Garden Sites Research Articles

Adaptive genetic potential and plasticity of trait variation in the foundation prairie grass Andropogon gerardii across the US Great Plains' climate gradient: Implications for climate change and restoration.

Plant response to climate depends on a species’ adaptive potential. To address this, we used reciprocal gardens to detect genetic and environmental plasticity effects on phenotypic variation and combined with genetic analyses. Four reciprocal garden sites were planted with three regional ecotypes of Andropogon gerardii, a dominant Great Plains prairie grass, using dry, mesic, and wet ecotypes originating from western KS to Illinois that span 500–1,200 mm rainfall/year. We aimed to answer: (a) What is the relative role of genetic constraints and phenotypic plasticity in controlling phenotypes? (b) When planted in the homesite, is there a trait syndrome for each ecotype? (c) How are genotypes and phenotypes structured by climate? and (d) What are implications of these results for response to climate change and use of ecotypes for restoration? Surprisingly, we did not detect consistent local adaptation. Rather, we detected co‐gradient variation primarily for most vegetative responses. All ecotypes were stunted in western KS. Eastward, the wet ecotype was increasingly robust relative to other ecotypes. In contrast, fitness showed evidence for local adaptation in wet and dry ecotypes with wet and mesic ecotypes producing little seed in western KS. Earlier flowering time in the dry ecotype suggests adaptation to end of season drought. Considering ecotype traits in homesite, the dry ecotype was characterized by reduced canopy area and diameter, short plants, and low vegetative biomass and putatively adapted to water limitation. The wet ecotype was robust, tall with high biomass, and wide leaves putatively adapted for the highly competitive, light‐limited Eastern Great Plains. Ecotype differentiation was supported by random forest classification and PCA. We detected genetic differentiation and outlier genes associated with primarily precipitation. We identified candidate gene GA1 for which allele frequency associated with plant height. Sourcing of climate adapted ecotypes should be considered for restoration.

Functional studies of flaked and ground stone artefacts reveal starchy tree nut and root exploitation in mid-Holocene highland New Guinea

Ground stone technology for processing starchy plant foods has its origins in the late Pleistocene, with subsequent intensification and transformation of this technology coinciding with the global emergence of agriculture in the early Holocene. On the island of New Guinea, agriculture first emerges in the highland Wahgi Valley, potentially from c. 9 kya, and clearly evident by 6.5 kya. Approximately 400 km further east in the highland Ivane Valley, long-term occupation sequences span the Holocene and late Pleistocene, but there is currently no direct evidence for wetland agriculture. Here, we report rare evidence for ground stone implements from a secure mid-Holocene archaeological context in the Ivane Valley. The Joe’s Garden site has flaked and ground stone artefacts with significant starch assemblages dating to approximately 4.4 kya. We present the first empirical evidence for the function of stone bowls from a New Guinea highland setting. Usewear and residues indicate the grinding and pounding of endemic starch-rich plant foods. Geometric morphometric analysis of starch grains shows that at least two taxa were processed: Castanopsis acuminatissima (nut) and Pueraria lobata (tuber). This regional example adds to our understanding of the trajectories of diverse plant food exploitation and ground stone technology development witnessed globally in the Holocene.

Deciduous trees as lichen phorophytes: biodiversity and colonization patterns under common garden conditions

