scholarly journals Beneficial insects are associated with botanically rich margins with trees on small farms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah E. J. Arnold ◽  
Filemon Elisante ◽  
Prisila A. Mkenda ◽  
Yolice L. B. Tembo ◽  
Patrick A. Ndakidemi ◽  
...  
Keyword(s):  
Natural Enemy ◽  
Crop Yields ◽  
Natural Habitat ◽  
Forest Fragments ◽  
Field Margins ◽  
Insect Community ◽  
Higher Plant ◽  
Insect Communities ◽  
Beneficial Insect ◽  
The Relationship

AbstractBeneficial insect communities on farms are influenced by site- and landscape-level factors, with pollinator and natural enemy populations often associated with semi-natural habitat remnants. They provide ecosystem services essential for all agroecosystems. For smallholders, natural pest regulation may be the only affordable and available option to manage pests. We evaluated the beneficial insect community on smallholder bean farms (Phaseolus vulgaris L.) and its relationship with the plant communities in field margins, including margin trees that are not associated with forest fragments. Using traps, botanical surveys and transect walks, we analysed the relationship between the floral diversity/composition of naturally regenerating field margins, and the beneficial insect abundance/diversity on smallholder farms, and the relationship with crop yield. More flower visits by potential pollinators and increased natural enemy abundance measures in fields with higher plant, and particularly tree, species richness, and these fields also saw improved crop yields. Many of the flower visitors to beans and potential natural enemy guilds also made use of non-crop plants, including pesticidal and medicinal plant species. Selective encouragement of plants delivering multiple benefits to farms can contribute to an ecological intensification approach. However, caution must be employed, as many plants in these systems are introduced species.

scholarly journals Floral Plantings in Large-Scale Commercial Agroecosystems Support Both Pollinators and Arthropod Predators

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 91
Author(s):  
Eric G. Middleton ◽  
Ian V. MacRae ◽  
Christopher R. Philips
Keyword(s):  
Large Scale ◽  
Agricultural Land ◽  
Field Margins ◽  
Crop Fields ◽  
Pollinator Abundance ◽  
Arthropod Predators ◽  
Commercial Potato ◽  
Insect Populations ◽  
Beneficial Insect ◽  
Potato Crops

Beneficial insect populations and the services that they provide are in decline, largely due to agricultural land use and practices. Establishing perennial floral plantings in the unused margins of crop fields can help conserve beneficial pollinators and predators in commercial agroecosystems. We assessed the impacts of floral plantings on both pollinators and arthropod predators when established adjacent to conventionally managed commercial potato fields. Floral plantings significantly increased the abundance of pollinators within floral margins compared with unmanaged margins. Increased floral cover within margins led to significantly greater pollinator abundance as well. The overall abundance of arthropod predators was also significantly increased in floral plantings, although it was unrelated to the amount of floral cover. Within adjacent potato crops, the presence of floral plantings in field margins had no effect on the abundance of pollinators or predators, although higher floral cover in margins did marginally increase in-crop pollinator abundance. Establishing floral plantings of this kind on a large scale in commercial agroecosystems can help conserve both pollinators and predators, but may not increase ecosystem services in nearby crops.

scholarly journals Influence of Gully Land Consolidation on Phreatic Water Transformation in the Loess Hilly and Gully Region

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 538
Author(s):  
Zihao Guo ◽  
Jianen Gao ◽  
Pengcheng Sun ◽  
Shaohui Dou ◽  
Juan Li ◽  
...  
Keyword(s):  
Crop Yields ◽  
Field Application ◽  
Land Consolidation ◽  
Transformation Rate ◽  
Soil Thickness ◽  
Phreatic Water ◽  
Artificial Rainfall ◽  
Outflow Rate ◽  
Water Outflow ◽  
The Relationship

Gully Land Consolidation (GLC) is a proven method to create farmlands and increase crop yields in the Loess Hilly and Gully Region, China. However, GLC influences phreatic water transformation and might cause the farmlands water disasters, such as salinization and swamping. For exploring the influence of GLC on phreatic water transformation and mitigating disasters, a series of indoor experiments were conducted in the artificial rainfall hall. Then, we simulated the phreatic water transformation patterns under more conditions with HYDRUS-3D. Finally, an engineering demonstration in the field was performed to validate our research. The indoor experiments indicated that GLC could increase phreatic water outflow rate 4.39 times and phreatic water coefficient (PWC) 2.86 times with a considerable delay. After calibration and validation with experimental data, the HYDRUS-3D was used to simulate phreatic water transformation under more soil thickness and rainfall intensities. Accordingly, we summarized the relationship among PWC, rainfall intensities, and soil thickness, and therefore suggested a blind ditch system to alleviate farmlands disasters. Field application showed that a blind ditch system could avoid disasters with 3.2 times the phreatic water transformation rate compared to loess. Our research provides implications for sustainable land uses and management in the region with thick soil covers.

