Visual Analysis of Crop Rotation Fallow Patterns in Recent 5 Years Based on CiteSpace

Based on the "Web of Science Core Collection" (SCIE database), this article used the visualization software CiteSpace to visualize and analyze the crop rotation fallow patterns in the past five years. It analyzed the countries, institutions, keywords and hot topics of related literature to explore their research characteristics and development, and to provide reference for crop rotation fallow research and practice. The research shows that: 1) developed countries are the main research force in the field of crop rotation and fallowing, and the connection between the research of each country and each institution is not close; 2) research hotspots can be mainly summarized as: crop growth and yield, greenhouse gas emissions and soil health analysis, and the research in this field is constantly refined, combining macro and micro; 3) In recent years, there is a big gap between China and foreign countries in the field of crop rotation and fallow research. It is necessary to strengthen the cooperation with research institutions in developed countries in Europe and the United States, and to carry out crossregional and interdisciplinary research cooperation to improve the quality of papers and scientific research level.

Medium-term Air Quality Benchmarking for Ecosystem Monitoring and Sustainability Planning: Case Study Dallas County (U.S.A.) 2015 to 2020

Medium-term air quality assessment, benchmarking it to recent past data can usefully complement short-term air quality index data for monitoring purposes. By using daily and monthly averaged data, medium-term air quality benchmarking provides a distinctive perspective with which to monitor air quality for sustainability planning and ecosystem perspectives. By normalizing the data for individual air pollutants to a standard scale they can be more easily integrated to generate a daily combined local area benchmark (CLAB). The objectives of the study are to demonstrate that medium-term air quality benchmarking can be tailored to reflect local conditions by selecting the most relevant pollutants to incorporate in the CLAB indicator. Such a benchmark can provide an overall air quality assessment for areas of interest. A case study is presented for Dallas County (U.S.A.) applying the proposed method by benchmarking 2020 data for air pollutants to their trends established for 2015 to 2019. Six air pollutants considered are: ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, benzene and particulate matter less than 2.5 micrometres. These pollutants are assessed individually and in terms of CLAB, and their 2020 variations for Dallas County compared to daily trends established for years 2015 to 2019. Reductions in benzene and carbon monoxide during much of 2020 are clearly discernible compared to preceding years. The CLAB indicator shows clear seasonal trends for air quality for 2015 to 2019 with high pollution in winter and spring compared to other seasons that is strongly influenced by climatic variations with some anthropogenic inputs. Conducting CLAB analysis on an ongoing basis, using a relevant nearpast time interval for benchmarking that covers several years, can reveal useful monthly, seasonal and annual trends in overall air quality. This type of medium-term, benchmarked air quality data analysis is well suited for ecosystem monitoring.

Impacts of Rice Field Winter Planting on Soil Organic Carbon and Carbon Management Index

To tackle with the problem of prevailing farmland abandonment in winter, 5 treatments includes Chinese milk vetch-double cropping rice (CRR), rape-double cropping rice (RRR), garlic-double cropping rice (GRR), winter crop multiple cropping rotation (ROT), winter fallow control (WRR) were set up. By measuring soil total organic carbon, active organic carbon and its components and calculating the soil carbon pool management index in 0~15 cm and 15~30 cm soil layers in the early and late rice ripening stage. The effects of different winter planting patterns on the changes of soil organic carbon and carbon pool management index were discussed. In order to provide theoretical basis for the optimization and adjustment of winter planting pattern of double cropping rice field in the middle reaches of Yangtze River. The results showed that soil total organic carbon, active organic carbon and its components in different winter cropping patterns were increased, and ROT and CRR treatments were more beneficial to the accumulation of soil total organic carbon, active organic carbon and its components as well as the improvement of soil carbon pool management index, which should be preferred in the adjustment of cropping patterns.

Principal-agent Relationships: A Note on Biomass Depletion

Public authorities frequently mandate public or private agencies to manage their renewable natural resources. Contrary to the agency, which is an expert in renewable natural resource management, public authorities usually ignore the sustainable level of harvest. In this note, we first model the contractual relationship between a principal, who owns the renewable natural resource, and an agent, who holds private information on its sustainable level of harvest. We then look for the Pareto-optimal allocations. In the situation of an imperfect information setting, we find that the Pareto-optimal contracting depends on the probability that the harvesting level stands outside the sustainability interval. The information rent held by the agent turns out to be unavoidable, such that stepping outside the sustainability interval implies the possibility of depletion of the renewable natural resource. This, in turn, compromises the maintenance of the ecological balance in natural ecosystems.

Floristic Composition and Community Structure of Epiphytic Angiosperms in an Urban Forest Fragment in the Eastern Amazon

Vascular epiphytes are one of the most important forest components, contributing to microclimatic maintenance. These plants find ideal conditions for development in the Amazon due to the spatial heterogeneity and high temperature and humidity typical of this biome. In recent years, the Brazilian Amazon has undergone dramatic changes in its landscape, mainly due to the increase in deforestation and fire rates. We present here the floristic composition and analyze the community structure of epiphytic angiosperms of an urban forest fragment in Eastern Amazon. A total of 71 epiphytic individuals were recorded belonging to eight species and four families. Orchidaceae was the most representative family, corroborating the pattern for surveys of epiphytic diversity in the Neotropical region. Epiphytic species were found on 24 individuals of 10 tree species. The epiphytic importance value (IVe) was low for all species, except for Aechmea tocantina and Rhipsalis baccifera. Cactaceae was the family with the highest IVe. Most epiphytes were found in the crown of trees (83.1%). The diversity index of the fragment was H’ = 1.80 and the equity index was J= 0.87, reflecting the absence of highly dominant species. Conservation of urban forest fragments is necessary for the maintenance of epiphytic flora and ecosystem services.