AbstractCommon gardens are experimental plantations for comparing the performance of tree species while eliminating many of the variables that prevail in natural tree stands. The aim of this study was to evaluate the biodiversity of corticolous lichens on Danish tree species (Acer pseudoplatanus, Alnus glutinosa, Betula pendula, Fagus sylvatica, Fraxinus excelsior, Quercus robur and Tilia cordata) under common garden conditions and to examine the height distribution of particular lichen species. Observations were recorded through regular sampling of at least 36 lichen species on the main stems (from the base of the stem to the treetops) of 44-year-old trees at four common garden sites. Acer pseudoplatanus and Fraxinus excelsior had the greatest lichen species richness and Shannon diversity values while these measures were significantly lower for Betula pendula and Fagus sylvatica. The distribution of lichen species appeared biased among tree species. The general lichen distribution and relative sample height were weakly related (nonmetric multidimensional scaling). However, single lichen species showed a clear differential distribution along the tree stem (P < 0.001, non-parametric multiplicative regression and logistic log-binomial regression). Lepraria incana, Pseudosagedia aenea and Arthonia atra were mainly found at the stem base while Lecanora carpinea, L. chlarotera, Lecidella elaeochroma, Physcia tenella and Xanthoria parietina, were most abundant at around 70% of the total tree height. The differential distribution of single lichen species presumably reflects different specific requirements during spore germination and thallus growth. By isolating the unique effect of key variables (tree species and height), this study contributes to the knowledge base of corticolous lichen ecology.

Environmentally triggered variability in the genetic variance-covariance of herbivory resistance of an exotic plant Solidago altissima.

The variability in the genetic variance–covariance (G‐matrix) in plant resistance and its role in the evolution of invasive plants have been long overlooked. We conducted an additional analysis of the data of a reciprocal transplant experiment with tall goldenrod, Solidago altissima, in multiple garden sites within its native range (USA) and introduced range (Japan). We explored the differences in G‐matrix of resistance to two types of foliar herbivores: (a) a lace bug that is native to the USA and recently introduced to Japan, (b) and other herbivorous insects in response to plant origins and environments. A negative genetic covariance was found between plant resistances to lace bugs and other herbivorous insects, in all combinations of garden locations and plant origins except for US plants planted in US gardens. The G‐matrix of the resistance indices did not differ between US and Japanese plants either in US or Japanese gardens, while it differed between US and Japanese gardens in both US and Japanese plants. Our results suggested that the G‐matrix of the plant resistance may have changed in response to novel environmental differences including herbivore communities and/or other biotic and abiotic factors in the introduced range. This may have revealed a hidden trade‐off between resistances, masked by the environmental factors in the origin range. These results suggest that the stability of the genetic covariance during invasion, and the environmentally triggered variability in the G‐matrices of plant resistance may help to protect the plant against multiple herbivore species without changing its genetic architecture and that this may lead to a rapid adaptation of resistance in exotic plants. Local environments of the plant also have a critical effect on plant resistance and should be considered in order to understand trait evolution in exotic plants.

Genetic Variation Related to High Elevation Adaptation Revealed by Common Garden Experiments in Pinus yunnanensis.

Local adaptation, adaptation to specialized niches and environmental clines have been extensively reported for forest trees. Investigation of the adaptive genetic variation is crucial for forest resource management and breeding, especially in the context of global climate change. Here, we utilized a Pinus yunnanensis common garden experiments established at high and low elevation sites to assess the differences in growth and survival among populations and between the two common garden sites. The studied traits showed significant variation between the two test sites and among populations, suggesting adaptive divergence. To detect genetic variation related to environment, we captured 103,608 high quality SNPs based on RNA sequencing, and used them to assess the genetic diversity and population structure. We identified 321 outlier SNPs from 131 genes showing significant divergence in allelic frequency between survival populations of two sites. Functional categories associated with adaptation to high elevation were found to be related to flavonoid biosynthesis, response to UV, DNA repair, response to reactive oxygen species, and membrane lipid metabolic process. Further investigation of the outlier genes showed overrepresentation of the flavonoid biosynthesis pathway, suggesting that this pathway may play a key role in P. yunnanensis adaptation to high elevation environments. The outlier genes identified, and their variants, provide a basic reference for advanced investigations.

