Nicolas Velasco

Dr. Nicolas Velasco

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2022 in Global Change Biology
Verified
Journal Article
Open access
BZBing‐Run Zhu
Bing‐Run Zhu
MVMo A. Verhoeven
Mo A. Verhoeven
NVNicolas Velasco
Nicolas Velasco
LSLisa Sanchez‐Aguilar
Lisa Sanchez‐Aguilar
ZZZhengwang Zhang
Zhengwang Zhang
TPTheunis Piersma
Theunis Piersma
Habitat loss and shifts associated with climate change threaten global biodiversity, with impacts likely to be most pronounced at high latitudes. With the disappearance of the tundra breeding habitats, migratory shorebirds that breed at these high latitudes are likely to be even more vulnerable to climate change than those in temperate regions. We examined this idea using new distributional information on two subspecies of Black‐tailed Godwits Limosa limosa in Asia: the northerly, bog‐breeding L. l. bohaii and the more southerly, steppe‐breeding L. l. melanuroides. Based on breeding locations of tagged and molecularly assayed birds, we modelled the current breeding distributions of the two subspecies with species distribution models, tested those models for robustness and then used them to predict climatically suitable breeding ranges in 2070 according to bioclimatic variables and different climate change scenarios. Our models were robust and showed that climate change is expected to push bohaii into the northern rim of the Eurasian continent. Melanuroides is also expected to shift northward, stopping in the Yablonovyy and Stanovoy Ranges, and breeding elevation is expected to increase. Climatically suitable breeding habitat ranges would shrink to 16% and 11% of the currently estimated ranges of bohaii and melanuroides, respectively. Overall, this study provides the first predictions for the future distributions of two little‐known Black‐tailed Godwit subspecies and highlights the importance of factoring in shifts in bird distribution when designing climate‐proof conservation strategies.

8 January 2024 in Journal of Ecology
Verified
Journal Article
Open access
NVNicolas Velasco
Nicolas Velasco
CSCristina Soto‐Agurto
Cristina Soto‐Agurto
LCLucas Carbone
Lucas Carbone
CMCesar Massi
Cesar Massi
Ramiro O. BustamanteRamiro O. Bustamante
Ramiro O. Bustamante
CSChristian Smit
Christian Smit
Importance of nurse plants structuring plant communities is well‐appreciated at local scales, yet the effect of a single nurse on large scales has been neglected in analyses. So far, studies only use environmental gradients within one type of ecosystem and tend to generalize the nurse effects. To assess how the effect of a single nurse species is modulated by different environmental settings, interactions between the shrub Vachellia caven and the surrounding plant communities were evaluated at 481 paired plots (outside vs. underneath the plant crown), in 39 sites across two distribution ranges, the Mediterranean west and the mostly subtropical east of the Andes Mountains (covering ca. 2 × 106 km2). Cover, abundance and richness of perennial plants underneath and outside V. caven were used as response variables to estimate an index indicative of plant interactions (relative interaction index [RII]) and tested how this was affected by the rainfall gradient and distribution range. Overall, RII responses to rainfall gradients had low conditional R2 (~0.25) in this large scale of analysis, but were significantly different between ranges: the RII followed a quadratic trend across the rainfall gradient in the western range, while this relationship was positive and close to linear at the eastern range. Then, by projecting the RII models (i.e. for abundance, cover and richness) spatially through a consensus map, we show that most positive effects of V. caven are geographically found in dissimilar areas: the central part of Chile (western range) and across the Paraná River (eastern range). When local fine‐scale predictors (i.e. annual herbs' cover and height, and herbivores' faeces cover) were used to model each response variable at the plot level (underneath or outside V. caven), we observed similar trends as when we considered only the large‐scale predictors. Synthesis. Here, we show that the effect of the same nurse species on neighbouring plant communities can be very different depending on ranges of distribution, stressing that its ecological function cannot be generalized and not only depends on local factors but also is large‐scale context‐dependent.

10 June 2023 in Heliyon
Verified
Journal Article
Open access
NVNicolas Velasco
Nicolas Velasco
RBRamiro Bustamante
Ramiro Bustamante
CSChristian Smit
Christian Smit
Vachellia caven has a disjunct distribution at the southern cone of South America, occupying two major ranges: west of Andes (Central Chile) and east of them (mainly the South American Gran Chaco). For decades, the species has been subject to various ecological and natural history studies across its distribution, but questions concerning its origin in the western range remain unresolved. Thus far, it is unclear whether Vachellia caven was always a natural component of the Chilean forests, and "how" and "when" the species arrived in the country. In this study, we revised the dispersal syndromes of the species and contrast the two main hypotheses of dispersion to the west of Andes that have been proposed in the 90's, namely animal versus human-mediated dispersal. For this, we reviewed all scientific literature on the species and explored the available information on morphology, genetics, fossil records and distribution patterns of closely related species. Here we illustrate how the collected evidence provides support for the human-mediated dispersal hypothesis, by including a conceptual synthesis that summarizes the outcomes of different dispersal scenarios. Lastly, and regarding the positive ecological effects this species has in the introduced area, we suggest reconsidering the (underappreciated) historical impacts of archaeophytes and rethinking the role that indigenous human tribes may have had in the dispersion of different plants in South America.

