Bird-plant interaction networks in native forests and eucalyptus plantations within a protected area

Frugivory is a plant-animal mutualistic interaction carried out mostly by birds. It consists in the bird consumption of fruits with later dispersion of the plants' seeds, helping in the vegetation regeneration. Frugivory can be affected by the habitat fragmentation and introduction of exotic species, which may alter the species interaction by extinction or competitor introduction. This study aimed to compare the structure of the network of frugivorous interactions between birds and plants in native forest and eucalyptus plantation. Birds were captured by mist nets and had their feces collected. Later, the seeds were identified in laboratory. The records of fruit consumption by birds in the zoochoric plant species present in the study area were also conducted. The data collected was used to build a network of interactions and identify the most important network metrics, species, and ecological functional groups in the studied environments. The results showed that the species composition, the connectivity of the relationships, the importance of the species for the interaction networks and the number of subgroups within the networks were highly similar between the native forest and the eucalyptus plantation. This could be explained by the favorable conditions that the studied eucalyptus plantations presented, such as the lack of anthropogenic activities, well-developed understory, and the presence of native surrounding vegetation, allowing practically the same seed dispersal capacity in both types of environments.

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Avian Breeding Season Diversity and Community Composition in Camden White Gum and Slash Pine Plantations

Forest Science ◽

10.1093/forsci/fxaa050 ◽

2021 ◽

Author(s):

Elizabeth J Messick ◽

Christopher E Comer ◽

Michael A Blazier ◽

T Bently Wigley

Keyword(s):

United States ◽

Species Richness ◽

Community Composition ◽

Pinus Elliottii ◽

The United States ◽

Slash Pine ◽

Planted Forests ◽

Eucalyptus Plantation ◽

Short Rotation Woody Crops ◽

Eucalyptus Plantations

Abstract In the southern United States, some landowners have established plantations of eucalyptus (Eucalyptus spp.) and are managing them on short rotations (<15 years) to provide wood for fiber and other potential uses. Establishment of short-rotation woody crops dominated by nonnative species has implications for resident fauna in the United States that are largely unknown. We compared avifauna abundance, diversity, and community composition in newly established Camden white gum (Eucalyptus benthamii) plantations with slash pine (Pinus elliottii) plantations of the same age and height (one to two and six to seven years old, respectively) in southwestern Louisiana, USA. Species richness, diversity, and community composition in newly established eucalyptus plantations and six- to seven-year-old pines were similar. More birds were observed, and bird detections varied less in eucalyptus plantations. Indigo buntings (Passerina cyanea) and other shrub-associated species were detected more often in eucalyptus stands. In contrast, species that inhabit herbaceous-dominated communities, such as eastern meadowlarks (Sturnella magna), or that were associated with a dense graminoid community (e.g., Bachman’s sparrow [Peucaea aestivalis]) were detected less often in eucalyptus. Overall, breeding bird communities in eucalyptus plantations one to two years postestablishment differed little from plantations dominated by slash pine. Study Implications Compared with slash pine (Pinus elliottii Englem) plantations of similar age and height (one to two years and six to seven years old, respectively) we found one- to two-year-old eucalyptus (Eucalyptus benthamii Maiden & Cambage) plantations supported similar avian species richness and diversity to six- to seven-year-old pine stands. Furthermore, we found these eucalyptus plantations (E13) supported an avian community that was intermediate to similar aged pine (S13) and pine of similar height (S08). However, avian communities will likely change as eucalyptus plantations age (Christian et al. 1997). Continued monitoring and assessment of community composition, richness, and abundance is important for determining the magnitude of this change. Future investigations focused on nest success, fecundity, postfledging monitoring, and survivorship compared with other types of planted forests and native cover types would help us better understand eucalyptus plantation effects on avifauna demographics (Van Horne 1983, Martin 1998, Jones 2001, Wood et al. 2004, Sage et al. 2006, Riffell et al. 2011).

