• Energy Research

Assessing the relationships between weather patterns and the likelihood of fire occurrence in the Caribbean has not been as central to climate change research as in temperate regions, due in part to the smaller extent of individual fires. However, the cumulative effect of small frequent fires can shape large landscapes, and fire-prone ecosystems are abundant in the tropics. Climate change has the potential to greatly expand fire-prone areas to moist and wet tropical forests and grasslands that have been traditionally less fire-prone, and to extend and create more temporal variability in fire seasons. We built a machine learning random forest classifier to analyze the relationship between climatic, socio-economic, and fire history data with fire occurrence and extent for the years 2003–2011 in Puerto Rico, nearly 35,000 fires. Using classifiers based on climate measurements alone, we found that the climate space is a reliable associate, if not a predictor, of fire occurrence and extent in this environment. We found a strong relationship between occurrence and a change from average weather conditions, and between extent and severity of weather conditions. The probability that the random forest classifiers will rank a positive example higher than a negative example is 0.8–0.89 in the classifiers for deciding if a fire occurs, and 0.64–0.69 in the classifiers for deciding if the fire is greater than 5 ha. Future climate projections of extreme seasons indicate increased potential for fire occurrence with larger extents.

Water availability may affect plant productivity because it limits a plant's ability to reproduce and defend itself. In this field study, we studied the effect of water increment in relation to : a) flower production, b) fruit production and c) herbivory, focusing on Fuchsia boliviana (Onagraceae) in the Yungas forest of Northwestern Argentina. We selected 10 pairs of plants of similar size separated at least 5 m from each other. We watered one plant of the pair with 20 L twice a week between September and December, 2016. The number of flowers and fruits of all plants were counted twice a week. Herbivory was quantified once from photographs of five leaves per plant using ImageJ version 1.5i. Based on Wilcoxon tests, we found no difference in the number of flowers, or fruits, nor in herbivory in plants of both treatments. We observed a trend for watered plants starting to flower later and with more intensity than unwatered plants. We discuss different options that may explain why water increase did not affect reproduction nor the level of herbivore damage in Fuchsia boliviana.https ://doi.org/10.25260/EA.19.29.2.0.806 Water availability may affect plant productivity because it limits a plant's ability to reproduce and defend itself. In this field study, we studied the effect of water increment in relation to: a) flower production, b) fruit production and c) herbivory, focusing on Fuchsia boliviana (Onagraceae) in the Yungas forest of Northwestern Argentina. We selected 10 pairs of plants of similar size separated at least 5 m from each other. We watered one plant of the pair with 20 L twice a week between September and December, 2016. The number of flowers and fruits of all plants were counted twice a week. Herbivory was quantified once from photographs of five leaves per plant using ImageJ version 1.5i. Based on Wilcoxon tests, we found no difference in the number of flowers, or fruits, nor in herbivory in plants of both treatments. We observed a trend for watered plants starting to flower later and with more intensity than unwatered plants. We discuss different options that may explain why water increase did not affect reproduction nor the level of herbivore damage in Fuchsia boliviana.https://doi.org/10.25260/EA.19.29.2.0.806 Water availability may affect plant productivity because it limits a plant's ability to reproduce and defend itself. In this field study, we studied the effect of water increment in relation to: a) flower production, b) fruit production and c) herbivory, focusing on Fuchsia boliviana (Onagraceae) in the Yungas forest of Northwestern Argentina. We selected 10 pairs of plants of similar size separated at least 5 m from each other. We watered one plant of the pair with 20 L twice a week between September and December, 2016. The number of flowers and fruits of all plants were counted twice a week. Herbivory was quantified once from photographs of five leaves per plant using ImageJ version 1.5i. Based on Wilcoxon tests, we found no difference in the number of flowers, or fruits, nor in herbivory in plants of both treatments. We observed a trend for watered plants starting to flower later and with more intensity than unwatered plants. We discuss different options that may explain why water increase did not affect reproduction nor the level of herbivore damage in Fuchsia boliviana.https://doi.org/10.25260/EA.19.29.2.0.806 قد يؤثر توفر المياه على إنتاجية النبات لأنه يحد من قدرة النبات على التكاثر والدفاع عن نفسه. في هذه الدراسة الميدانية، درسنا تأثير زيادة المياه فيما يتعلق بما يلي: أ) إنتاج الزهور، ب) إنتاج الفاكهة و ج) الحيوانات العاشبة، مع التركيز على الفوشيا البوليفية (Onagraceae) في غابة يونغاس في شمال غرب الأرجنتين. اخترنا 10 أزواج من النباتات ذات الحجم المماثل مفصولة عن بعضها البعض بما لا يقل عن 5 أمتار. قمنا بسقي نبات واحد من الزوج بـ 20 لتر مرتين في الأسبوع بين سبتمبر وديسمبر 2016. تم حساب عدد الزهور والفواكه من جميع النباتات مرتين في الأسبوع. تم تحديد كمية الحيوانات العاشبة مرة واحدة من صور خمس أوراق لكل نبات باستخدام ImageJ الإصدار 1.5i. بناءً على اختبارات ويلكوكسون، لم نجد فرقًا في عدد الزهور أو الفواكه ولا في الأعشاب في نباتات كلا العلاجين. لاحظنا اتجاهًا للنباتات المروية التي تبدأ في الإزهار لاحقًا وبكثافة أكبر من النباتات غير المروية. نناقش الخيارات المختلفة التي قد تفسر سبب عدم تأثير زيادة المياه على التكاثر ولا على مستوى تلف الحيوانات العاشبة في Fuchsia boliviana.https:// doi.org/10.25260/EA.19.29.2.0.806