Opportunities and Challenges of Rehabilitating Degraded Land in the Case of Cheha Woreda, Gurage Zone, SNNP Region, Ethiopia

The research was conducted in chaha wereda gurage zone SNNP region of Ethiopia. The aim of the study was to assess opportunity and challenges of degraded land rehabilitation. From the total population of the study area 20% (73) respondents were selected in order to achieve the objective of the study at hand, for the study both primary and secondary data was generated. The primary data collection was started with a preliminary survey followed by a key informant interview, focus group discussion, and household survey with questionnaires. The secondary data were collected from books, unpublished thesis, project report, and workshops, open ended questionnaire and checklists for interview. The households were selected using stratified sampling technique (Cochran) sample size formula the process of analysis of the study was carried out using qualitative description and quantitative analysis. The collected data were analyzed using descriptive statistics, the quantitative data were analyzed frequency and percentage when appropriate the qualitative data were discussed to substantiate the study. And the results were expressed in the form of tables and graphs. The findings of the study indicated that limited labor availability, high cost of maintenance. Lack of knowledge, soil conditions, high surfaces runoff, poor vegetation coverage, poor monitoring and evaluation, poor implementation and poor training on the technology use are major challenges.

A Challenge and Chance for Soil Ecology

The understanding of soil and its response to the global warming is important for the harmony of human and environment. Generally, soil has four majorcomponents as air, water, mineral matter, and organic matter. The relative proportions of these four components greatly influence the behavior and productivity of soils. Through interactions of energy flow and mass exchange,soil plays the role as the crucial interface medium for air, minerals, water and life, and forms a complex integrated body, ecosystem. To a great extent, soil ecology is one new branch of ecology that study the relationship between soil biota and environment, including ecological structure, function, balance and evolution of soil ecosystem. The application of soil ecology will be a benefit for the reasonable and sustainable use of land resources and be important for agriculture, forestry and grazing production.

A Review of Research on Ecological Economics Based on Bibliometrics

The development of ecological economics is a major strategy for development in the 21st century. Although scholars have been rising more and more interesting for ecological economic over the past 10 years, it is still unclear what is the change will be facing in the future. In order to provide a theoretical basis for the future development of ecological economy, our article analyzes the current research progress of ecological economy on the basis of a bibliometric analysis. The results show that (1) sustainable development of an ecological economy is a hot research topic; (2) there is little cooperation and exchange between institutions and among scholars regarding ecological economics; (3) the number of publications on ecological economics is increasing, with a relatively large number being published in China. Therefore, we must strengthen the cooperation between institutions and among scholars and improve the research content, vision, and methods in this field. This study provides a theoretical basis for the future development of ecological economy.

Assessment of Urban Greenery Status in Major Cities of Oromia, Ethiopia

This work aims at studying different green spaces’ experiences in developed countries and extrapolates the experiences to Oromia cities in Ethiopia; in order to investigate and promote greenery infrastructure in selected cities. To do that greenery practice performance data were collected in four cities, which were classified into two groups as good and weak performers. As a result, Adama and Bishoftu cities were good urban greenery performers whereas Burayu and Sebeta were weak performers. The cities were also selected non-randomly to investigate the current urban greenery practice and different green areas in each city. Eight green areas were taken as samples for observation, where qualitative and quantitative data were collected from primary and secondary sources. The assessment of data confirmed that green areas along the roadside, recreational parks, open areas, and nursery sites existed in most cities. The urban plan of some cities does exclude most green area components. Greenery sites in Bishoftu and Adama are relatively better, while in Burayu and Sebeta urban greenery are highly abused for changing to another type of land use, e.g., residential and institutional areas. The technical skills of tree planting, care, protection, and management were also observed as a collective resource.

Biodiversity-friendly agricultural practices in the Indigenous Agricultural Systems in the Biodiversity Corridor of the Alto Paraná Atlantic Forest (Paraguay)

Agricultural systems result of the coevolution between social and natural systems, where biodiversity and natural resources play an important role, emerging interactions between crops and the natural environment that allow the development of ecological processes which interact with external inputs. This research aims to describe the agricultural practices developed by the Guarani Indigenous People in the agricultural systems located within the biodiversity corridor of the Upper Paraná Atlantic Forest. This exploratory study is focused on multiple cases, with a qualitative approach and data were collected during 2017 and 2018 in eleven indigenous communities. The main practices developed for the management of biodiversity are polyculture, rotation, and embroideries; they also practice agroforestry and livestock-raising. The main difficulty they face is the reduction of the surrounding biodiversity, which affects the sustainability of the system. This study shows ways for nature-based solutions and ecosystem-based adaptation according to current needs for greening the economy.