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Dissolved organic nutrients at the interface of fresh and marine waters: flow regime changes, biogeochemical cascades and picocyanobacterial blooms—the example of Florida Bay, USA

Biogeochemistry ◽

10.1007/s10533-021-00760-4 ◽

2021 ◽

Author(s):

Patricia M. Glibert ◽

Cynthia A. Heil ◽

Christopher J. Madden ◽

Stephen P. Kelly

Keyword(s):

Water Quality ◽

Anthropogenic Activities ◽

Florida Bay ◽

Climate Conditions ◽

Regime Changes ◽

Physico Chemical ◽

Organic Nutrients ◽

High Concentrations ◽

Chemical Conditions ◽

Favorable Conditions

AbstractThe availability of dissolved inorganic and organic nutrients and their transformations along the fresh to marine continuum are being modified by various natural and anthropogenic activities and climate-related changes. Subtropical central and eastern Florida Bay, located at the southern end of the Florida peninsula, is classically considered to have inorganic nutrient conditions that are in higher-than-Redfield ratio proportions, and high levels of organic and chemically-reduced forms of nitrogen. However, salinity, pH and nutrients, both organic and inorganic, change with changes in freshwater flows to the bay. Here, using a time series of water quality and physico-chemical conditions from 2009 to 2019, the impacts of distinct changes in managed flow, drought, El Niño-related increases in precipitation, and intensive storms and hurricanes are explored with respect to changes in water quality and resulting ecosystem effects, with a focus on understanding why picocyanobacterial blooms formed when they did. Drought produced hyper-salinity conditions that were associated with a seagrass die-off. Years later, increases in precipitation resulting from intensive storms and a hurricane were associated with high loads of organic nutrients, and declines in pH, likely due to high organic acid input and decaying organic matter, collectively leading to physiologically favorable conditions for growth of the picocyanobacterium, Synechococcus spp. These conditions, including very high concentrations of NH4+, were likely inhibiting for seagrass recovery and for growth of competing phytoplankton or their grazers. Given projected future climate conditions, and anticipated cycles of drought and intensive storms, the likelihood of future seagrass die-offs and picocyanobacterial blooms is high.

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Dissimilarity of species interaction networks: how to partition rewiring and species turnover components

Ecosphere ◽

10.1002/ecs2.3653 ◽

2021 ◽

Vol 12 (7) ◽

Author(s):

Jochen Fründ

Keyword(s):

Species Turnover ◽

Species Interaction ◽

Interaction Networks

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Integrating Species Interaction Networks and Biogeography

Adaptive Food Webs ◽

10.1017/9781316871867.019 ◽

2017 ◽

pp. 289-304 ◽

Cited By ~ 3

Author(s):

José M. Montoya ◽

Núria Galiana

Keyword(s):

Species Interaction ◽

Interaction Networks

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Age and Species of Eucalyptus Plantations Affect Soil Microbial Biomass and Enzymatic Activities

Microorganisms ◽

10.3390/microorganisms8060811 ◽

2020 ◽

Vol 8 (6) ◽

pp. 811 ◽

Cited By ~ 1

Author(s):

Jie Xu ◽

Bing Liu ◽

Zhao-lei Qu ◽

Yang Ma ◽

Hui Sun

Keyword(s):

Microbial Biomass ◽

Enzyme Activities ◽

Fungal Biomass ◽

Soil Microbial Biomass ◽

Extracellular Enzymes ◽

Eucalyptus Species ◽

Eucalyptus Plantation ◽

Soil Microbial ◽

Eucalyptus Plantations ◽

Plantation Age

Soil microorganisms and extracellular enzymes play important roles in soil nutrient cycling. Currently, China has the second-largest area of eucalyptus plantations in the world. Information on the effects of eucalyptus age and species of trees on soil microbial biomass and enzyme activities, however, is limited. In this paper, the soil microbial biomass and enzyme activities were studied in eucalyptus plantations with different ages (1 and 5+ years) and species of trees (E. urophylla×E. grandis, E. camaldulens and E. pellita) in South China. The results showed that both plantation age and eucalyptus species could affect the total microbial biomass and fungal biomass, whereas the bacterial biomass was affected only by plantation age. The fungal biomass and the fungi-to-bacteria ratio significantly increased along with increasing plantation age. Similarly, the plantation age and eucalyptus species significantly affected the enzyme activities associated with carbon cycling (β-xylosidase, β-d-glucuronidase, β-cellobiosidase and β-glucosidase). The activities of β-d-glucuronidase and β-glucosidase were significantly higher in the E. camaldulens plantation. The enzymes involved in nitrogen (N-acetyl-glucosamidase) and sulfur (sulfatase) cycling were only affected by the eucalyptus plantation age and species, respectively. The results highlight the importance of the age and species of eucalyptus plantations on soil microbial activities.