Growing North Minneapolis: Connecting Youth and Community through Garden-based Experiential Learning

Growing North Minneapolis (GNM) is an urban agriculture and youth development summer program sited in the North Minneapolis, MN, neighborhood. The program is a university–community partnership between faculty at the University of Minnesota (UMN) and North Minneapolis community partners. We leverage resources from the city of Minneapolis Step-Up program to recruit, train, and employ youth (14–15 years old) who face barriers to employment—particularly youth from low-income families, youth of color, youth from immigrant families, and youth with disabilities. Youth interns are placed in a 10-week-long summer program and are matched with undergraduate student mentors from the UMN and North Minneapolis gardener mentors. The undergraduate students and garden mentors work together to lead teams of youth and work in multiple urban garden sites located in North Minneapolis, a designated low-resource community in the metro area. One of our goals is to develop leadership experience for UMN undergraduate students and improve food and horticultural skills among urban youth through garden-based education. Learning is experiential and contextualized in the various community garden sites through activities focused on food justice and accessibility, food production systems, and horticultural science. Youth learning and development outcomes are reported based on written postprogram qualitative survey questions prompting youth to identify what they learned throughout the program, what they enjoyed the most, and what challenged them after the summer program in 2018. Our results show that youth participants learned across multiple domains of knowledge and valued the social interaction offered by the intergenerational mentorship structure. The GNM program can serve as a model for garden-based experiential learning with early high school youth.

Soil-Transmitted Protozoans and Helminths from Market Gardening Sites of Yaounde, Cameroon

Background: In Cameroon, the practice of market gardening exposes both the farmers and consumers to a certain number of health-related hazards. Environmental health risks associated to this activity showed that it was responsible for the increased of transmission risk of the human and animal intestinal worms. Methods: The epidemiology of soil borne diseases associated with urban agriculture was furthermore considered in three market garden sites of the city of Yaounde (Tsinga, Nkolondom, Nkolbisson). From October to December 2016, water and soils from rivers, wells and furrows were analysed for physicochemical characteristics and parasite identification using Kato-Katz and Formol-Ether methods. Results: Means of water parameters and parasite composition varied per locations and environments in the 82 samples analyzed. Ranges of mean temperature, pH, electrical conductivity, turbidity and color of water samples were 25.2-25.5°C (), 6.53-7.01 UC, 308-502 µS.cm-1, 637-1,300 FTU and 2,451-6,422 Co-Pt, respectively. Soil parasites consisted of 3 protozoans (Entamoeba histolytica, Sarcocystis sp. and Giardia intestinalis) and 11 helminths (Fasciola hepatica, Diphyllibotrium latum, Ascaris lumbricoides, Trichuirus trichiura, Ancylostoma sp., Trichostrongylus sp., Schistosoma mansoni, Schistosoma sp., Paragonimus westermanii, Strongyloides stercoralis and Hymenolepis nana). Conclusion: The presence of viable helminths suggests that harmful soil pathogens such as protozoans and helminths can spread through market gardening. This reminds on the need to find better ways to alleviate the control of intestinal parasitic infections which, nevertheless, are classified as neglected tropical diseases.

Wild Leaves on Narrow STEMs: Exploring Formal and Non-Formal Education Tensions Through Garden-Based Learning

School gardens and garden-based learning, though not new in the landscape of United States public education, have gained great popularity in recent years. Scholars from myriad disciplines have examined school garden programs’ impact on outcomes ranging from standardized test scores to childhood obesity. As school gardens become commonplace across the country, scholars and practitioners must ask critical questions about program efficacy, sustainability, educational philosophy, and teaching methods. The public school garden site is a unique environment in which constructivist, non-formal educational philosophies are entangled in the structure of standardized, formal education. To examine these tensions and consider opportunities for student learning and the ongoing evolution of public education, we conducted a qualitative case study of a school garden program transitioning from non-profit to public school district control. We conceptualize the non-profit era of the Midwest Garden Education Project as an example of a non-formal education paradigm, and the school district-funded era as its formal education counterpart. Using the findings that emerged from this research, we argue for public education to embrace non-formal learning in the school garden, and put forth a call for broader legitimation of garden-based learning in curriculum.

