycoprotein produced by arbuscular mycorrhizal fungi in the phylum Glomeromycota, contributes to the mitigation of soil degradation. Moreover, AMF and glomalin are highly correlated with other soil physico-chemical parameters and are sensitive to changes in the environment. As a result of this, they have been recommended for monitoring the recovery of degraded soil or stages of soil degradation. In this review, we discuss the role of AMF and glomalin in the restoration of degraded soils, including improvements to the soil structure and soil organic matter (SOM), microbial activity, reduction of fertility loss, bioremediation, and mitigation of the effects of drought and saline stress. We highlight the research gaps and discuss the prospects. This knowledge will improve our understanding of the ecological conduct of glomalin and AMF, stimulate future research, and be useful to sustainable restoration of degraded lands. Furthermore, we discussed the challenges and obstacles in the legislation and future perspectives on the production of inoculants based on AMF in Brazil.

Potential of high-throughput eDNA sequencing of soil fungi and bacteria for monitoring ecological restoration in ultramafic substrates: The case study of the New Caledonian biodiversity hotspot

Due to their central role in ecosystems functioning and their ability to rapidly respond to environmental changes, soil microorganisms could potentially be used for monitoring ecosystems recovery in the context of degraded land restoration. However, these belowground organisms have been, to date, largely neglected. Here, we investigated fungal and bacterial community diversity, composition, and structure from ultramafic soils in New Caledonia, an archipelago in the southwest Pacific recognized as a priority for conservation and restoration. The emerging approach of high-throughput amplicon sequencing of environmental DNA (eDNA) – metabarcoding of eDNA – was used to compare soil microbial communities from four different native vegetation types, representing different stages of a chronosequence and defined as reference ecosystems, to five distinct post-mining sites revegetated several years ago. Our results clearly revealed changes in soil microbial phyla and functional groups along the reference chronosequence and variable responses at the different revegetated sites, with two of the five sites showing a good trajectory of recovery. We thus propose three ratios as metrics for monitoring the restoration trajectory of soil microorganisms: the Ascomycota:Basidiomycota and Saprotrophic:Ectomycorrhizal ratios for fungi, and the Cyanobacteria:Chloroflexi ratios for bacteria. Our study, combined with recent works undertaken in other geographical areas, underpins the great promise that could represent soil microbial eDNA metabarcoding for monitoring restoration progress and success. With the emergence of these new cost-effective and scalable sequencing technologies, soil microbes could, in the near future, be included in guidelines for restoration operations in complement to more conventional approaches.

Transpiration and canopy stomatal conductance dynamics of Mongolian pine plantations in semiarid deserts, Northern China

Mongolian pine (Pinus sylvestris var. mongolica) plantations have ecological significance for desertification control and degraded land restoration in drought-induced regions. To date, knowledge about the dynamics of transpiration and canopy stomatal conductance (gs) of Mongolian pine in the semiarid deserts in Northern China is quite limited. Thus, better understanding its physical response to environmental factors and exploring the mechanisms of forest transpiration can offer a theoretical basis for a reasonable tree planting program in semi-arid regions. In this study, transpiration and gs changes in Mongolian pine plantations for a mature forest (MMPP), half-mature forest (HMPP), and young forest (YMPP) were obtained using sap flow observations, while simultaneously monitoring the atmospheric and soil moisture contents. The results showed that the canopy transpiration per unit leaf area (EL) averaged 0.97 mm d–1, 0.60 mm d–1, and 0.45 mm d–1 in MMPP, HMPP, and YMPP, respectively, and the EL of Mongolian pine could be attributed to evaporative demand, soil moisture status, and gs. EL was obviously affected by air temperature, photosynthetic active radiation (PAR), and vapor pressure deficit (VPD) with the highest determined coefficient. The low values measured for the dimensionless coefficient (Ω = 0.041, 0.15, and 0.18) indicated that the canopy and the atmosphere were highly coupled. gs had more control over EL, and thus gs was more limited by VPD than that PAR. The average gs was 105.27, 105.26, and 99.44 mmol m–2 s–1 for MMPP, HMPP, and YMPP, respectively; Both MMPP and YMPP had lower sensitivity for stomatal regulation than HMPP, and the maximum gs was found in trees with both small and large tree diameters at breast height. Therefore, MMPP and YMPP were suspected to vary based on environmental conditions and were more susceptible to decline under mega drought conditions.