scholarly journals Effect of Three Ca Sources Applied On Peanuts I. Productivity and Seed Quality1

1980 ◽  
Vol 7 (1) ◽  
pp. 19-25 ◽  
Author(s):  
D. L. Hallock ◽  
A. H. Allison
Keyword(s):  
Crop Yields ◽  
Relative Effectiveness ◽  
Correlation Coefficients ◽  
Early Flowering ◽  
Lower Yield ◽  
Flowering Stage ◽  
Arachis Hypogaea L ◽  
Dry Conditions ◽  
Increase Productivity ◽  
The Relationship

Abstract The relative effectiveness of United States Gypsum granular 420 Landplaster Bulk (420-Bulk) and Texasgulf Gypsum (Tg Gypsum) were compared with finely ground anhydrite (Bagged-LP) as sources of supplemental Ca for Florigiant peanuts (Arachis hypogaea L.). Treatments included the above sources at rates of 605 kg/ha banded (61 cm) or 907 kg/ha broadcast (91-cm wide rows) of CaSO4 equivalent per unit area covered (double these rates of 420-Bulk and Bagged-LP also were applied in 1977). Times of application were planting, planting + ca 30 days, and early flowering stage. The experiments were located on Kenansville lfs (Arenic Hapludult) in 1977 and on Rumford lfs (Typic Hapludult) in 1978. The Ca treatments increased crop yields from 360 to 1,200 kg/ha and crop value (yield × price) from $343 to $889/ha over the check in 1977. Slightly lower yield increases were obtained in 1978 when dry conditions prevailed during fruit maturation. Kernel size grades were improved markedly by all Ca treatments in 1977. There was a definite trend both years (significant in 1978) toward higher productivity when the Ca sources were applied at the early flowering stage compared to earlier applications. No difference was noted between methods of application of Bagged-LP or Tg Gypsum in 1978. Double rates of Bagged-LP or 420-Bulk in 1977 did not increase productivity over the low rates. A single application of Bagged-LP was as effective as split applications in the 1978 test. Germinability of seed in 1977 averaged 85% or higher for all Ca treatments. Seed germination in 1978 averaged 75%, 69% and 74% in plots where Tg Gypsum, 420-Bulk or Bagged-LP was applied, respectively. Germination was lowest in the check plots both years. Germinability and seed-Ca contents were significantly higher in 1978 when the Ca sources were applied at the early flowering stage (ca July 1) than 15 days earlier. Seed-Ca contents both years and K contents in 1978 were significantly correlated with germinability. The correlation coefficients were only 0.4 in each case and the relationship was negative for K. In general, 420-Bulk, Tg Gypsum, or Bagged-LP were equally effective sources of supplemental Ca for peanuts. However, when fruit mature under very dry conditions 420-Bulk may be somewhat inferior to the other Ca sources especially when applied before early flowering.

Spatial and seasonal variability of emergent aquatic insects and nearshore spiders in a subtropical estuary

2019 ◽  
Vol 70 (4) ◽  
pp. 541 ◽  
Author(s):  
Martha J. Zapata ◽  
S. Mažeika P. Sullivan
Keyword(s):  
Aquatic Insects ◽  
High Salinity ◽  
Aquatic Insect ◽  
Freshwater Ecosystems ◽  
Dispersal Ability ◽  
Insect Community ◽  
Insect Communities ◽  
Low Salinity ◽  
Subtropical Estuary ◽  
Adult Aquatic Insects

Variability in the density and distribution of adult aquatic insects is an important factor mediating aquatic-to-terrestrial nutritional subsidies in freshwater ecosystems, yet less is understood about insect-facilitated subsidy dynamics in estuaries. We surveyed emergent (i.e. adult) aquatic insects and nearshore orb-weaving spiders of the families Tetragnathidae and Araneidae in a subtropical estuary of Florida (USA). Emergent insect community composition varied seasonally and spatially; densities were lower at high- than low-salinity sites. At high-salinity sites, emergent insects exhibited lower dispersal ability and a higher prevalence of univoltinism than low- and mid-salinity assemblages. Orb-weaving spider density most strongly tracked emergent insect density rates at low- and mid-salinity sites. Tetragnatha body condition was 96% higher at high-salinity sites than at low-salinity sites. Our findings contribute to our understanding of aquatic insect communities in estuarine ecosystems and indicate that aquatic insects may provide important nutritional subsidies to riparian consumers despite their depressed abundance and diversity compared with freshwater ecosystems.