Каталог та особливості його укладання (на прикладі каталога власних назв садово-паркових об’єктів, які належать до культурно-історичного фонду міста Києва)

. The article first describes the features of the catalog, which includes the names of landscaping sites that represent the cultural and historical fund of the capital. The purpose of the study is to analyze the components of this catalog, which includes its own park names. Materials and methods of research. The research is based on the use of common scientific methods of analysis, synthesis and comparison. The work was carried out within the framework of the project № 110/551-pr "Development of the newest principles of creation of the register of valuable plants of parks and squares of Kyiv based on terminological standards". Discussion . The creation of the Catalog was preceded by the filing of a filing cabinet, which included expanded information on gardens and landmarks (from the history of foundation to the present, their planning style, past and present status, etc.), taking into account the status of the object category, its current cultural, historical values. Conclusions . It is proposed to make changes to the unification of park names, to refrain from double-spelling them, and to make proper remarks regarding the preservation, provision and updating of information on garden sites.

Learning from methylomes: epigenomic correlates of Populus balsamifera traits based on deep learning models of natural DNA methylation.

SummaryEpigenomes have remarkable potential for the estimation of plant traits. This study tested the hypothesis that natural variation in DNA methylation can be used to estimate industrially important traits in a genetically diverse population of Populus balsamifera L. (balsam poplar) trees grown at two common garden sites. Statistical learning experiments enabled by deep learning models revealed that plant traits in novel genotypes can be modelled transparently using small numbers of methylated DNA predictors. Using this approach, tissue type, a nonheritable attribute, from which DNA methylomes were derived was assigned, and provenance, a purely heritable trait and an element of population structure, was determined. Significant proportions of phenotypic variance in quantitative wood traits, including total biomass (57.5%), wood density (40.9%), soluble lignin (25.3%) and cell wall carbohydrate (mannose: 44.8%) contents, were also explained from natural variation in DNA methylation. Modelling plant traits using DNA methylation can capture tissue‐specific epigenetic mechanisms underlying plant phenotypes in natural environments. DNA methylation‐based models offer new insight into natural epigenetic influence on plants and can be used as a strategy to validate the identity, provenance or quality of agroforestry products.

Leaf Canopy Layers Affect Spectral Reflectance in Silver Birch

The availability of light within the tree canopy affects various leaf traits and leaf reflectance. We determined the leaf reflectance variation from 400 nm to 2500 nm among three canopy layers and cardinal directions of three genetically identical cloned silver birches growing at the same common garden site. The variation in the canopy layer was evident in the principal component analysis (PCA), and the influential wavelengths responsible for variation were identified using the variable importance in projection (VIP) based on partial least squares discriminant analysis (PLS-DA). Leaf traits, such as chlorophyll, nitrogen, dry weight, and specific leaf area (SLA), also showed significant variation among the canopy layers. We found a shift in the red edge inflection point (REIP) for the canopy layers. The canopy layers contribute to the variability in the reflectance indices. We conclude that the largest variation was among the canopy layers, whereas the differences among individual trees to the leaf reflectance were relatively small. This implies that within-tree variation due to the canopy layer should be taken into account in the estimation of intraspecific variation in the canopy reflectance.

Phenological Features of (Mamestra Brassicae L. 1758) Development in Agrocoenosis of Cabbage in the Kamin-Kashyrskyi District (Volyn Region, Ukraine)