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Combined deep sampling and mass-based approaches to assess soil carbon and nitrogen losses due to land-use changes in karst area of Southwestern China

10.5194/se-2016-57 ◽

2016 ◽

Author(s):

Yecui Hu ◽

Zhangliu Du ◽

Qibing Wang ◽

Guichun Li

Keyword(s):

Land Use ◽

Land Use Changes ◽

Soil Mass ◽

Karst Area ◽

Southwestern China ◽

Native Forest ◽

Eucalyptus Plantation ◽

Carbon And Nitrogen ◽

Managed Ecosystems ◽

Effect Magnitude

Abstract. The conversion of natural vegetation to managed ecosystems may negatively influence soil organic carbon (SOC) and total nitrogen (TN) stocks, particularly in the fragile ecosystems. The objective of present study was to assess SOC and TN stocks losses by combining deep sampling with mass-based calculations upon land-use changes in a typical karst area of Southwestern China. We quantified the changes from native forest to grassland, secondary shrub, eucalyptus plantation, sugarcane and corn fields (both defined as croplands), on the SOC and TN stocks down to 100 cm depth using fixed-depth (FD) and equivalent soil mass (ESM) approaches. The results showed that converting forest to cropland and other types significantly led to SOC and TN losses, although the effect magnitude partly depended on both sampling depths and soil mass considered. On average, the shifting from native forest to cropland led to SOC losses by 19.1 %, 25.1 %, 30.6 %, 36.8 % and 37.9 % for the soil depths of 0–10, 0–20, 0–40, 0–60 and 0–100 cm, respectively, which highlighted that shallow sampling underestimated SOC losses. Moreover, the FD method underestimated SOC and TN losses for the upper 40 cm layer, but overestimated the losses in the deeper profiles. We suggest that the ESM together with deep sampling should be encouraged to detect the differences in SOC stocks. In conclusion, the conversion of forest to managed systems, in particular croplands significantly decreased in SOC and TN stocks, although the effect magnitude to some extent depended on sampling depth and calculation approach selected.

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Genetics-based interactions of foundation species affect community diversity, stability and network structure

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2016.2703 ◽

2017 ◽

Vol 284 (1854) ◽

pp. 20162703 ◽

Cited By ~ 12

Author(s):

Arthur R. Keith ◽

Joseph K. Bailey ◽

Matthew K. Lau ◽

Thomas G. Whitham

Keyword(s):

Network Structure ◽

Experimental Manipulation ◽

Species Interaction ◽

Foundation Species ◽

Interaction Networks ◽

Community Diversity ◽

Arthropod Community ◽

Pemphigus Betae ◽

In The Wild ◽

The Stability

We examined the hypothesis that genetics-based interactions between strongly interacting foundation species, the tree Populus angustifolia and the aphid Pemphigus betae , affect arthropod community diversity, stability and species interaction networks of which little is known. In a 2-year experimental manipulation of the tree and its aphid herbivore four major findings emerged: (i) the interactions of these two species determined the composition of an arthropod community of 139 species; (ii) both tree genotype and aphid presence significantly predicted community diversity; (iii) the presence of aphids on genetically susceptible trees increased the stability of arthropod communities across years; and (iv) the experimental removal of aphids affected community network structure (network degree, modularity and tree genotype contribution to modularity). These findings demonstrate that the interactions of foundation species are genetically based, which in turn significantly contributes to community diversity, stability and species interaction networks. These experiments provide an important step in understanding the evolution of Darwin's ‘entangled bank’, a metaphor that characterizes the complexity and interconnectedness of communities in the wild.

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