The effect of lands surrounding fragmented landscapes: theory development and novel experimental tests

世界各地的物种都在减少。动植物栖息地的破坏是造成这种下降的一个众所周知的原因。人们很少认识到，在剩余的适宜栖息地周围的土地，称为“基质”，对物种来说可能很重要。观察表明，在许多情况下，这些土地可能是物种生存所必需的。了解这些影响发生的原因对于提高我们对土地利用变化的认识非常重要。本研究将通过提供新的野外实验来了解生境和非生境对物种的影响，从而解决这些问题。研究结果将用于提供解决办法，以减轻生境破坏对自然种群的有害影响。它还将制作有关研究结果的视频，并在自然历史博物馆向公众展示，从而对社会产生更广泛的影响。在这个项目中，研究人员将进行实地实验，旨在阐明基质对种群的影响。他们还将开发这个研究系统的理论模型，该模型可以应用于其他类似的系统，在这些系统中，物种通常生活在被不合适的土地包围的栖息地（基质）中。该研究系统由两种昆虫食草动物组成，它们专门以刺梨仙人掌为食，传播能力各不相同。仙人掌植物是适宜的栖息地，簇生在各种草的周围，草是基质。实验将操纵栖息地的大小、破碎化程度（栖息地数量和栖息地之间的距离）和基质土地的质量，以测试这些因素如何影响目标物种的种群动态。研究结果将用于评价基质效应相对于众所周知的生境丧失和破碎化效应的重要性。模型开发将把这些结果置于背景中，并将为预测矩阵对连通性和人口动态的影响提供新的解决方案。

Species are declining across the world. The destruction of plant and animal habitat is a well-known cause for such declines. It is less appreciated that lands surrounding remaining suitable habitats, termed "the matrix" can be important for species. Observations suggest that in many situations, these lands can be necessary for the survival of species. Understanding why these effects occur is important for advancing our knowledge on land-use change. This research will address these issues by providing novel field experiments to understand both habitat and non-habitat effects on species. The results will be used to provide solutions for mitigating the deleterious effects of habitat destruction on natural populations of species. It will also provide broader impacts to society by developing videos on the findings which will be presented to the public at a natural history museum. In this project, the researchers will conduct field experiments designed to elucidate effects of the matrix on populations. They will also develop theoretical models of this study system which can be applied to other similar systems in which species typically live in habitats surrounded by unsuitable lands (the matrix). The study system consists of two species of insect herbivores that specialize on prickly pear cactus and vary in dispersal ability. The cactus plants are the suitable habitats, occurring in clumps surrounded by a variety of grass species which is the matrix. The experiments will manipulate habitat size, degree of fragmentation (number of habitats and distance between habitats) and quality of the matrix land to test how each of these factors affects the population dynamics of the subject species. The results will be used to evaluate the importance of matrix effects relative to the well-known effects of habitat loss and fragmentation. Model development will contextualize these results and will provide new solutions for predicting the effects of the matrix on connectivity and population dynamics.