Mellink Eric, Riojas-López Mónica E, Cárdenas-García Melinda
Departamento de Biología de la Conservación, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, B.C., México.
Departamento de Ecología, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Zapopan, Jalisco, México.
PLoS One. 2017 Jul 7;12(7):e0179438. doi: 10.1371/journal.pone.0179438. eCollection 2017.
One of the most typical agro-ecosystems in the Llanos de Ojuelos, a semi-arid region of central Mexico, is that of fruit-production orchards of nopales (prickly pear cacti). This perennial habitat with complex vertical structure provides refuge and food for at least 112 species of birds throughout the year. Nopal orchards vary in their internal structure, size and shrub/tree composition, yet these factors have unknown effects on the animals that use them. To further understand the conservation potential of this agro-ecosystem, we evaluated the effects of patch-size and the presence of trees on bird community composition, as well as several habitat variables, through an information-theoretical modelling approach. Community composition was obtained through a year of census transects in 12 orchards. The presence of trees in the orchards was the major driver of bird communities followed by seasonality; bird communities are independent of patch size, except for small orchard patches that benefit black-chin sparrows, which are considered a sensitive species. At least 55 species of six trophic guilds (insectivores, granivores, carnivores, nectivores, omnivores, and frugivores) used the orchards. Orchards provide adequate habitat and food resources for several sensitive species of resident and migratory sparrows. The attributes that make orchards important for birds: trees, shrubs, herb seeds, and open patches can be managed to maintain native biodiversity in highly anthropized regions with an urgent need to find convergence between production and biological conservation.
墨西哥中部半干旱地区奥胡埃洛斯平原最典型的农业生态系统之一是胭脂仙人掌（刺梨仙人掌）果园。这种具有复杂垂直结构的多年生栖息地全年为至少112种鸟类提供庇护所和食物。胭脂仙人掌果园的内部结构、规模以及灌木/树木组成各不相同，但这些因素对利用它们的动物的影响尚不清楚。为了进一步了解这种农业生态系统的保护潜力，我们通过信息论建模方法评估了斑块大小和树木的存在对鸟类群落组成以及几个栖息地变量的影响。通过对12个果园进行为期一年的普查样带调查获得了群落组成信息。果园中树木的存在是鸟类群落的主要驱动因素，其次是季节性；鸟类群落与斑块大小无关，不过小型果园斑块对黑颏雀鹀有益，黑颏雀鹀被视为敏感物种。六个营养类群（食虫动物、食谷动物、食肉动物、食蜜动物、杂食动物和食果动物）中至少55种鸟类利用这些果园。果园为几种敏感的留鸟和候鸟雀鹀提供了充足的栖息地和食物资源。使果园对鸟类至关重要的属性：树木、灌木、草本植物种子和开阔斑块，可以加以管理，以便在迫切需要在生产与生物保护之间找到契合点的高度人为化地区维持本地生物多样性。