Aromatic plants based environmental sustainability with special reference to degraded land management

Land resources are under severe threat to meet its present demand due to unsustainable land use practices worldwide, industrialization, urbanization and pollution. In the present era of limited fertile land, degraded land including polluted and marginal lands are focal to meet the global needs of population. Degraded land restoration and marginal land utilization are vital for economical, environmental and social point of view including all aspects of ecosystem services of present and future. The present technologies for degraded land restoration include costly and unsustainable physical, chemical and biological methods which cannot be imposed without proper technological input. Aromatic crops are in high demand for industries like aroma, food, cosmetic, perfumery, toiletary etc. Certain perennial and annual aromatic crops are adaptable to the harsh environmental conditions of degraded lands. In the present literature, we recommend the adoption of aromatic plants for sustainable management of degraded and marginal lands to achieve the objectives of sustainable development goals (SDGs), boost circular economy and in situ restoration of degraded and marginal lands to achieve various tangible and intangible benefits including ecosystem services.

Degraded Land Restoration Works of the Toki Area, Gifu Prefecture

Degraded Land Restoration Works of the Toki Area, Gifu Prefecture

Butea monosperma: a leguminous species for sustainable forestry programmes

Forestry and greening programs in urban area are faced due to lack of awareness about multiple roles/benefits of trees, especially their role in drought proofing, prevention of soil and water run-off, degraded land restoration, livelihood security and sustainable development. In this regard, Butea monosperma (Lam.) Taubert, a medium-sized legume tree species, has gained much importance because of its multipurpose usage and well adaptability to forestry programs. We have documented the importance of Butea monosperma by surveys and compared with available literature. During the exhaustive surveys, 250 locals were interviewed between 2014 and 2016. We recorded maximum information of Butea monosperma viz. botanical description, traditional knowledge, commercial status, medicinal values and ecological importance. Globally, a reduction in its distribution has categorized it as an endangered species; the main reasons are overexploitation and inadequate awareness. Thus, the present paper deals with the beneficial uses and effectiveness of Butea monosperma for urban forestry and greening which could lead to generate interest in rising demand and value to broaden the scope for conservation, value addition and identification of multipurpose species.

Legacy nitrate in the deep loess deposits after conversion of arable farmland to non‐fertilized land uses for degraded land restoration

AbstractThe legacy nitrate–nitrogen (NO3−−N) in the soils is a long‐term threat to groundwater in regions with thick unsaturated zones, and it is thus important to investigate the amounts and sources of NO3−−N for effective environmental management. Given the substantial conversions of arable farmlands to non‐fertilizer land uses for the restoration of degraded land, the legacy effects of NO3−−N in thick loessial unsaturated zones in China remain uncertain. We collected soil samples from loess profiles &gt;13‐m deep under arable farmland and grassland, apricot, pine, peashrub, willow, and poplar converted from arable farmland over 15–35 years. We determined their nitrate content and isotope compositions to quantify the accumulation and sources of the former and its potential threat to groundwater. The seven NO3−−N profiles exhibited a parabolic shape with peak depths at 2.6–9.2 m. Greater peak depths corresponded to greater NO3−−N values, and the peak nitrate level varied from 0 to 10 m. The total NO3−−N accumulation ranged 3,181–9,018 kg N ha−1, and the non‐fertilizer profiles accounted for 35–73% of the arable farmland. The nitrate sources varied with depths. According to the isotope mass balance, the nitrate above, near, and below the peak depths mainly originated from atmospheric NO3− (25–34%), synthetic N fertilizer (49–68%), and soil organic N and manure (50–73%). The estimated residence time of nitrate in the soil ranged from 270 to 620 years. As such, the nitrate legacy effects should be given considerable attention for the protection of the soil and groundwater environment.