The animal world of Ukraine is characterized by a large variety of species. Among the lepidoptera there are a lot of pests whose larvae cause significant damage to agriculture. In the paper, we investigated the seasonal and perennial dynamics of vegetable crops pests’ population of Mamestra brassicae in the agrobiocenoses of white cabbage. The basis of our study was the investigation of the relative quantity of the pest larvae, we demonstrated the damage to plants, as well as the periods of intensive emergence of the imago and the number of generations per year. In future, this will enable the development of effective ecologically sound methods for controlling the number of species of white cabbage pests in the conditions of Kamin-Kashyrskyi district of Volyn region. Kamin-Kashyrskyi area has a flat terrain and is characterized by a warm temperate continental climate with sufficient amount of moisture, the presence of impoverished sod-podzolic soils. The area is mostly plain, with large marsh massifs, which are favorable conditions for the existence of Mamestra brassicae, as this species is moisture-loving. Observation of biocenotic connections in the agrobiocenoses of white cabbage and stationary research on the development of protection, testing and implementation systems was carried out during 2017-2018 at the garden sites of Kamin-Kashirsky district during the entire vegetation period of the plants. White cabbage is damaged throughout the period of vegetation, however, the damage that appear after emergence of seedlings and planting of seedlings into the soil are dangerous due to their consequences. In the second half of summer and in autumn, the larvae of Mamestra brassicae caused significant damage to cabbage plants in the gardens of Novi Chervyshcha. Within this area, Mamestra brassicae develops two generations per year, causing tangible damage to the agrocoenosis of cabbage of different sowing dates. The contamination of cabbage by the larva of the first and second generations approximately accounts to 24%, where 2-3 larvae live on one plant. The massive emergence of the imago occurs in the middle of May the first half of June while the average daily temperature is +20°С to +22°С. The first egg laying was recorded at the end of May, which the female lays in groups, 20-80 units on the underside of the leaves, and the embryonic development lasts 6 to 8 days. Pupae hibernate in the soil, at a depth of 8-12 cm. Significant damage to white cabbage plants was caused by the larvae of the first generation in June and early July, and of the second generation in August and early September. They intensively feed at night and at dawn, and in the daytime there is a decline in mobility and nutritional activity. Second-generation larvae often bite into cabbage heads where they make holes and pollute them with their liquid excrement, which leads to a decrease in crops. The use of microbiological drugs Dimilin and Insehar are some of the most effective ways to get rid of Lepidoptera, including larvae of Mamestra brassicae, which provide protection of cabbage plants by 93-97%.

Material and social relations in a coastal community garden assemblage

ABSTRACT This paper draws upon Actor Network Theory (ANT) to explore material and social dynamics of a coastal community garden site on public housing grounds in Rockaway, NY after Hurricane Sandy. Through a participatory design-research project, we examine shifting associations between humans and non-humans as a way of interrogating agency, power dynamics, and governance. Acknowledging our own outsider status, we draw upon the frame of ‘contact zones’ for thinking through encounters in conditions of power differentials. In describing our encounter with the Beach 41st Street Community Garden as a contact zone, we identify three assemblages with different governance arrangements – tidal shore, garden plots, and treed lawn. These assemblages are networked through material flows and include nonhuman actants such as freshwater, soil, plants, and wood. Unruly actors and actants – people, saltwater, poison ivy, dogs, and trash – can spark controversy and resist governing. We reflect upon the role of design, research, and community organizing as interventions that can cause rearrangements of the assemblages, shedding new light on power dynamics and potential apertures for change in a dynamic site. In so doing, we mobilize contact zones and ANT to better understand and act within shifting associations between humans and non-humans.

Phenotype plasticity, local adaptation, and biofouling influence on growth of the pearl oyster Pinctada margaritifera: A common garden approach

The purpose of our study is to investigate (1) the influence of phenotype plasticity and local adaptation on pearl-oyster physiology by testing the persistence of growth differentiation of two pearl oyster populations (Arutua and Mangareva) in common garden experiment; (2) to quantify the influence of biofouling development on the growth of each pearl oyster population. According to our observations, the growth rate in terms of total oyster weight suggested better growth performance of the pearl oyster Pinctada margaritifera in Mangareva (0.21–0.24 ± 0.01 g.day−1) than Arutua (0.14–0.15 ± 0.01 g.day−1). However, similar growth performances are observed at the Vairao common garden site for oyster stocks from Mangareva (0.07 ± 0.01 mm.day−1 or 0.15 ± 0.01 g.day−1) and Arutua (0.07 ± 0.01 mm.day−1 or 0.13 ± 0.01 g.day−1). Our results suggest that growth performance variability observed at the pearl farming sites of Arutua and Mangareva is due more to phenotypic plasticity than to local adaptation. This result thus accords a major importance to site selection for the pearl farming optimization process.Biofouling dynamics on Pinctada margaritifera shells differed radically between Arutua and Mangareva sites. In Arutua, biofouling colonization was relatively slow (0.016 g.oyster−1.month−1) and was mainly composed of sponges and bivalves. On Mangareva, the colonization process appeared faster and more continuous over the study period (0.15–0.18 g.oyster−1.month−1) and the biofouling community was dominated by tunicates. On the basis of our results obtained on growth performance between cleaned and uncleaned stock in Arutua and Mangareva, biofouling development after 14–15 months of colonization does not appear to have any negative effect on P. margaritifera growth. Due to the high cost of biofouling management in pearl farming facilities, our results suggest once more that reconsideration of the pearl farming management process is needed.