scholarly journals Agroecological Determinants of Potato Spatiotemporal Yield Variation at the Landscape Level in the Central and Northern Ukraine

2021 ◽  
Vol 4 (2) ◽  
pp. 34-47
Author(s):  
Anastasiia Zymaroieva ◽  
Tetiana Fedoniuk ◽  
Svitlana Matkovska ◽  
Olena Andreieva ◽  
Victor Pazych
Keyword(s):  
Crop Yields ◽  
Climatic Factors ◽  
High Sensitivity ◽  
Potato Yield ◽  
Limiting Factors ◽  
Forest Steppe ◽  
Yield Parameters ◽  
Bioclimatic Variables ◽  
Potato Yields ◽  
The Relationship

Global food security largely depends on the crop yield increase, so the study of the yield-limiting factors of potato (the second bread) is a pressing issue today. This study determines the contribution of the agroecological factors, namely, bioclimatic variables, soil indicators, and factors of landscape diversity, to the variation in potato yields. Conducted in Polissya and Forest-steppe zones of Ukraine during 1991–2017, this study has not only addressed the relationship between ecological determinants and potato yields, but also considered crop yields as a dynamic system. The dynamics of potato yields from the mid-1990s to the present is described by a log-logistic model. There are statistically significant regression dependencies between potato yield parameters and agroecological factors. Potato yield is dependent on the diversity of landscape cover. The relationship between yield parameters and landscape-ecological diversity is non-linear, which determines the presence of optimal landscape structure for the highest potato yields. Among climatic factors, the continental climate is of the greatest importance for potato yield. The high sensitivity of potato yield parameters to soil indices was found, and mostly the soil texture components (silt content), which largely determines the potato yield spatial variation.

scholarly journals Functional relationship between woody plants and insect communities in response to Bursaphelenchus xylophilus infestation in the Three Gorges Reservoir region

2021 ◽  
Author(s):  
Zhuang Wang ◽  
Lijuan Zhao ◽  
Jiaqi Liu ◽  
Yajie Yang ◽  
Juan Shi ◽  
...  
Keyword(s):  
Plant Communities ◽  
Tree Species ◽  
Woody Plants ◽  
Functional Relationship ◽  
Woody Plant ◽  
Principal Component ◽  
Bursaphelenchus Xylophilus ◽  
Insect Community ◽  
Insect Communities ◽  
Masson Pine

To study the effect of the invasion of Bursaphelenchus xylophilus on the functional relationship between woody plants and insect communities, the populations of tree species and insect communities were investigative in the Masson pine forests with different infestation durations of B. xylophilus. In this study, the number of Pinus massoniana began to decrease sharply, whereas the total number of other tree species in the arboreal layer increased gradually with the infestation duration of B. xylophilus. The principal component analysis ordination biplot shows that there was a significant change in the spatial distribution of woody plant species in different Masson pine forest stands. Additionally, a total of 7,188 insect specimens was obtained. The insect population showed an upward trend in stand types with the increase of pine wilt disease infection periods, which demonstrated that the insect community had been significantly affected by the invasion of B. xylophilus. The structure of insect functional groups changed from herbivorous (He) > omnivorous (Om) > predatory (Pr) > parasitic (Pa) > detritivorous (De) in the control stand to He > Pa > Om, De > Pr after B. xylophilus infestation in the forests. The results showed that the populations of He, Pa, and De increased after the invasion of B. xylophilus, but the populations of Pr decreased. Moreover, the redundancy analysis ordination bi-plots reflected the complicated functional relationship between woody plant communities and insects after the invasion of B. xylophilus. The present study provides insights into the changes in the community structure of woody plants and insects, as well as the functional relationship between woody plant communities and insect communities after invasion of B. xylophilus.

scholarly journals Inoculation and N Fertilization Affect the Dry Matter, N Fixation, and Bioactive Compounds in Sulla Leaves

Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 289 ◽  
Author(s):  
Leonardo Sulas ◽  
Giuseppe Campesi ◽  
Giovanna Piluzza ◽  
Giovanni A. Re ◽  
Paola A. Deligios ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Dry Matter ◽  
Seed Set ◽  
Natural Habitat ◽  
N Fertilization ◽  
N Fixation ◽  
N Application ◽  
Uninoculated Control ◽  
The Relationship ◽  
Leaf N