Degraded land restoration ecological way through horti‐pasture systems and soil moisture conservation to sustain productive economic viability

AbstractAlternate land uses that restore ecological balance with economic viability are desirable. Alternate land uses, that is, horti‐pasture systems (HPSs) with Emblica officinalis and Psidium guajava trees and pasture (Cenchrus ciliaris + Stylosanthes seabrana), were introduced with different soil moisture conservation measures (staggered contour trenches [T1], continuous contour trenches [T2], stone mulch [T3], vegetative barriers [T4], and control [T5]) for reclamation of degraded land and to test their capacity to perform ecological functions and provide economic return to the farmers. After 10 years, T1 increased soil organic carbon by ~58% and 15% over control in Emblica‐ and Psidium‐based HPS, respectively. T1 stipulated fruit and pasture yield by ~45% and 90% and 32% and 22% over control plots, in those HPS, respectively; T1 also improved fodder and fruit quality. Changing climates significantly affected the fruit and pasture yield. Despite this, T1 assured a benefit–cost ratio of 3.78 and 4.23 in those HPSs, respectively. The sustainable yield index for fruit and pasture in T1 were approximately (a) 1.85 and 1.68 and (b) 1.33 and 1.25 times higher than control, for Emblica‐ and Psidium‐based HPS, respectively. Soil moisture conservation could enhance profit by ~30% and 20% in those HPSs, respectively over control. T1 can potentially recycle approximately (a) 83%, 77%, and 71% and (b) 62%, 122%, and 81% higher N, P, and K than control in those HPSs, respectively. Thus, Emblica‐ and Psidium‐based HPS with staggered trenching could be replicated on a wide scale to enhance income, ensure fodder supply, and improve degraded land.

Introduction to the Special Issue on Tropical Forests: Management and Ecology in the Anthropocene

This Special Issue of Forests is based on papers presented at the 75th anniversary of the United States Department of Agriculture (USDA) Forest Service International Institute of Tropical Forestry as well as other papers relevant to the topic of the Special Issue. The Institute is but one leg of a conservation relay among cultures and institutions that began in Puerto Rico a millennium ago. The Institute began operations in 1939 and celebrated its 75th anniversary on May, 2014. Over its 75 years of operation, the Institute has focused its research on tropical forests, with the scope of the research expanding over the years. An analysis of the lines of research of the Institute showed that over its history about 69 lines of research have been established and that of the original 17 lines of research between 1939 and 1949, all but one remained active in 2014. This history and continuity of the research program has allowed the Institute to observe ecological phenomena over decades, including the evolving forest structure and functioning on degraded land restoration experiments that began before the formal establishment of the Institute and are now over 80 years old.

Potential of exclosure on aboveground biomass carbon stock and ecological fitness of woody species in Jabi Tehnane district, northwestern Ethiopia

ABSTRACT Assessment of ecological fitness of woody species across land use is critical issues in degraded land restoration. However, little is known about AGBC stored capacity, important value and distribution index of woody species grows in exclosure and adjacent open lands. Therefore, this research is aimed to (i) analyse impact of exclosure on AGBC (ii) ecological fit species. A random sampling method was employed. Forty sample plots (50m*50m) were used. AGBC stocks (mean± SE) of woody species in adjacent open grazing and exclosure land use of GW site was 0.11±0.07 and 1.24±0.27Mg ha-1 respectively. While in adjacent open grazing and exclosure land use of WG site, the value was 0.27±0.03 and 2.79±0.27Mgha-1 respectively. In both site exclosure land uses, the proportion of rare, occasional and common woody species were better than their adjacent open grazing land. Cupressus lustanica from open grazing and Vernonia auriculifera from exclosure land use of WG as well as Croton macrostachyus from open grazing and Leucaena leucocephala from exclosure land use of GW site were recorded as top ecologically fit species. It is recommended to protect degraded lands via integrating ecologically adapted native species and fully used their diversity to achieve the potential benefits of land restoration.