The spatial and temporal variation of water quality at a community garden site in an urban setting: citizen science in action

AbstractInterest in urban agriculture has increased rapidly in recent decades, but little is known about the effect of potential contaminants, such as groundwater pollution, in urban areas. Further...

Carrying Capacity of Diving Tourism in Dampier Strait Marine Conservation Area – District of Raja Ampat

Raja Ampat has biodiversity in marine waters so it qualifies as a conservation area as well as a tourism destination. The number of tourist visits to this area has increased significantly, from 998 people in 2007 to 29,653 people in 2016. Increasing number of tourists have become a threat if the behavior of tourist are not concerned on the environment sustainability and damage the attractions for diving. Assessment of the carrying capacity of the area becomes an important factor to know for sure the maximum number of visitors that can be accommodated by the region at any given time without causing disturbance to the environment and human. The study was conducted from September 2015 to August 2016. Data collection of dive sites was conducted by measuring the extent of coral reefs, coral slope, coral reef condition, and water depth. Calculation of carrying capacity used is Physical Carrying Capacity (PCC) and Real Carrying Capacity (RCC). There are 15 main dive sites frequented by divers. The number of people allowed to dive based on physical carrying capacity ranges from 20 to 500 diver/day, for Actual carrying capacity (RCC) of 14 - 335 diver/day. Locations that have the lowest carrying capacity on The Passage site and highest on the Melissa Garden site. The process of integrating dive attractions with other tours and monitoring of travel activities is a key factor in the sustainability of Raja Ampat regency tourism.

Grow Heathrow: a Lockean analysis

ABSTRACT On 29 June 2017, Judge Marc Dight authorised the eviction of a community project established on a derelict market garden site to protest against the third runway at Heathrow Airport. Dight’s reasoning was that ‘private landowner [is] entitled to put its land to any form of lawful use, including doing nothing with it’. Using the arguments of John Locke in what some may see as a counter-intuitive way, this paper offers a critique of the judgement based on the principles of avoiding spoilage, leaving enough and as good for others and improving land through the application of labour. I will also examine the specific question of land which is neglected to the point that it is detrimental to the well-being of those around it and provide a counter to the overall anti-expropriation sentiment found in Locke’s work. Although the analysis in this article focuses on a specific paradigm case, it could have wider implications, which will be explored near the end of the article.

Quantifying Fossil Fuel CO<sub>2</sub> Component over Dakar from 1960 to 2010 by Radiocarbon Observation in Atmospheric CO<sub>2</sub> and Using Mauna Loa as Background