Sulla (Sulla coronaria [L.] Medik), a Mediterranean short-lived legume with tolerance to drought-prone environments, requires inoculation outside its natural habitat. Its leaves are appreciated for the bromatological composition and content of bioactive compounds. However, no information is available regarding the distinct effects of inoculation and nitrogen (N) applications on leaf dry matter (DM), fixed N, and bioactive compounds. Sulla leaves were sampled from the vegetative stage to seed set in Sardinia (Italy) during 2013–2014 and leaf DM, N content, and fixed N were determined. Compared to the best performing inoculated treatments, DM yield and fixed N values of the control only represented 8% to 20% and 2% to 9%, respectively. A significant relationship between fixed N and leaf DM yield was established, reaching 30 kg fixed N t–1 at seed set. Significant variations in leaf atom% 15N excess and %Ndfa quantified decreases in leaf N fixation coupled with N application. Moreover, the petiole content of phenolic compounds markedly increased in the uninoculated control, suggesting deeper investigations on the relationship between bioactive compounds and inoculation treatments. Results highlighted substantial variation in DM, N yields, N-fixation ability, and content of bioactive compounds of sulla leaves caused by inoculation and N fertilization.

scholarly journals A PAISAGEM COMO CONDICIONADORA DE BORDAS DE FRAGMENTOS FLORESTAIS

FLORESTA ◽  
2005 ◽  
Vol 35 (1) ◽  
Author(s):  
Bethania Cristiane Herrmann ◽  
Efraim Rodrigues ◽  
André De Lima
Keyword(s):  
Species Composition ◽  
Patch Size ◽  
Nearest Neighbor ◽  
Core Area ◽  
Forest Fragments ◽  
Spatial Structures ◽  
Landscape Index ◽  
Area Index ◽  
Components Analysis ◽  
The Relationship

Fragmentos florestais diferem em sua estrutura espacial afetando a composição de espécies em suas bordas. O objetivo deste trabalho foi analisar a influência dos índices da paisagem sobre as bordas de fragmentos florestais próximos à cidade de Londrina - PR. As características estruturais dos fragmentos aqui consideradas incluem área, forma, área central e índice de área central; e as características estruturais da paisagem: área da classe, tamanho médio e coeficiente de variação do tamanho dos fragmentos de floresta, distância média até o fragmento florestal mais próximo e total de bordas de floresta. A relação entre composição de espécies, fragmentos florestais e índices de paisagem foi estudada através de Análise de Correspondência Canônica. Os índices de maior importância foram: área, forma e área central dos fragmentos. Godoy, fragmento com 2371,14 ha e inclui o Parque Estadual Mata dos Godoy, apresentou maior variação na composição de espécies quando comparado com os demais. The landscape as conditioning of edges of forest fragments Abstract Forests fragments differ in their spatial structure afecting the species composition of edges. The objective of this paper was to analyze the influence of some landscape index over sapling species composition in edges of forests fragments near Londrina - PR. The spatial structures of fragments considered in this paper involved area, shape, core area and core area index; and the spatial structures of landscape: class area, mean patch size, coefficient of variation of the size of the patch (%), mean nearest neighbor distance and total edge of forest. The relationship between sapling species composition, forests fragments and landscape index were evaluated through Principal Components Analysis. Godoy, fragment with 2371,14 ha showed more variation in the species composition when compared with other fragments.

scholarly journals DOMESTICATION, DEGENERATION, AND THE ESTABLISHMENT OF THE ADDO ELEPHANT NATIONAL PARK IN SOUTH AFRICA, 1910s–1930s

2020 ◽  
pp. 1-27
Author(s):  
JULES SKOTNES-BROWN
Keyword(s):  
South Africa ◽  
Nature Conservation ◽  
National Park ◽  
Natural Habitat ◽  
Artificial Feeding ◽  
Game Reserve ◽  
The Relationship

Abstract This article examines conflict between farmers and elephants in the Addo region in 1910s–1930s South Africa to explore the porosity of the concepts ‘wild’, ‘tame’, and ‘domestic’, and their relationship to race, degeneration, nature conservation, and colonialism. In the 1910s, settler farmers indicted the ‘Addo Elephants’, as ‘vicious’ thieves who raided crops and ‘hunted’ farmers. This view conflicted with a widespread perception of elephants as docile, sagacious, and worthy of protection. Seeking to reconcile these views, bureaucrats were divided between exterminating the animals, creating a game reserve, and drawing upon the expertise of Indian mahouts to domesticate them. Ultimately, all three options were attempted: the population was decimated by hunter Phillip Jacobus Pretorius, an elephant reserve was created, the animals were tamed to ‘lose their fear of man’ and fed oranges. Despite the presence of tame elephants and artificial feeding, the reserve was publicized as a natural habitat, and a window onto the prehistoric. This was not paradoxical but provokes a need to rethink the relationship between wildness, tameness, and domesticity. These concepts were not implicitly opposed but existed on a spectrum paralleling imperialist hierarchies of civilization, race, and evolution, upon which tame elephants could still be considered wild.

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