Effectiveness and sustainability of remedial actions for land restoration in Abeokuta urban communities, Ogun state, Nigeria

Abstract The destructive impact of land degradation on social and economic endeavours of the residents of certain urban areas of Abeokuta communities in Ogun State, Nigeria calls for remedial actions to restoring the affected land areas. This becomes essential in order to ensure safe inhabitation and enhanced socioeconomic engagements of the residents. Taken remedial actions in this regard included the use of sandbags, debris and wood logs, rubbles and stones, construction of contours and drainages. While each of these actions, in one way or the other, effectively improves the degraded land, it was concluded that the use of rubbles and stones, and drainage construction were sustainably durable for land restoration on the premise that these actions does not allow for water logging or flooding in of the study area. It was however recommended that these sustainable remedial actions should rather be pro-actively taken for prevention of land degradation than being taken as degraded land restoration actions basically because it is much cheaper to prevent environmental degradation than to have the degraded land restored.

Genomic characterization of Ensifer aridi, a proposed new species of nitrogen-fixing rhizobium recovered from Asian, African and American deserts

BackgroundNitrogen fixing bacteria isolated from hot arid areas in Asia, Africa and America but from diverse leguminous plants have been recently identified as belonging to a possible new species of Ensifer (Sinorhizobium). In this study, 6 strains belonging to this new clade were compared with Ensifer species at the genome-wide level. Their capacities to utilize various carbon sources and to establish a symbiotic interaction with several leguminous plants were examined.ResultsDraft genomes of selected strains isolated from Morocco (Merzouga desert), Mexico (Baja California) as well as from India (Thar desert) were produced. Genome based species delineation tools demonstrated that they belong to a new species of Ensifer. Comparison of its core genome with those of E. meliloti, E. medicae and E. fredii enabled the identification of a species conserved gene set. Predicted functions of associated proteins and pathway reconstruction revealed notably the presence of transport systems for octopine/nopaline and inositol phosphates. Phenotypic characterization of this new desert rhizobium species showed that it was capable to utilize malonate, to grow at 48 °C or under high pH while NaCl tolerance levels were comparable to other Ensifer species. Analysis of accessory genomes and plasmid profiling demonstrated the presence of large plasmids that varied in size from strain to strain. As symbiotic functions were found in the accessory genomes, the differences in symbiotic interactions between strains may be well related to the difference in plasmid content that could explain the different legumes with which they can develop the symbiosis.ConclusionsThe genomic analysis performed here confirms that the selected rhizobial strains isolated from desert regions in three continents belong to a new species. As until now only recovered from such harsh environment, we propose to name it Ensifer aridi. The presented genomic data offers a good basis to explore adaptations and functionalities that enable them to adapt to alkalinity, low water potential, salt and high temperature stresses. Finally, given the original phylogeographic distribution and the different hosts with which it can develop a beneficial symbiotic interaction, Ensifer aridi may provide new biotechnological opportunities for degraded land restoration initiatives in the future.

Degraded Land Restoration in Reinstating CH4 Sink.