We investigated the atmospheric ∆¹⁴C level and the fossil fuel CO₂ concentration in Dakar area from 1960 to 2010 by using the radiocarbon measurements obtained from tree leaves samples. We used the Carbon-14 dating method with a Liquid Scintillation Counter and an Accelerator Mass Spectrometer. The samples were subjected to physical and chemical pretreatments, then, they were transformed into benzene for the counting. The results show that the largest maxima of the ¹⁴C concentration (∆¹⁴C) are recorded at sites such as the SAR Factory (773‰ in 1964), Mbao Forest 2 (677‰ in 1966) and UCAD Botanic Garden (522‰ in 1970) and the smallest minima are the Airport Runway (45‰ in 2010), the Beach 2 (48‰ in 2009), the Mbao Forest 2 (59‰ in 2007), the SAR Factory (71‰ in 2005), Soumbedioune Market (80‰ in 2003) and Ucad Botanic Garden (91‰ in 2000). The Comparative curve of the minimum and the maximum values of ∆¹⁴C_bg (background) and ∆¹⁴C_meas (measured) show that ¹⁴C concentration of the sites are lower than ¹⁴C concentration in clean air. This can be correlated with the increase of the fossil fuel derived CO₂ caused by human activities such as population density, industrials emissions, and traffic. The evaluation of the fossil fuel concentration (CO_2ff) by mass balance equations, show, in most of the sites, an increase of the level of CO_2ff. Exceptional cases are obtained in Mbao Forest 1 and for UCAD Botanic Garden sites. One explanation of the values is that sites are much wooded these last years.

Litter decomposition driven by soil fauna, plant diversity and soil management in urban gardens

In the face of growing urban densification, green spaces in cities, such as gardens, are increasingly important for biodiversity and ecosystem services. However, the influences of urban green space management on biodiversity and ecosystem functioning (BEF) relationships is poorly understood. We investigated the relationship between soil fauna and litter decomposition in 170 urban garden sites along a gradient of urbanisation intensity in the city of Zurich, CH. We used litter bags of 1 and 4 mm mesh size to evaluate the contribution of soil meso- and macrofauna on litter decomposition. By using multilevel structural equation models (SEM), we investigated direct and indirect environmental effects and management practices on litter decomposition and litter residue quality. We evaluated the role of taxonomic, functional and phylogenetic diversity of soil fauna species on litter decomposition, based on a sample of 120 species (81,007 individuals; 39 collembola, 18 earthworm, 16 isopod, 47 gastropod species). We found highest litter decomposition rates using 4 mm mesh size litter bags, highlighting the importance of soil macrofauna. Urban warming, a proxy for urbanisation intensity, covaried positively, whereas soil disturbances, such as intensive soil and crop management, were negatively correlated with decomposition rates. Interestingly, soil fauna species richness decreased, with the exception of gastropods, and soil fauna abundance increased with urban warming. Our data also show that plant species richness positively affected litter decomposition by increasing soil fauna species richness and microbial activity. A multivariate analysis of organic compounds in litter residues confirmed the importance of soil fauna species richness and garden management on litter decomposition processes. Overall, we showed, that also in intensively managed urban green spaces, such as gardens, biodiversity of plants and soil fauna drives key ecosystem processes. Urban planning strategies that integrate soil protecting management practices may help to maintain important ecosystem services in this heavily used urban environment.

The effect of traditional slash‐and‐burn agriculture on soil organic matter, nutrient content, and microbiota in tropical ecosystems of Papua New Guinea

AbstractSlash‐and‐burn agriculture followed by tillage and western style agriculture often lead to loss of soil organic matter and soil degradation. Traditional slash‐and‐burn agriculture affects large areas of land across the tropical zone. However, there are few detailed studies about this practice. To evaluate the effect of traditional slash‐and‐burn agriculture on soil properties (total C, N, P, and C fractions of soil and available P, Ca, Mg, K, NO3, pH, and microbial community biomass and composition), we studied a chronosequence represented by active gardens, abandoned gardens (5–10 years old), secondary forest in abandoned garden sites (20–40 years old), and primary forest with no evidence of cultivation for at least 60 years. No significant differences between individual succession stages were found in total C, N, and P and in C fractions, pH, conductivity, and microbial biomass. In addition, stocks of C, N, and P in the soil did not differ between succession stages. By contrast, the concentration of available P, Ca, Mg, K, and NO3 was highest in active gardens. Litter was absent in active gardens, and the highest amount of litter on the soil surface was found in primary forest. Our results show that traditional slash‐and‐burn agriculture had a strong effect on nutrient availability but no effect on the total CNP stocks and soil C fractions.