9 June 2023 in Horticulturae
Verified
Journal Article
Open access
PDF file
Patricia Jaramillo DíazPatricia Jaramillo Díaz
Patricia Jaramillo Díaz
ACAnna Gabriela Calle-Loor
Anna Gabriela Calle-Loor
NVNicolas Velasco
Nicolas Velasco
Javier David CevallosJavier David Cevallos
Javier David Cevallos
Water scarcity and salinity pose significant challenges for agriculture in the Galapagos Islands, severely limiting crop yields needed to sustainably meet the growing demands of the human population in the archipelago. To address this issue, environmentally friendly water-saving technologies such as Hydrogel and Groasis Growboxx were considered to be potential solutions. This study focused on evaluating the effectiveness of Hydrogel application on five crops: Broccoli (Brassica oleracea), Cucumber (Cucumis melo), Pepper (Capsicum annuum), Tomato (Solanum lycopersicum), and Watermelon (Citrullus lanatus), from 2017 to 2018. The experiment stopped due to the pandemic in 2019–2020. When the study continued in 2021, Growboxx® was introduced as a treatment for Pepper and Tomato. This study revealed that the application of Hydrogel resulted in enhanced yields, with the degree of improvement varying across different crops and cultivation periods. Notably, when comparing Hydrogel and Growboxx treatments, differences of up to 30% in fruit weight were observed. However, it is important to note that these results can vary in different environments. For example, in Tomato cultivation, Growboxx exhibited 10% higher fruit weight in San Cristobal compared to Santa Cruz Island. Our findings provide valuable insights for stakeholders in the Galapagos Islands, offering crop-specific guidance to support informed decisions on adopting the most appropriate technologies for their farms.

8 June 2023 in Scientific Reports
Verified
Journal Article
Open access
PDF file
NVNicolas Velasco
Nicolas Velasco
NANicolás Andrade
Nicolás Andrade
CSChristian Smit
Christian Smit
RBRamiro Bustamante
Ramiro Bustamante
Based on the niche conservatism hypothesis, i.e. the idea that niches remain unchanged over space and time, climatic niche modelling (CNM) is a useful tool for predicting the spread of introduced taxa. Recent advances have extended such predictions deeper in time for plant species dispersed by humans before the modern era. The latest CNMs successfully evaluate niche differentiation and estimate potential source areas for intriguing taxa such as archaeophytes (i.e., species introduced before 1492 AD). Here, we performed CNMs forAcacia caven, a common Fabaceae tree in South America, considered an archaeophyte west of the Andes, in Central Chile. Accounting for the infraspecific delimitation of the species, our results showed that even when climates are different, climatic spaces used by the species overlap largely between the eastern and western ranges. Despite slight variation, results were consistent when considering one, two, or even three-environmental dimensions, and in accordance with the niche conservatism hypothesis. Specific distribution models calibrated for each region (east vs west) and projected to the past, indicate a common area of occupancy available in southern Bolivia—northwest Argentina since the late Pleistocene, which could have acted as a source-area, and this signal becomes stronger through the Holocene. Then, in accordance with a taxon introduced in the past, and comparing regional vs continental distribution models calibrated at the infraspecific or species level, the western populations showed their spread status to be mostly in equilibrium with the environment. Our study thus indicates how niche and species distribution models are useful to improve our knowledge related to taxa introduced before the modern era.

17 May 2024 in PLOS ONE
Verified
Journal Article
Open access
PDF file
NVNicolas Velasco
Nicolas Velasco
Patricia Jaramillo DíazPatricia Jaramillo Díaz
Patricia Jaramillo Díaz
Scalesia pendunculata Hook.f. is the dominant tree in several highlands’ areas of the Galapagos Archipelago, yet in inhabited islands the conversion to agricultural fields has reduced its cover. The transition to agroforestry systems including the species shows promising scenarios to restore its cover and to provide ecosystem services such as carbon sequestration. Here, based on field gathered data, we model the potential contribution of S. pedunculata stands in the carbon sequestration of Galapagos. Between 2013–2021, 426 S. pedunculata seedlings were planted in the highlands of Santa Cruz and Floreana islands using several restoration technologies, and their height and survival were monitored every three months. A sub-sample of 276 trees alive since 2020 was used to estimate the DBH based on plant age and height. Based on scientific literature, biomass and carbon content were estimated across time. The final modelling included the density of plants in the restoration sites, estimated DBH, potential survival by restoration treatment, and a Brownian noise to add stochastic events. Overall, survival of S. pedunculata was high in control and slightly increased by most restoration treatments. A stand of 530 trees/ha was projected to sequester ~21 Mg C/ha in 10 years. If this is replicated over all Galapagos coffee production would contribute to the reduction of -1.062% of the Galapagos carbon footprint for the same period. This study adds to compiling benefits of restoring Galapagos flora.