Methane (CH4), a potent greenhouse gas, contributes about one third to the global green house gas emissions. CH4-assimilating microbes (mostly methanotrophs) in upland soils play very crucial role in mitigating the CH4 release into the atmosphere. Agricultural, environmental, and climatic shifts can alter CH4 sink profiles of soils, likely through shifts in CH4-assimilating microbial community structure and function. Landuse change, as forest and grassland ecosystems altered to agro-ecosystems, has already attenuated the soil CH4 sink potential, and are expected to be continued in the future. We hypothesized that variations in CH4 uptake rates in soils under different landuse practices could be an indicative of alterations in the abundance and/or type of methanotrophic communities in such soils. However, only a few studies have addressed to number and methanotrophs diversity and their correlation with the CH4 sink potential in soils of rehabilitated/restored lands. We focus on landuse practices that can potentially mitigate CH4 gas emissions, the most prominent of which are improved cropland, grazing land management, use of bio-fertilizers, and restoration of degraded lands. In this perspective paper, it is proposed that restoration of degraded lands can contribute considerably to improved soil CH4 sink strength by retrieving/conserving abundance and assortment of efficient methanotrophic communities. We believe that this report can assist in identifying future experimental directions to the relationships between landuse changes, methane-assimilating microbial communities and soil CH4 sinks. The exploitation of microbial communities other than methanotrophs can contribute significantly to the global CH4 sink potential and can add value in mitigating the CH4 problems.

Macrofauna do solo em uma cronosequência de capoeiras, florestas e pastos no Centro de Endemismo Belém, Amazônia Oriental

O Centro de Endemismo Belém (CEB) -região biogeográfica localizada entre os rios Tocantins e Pindaré- é a área mais desmatada da Amazônia. Estudar a biota do solo dos remanescentes florestais e de áreas em regeneração (capoeiras) do CEB é fundamental para promover práticas agrícolas mais sustentáveis e orientar ações de restauração de áreas degradadas. Dessa forma, o objetivo desse estudo foi identificar os principais determinantes da composição e da diversidade dos grandes táxons de macrofauna do solo (uso atual do solo, núcleos geográficos, histórico de uso, freqüência de fogo) em uma cronoseqüência de capoeiras e florestas no CEB. A macrofauna foi amostrada em oito áreas de capoeiras baixas (4-7 anos), seis áreas de capoeiras médias (11-15 anos), sete áreas de capoeiras altas (20-40 anos), oito áreas de remanescentes de florestas e três áreas de pastagem. Sua composição e diversidade foi estudada através de Análises de Componentes Principais e Entre-classes. Um total de 9.225 indivíduos pertencentes a 29 grandes taxóns (ordens ou famílias) foram coletados nas 32 parcelas amostradas. A composição da macrofauna se mostrou sensível ao efeito do histórico de uso do solo e identificou comunidades significativamente distintas entre as micro-regiões, havendo nessa escala efeito da cronosequência de capoeiras e florestas. A intensidade do uso do solo levou a redução da abundância e da riqueza de predadores, indicando alterações significativas no funcionamento do solo. Esses resultados mostram um efeito duradouro da degradação sobre a macrofauna do solo e conseqüentemente sobre suas funções ecológicas.

Fractal Scaling of Particle Size Distribution and Relationships with Topsoil Properties Affected by Biological Soil Crusts

BackgroundBiological soil crusts are common components of desert ecosystem; they cover ground surface and interact with topsoil that contribute to desertification control and degraded land restoration in arid and semiarid regions.Methodology/Principal FindingsTo distinguish the changes in topsoil affected by biological soil crusts, we compared topsoil properties across three types of successional biological soil crusts (algae, lichens, and mosses crust), as well as the referenced sandland in the Mu Us Desert, Northern China. Relationships between fractal dimensions of soil particle size distribution and selected soil properties were discussed as well. The results indicated that biological soil crusts had significant positive effects on soil physical structure (P<0.05); and soil organic carbon and nutrients showed an upward trend across the successional stages of biological soil crusts. Fractal dimensions ranged from 2.1477 to 2.3032, and significantly linear correlated with selected soil properties (R2 = 0.494∼0.955, P<0.01).Conclusions/SignificanceBiological soil crusts cause an important increase in soil fertility, and are beneficial to sand fixation, although the process is rather slow. Fractal dimension proves to be a sensitive and useful index for quantifying changes in soil properties that additionally implies desertification. This study will be essential to provide a firm basis for future policy-making on optimal solutions regarding desertification control and assessment, as well as degraded ecosystem restoration in arid and semiarid regions.